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BACKGROUND OF THE INVENTION The search for new sweeteners which are many times sweeter than sucrose and which are also non-caloric and non-cariogenic has been a continuing search for many years. In particular the search has been to provide new sweeteners which are not only many times sweeter than sucrose but which are free of the bitter aftertaste particularly associated with such artificial sweeteners as saccharine, and which in addition do not break down into products which are physiologically harmful and also which remain stable in aqueous systems and upon exposure to heat, for example during cooking. U.S. Pat. No. 3,492,131 describes certain lower alkyl esters of L-aspartyl-L-phenylalanine which are up to 200 times as sweet as sucrose and which are free of bitter aftertaste. These compounds, however, possess only limited solubility in aqueous systems and are unstable due to diketopiperazine formation and hydrolysis especially in the neutral to acid pH range of most food systems (the diketopiperazine forms more slowly under acidic conditions). European Patent Application No. 0034876, published Sept. 2, 1981, describes branched amides of L-aspartyl-D-amino acid dipeptides as sweeteners. These compounds are stated as being free of undesirable flavor qualities at conventional use levels and as having high stability both in solid form and in aqueous systems. The breakdown products thereof are not given so that the final possible uses of these sweeteners are not yet known. SUMMARY OF THE INVENTION It has now been found that a new series of derivatives of gem-diaminoalkanes of the formula: ##STR2## wherein n is 0 or 1, R is lower alkyl (substituted or unsubstituted), R' is H or lower alkyl, and R" is a branched alkyl, alkyl-cycloalkyl, cycloalkyl, polycycloalkyl (poly=2 or more, fused or non-fused), phenyl or alkyl-substituted phenyl, and physiologically acceptable cationic and acid addition salts thereof, possess a high degree of sweetness, without undesirable flavor notes, and in addition possess significant advantages as compared to known sweeteners. It is accordingly a primary object of the present invention to provide a new series of sweeteners which are free of undesirable flavor notes and which possess a high degree of stability in all types of aqueous systems and even upon cooking. It is another object of the present invention to provide a new series of sweeteners which break down only into compounds which are physiologically compatible with the body. It is yet another object of the present invention to provide compositions for sweetening edible materials which comprise a sweetening amount of the new compounds of the invention and a nontoxic carrier. Still further, the present invention provides sweetened edible compositions comprising an edible material and a sweetening amount of the compounds of the invention. Still further, the invention provides a method of sweetening edible compositions by the addition thereto of a sweetening effective amount of the compounds of the invention. The invention further provides methods for producing the new sweetening compounds thereof. With the above and other objects in view, the present invention mainly comprises new compounds of the formula: ##STR3## wherein n=0 or 1; R is lower alkyl, such as methyl, ethyl, n-propyl, isopropyl, isobutyl, etc., or substituted lower alkyl, such as hydroxymethyl, methyl thiomethyl, etc.; R' is H or lower alkyl, preferably methyl or ethyl; and R" is a branched alkyl group, preferably of 3-10 carbon atoms, e.g. ##STR4## where R 1 is H or lower alkyl, preferably methyl or ethyl, R 2 and R 3 are H or lower alkyl such as methyl, ethyl, n-propyl, isopropyl, isobutyl, t-butyl, etc.; R" may also be alkyl-cycloalkyl or dicycloalkyl, i.e. ##STR5## where R 4 and R 8 are H or methyl, R 5 , R 6 and R 7 are H or lower alkyl, preferably methyl, ethyl or isopropyl, and n and n'=0, 1 or 2; R" may also be cycloalkyl, preferably of 3-7 carbon atoms, most preferably of 5-6 carbon atoms, or substituted cycloalkyl, the cycloalkyl group most preferably being of 4-6 carbon atoms and substituted by 1-4 alkyl groups, e.g. where R 9 is H or methyl, R 10 , R 11 , R 12 and R 13 are H or lower alkyl, such as methyl, ethyl, isopropyl, isobutyl, t-butyl, etc., and x=0, 1, 2 or 3; R" may also be heterocycloalkyl or alkyl-substituted heterocycloalkyl, where the heteroatom is oxygen, nitrogen or sulfur and the preferred ring size is 4-7 atoms, e.g. ##STR6## where R 14 is H or methyl, R 15 , R 16 , R 17 and R 18 are H or lower alkyl, such as methyl, ethyl, isopropyl, isobutyl, t-butyl, etc., y and z=0, 1 or 2, and Q is 0, NH, S, SO or SO 2 ; R" may also be polycycloalkyl, such as norbornyl, ##STR7## or 1- or 2-adamantyl ##STR8## or phenyl or alkyl-substituted phenyl, the alkyl group(s) preferably being lower alkyl, e.g. ##STR9## where R 19 and R 20 are H, lower alkyl such as methyl, ethyl, isopropyl, etc. The preferred sweeteners of the present invention are those wherein R" is cycloalkyl or alkyl substituted cycloalkyl substituted by 1-5 alkyl groups, the alkyl preferably being lower alkyl. Examples of the most valuable compounds are those wherein R" is: tetramethylcyclopentyl, cyclopentyl, methylcyclohexyl, dicyclopropylmethyl, dimethylcyclopentyl, trimethylcyclopentyl, dimethylcyclohexyl, trimethylcyclohexyl, t-butylcyclohexyl. As indicated above, the invention provides compositions for sweetening edible materials comprising a sweetening effective amount of a compound of the above formula along with a nontoxic carrier, for example lactose, dextrose or sucrose. Still further, the invention provides sweetened edible compositions which comprise an edible material plus a sweetening effective amount of a compound of the invention. Still further, the invention comprises the method of sweetening edible compositions by the addition thereto of a sweetening effective amount of a compound of the invention. The invention further provides compositions for sweetening edible materials comprising a sweetening amount of a mixture of a compound of the invention with another artificial sweetener such as saccharine or a physiologically acceptable salt thereof, cyclamate or a physiologically compatible salt thereof, aspartame, acesulfame-K or thaumatin. The physiologically acceptable salts of saccharine and of cyclamate are the salts thereof with physiologically acceptable cations such as sodium, potassium, calcium or ammonium. The physiologically acceptable cationic salts of the compounds of the invention are the salts thereof formed by neutralization of the carboxylic acid group of the compounds of the invention by bases of physiologically acceptable metals, such as sodium and potassium, ammonia and amines such as N-methyl glucamine and ethanolamine. The physiologically acceptable acid addition salts are those formed of physiologically acceptable acids such as acetic acid, benzoic acid, hydrobromic acid, hydrochloric acid, citric acid, fumaric acid, gluconic acid, lactic acid, maleic acid, malic acid, nitric, phosphoric, saccharic, succinic and tartaric acid. DETAILED DESCRIPTION OF THE INVENTION The following is a general scheme for the production of the gem-diaminoalkane sweeteners of the present invention: ##STR10## The sweeteners (I) may be synthesized by the general route outlined in Scheme 1 above. In this route, a protected aminomalonic acid derivative (II, n=0) or aspartic acid derivative (II, n=1) is employed as starting material. The amine protecting group X may be any of the groups which are commonly employed for this purpose, as described by Bodanszky et al, in "Peptide Synthesis", Wiley-Interscience, New York (1976), pp. 18-48. Particularly preferred groups are benzyloxycarbonyl, t-butyloxycarbonyl and 9-fluorenylmethyloxycarbonyl. The carboxyl-protecting group, Y, may be any of the groups which are normally used for this purpose, as described by Bodanszky et al. in "Peptide Synthesis", pp. 49-57. Preferred groups include benzyl, t-butyl or lower alkyl, such as methyl or ethyl. A particularly preferred combination of protecting groups for the protection of the amine and carboxyl functions in (II) is benzyloxycarbonyl/benzyl, since these groups may be removed selectively by hydrogenolysis under mild conditions. When use of this deprotection method is precluded, for example in compounds containing sulfur, the combination of t-butyloxycarbonyl/t-butyl, which are removable under acidic conditions, may be employed. Alternatively, the combination of 9-fluorenylmethyloxycarbonyl/benzyl or alkyl, which are cleaved simultaneously under basic conditions, may be used. In the first step of the synthesis, the carboxyl component (II) is activated by a suitable method and coupled with an amino acid derivative (III). Any of the methods commonly used for the formation of amide bonds, as described by Bodanszky et al. in "Peptide Synthesis", pp. 85-128, may be used. However, a particularly preferred method is the mixed carboxylic-carbonic anhydride method, using isobutyl or ethyl chloroformate. The amino acid derivative (III) may be a free amino acid (i.e. Z=H) or may be a derivative in which the carboxyl group is protected by a suitable protecting group Z which may be cleaved selectively in the presence of the other protecting groups, X and Y, in the protected derivative (IV). A particularly preferred method of protection involves the use of trialkylsilyl esters (i.e. Z=trialkylsilyl), such as trimethylsilyl, since these groups may be removed under aqueous acidic conditions. In this case, removal of this protecting group may be effected during the work-up procedure, following the coupling of the carboxyl component (II) with the amino acid derivative (III), so that the partially deprotected product (IV) may be isolated directly, without the necessity for a separate deprotection step. The product (IV) may be purified, if necessary, by conventional methods, such as recrystallization or column chromatography. The key step in the synthesis of the novel, gem-diaminoalkane-derived sweeteners of the invention involves the transformation of the carboxylic acid derivatives (V) to the monoacylated gem-diaminoalkane salts (VII). This may be accomplished by one of several standard methods, such as the Curtius rearrangement or the Schmidt rearrangement. Alternatively, the carboxylic acid derivative may first be transformed to the amide (VI) by activation and condensation with ammonia. In a preferred method, the dipeptide (V) is activated via the mixed carboxylic-carbonic anhydride at low temperature and condensed with the ammonium salt of 1-hydroxybenzotriazole. The amide (VI) may then be transformed to the gem-diaminoalkane salt (VII) via the Hofmann rearrangement using sodium hypobromite. Alternatively, a preferred reagent for effecting this transformation is iodobenzene bis(trifluoroacetate), as described by Radhakrishna et al., J. Org. Chem. 44, 1746-1747(1979). The monoacylated gem-diaminoalkane salt (VII) is acylated by the appropriate acid chloride R"COCl under basic conditions to provide the protected sweetener derivative (VIII). This reaction may be carried out under a variety of conditions, for example in a mixture of an organic solvent such as acetonitrile and aqueous potassium bicarbonate. Alternatively, the coupling reaction may be carried out in an anhydrous organic solvent, such as tetrahydrofuran, in the presence of an equivalent of an organic base such as triethylamine. The protected sweetener derivative (VIII) may be purified if required by conventional techniques, such as recrystallization or column chromatography. In the final step of the synthesis, the protected sweetener (VIII) is deprotected under appropriate conditions to give the final gem-diaminoalkane-derived sweetener (I). The conditions used for deprotection will depend upon the nature of the protecting groups used, i.e. X and Y. As outlined above, when the preferred combination of benzyloxycarbonyl and benzyl protecting groups is used, deprotection may be effected by hydrogenolysis at pressures of 1-10 atmospheres in the presence of a noble metal catalyst such as palladium or platinum. In the event that the molecule contains sulfur and an alternate combination of protecting groups is used, hydrolytic methods must be used for their cleavage. For example, if 9-fluorenylmethyloxycarbonyl and benzyl are used, the protecting groups may be cleaved simultaneously by basic hydrolysis, for example by treatment with excess potassium hydroxide in anhydrous methanol. While the final sweetener (I), obtained by these techniques, may be substantially pure, further purification, for example by recrystallization, is desirable. In an alternate route (Scheme 2), the gem-diaminoalkane derivatives (I) may be prepared by first treating the amino acid derivative (III) with the appropriate acid chloride RCOCl. As described above, the amino acid derivative (III) may be a free amino acid (i.e. Z=H) or may be ##STR11## carboxyl-protected. A preferred carboxyl-protecting group is the trialkylsilyl ester group, such as the trimethylsilyl group, which may be removed by aqueous acid, as described above. The next step, the key transformation of the acylated amino acid derivative (X) to the monoacylated gem-diaminoalkane salt (XII), may be accomplished by any of the methods discussed above, although the preferred route involves transformation to the primary amide derivative (XI) and rearrangement using iodobenzene bis(trifluoroacetate). Condensation of this diaminoalkane derivative (XII) with a protected aminomalonic acid or aspartic acid derivative (II) by techniques described above results in the same, fully protected sweetener derivative (VIII) as that obtained in Scheme 1. Deprotection and purification may be effected by the same techniques as those described previously. In a preferred method, the amine salt (XII) is acylated by a cyclic derivative of aminomalonic acid or aspartic acid, such as the N-carboxyanhydride or the thiocarboxyanhydride (XIII, X═O or S). Use of these intermediates avoids the need for protection of the aminomalonic or aspartic acid residues. In yet another variation, partially protected aspartic acid derivatives, such as N-formyl aspartic anhydride, may also be used to acylate the amine salt (XII). In this case, cleavage of the formyl protecting group may be effected by treatment with aqueous acid. The carboxylic acid chlorides R"COCl used for the synthesis of these sweeteners may be commercially available or may be synthesized by standard techniques. A preferred route for the synthesis of the carboxylic acid precursors utilizes ketones as the starting materials, as described by Martin, Synthesis (1979), 633-664 and is outlined in Scheme 3. By this route, the ketone (XIV) is first converted to the alkene (XVI). Several possible methods may be used for this purpose. Use of the Wittig method, involving treatment of the ketone with methylene triphenylphosphorane, results in the alkene directly. An alternate procedure, useful for ketones in which R 21 and R 22 contain tertiary carbon atoms adjacent to the ketone, ##STR12## involves the two-step treatment of the ketone with methyl magnesium bromide, to give the methyl carbinol (XV), followed by dehydration with thionyl chloride in the presence of excess pyridine. The alkene (XVI) is next transformed to the alcohol (XVII) by hydroboration (treatment with borane, followed by aqueous sodium hydroxide and hydrogen peroxide). Finally, the alcohol is oxidized to the carboxylic acid (XVIII) by one of many standard techniques, such as treatment with sodium dichromate in concentrated sulfuric acid. The carboxylic acid may be transformed to the acid chloride form required for the synthesis described above by one of several standard techniques, such as treatment with thionyl chloride or phosphorus pentachloride. The requisite ketone precursors for the carboxylic acids required for the invention are either commercially available, known in the prior art, or may be prepared by known methods. For example, the cycloalkanones and heterocycloalkanones of the general formula (XIX) and (XX), where R 10 -R 13 , ##STR13## R 15 -R 18 , x, y, z and Q are as defined above, may be prepared by alkylation of the corresponding ketones in which R 10 -R 13 and R 15 -R 18 are hydrogen. Alkylation may be effected by treatment with a strong base, such as sodium hydride, sodium amide or sodium amylate, in the presence of an alkylating agent such as an alkyl halide or dialkyl sulfate. The methods described above are provided for the purpose of illustrating the invention but in no way are meant to limit the scope of the invention. Alternate methods, obvious to those skilled in the art, may be substituted at any stage of the syntheses described. The degree of sweetness of the compounds of the invention is dependent on a number of factors. The most important of these is the nature of the acylating group, R", derived from the carboxylic acid precursor. In general, branched, bulky, hydrophobic groups are preferred, but, more specifically, cycloalkyl and heterocycloalkyl groups containing alkyl substituent groups adjacent to the carbonyl group are preferred. Thus, for example, a cyclopentyl group containing geminal dimethyl substituents in the 2- and 5- positions on the ring is particularly preferred (see Table 1). Substitution in the 3- and 4-positions on the ring does not generally lead to high levels of sweetness. TABLE 1______________________________________Sweetness Data for Gem-Diaminoalkane Derived Sweeteners.sup.a ##STR14##R R' R" Sweetness.sup.b______________________________________CH.sub.3 H C(CH.sub.3).sub.3 75-100" " ##STR15## 50-75" " ##STR16## 10-25" " ##STR17## 500-700" " ##STR18## 5-20" " ##STR19## 50-75" " ##STR20## 35-50" " ##STR21## 150-250" " ##STR22## 150-200" " ##STR23## 150-200" " ##STR24## 75-100" " ##STR25## 300-400" " ##STR26## 800-1000" " " .sup. 600-800.sup.cCH.sub.2 CH.sub.3 " " 200-300CH.sub.2 OH " " 400-500CH.sub.3 " ##STR27## 150-200" " ##STR28## 75-100" " ##STR29## 5-15" CH.sub.3 ##STR30## 50-100______________________________________ .sup.a Sweeteners derived from Laspartyl-Rgem-diaminoalkanes, unless otherwise noted. .sup.b Relative to sucrose. .sup.c Derived from Laspartyl-S1,1-diaminoethane. A second aspect of the invention relates to the stereochemistry of the two primary chiral centers. The chirality of the first center (aspartic acid or aminomalonic acid) is important. In the case of aspartic acid-containing sweeteners (i.e. I, n=1), it is preferred that the amino acid of the L-configuration be used, although use of racemic (i.e. D,L-) aspartic acid still results in useful sweeteners. However, incorporation of a D-aspartic acid moiety does not lead to useful sweeteners. In the case of aminomalonic acid-containing sweeteners (i.e. I, n=0), the R-enantiomer is preferred, although the racemic, R,S-mixture is most often used in order to avoid the difficult problem of resolution of diastereomers. The chemistry at the second chiral center (i.e. the gemdiaminoalkane moiety) in the sweeteners is less critical. Thus, while diaminoalkanes of the R-configuration (i.e. those derived from the D-amino acid amides when the sweeteners are synthesized via Scheme 1, or from L-amino acid amides when prepared via Scheme 2) are generally preferred, S-diaminoalkanes may also be used with only minimal loss of sweetness. This result is surprising since in other classes of amino acid-derived sweeteners known in the prior art, chirality at the second center is extremely critical. L-Aspartyl-L-phenylalanine methyl ester, for example, is extremely sweet, while L-aspartyl-D-phenylalanine methyl ester is bitter. This novel discovery is of considerable economic significance since the sweeteners of the present invention may be derived from racemic amino acids, such as alanine, serine, etc., which are much cheaper than their optically pure counterparts. The novel sweeteners of the invention may also be derived from amino acids which are achiral, such as α-aminoisobutyric acid (I, R═R'═CH 3 ), or from unnatural, optically active amino acids, such as α-methylserine (I, R═CH 2 OH, R'═CH 3 ). As noted above, a most important, novel aspect of the invention relates to the use of gem-diaminoalkane derivatives for the preparation of useful sweeteners. However, the placement of this diaminoalkane residue in the molecules is also extremely critical. In other words, if the other amide bond in the molecule is reversed to give structures of the type: ##STR31## the compounds are not useful as sweeteners. Thus, the invention is characterized by a number of important features, which include the nature of the substituent group, R", the inclusion of the diaminoalkane moiety and its position in the molecule and also the stereochemistry of the chiral centers in the molecule. The proper combination of these features provides for optimum sweetness in these molecules. While the degree of sweetness of the compounds of the invention, as compared to sucrose on a weight to weight basis varies considerably depending upon the substituent R", all of these compounds provide considerable advantages as sweetening agents due to the fact that the breakdown products thereof are all compatible to the human physiology, e.g. acetic acid and amino acids, and further due to the high stability thereof in both solid form and in solution form. Still further, the compounds of the invention when used with other sweeteners such as saccharine help to avoid the undesired bitter aftertaste of the other sweeteners. Consequently, the compounds of the invention can be used for the sweetening of edible materials of all types, such as foods, prepared food items, chewing gum, beverages, etc. The compounds of the invention can be prepared in many forms suitable for use as sweetening agents, such as powders, tablets, granules, solutions, suspensions, syrups, etc. The invention provides sweetened edible compositions comprising an edible material and a sweetening amount of the compound of the invention either alone or in combination with another sweetening agent such as saccharine. There is actually no limitation as to the edible materials that can be sweetened with the present invention compositions, including fruits, vegetables, juices, meats, egg products, gelatins, jams, jellies, preserves, milk products such as ice cream, sherbert, syrups, beverages such as coffee, tea, carbonated soft drinks, non-carbonated soft drinks, wines, liquors, confections such as candies, etc. The compounds of the present invention in addition to providing a high degree of sweetness, are of particular interest because these compounds are actually amino acid derivatives rather than peptides. As a consequence, the degree of safety provided by the compounds of the present invention is much greater than with any of the known synthetic sweeteners. Thus, the compounds of the invention are highly stable, do not form diketopiperazines, and the safety of these compounds is implicit in the fact that the compounds are formed from natural amino acids and are formed into stable molecules. Any possible breakdown products of the compounds of the invention are likely to be either easily metabolized or in the pathway of normal ingredients of intermediary metabolism. Still further, the compounds can be used over a much wider pH range than compounds such as L-aspartyl-L-phenylalanine methyl ester and related dipeptide sweeteners and the compounds also remain stable under conditions of high temperature. The compounds of the present invention are non-caloric in the amount which would be used for sweetening purposes, are noncariogenic and are safe. The following examples are given to further illustrate the present invention. The scope of the invention is not, however, meant to be limited to the specific details of the examples: EXAMPLE 1 N-(L-Aspartyl)-N'-Cyclopentanecarbonyl-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=cyclopentyl] A. D-Alanine (20 g, 0.225 mole) was dissolved in dimethylformamide (400 ml), treated with chlorotrimethylsilane (26.8 g, 0.250 mole) and the mixture stirred at room temperature until a homogeneous solution was obtained (approx. 45 minutes). Meanwhile, N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartic acid (72 g, 0.200 mole) was dissolved in a 1:1 mixture of dimethylformamide and tetrahydrofuran (880 ml), cooled to a -15° C. and treated with N-methylmorpholine (22.4 ml, 0.200 mole) and isobutyl chloroformate (26.2 ml, 0.200 mole). After 8 minutes' activation at -15° C. the precooled solution of D-alanine silyl ester from above was added, followed by the dropwise addition of N-methylmorpholine (22.4 ml, 0.200 mole), ensuring that the temperature of the reaction mixture was maintained at -15° C. The solution was allowed to warm to room temperature slowly and stirred for several hours before acidifying to pH 1-2 (with cooling) using aqueous hydrochloric acid. Chloroform was added, the phases separated and the aqueous layer re-extracted with chloroform. The combined organic extracts were washed with 1N hydrochloric acid (3×), saturated aqueous sodium chloride and dried (MgSO 4 ). After evaporation of the solvent under reduced pressure, the oily residue was triturated with ether. The resulting solid was filtered and dried in vacuo to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanine (67 g), m.p. 158°-159° C., which was homogeneous by TLC. B. The product from Part A (64 g, 0.150 mole) was dissolved in dimethylformamide (600 ml), cooled to -15° C. and treated with N-methylmorpholine (16.5 ml, 0.150 mole) and isobutyl chloroformate (19.5 ml, 0.150 mole). After 5 minutes' activation at -15° C., 1-hydroxybenzotriazole ammonium salt (34 g, 0.225 mole) was added as a solid, and the mixture stirred at -15° C. for 15 minutes. After warming slowly to room temperature over 4 hours, chloroform and water were added, the phases separated and the aqueous phase reextracted with chloroform. The combined organic extracts were washed with 1N hydrochloric acid (3×), saturated aqueous sodium bicarbonate (3×), saturated sodium chloride and dried (MgSO 4 ). The solvent was evaporated under reduced pressure and the solid residue recrystallized from ethyl acetate/hexanes to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (50 g), m.p. 170°-171° C., which was homogeneous by TLC. C. The product from Part B (2.2 g, 5.1 mmole) was dissolved in acetonitrile (50 ml) and the solution diluted with an equal volume of water. Iodobenzene bis(trifluoroacetate) (2.4 g, 5.6 mmole) was then added and the reaction mixture stirred at room temperature for 4 hours (clear solution after approximately 2 hours). The solution was evaporated and the residue redissolved in aqueous HCl and lyophilized, to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride in quantitative yield, which was used without further purification. D. The product from Part C, (2.95 g, 5.1 mmole) was dissolved in tetrahydrofuran (50 ml), cyclopentanecarbonyl chloride (1.5 g, 10.6 mmole) added, followed by potassium bicarbonate (2.5 g, 25 mmole) and water (50 ml) and the mixture stirred at room temperature. After 2.5 hours, a clear solution was obtained but TLC indicated that reaction was incomplete and second portions of cyclopentanecarbonyl chloride (1.5 g, 10.6 mmole) and potassium bicarbonate (2 g, 20 mmole) were therefore added. The process was repeated 15 minutes later. After 20 minutes, ethyl acetate and water were added, the phases separated and the aqueous phase extracted with ethyl acetate. The combined organic phases were washed with 1M sodium bicarbonate (2×), 2N hydrochloric acid (3×), again with 1M sodium bicarbonate (2×) and finally with saturated sodium chloride and dried (MgSO 4 ). The solution was filtered, evaporated under reduced pressure and the residue triturated with ether to provide N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-cyclopentanecarbonyl-R-1,1-diaminoethane (1.5 g) as a crystalline solid which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. E. The product from Part D (1.5 g, 3.03 mmole) was hydrogenated in glacial acetic acid (50 ml) over 10% palladium on carbon (approx. 0.2 g) at 40 p.s.i. overnight. The catalyst was filtered, washed with glacial acetic acid and the filtrate lyophilized. The resultant powder was redissolved in water and relyophilized (twice) to give N-(L-aspartyl)-N'-cyclopentanecarbonyl-1,1-diaminoethane in quantitative yield, m.p. 220° C. dec. Sweetness=75-100×sucrose. EXAMPLE 2 N-(L-Aspartyl)-N'-Trimethylacetyl-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=C(CH.sub.3).sub.3 ] A. N-(N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride (5.2 g, 12 mmole), prepared as described in Example 1, Part C, was suspended in water (50 ml) at room temperature. Potassium bicarbonate (6 g, 60 mmole) was added, followed by pivaloyl chloride (1.5 ml, 12 mmole) dissolved in acetonitrile (50 ml). The homogeneous reaction mixture was stirred at room temperature for 3 hours when TLC showed incomplete reaction. Further aliquots of the acid chloride (0.8 ml) and potassium bicarbonate (5 g) were therefore added and the reaction mixture stirred for a further 1 hour. The solution was then diluted with ethyl acetate (500 ml) and extracted with 1N hydrochloric acid (3×), saturated aqueous sodium bicarbonate (3×) and saturated sodium chloride (1×). The organic phase was dried (MgSO 4 ), filtered and evaporated to dryness under reduced pressure. The residue was crystallized from ethyl acetate/hexanes to provide N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-trimethylacetyl-R-1,1-diaminoethane (4.8 g) which was homogeneous by TLC, m.p. 66°-69° C. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (4 g) was dissolved in glacial acetic acid (150 ml) and hydrogenated overnight at 40 p.s.i. over 10% palladium on carbon (approx. 0.5 g). The catalyst was filtered, washed with glacial acetic acid and the filtrate lyophilized. The resultant powder was redissolved in water and relyophilized (twice) to give N-(L-aspartyl)-N'-trimethylacetyl-R-1,1-diaminoethane in quantitative yield, m.p. 150° C. Sweetness=75-100×sucrose EXAMPLE 3 N-(L-Aspartyl)-N'-Cyclohexanecarbonyl-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=cyclohexyl] A. N-(N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride (Example 1, Part C) (5.2 g, 12 mmole) was treated with cyclohexanecarbonyl chloride (1.75 ml, 12 mmole) and potassium bicarbonate (6 g, 60 mmole), as described in Example 2, Part A. A second aliquot of the acid chloride (0.8 ml) and potassium bicarbonate (5 g) were added after 3 hours. The product precipitated and was collected by filtration, dried, triturated with hexane and dried in vacuo to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-cyclohexanecarbonyl-R-1,1-diaminoethane (5.8 g) which was homogeneous by TLC, m.p. 178°-180° C. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (5 g) was hydrogenated in the usual manner in glacial acetic acid (150 ml) over palladium on carbon. After lyophilization several times from water, N-(L-aspartyl)-N'-cyclohexanecarbonyl-R-1,1-diaminoethane was obtained in quantitative yield. Sweetness=50-75×sucrose. EXAMPLE 4 N-(L-Aspartyl)-N'-Benzoyl-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=phenyl] A. N-(N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride (Example 1, Part C) (5.2 g, 12 mmole) was dissolved in tetrahydrofuran (100 ml) at room temperature. Triethylamine (1.68 ml, 12 mmole) was added, followed by benzoyl chloride (1.62 g, 12 mmole) and a second equivalent of triethylamine (1.68 ml) and the mixture stirred at room temperature. After 3 hours reaction was incomplete by TLC and another aliquot of triethylamine (1.15 ml) was therefore added and the mixture stirred at room temperature for a further 1 hour. The reaction mixture was then evaporated to dryness, the residue redissolved in ethyl acetate (approx. 1000 ml), and extracted in the usual manner. (This procedure proved to be difficult because of the formation of emulsions and precipitates.) After drying (MgSO 4 ) the organic phase was evaporated to dryness under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-benzoyl-R-1,1-diaminoethane (1.5 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (1 g) was hydrogenated in the usual manner in glacial acetic acid (50 ml) over 10% palladium on carbon. Lyophilization several times from water gave N-(L-aspartyl)-N'-benzoyl-R-1,1-diaminoethane in quantitative yield. Sweetness=5-20×sucrose. EXAMPLE 5 N-(L-Aspartyl)-N'-(2-Norbornanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2-norbornyl] A. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was suspended in 1:1 acetonitrile:water (200 ml) and iodobenzene bis(trifluoroacetate) (12 g, 28 mmole) added. The reaction mixture was stirred at room temperature for 4 hours (a homogeneous solution was obtained after 2 hours) and then treated with norbornane-2-carboxyl chloride (10 g, 63 mmole) and potassium bicarbonate (12 g, 120 mmole). After stirring for 2 hours at room temperature, TLC showed complete reaction and the product was extracted and worked up in the usual manner. After drying (MgSO 4 ), the organic phase was evaporated to dryness under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2-norbornanecarbonyl)-R-1,1-diaminoethane (10.3 g), m.p. 127°-130° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (9 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization several times from water, N-(L-aspartyl)-N'-(2-norbornanecarbonyl)-R-1,1-diaminoethane was obtained in quantitative yield, m.p. 177°-178° C. Sweetness=75-100×sucrose. EXAMPLE 6 N-(L-Aspartyl)-N'-(1-Adamantanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=1-adamantyl] A. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (8.54 g, 20 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with 1-adamantanecarbonyl chloride (6 g, 30 mmole) and potassium bicarbonate (15 g, 150 mmole) and stirred at room temperature for 4 hours. After the usual workup, the crude product was obtained as an oil which was purified by chromatography on silica gel, eluting with chloroform:hexane (3:1, v/v). N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(1-adamantanecarbonyl)-R-1,1-diaminoethane was obtained as an oil (2.5 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (2.0 g) was hydrogenated in the usual manner in glacial acetic (50 ml) over 10% palladium on carbon. After lyophilization several times from water, N-(L-aspartyl)-N'-(1-adamantanecarbonyl)-R-1,1-diaminoethane was obtained in quantitative yield, m.p. 174°-175° C. Sweetness=5-15×sucrose. EXAMPLE 7 N-(L-Aspartyl)-N'-(2-Methylcyclohexanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2-methylcyclohexyl] A. Ethyl 2-methylcyclohexanecarboxylate (50 g, 0.295 mmole) was added to a solution of potassium hydroxide (27 g, 0.48 mole) in anhydrous methanol (300 ml). The mixture was stirred overnight at room temperature and then evaporated to dryness under reduced pressure. The residue was redissolved in water and the solution extracted with ether (3×200 ml), then acidified (pH<2), and re-extracted with ether (3×200 ml). The final, combined organic extracts were washed with water, dried (MgSO 4 ) and evaporated under reduced pressure to yield 2-methylcyclohexanecarboxylic acid. The crude product was converted to the acid chloride by treatment with excess thionyl chloride (100 ml) at room temperature for 30 minutes. The thionyl chloride was evaporated under reduced pressure and the residue distilled in vacuo to give 2-methylcyclohexanecarboxyl chloride (33 g). B. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole), followed by 2-methylcyclohexanecarboxyl chloride (5.5 g, 35 mmole). The reaction was followed by TLC. Addition of two further aliquots (3 g each) of the acid chloride was required for complete reaction. The reaction mixture was worked up in the usual manner and the product crystallized from ethyl acetate/hexanes (yield=10.0 g) and then chromatographed on silica gel, eluting with 5% methanol in chloroform, to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2-methylcyclohexanecarbonyl)-R-1,1-diaminoethane (8.0 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. C. The product from Part B (8.0 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization from water several times N-(L-aspartyl)-N'-(2-methylcyclohexanecarbonyl)-R-1,1-diaminoethane was obtained in quantitative yield, m.p. 203°-204° C. Sweetness=150-250×sucrose. EXAMPLE 8 N-(L-Aspartyl)-N'-(1-Methylcyclohexanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=1-methylcyclohexyl] A. 1-Methylcyclohexanecarboxylic acid (50 g, 350 mmole) was converted to the acid chloride by treatment with an excess of thionyl chloride (75 ml) at room temperature. The excess thionyl chloride was evaporated under reduced pressure and the residue distilled in vacuo to provide 1-methylcyclohexanecarboxyl chloride (49 g). B. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bix(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole), followed by 1-methylcyclohexanecarboxyl chloride (5.5 g, 35 mmole), and two further aliquots (3 g each) over 3 hours. When reaction was complete by TLC, the reaction mixture was worked up in the usual manner and the crude product purified by chromatography on silica gel, eluting with 5% methanol in chloroform to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(1-methylcyclohexanecarbonyl)-R-1,1-diaminoethane (8.2 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. C. The product from Part B (8.2 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization several times from water, N-(L-aspartyl)-N'-(1-methylcyclohexanecarbonyl)-R-1,1-diaminoethane was obtained in quantitative yield, m.p. 142°-143° C. Sweetness=35-50×sucrose. EXAMPLE 9 N-(L-Aspartyl)-N'-(1-Methylcyclopropanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=1-methylcyclopropyl] A. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole), followed by 1-methylcyclopropanecarboxyl chloride (3.65 g, 35 mmole), and two further aliquots (2 g each) over 3 hours. When reaction was complete by TLC the reaction mixture was worked up in the usual manner and the product crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(1-methylcyclopropanecarbonyl)-R-1,1-diaminoethane (8 g) which was homogeneous by TLC, m.p. 120°-123° C. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (7 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization from water several times N-(L-aspartyl)-N'-(1-methylcyclopropanecarbonyl)-R-1,1-diaminoethane was obtained in quantitative yield, m.p. 134°-135° C. Sweetness=10-25×sucrose. EXAMPLE 10 N-(L-Aspartyl)-N'-(2,2,4-trimethylpentanoyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=1,1,3-trimethylbutyl] A. 2,4-Dimethyl-3-pentanol (29 g, 0.25 mole), dissolved in formic acid (98%, 46 g, 1 mole), was added dropwise over one hour to a rapidly-stirred, ice-cooled mixture of formic acid (98%, 3 ml) and concentrated sulfuric acid (270 ml). During the addition the reaction mixture foamed vigorously and was stirred for a further one hour at 10°-20° C. The mixture was poured on to ice (1 kg) and the resulting solution extracted with hexanes (3×200 ml). The combined organic phases were extracted with 2N potassium hydroxide (2×200 ml) plus ice (50 g) and the aqueous extracts washed with hexanes (100 ml). The aqueous phase was then acidified (pH 2) and the product extracted into hexanes (3×200 ml). After washing with saturated sodium chloride and drying (MgSO 4 ), the solution was evaporated under reduced pressure and the residue distilled to give 2,2,4-trimethylpentanoic acid (36 g). B. The product from Part A (36 g) was treated with an excess of thionyl chloride (50 ml) and the mixture stirred at room temperature overnight. The thionyl chloride was evaporated under reduced pressure and the product distilled in vacuo to give 2,2,4-trimethylpentanoyl chloride (35 g). C. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole) followed by 2,2,4-trimethylpentanoyl chloride (5.4 g, 30 mmole) and a second portion (2.7 g, 15 mmole) after 30 minutes. The reaction mixture was stirred at room temperature for a further 1.5 hours, when reaction was completed by TLC. The reaction mixture was worked up in the usual manner and the product crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,2,4-trimethylpentanoyl)-R-1,1-diaminoethane (9.4 g), which was homogeneous by TLC, m.p. 98°-101° C. The nmr spectrum of the product was consistent with the assigned structure. D. The product from Part C (9.0 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization from water several times N-(L-aspartyl)-N'-(2,2,4-trimethylpentanoyl)-1,1-diaminoethane was obtained in quantitative yield, m.p. 120° C. dec. Sweetness=50-75×sucrose. EXAMPLE 11 N-(L-Aspartyl)-N'-(Trimethylcyclohexanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=trimethylcyclohexyl] A. A solution of 2,6-dimethylcyclohexanone (35 g, 0.277 mole) in ether (200 ml) was cooled to -78° C. and treated with a 2-fold excess of a solution of methyl magnesium bromide in ether (2.8M, 198 ml). After stirring at -78° C. for 3 hours the reaction mixture was warmed to 0° C. and quenched carefully with water and brine. The organic layer was separated, dried (MgSO 4 ) and the ether evaporated under reduced pressure to give 1,2,6-trimethylcyclohexanol (32.2 g). B. A solution of 1,2,6-trimethylcyclohexanol (32.2 g, 0.226 mole) in formic acid (98%, 46 g, 1 mole) was added dropwise to an ice-cooled mixture of formic acid (90%, 3 ml) and sulfuric acid (90%, 270 ml, 4.86 mole). The solution foamed vigorously during the addition. After stirring for a further one hour the reaction mixture was poured on to crushed ice (2 kg) and worked up as described for Example 10, Part A. Yield of trimethylcyclohexanecarboxylic acid was 29.9 g. C. The product from Part B (29.9 g, 0.176 mole) was added carefully to excess thionyl chloride (65 ml) and the mixture stirred at room temperature overnight. The thionyl chloride was evaporated under reduced pressure to give trimethylcyclohexanecarboxyl chloride (25.5 g) which was used without further purification. D. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole) and trimethylcyclohexanecarboxyl chloride (6.15 g, 30 mmole), followed by a second portion (3 g) after 30 minutes. After 3 hours, when TLC showed that the reaction was complete, the reaction mixture was worked up in the usual manner. The product was crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(trimethylcyclohexanecarbonyl)-R-1,1-diaminoethane (8.6 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. E. The product from Part D (8 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization from water several times N-(L-aspartyl)-N'-trimethylcyclohexanecarbonyl-R-1,1-diaminoethane was obtained in quantitative yield. Sweetness=25-50×sucrose. EXAMPLE 12 N-(L-Aspartyl)-N'-(1,1-Dicyclopropylacetyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=dicyclopropylmethyl] A. Methyltriphenylphosphonium bromide (116 g, 0.325 mole) was suspended in dry ether (600 ml), cooled to -10° C. and treated with a solution of n-butyllithium in hexane (2.2M, 175 ml). The mixture was stirred for 5 minutes before adding a solution of dicyclopropyl ketone (35.6 g, 0.325 mole) in ether (100 ml) which had been precooled to 0° C. The suspension was allowed to warm to room temperature and then stirred for a further 2 hours. Water (1000 ml) was then added, in small portions at first, and the mixture stirred until the precipitate dissolved. The organic layer was separated, washed with water, dried (MgSO 4 ) and the solvent evaporated under reduced pressure. The residue contained a solid (triphenylphosphine oxide) which was separated from the oil, washed with a little ether and the combined etheral/organic residues were fractionated to yield dicyclopropyl ethylene (6.5 g), b.p. 130° C./760 mm, which was pure by GC. B. Dicyclopropyl ethylene (19 g, 0.176 mole) was dissolved in dry tetrahydrofuran (100 ml) in a three-neck flask under nitrogen and treated with borane-tetrahydrofuran in tetrahydrofuran (1M, 210 ml). The mixture was stirred at room temperature for 4 hours before adding cautiously (foaming occurs) 3N sodium hydroxide (60 ml). After addition was complete, aqueous hydrogen peroxide (30%, 60 ml) was added dropwise at a rate sufficient to maintain reflux. When addition was complete, the mixture was refluxed for a further 30 minutes, cooled and the aqueous layer saturated with sodium chloride. The layers were separated, the organic layer dried (MgSO 4 ) and evaporated under reduced pressure to give a quantitative yield of 2,2-dicyclopropylethanol which was pure by GC. (The product could also be distilled, b.p. 99° C./25 mm.) C. The product from Part B (16 g, 0.127 mole) was dissolved in ether (300 ml) and the solution added to a mixture of potassium dichromate (60 g) dissolved in concentrated sulfuric acid (120 ml) and ice-water (600 ml). The reaction mixture, which immediately became dark, was stirred at room temperature for one hour. The organic layer was then separated, washed with water (3×), dried (MgSO 4 ) and the ether evaporated under reduced pressure. The residue was distilled to give 1,1-dicyclopropylacetic acid (10.3 g), b.p. 130°-141° C./25 mm, which was pure by GC. D. The product from Part C (10 g, 0.071 mole) was dissolved in dry tetrahydrofuran (25 ml) and treated with excess thionyl chloride (25 ml). After stirring the mixture at room temperature for one hour, conversion to the acid chloride was complete by GC. The solvent and excess thionyl chloride were evaporated under reduced pressure to give 1,1-dicyclopropylacetyl chloride in quantitative yield, which was used without further purification. E. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (8.54 g, 20 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (16 g, 160 mmole), followed by dropwise addition of 1,1-dicyclopropylacetyl chloride (4.7 g, 30 mmole). A precipitate formed almost immediately and the reaction mixture was stirred at room temperature for one hour. Water and chloroform were then added, the phases separated and the organic layer washed with saturated aqueous sodium bicarbonate (3×), 3N aqueous hydrochloric acid and saturated sodium chloride. After drying (Na 2 SO 4 ) the solvent was evaporated under reduced pressure and the solid residue recrystallized from ethyl acetate to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(1,1-dicyclopropylacetyl)-R-1,1-diaminoethane (6.5 g), which was homogeneous by TLC, m.p. 200°-201° C. The nmr spectrum of the product was consistent with the assigned structure. F. The product from Part E (4 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on charcoal. After lyophilization several times from water, the residue was crystallized from ethanol/water to give N-(L-aspartyl)-N'-(1,1-dicyclopropylacetyl)-R-1,1-diaminoethane (1.0 g), m.p. 209°-210° C. Sweetness=500-700×sucrose. EXAMPLE 13 N-(L-Aspartyl)-N'-(2,5-Dimethylcyclopentanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2,5-dimethylcyclopentyl] A. Sodium metal (16 g, 0.7 mole) was dissolved in absolute ethanol (500 ml) under argon with cooling as necessary to maintain a temperature of <70° C. The solution was cooled and redistilled diethyl malonate (54.3 g, 0.362 mole) was added dropwise, with cooling as necessary, followed by 2,5-dibromohexane (85 g, 0.348 mole) in a single portion. The reaction mixture was stirred overnight at room temperature and then refluxed for 2 hours. The mixture was then concentrated to approximately half the volume under reduced pressure, water (500 ml) added and the mixture extracted with ether (3×200 ml). The combined extracts were dried (Na 2 SO 4 ), filtered, and evaporated under reduced pressure. The residue was fractionated in vacuo to yield diethyl 2,5-dimethylcyclopentane-1,1-dicarboxylate (35 g), which was homogeneous by GC. B. The product from Part A (35 g, 0.145 mole) was added to a solution of potassium hydroxide (55 g) in absolute ethanol (300 ml) and the mixture refluxed overnight. The reaction mixture was evaporated under reduced pressure and the residue dissolved in water (500 ml). The aqueous solution was extracted with ethyl acetate (200 ml), acidified to pH 1 (conc. HCl) and extracted with ether (3×200 ml). The combined extracts were washed with 1N hydrochlorid acid and dried (Na 2 SO 4 ). The solution was evaporated under reduced pressure and the residual oil triturated with pentane to induce crystallization. The product was filtered and dried in vacuo to give 2,5-dimethylcyclopentane-1,1-dicarboxylic acid (10.5 g) which was homogeneous by GC. C. The product from Part B (10.5 g, 56 mmole) was heated to 230° C. in a stream of argon for 1.25 hour. The residue was dissolved in tetrahydrofuran, decolorized (Norit A), and the solvent evaporated under reduced pressure. The residual oil crystallized on standing to give 2,5-dimethylcyclopentanecarboxylic acid (6.3 g), m.p. 45° C., which was pure by GC. D. The product from Part C (6.3 g, 48 mmole) was dissolved in tetrahylrofuran/thionyl chloride (1:1, v/v; 100 ml) and the mixture stirred at room temperature for one hour. The solution was evaporated under reduced pressure to give a quantitative yield of 2,5-dimethylcyclopentanecarbonyl chloride which was used without further purification. E. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (8.6 g, 20 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole), followed by 2,5-dimethylcyclopentanecarboxyl chloride (4.8 g, 30 mmole), added dropwise over 5 minutes. The product precipitated almost immediately and stirring was continued for a further 2 hours at room temperature. The reaction mixture was worked up in the usual manner, except that the product crystallized during the drying of the final extracts over Na 2 SO 4 . The solution was therefore heated to boiling, filtered hot and the Na 2 SO 4 washed with ethyl acetate. The filtrate was evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,5-dimethylcyclopentanecarbonyl)-1,1-diaminoethane, (6.1 g) which was homogeneous by TLC, m.p. 193°-195° C. The nmr spectrum of the product was consistent with the assigned structure. F. The product from Part E (5.5 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization several times from water, the solid residue was recrystallized from ethanol/water to give N-(L-aspartyl)-N'-(2,5-dimethylcyclopentanecarbonyl)-R-1,1-diaminoethane (2.6 g), m.p. 208°-209° C. Sweetness=300-400×sucrose. EXAMPLE 14 N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylcyclopentanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2,2,5,5-tetramethylcyclopentyl] A. Sodium hydride (50% dispersion in oil; 144 g, 3.0 mole) was added to a 3-liter, 3-neck flask fitted with a reflux condenser, a mechanical stirrer and a nitrogen inlet. A moderate stream of nitrogen was passed through the flask and dry tetrahydrofuran (1.5 l) added. Solutions of cyclopentanone (53.6 g, 0.64 mole) in dry tetrahydrofuran (350 ml) and dimethyl sulfate (285 ml, 3.0 mole) in the same solvent (120 ml) were added simultaneously in small portions (20-40 ml) to the stirred suspension, so as to maintain a gentle evolution of hydrogen. The reaction mixture was cooled as necessary to maintain a temperature of <40° C. When addition was complete (several hours) the reaction mixture was refluxed for 2 hours. After cooling, t-butanol (100 ml) was added slowly to destroy excess hydride, followed by water (1 l), cautiously at first. The reaction mixture was then refluxed 2 hours to destroy excess dimethyl sulfate. On cooling, the layers were separated and the organic phase washed with saturated sodium chloride and dried (Na 2 SO 4 ). The solvent was evaporated under reduced pressure and the residue fractionated in vacuo to give 2,2,5,5-tetramethylcyclopentanone (59 g), b.p. 55° C./20 mm. B. A solution of 2,2,5,5-tetramethylcyclopentanone (30 g, 0.215 mole) in ether (50 ml) was treated, under nitrogen, with a 3M solution of methyl magnesium bromide in ether (100 ml). The reaction mixture was stirred overnight at room temperature and saturated aqueous ammonium chloride (65 ml) then added dropwise. The mixture was stirred for 10 minutes, the ether solution decanted and the solid residue triturated with ether. The ether extracts were dried (Na 2 SO 4 ) and evaporated under reduced pressure to give crude 1,2,2,5,5-pentamethylcyclopentanol (30 g) which was used without further purification. C. The crude product from Part B (30 g) was dissolved in pyridine (150 ml), the solution cooled to 0° C. and treated (dropwise) with thionyl chloride (20 ml, 0.28 mole), maintaining a temperature of <5° C. The reaction mixture was stirred overnight, filtered and ether and water added. The phases were separated and the organic phase washed with water (2×200 ml) and dried (Na 2 SO 4 ). The solvent was evaporated under reduced pressure to give 1-methylene-2,2,5,5-tetramethylcyclopentane (10.8 g) which was pure by GC. D. The product from Part C (10.8 g, 78 mmole) was dissolved in dry tetrahydrofuran (100 ml) and treated under nitrogen with 1M borane-tetrahydrofuran in tetrahydrofuran (100 ml). The reaction mixture was stirred overnight at room temperature and treated with 3N aqueous sodium hydroxide (40 ml), followed by dropwise addition of 30% aqueous hydrogen peroxide (40 ml) at a rate sufficient to maintain a gentle reflux. The mixture was refluxed for a further one hour, sodium chloride added to saturation, and the mixture cooled to room temperature with stirring. The phases were separated, the organic phase dried (Na 2 SO 4 ) and evaporated under reduced pressure to give a quantitative yield of crude 2,2,5,5-tetramethylcyclopentylmethanol which was used without further purification. E. The product from Part D was dissolved in ether (300 ml) and added to a solution of potassium dichromate (45 g, 0.15 mole) in concentrated sulfuric acid (90 ml, 1.7 mole) and water (450 ml). The mixture was stirred at room temperature for 3 hours. The phases were then separated, the organic phase washed with saturated sodium chloride and dried (Na 2 SO 4 ). The solvent was evaporated under reduced pressure and the residue distilled in vacuo to give 2,2,5,5-tetramethylcyclopentanecarboxylic acid (6.6 g) which was homogeneous by GC. F. The product from Part E (6.5 g, 38 mmole) was dissolved in tetrahydrofuran (100 ml) and treated dropwise with excess thionyl chloride (20 ml, 270 mmole). The solution was refluxed for two hours, evaporated under reduced pressure and the residue distilled in vacuo to give 2,2,5,5-tetramethylcyclopentanecarboxyl chloride (4.8 g), b.p. 65°-75° C./4 mm. G. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) as described in Example 5, Part A. The resulting solution was evaporated to near dryness under reduced pressure, water and a large excess of concentrated hydrochloric acid added, and the mixture re-evaporated to dryness. The solid residue was dissolved in 4.4M HCl/dioxane (20 ml), the solution evaporated to dryness, and the residue redissolved in dioxane (100 ml) and lyophilized to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride (10.2 g), which was homogeneous by TLC. H. The product from Part G (6.6 g, 15 mmole) was dissolved in dry tetrahydrofuran (150 ml) and treated with 2,2,5,5-tetramethylcyclopentanecarboxyl chloride (from Part F; 3.1 g, 15 mmole) followed by triethylamine (4.2 ml, 30 mmole). The reaction mixture was stirred at room temperature for one hour, ethyl acetate added, and the product worked up in the usual manner. Crystallization from ethyl acetate/hexanes gave N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-R-1,1-diaminoethane (6.0 g), which was homogeneous by TLC, m.p. 122°-125° C. The nmr spectrum was consistent with the assigned structure. I. The product from Part H (5.5 g) was hydrogenated in the usual manner in glacial acetic acid (200 ml) over 10% palladium on carbon. After lyophilization from water several times, the solid residue was crystallized from ethanol/hexanes to give N-(L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-R-1,1-diaminoethane (2.0 g), m.p. 171°-172° C. The compound was homogeneous by high pressure liquid chromatography (HPLC) (Conditions: Lichrosorb RP-18; linear gradient of 24-33% acetonitrile in 0.01M triethylammonium phosphate, pH 4.5; flow rate=1 ml/min.; retention time=12.31 min.). Sweetness=800-1000×sucrose. EXAMPLE 15 N-(L-Aspartyl)-N'-(2,6-Dimethylcyclohexanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2,6-dimethylcyclohexyl] A. Methyltriphenylphosphonium bromide (286 g, 0.80 mole) was suspended in ether (1500 ml) and treated with n-butyllithium (1.6M in ether; 500 ml, 0.80 mole), followed by 2,6-dimethylcyclohexanone (50.4 g, 0.40 mole), following the procedure described in Example 12, Part A. The crude product was distilled to give 1-methylene-2,6-dimethylcyclohexane (24 g), b.p. 146°-154° C./760 mm. B. The product from Part A (24 g, 0.10 mole) was dissolved in dry tetrahydrofuran (50 ml) and treated under nitrogen with 1M borane-tetrahydrofuran in tetrahydrofuran (250 ml). The reaction mixture was stirred overnight at room temperature and treated with 3N aqueous sodium hydroxide (20 ml) dropwise (foaming occurs), followed, dropwise, by 30% aqueous hydrogen peroxide (20 ml). The mixture was refluxed for 30 minutes, sodium chloride added to saturation and the mixture cooled to room temperature with stirring. The phases were separated and the organic phase dried (Na 2 SO 4 ) and evaporated under reduced pressure to give a quantitative yield of 2,6-dimethylcyclohexylmethanol. The product was purified by fractionation in vacuo b.p. 187°-210° C./760 mm. C. The product from Part B (20 g, 0.14 mole) was dissolved in ether (300 ml) and added to a solution of potassium dichromate (90 g, 0.30 mole) in concentrated sulfuric acid (175 ml) and water (900 ml) in an ice bath. The mixture was warmed to room temperature and stirred for 2 days. The phases were separated, the organic phase washed with water, dried (MgSO 4 ) and evaporated under reduced pressure. The residue was fractionated to give 2,6-dimethylcyclohexanecarboxylic acid (16.7 g), which was pure by GC, b.p. 145°-148° C. D. The product from Part C (16.7 g) was dissolved in tetrahydrofuran (100 ml) and treated with excess thionyl chloride (30 ml) at room temperature. After stirring at room temperature for one hour, the solvent and excess thionyl chloride were evaporated under reduced pressure to provide a quantitative yield of 2,6-dimethylcyclohexanecarboxyl chloride which was used without further purification. E. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (Example 1, Part B) (10.7 g, 25 mmole) was treated with iodobenzene bis(trifluoroacetate) using the procedure described in Example 5, Part A. The resulting solution was treated with potassium bicarbonate (20 g, 200 mmole), followed by 2,6-dimethylcyclohexanecarboxyl chloride (6.1 g, 35 mmole) added dropwise over 2 minutes. The reaction mixture was stirred for 3 hours at room temperature, and then worked up in the usual manner, except that the product crystallized during drying of the final extracts over Na 2 SO 4 . The solution was therefore heated to boiling, filtered hot and the Na 2 SO 4 washed with ethyl acetate. The filtrate was evaporated under reduced pressure and the residue recrystallized from ethyl acetate to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,6-dimethylcyclohexanecarbonyl)-R-1,1-diaminoethane, (4.5 g) which was homogeneous by TLC, m.p. 146°-150° C. The nmr spectrum of the product was consistent with the assigned structure. F. The product from Part E (4 g) was hydrogenated in the usual manner in glacial acetic acid (150 ml) over 10% palladium on carbon. After lyophilization from water several times, the solid residue was crystallized from ethanol/water to give N-(L-aspartyl)-N'-(2,6-dimethylcyclohexanecarbonyl)-R-1,1-diaminoethane (0.8 g). Sweetness=150-200×sucrose. EXAMPLE 16 N-(L-Aspartyl)-N'-(2-t-Butylcyclohexanecarbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2-t-butylcyclohexyl] A. Methyltriphenylphosphonium bromide (346 g, 0.97 mole) was suspended in ether (1500 ml) and treated with n-butyllithium (2.5M in ether; 388 ml, 0.97 mole), followed by 2-t-butylcyclohexanone (50 g, 0.324 mole), following the procedure described in Example 12, Part A. The reaction mixture was heated under reflux for 2 days and then worked up in the usual manner. The crude product was fractionated to provide methylene-2-t-butylcyclohexane (22 g), which was pure by GC. B. The product from Part A (22 g, 0.146 mole) was dissolved in dry tetrahydrofuran (50 ml) and treated under nitrogen with boranetetrahydrofuran in tetrahydrofuran (1M; 160 ml, 0.16 mole). The reaction mixture was stirred at room temperature for 2 days and treated with 4N aqueous sodium hydroxide (40 ml) dropwise (foaming occurs), followed by 30% aqueous hydrogen peroxide (40 ml). The reaction mixture was refluxed overnight and then quenched with ice water, extracted with ether and the combined extracts dried (MgSO 4 ). The solvent was evaporated under reduced pressure to give 2-t-butylcyclohexylmethanol (17 g) which was used without further purification. C. The product from Part B (15 g, 0.088 mole) was added to a solution of potassium dichromate (51.8 g, 0.176 mole) in sulfuric acid (102 ml) and water (600 ml). The reaction mixture was stirred at room temperature until all of the starting material had disappeared by GC. The reaction was quenched with water, extracted with ether and the combined extracts dried (MgSO 4 ). The solvent was evaporated under reduced pressure to give 2-t-butylcyclohexanecarboxylic acid (10 g) which was used without further purification. D. The product from Part C (10 g, 0.054 mole) was dissolved in pyridine:ether (1:1, 100 ml) and treated with an excess of thionyl chloride (12 ml, 0.162 mole). The reaction mixture was stirred at room temperature for 12 hours and then evaporated under reduced pressure. The residue was fractionated to give 2-t-butylcyclohexanecarboxyl chloride (7 g). E. N-(N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride (8.52 g, 20 mmole), prepared as described in Example 14, Part G, was dissolved in dry tetrahydrofuran (200 ml) and treated with 2-t-butylcyclohexanecarboxyl chloride (from Part D; 4.05 g, 20 mmole), followed by triethylamine (5.6 ml, 40 mmole). The reaction mixture was stirred at room temperature for 3 hours, ethyl acetate added and the product worked up in the usual manner. Crystallization from ethyl acetate/hexanes gave N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2-t-butylcyclohexanecarbonyl)-1,1-diaminoethane (4.5 g), which was homogeneous by TLC, m.p. 165°-166° C. The nmr spectrum of the product was consistent with the assigned structure. F. The product from Part E (4 g) was hydrogenated in the usual manner in glacial acetic acid (150 ml) over 10% palladium on carbon. After lyophilization several times from water, the solid residue was crystallized from isopropanol/water to give N-(L-aspartyl)-N'-(2-t-butylcyclohexanecarbonyl)-R-1,1-diaminoethane (1.5 g), m.p. 195°-198° C. Sweetness=150-200×sucrose. EXAMPLE 17 N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylcyclopentanecarbonyl)-R-1,1-Diamino-2-Hydroxyethane [Formula I, R=CH.sub.2 OH, R'=H, R"=2,2,5,5-tetramethylcyclopentyl] A. O-Benzyl-D-serine (5.0 g, 25.6 mmole) was dissolved in dimethylformamide (50 ml), treated with chlorotrimethylsilane (3.053 g, 28.1 mmole) and the mixture stirred at room temperature until a homogeneous solution was obtained (approx. 1 hour). Meanwhile, N-benzyloxycarbonyl-β-benzyl-L-aspartic acid (9.14 g, 25.6 mmole) was dissolved in a 1:1 mixture of dimethylformamide and tetrahydrofuran, cooled to -15° C. and treated with N-methylmorpholine (2.81 ml, 25.6 mmole), followed by isobutyl chloroformate (3.32 ml, 25.6 mmole). After 10 minutes' activation, the precooled solution of O-benzyl-D-serine silyl ester was added, followed by dropwise addition of N-methylmorpholine (2.81 ml, 25.6 mmole), ensuring that the temperature of the reaction mixture was maintained at -15° C. The solution was allowed to warm to room temperature slowly and stirred for 4 hours before acidifying to pH 1-2 (with cooling) using aqueous hydrochloric acid. Chloroform was added, the phases separated and the aqueous layer re-extracted with chloroform. The combined organic extracts were washed with 1N hydrochloric acid (3×) and with saturated sodium chloride and dried (MgSO 4 ) The solvent was evaporated under reduced pressure and the solid residue crystallized from ethyl acetate/hexanes to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-O-benzyl-D-serine (11.0 g), m.p. 107°-108° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (10.0 g, 18.72 mmole) was dissolved in dimethylformamide (100 ml), cooled to -15° C. and treated with N-methylmorpholine (2.05 ml, 18.72 mmole), followed by isobutyl chloroformate (2.43 ml, 18.72 mmole). After 4 minutes' activation at -15° C., 1-hydroxybenzotriazole ammonium salt (3.13 g, 20.5 mmole) was added as a solid and the mixture stirred at -15° C. for 30 minutes. After warming to room temperature with stirring over 4 hours, chloroform and water were added, the phases separated and the aqueous phase re-extracted with chloroform. The combined organic phases were washed with 1N hydrochloric acid (3×), saturated aqueous sodium bicarbonate (3×), saturated sodium chloride and dried (MgSO 4 ) The solvent was evaporated under reduced pressure and the solid residue recrystallized from ethyl acetate/hexanes to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-O-benzyl-D-seryl amide (7.4 g), m.p. 150° C. which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. C. The product from Part B (5.33 g, 10 mmole) was dissolved in acetonitrile (50 ml) and the solution diluted with an equal volume of water. Iodobenzene bis(trifluoroacetate) (4.8 g, 11.2 mmole) was then added and the reaction mixture stirred at room temperature for 5 hours. The solution was evaporated under reduced pressure and the residue redissolved in anhydrous HCl/dioxane (4N) and the solution lyophilized to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diamino-2-hydroxyethane hydrochloride in quantitative yield which was used without further purification. D. The product from Part C was dissolved in tetrahydrofuran (50 ml), N-methylmorpholine (3.30 ml, 30 mmole) added, followed by 2,2,5,5-tetramethylcyclopentanecarbonyl chloride (3.1 g, 16 mmole) and the mixture stirred at room temperature for 4 hours. Ethyl acetate and water were added, the phases separated and the aqueous phase re-extracted with ethyl acetate. The combined organic phases were washed with 1M sodium bicarbonate (2×), 2N hydrochloric acid (3×), again with 1M sodium bicarbonate (2×), finally with saturated sodium chloride and dried (MgSO 4 ). The solution was filtered, the filtrate evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-2,2,5,5-tetramethylcyclopentanecarbonyl-1,1-diamino-2-hydroxyethane (4.0 g), m.p. 90°-93° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. E. The product from Part D (3.8 g) was hydrogenated in the usual manner in glacial acetic acid (150 ml) over 10% palladium on carbon. After lyophilization and relyophilization from water several times, N-(L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-R-1,1-diamino-2-hydroxyethane was obtained in quantitative yield, m.p. 174°-176° C. dec. Sweetness=400-500×sucrose. EXAMPLE 18 N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylcyclopentanecarbonyl)-S-1,1-Diaminoethane [Formula I, R=H, R'=CH.sub.3, R"=2,2,5,5-tetramethylcyclopentyl] A. N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartic acid (1.70 g, 5 mmole) was dissolved in tetrahydrofuran (100 ml), the solution cooled to -15° C. and treated with N-methylmorpholine (0.55 ml, 5 mmole). After 10 minutes' activation at -15° C., a precooled solution of L-alanineamide hydrochloride (0.75 g, 6 mmole) in dimethylformamide (50 ml) was added, followed by N-methylmorpholine (0.66 ml, 6 mmole). The solution was allowed to warm to room temperature and stirred overnight. Chloroform and water were then added, the phases separated and the aqueous phase re-extracted with chloroform. The combined organic phases were washed with 1N hydrochloric acid (3×), saturated sodium chloride and dried (MgSO 4 ). The solution was filtered, the filtrate evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-L-alanyl amide (2.0 g), m.p. 180°-180.5° C. which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (1.0 g, 4.4 mmole) was dissolved in acetonitrile (25 ml), diluted with an equal volume of water and treated with iodobenzene bis(trifluoroacetate) (2.13 g, 5 mmole). After stirring the solution at room temperature for 5 hours the product was worked up as described in Example 17, Part C, to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-S-1,1-diaminoethane hydrochloride in quantitative yield, which was used without further purification. C. The product from Part B was dissolved in tetrahydrofuran (100 ml), N-methylmorpholine (1.1 ml, 10 mmole) added, followed by 2,2,5,5-tetramethylcyclopentanecarbonyl chloride (1.25 g, 6.5 mmole) and the mixture stirred at room temperature for 5 hours. Ethyl acetate and water were then added, the phases separated and the aqueous phase re-extracted with ethyl acetate. The combined organic phases were washed with 1M sodium bicarbonate (2×), 2N hydrochloric acid (3×), again with 1M sodium bicarbonate (2×), finally with saturated sodium chloride and dried (MgSO 4 ). The solution was filtered, the filtrate evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-S-1,1-diaminoethane (1.3 g), m.p. 129°-131° C. which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. D. The product from Part C was hydrogenated in the usual manner in glacial acetic acid (50 ml) over 10% palladium on carbon. After lyophilization and relyophilization from water several times, N-(L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-S-1,1-diaminoethane was obtained in quantitative yield, m.p. 174°-176° C. dec. The compound was homogeneous by HPLC (Conditions: see Example 14; retention time=10.27 min.). Sweetness=600-800×sucrose. EXAMPLE 19 N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylthietane-3-carbonyl)-R-1,1-Diaminoethane [Formula I, R=CH.sub.3, R'=H, R"=2,2,4,4-tetramethylthietane-3-yl] A. A solution of 1,3-dithiane (25.0 g, 0.208 mole) in tetrahydrofuran (200 ml) was cooled to -30° C. and treated with a solution of n-butyllithium in hexane (2.5M, 83.17 ml, 0.208 mole). The reaction mixture was stirred at this temperature for one hour, the bath lowered to -78° C. and chlorotrimethylsilane (26.4 ml, 0.208 mole) added dropwise. The reaction mixture was stirred at -78° C. for two hours and then quenched at 0° C. with water. The mixture was then extracted twice with ether, the organic extracts combined, dried (MgSO 4 ) and evaporated under reduced pressure to give trimethylsilyldithiane (38.0 g) as a pale yellow oil. The product was >95% pure by GC and was used without further purification. B. The product from Part A (27.08 g, 0.174 mole) was dissolved in tetrahydrofuran (150 ml), cooled to -78° C. and treated dropwise with a solution of n-butyllithium in hexane (2.5M, 69.44 ml, 0.174 mole). The reaction mixture was stirred at this temperature for one hour and then treated with a solution of 3-oxo-2,2,4,4-tetramethylthietane (25.0 g, 0.174 mole) in tetrahydrofuran (200 ml). The reaction mixture was stirred at -78° C. for two hours, warmed to room temperature and stirred for a further two hours when reaction was 75% complete by GC. A further aliquot of lithio trimethylsilyldithiane (9.61 g, 0.062 mole) was added to complete the reaction. After stirring overnight at room temperature the reaction mixture was quenched with water, extracted with ether (2×), the organic extracts dried (MgSO 4 ) and evaporated under reduced pressure. The residue was recrystallized from methanol to give 2,2,4,4-tetramethylthietane-3-ketene thioacetal (39.0 g), m.p. 102°-105 ° C., which was homogeneous by GC. The nmr spectrum of the product was consistent with the assigned structure. C. The product from Part B (39.0 g, 0.159 mole) was dissolved in aqueous methanol (1:2, v/v, 150 ml), diluted with tetrahydrofuran (50 ml) and treated with p-toluenesulfonic acid (150.7 g, 0.79 mole). The solution was heated under reflux until reaction was complete (disappearance of ketene thioacetal) by GC. The solution was cooled, diluted with water, extracted with ether (2×), the organic extracts dried (MgSO 4 ) and evaporated under reduced pressure. The solid residue contained 1,3-propanedithio-2,2,4,4-tetramethylthietane-3-carboxylate (29.0 g), m.p. 133°-136° C., which was pure by GC. The nmr spectrum of the product was consistent with the assigned structure. D. The product from Part C (29.0 g, 0.110 mole) was dissolved in aqueous methanol (1:2, v/v, 150 ml), diluted with tetrahydrofuran (50 ml) and solid potassium hydroxide (61.8 g, 1.10 mole) added. The solution was heated under reflux until reaction was complete (disappearance of the thioester) by GC. The solution was cooled, ether and water added and the phases separated. The ether layer was extracted with water (3×) and the aqueous phases combined, acidified and re-extracted with ether (3×) and hexanes (3×). The combined organic extracts were washed with water, dried (MgSO 4 ) and evaporated under reduced pressure. The residue was recrystallized from methanol to give 2,2,4,4-tetramethylthietane-3-carboxylic acid (12.1 g), m.p. 149°-151° C. which was pure by GC. The nmr spectrum of the product was consistent with the assigned structure. E. The product from Part D (10 g, 0.057 mole) was dissolved in tetrahydrofuran (50 ml) and treated with excess thionyl chloride (25 ml). The reaction mixture was stirred at room temperature for 5 hours and then evaporated under reduced pressure to give 2,2,4,4 -tetramethylthietane-3-carboxyl chloride in quantitative yield which was used without further purification. F. D-Alanine (5 g, 0.056 mole) was dissolved in dimethylformamide (100 ml) and treated with chlorotrimethylsilane (6.7 g, 0.063 mole). The reaction mixture was stirred at room temperature until homogeneous (approx. 1 hour). Meanwhile, N.sup.α -9-fluorenylmethyloxycarbonyl-β-benzyl-L-aspartic acid (22.3 g, 0.050 mole) was dissolved in dimethylformamide/tetrahydrofuran (1:1, v/v, 200 ml), cooled to -15° C. and treated with N-methylmorpholine (5.5 ml, 0.050 mole) and isobutyl chloroformate (6.5 ml, 0.050 mole). After 10 minutes' activation at -15° C., the precooled solution of D-alanine silyl ester from above was added, followed by a second equivalent of N-methylmorpholine (5.5 ml, 0.050 mole). The reaction mixture was allowed to warm to room temperature, stirred for 3 hours and then acidified (pH 1-2) using aqueous hydrochloric acid. The reaction mixture was stirred for 30 minutes and ethyl acetate added and the phases separated. The aqueous phase was re-extracted with ethyl acetate and the combined organic extracts washed with 1N hydrochloric acid (3×) and dried (MgSO 4 ). After evaporation of the solvent under reduced pressure the residue was crystallized from ethyl acetate/hexanes to give N.sup.α -9-fluorenylmethyloxycarbonyl-β-benzyl-L-aspartyl-D-alanine (22.5 g), m.p. 114°-116° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. G. The product from Part F (20.6 g, 0.040 mole) was dissolved in dimethylformamide (150 ml), cooled to -15° C. and treated with N-methylmorpholine (4.4 ml, 0.040 mole) and isobutyl chloroformate (5.2 ml, 0.040 mole). After 4 minutes' activation at -15° C., 1-hydroxybenzotroazole ammonium salt (9.1 g, 0.060 mole) was added and the mixture stirred at -15° C. for 15 minutes. After warming to room temperature the mixture was stirred for a further 4 hours. Chloroform (large amounts were required because of emulsion formation) and water were added, the phases separated and the organic layer washed with saturated aqueous sodium bicarbonate (3×), 2N hydrochloric acid (3×) and dried (MgSO 4 ). After evaporation of the solvent under reduced pressure the solid residue was recrystallized from ethyl acetate to give N.sup.α -9-fluorenylmethyloxycarbonyl-β-benzyl-L-aspartyl-D-alanyl amide (5.6 g) m.p. 200°-204° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. H. The product from Part G (2 g, 3.0 mmole) was dissolved in acetonitrile/water (1:1, v/v, 500 ml) and treated with iodobenzene bis(trifluoroacetate) (1.9 g, 4.4 mmole). The reaction mixture was stirred overnight at room temperature, evaporated to dryness and the product dissolved in HCl/dioxane (4N) and re-evaporated. The process was repeated and the product finally redissolved in dioxane and lyophilized to give N-(N.sup.α -9-fluorenylmethyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminoethane hydrochloride in quantitative yield which was used without further purification. I. The product from Part H was dissolved in tetrahydrofuran (50 ml) and treated with 2,2,4,4-tetramethylthietane-3-carboxyl chloride (from Part E, 1.35 g, 7 mmole) followed by N-methylmorpholine (1.32 ml, 12 mmole). The reaction mixture was stirred for a further 20 minutes. Ethyl acetate was then added, the phases separated and the organic phase washed with 2N HCl (3×), saturated aqueous sodium bicarbonate (3×) and dried (MgSO 4 ). The solvent was evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N-(N.sup.α -9-fluorenylmethyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(2,2,4,4-tetramethylthietane-3-carbonyl)-R-1,1-diaminoethane (1.5 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. J. The product from Part I was dissolved in a mixture of methanol (20 ml) and aqueous potassium hydroxide (1N, 20 ml). A precipitate formed immediately which partially dissolved on addition of tetrahydrofuran (10 ml). The mixture was stirred at room temperature for 5 hours and then acidified (pH 5) with acetic acid. After stirring for several hours at room temperature, the mixture was concentrated under reduced pressure and the solution filtered. The filtrate was lyophilized and the residue recrystallized from ethanol/hexanes to give N-(L-aspartyl)-N'-(2,2,4,4-tetramethylthietane-3-carbonyl)-R-1,1-diaminoethane (0.4 g), m.p. 158°-161° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. Sweetness=150-200×sucrose. EXAMPLE 20 N-(L-Aspartyl)-N'-(Cyclopentanecarbonyl)-2,2-Diaminopropane [Formula I, R=R'=CH.sub.3, R"=cyclopentyl] A. α-Aminoisobutyric acid (20 g, 0.194 mole) was suspended in tetrahydrofuran (400 ml), treated with a solution of phosgene in toluene (3M, 160 ml) and the mixture heated at 65° C. overnight. The resulting clear solution was evaporated under reduced pressure, redissolved in tetrahydrofuran and re-evaporated to give α-aminoisobutyric acid N-carboxyanhydride as a thick oil which was used without further purification. B. The product from Part A was dissolved in tetrahydrofuran (200 ml), cooled to -20° C. and treated with excess ammonia gas. The solution was allowed to warm to room temperature slowly and then evaporated to dryness under reduced pressure. The solid residue was extracted with ethyl acetate using a soxhlet extractor over 3 hours, the resultant solution filtered and the product allowed to crystallize. α-Aminoisobutyramide was obtained as a crystalline solid (10 g), m.p. 115°-118° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. C. N.sup.α -Benzyloxycarbonyl-β-benzyl-L-aspartic acid (24.2 g, 67 mmole) was dissolved in dry dimethylformamide (300 ml), the solution cooled to -20° C. and treated with dicyclohexylcarbodiimide (14.5 g, 71 mmole). After 30 minutes' activation at this temperature a precooled solution of α-aminoisobutyramide (6.9 g, 67 mmole) in dimethylformamide (125 ml) was added and the mixture allowed to warm to room temperature. After stirring for 2 days, the mixture was evaporated to dryness under reduced pressure and the residue purified by flash chromatography on silica gel, eluting with a stepwise gradient of chloroform/hexanes (3:1, v/v), chloroform and then chloroform/methanol (95:5, v/v). The final product to elute was N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-α-aminoisobutyramide (10.0 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. D. The product from Part C (5.0 g, 11 mmole) was dissolved in acetonitrile (30 ml), the solution diluted with an equal volume of water and treated with iodobenzene bis(trifluoroacetate) (5.16 g, 12 mmole). The reaction mixture was stirred at room temperature for 7 hours when reaction was complete by TLC. The solution was evaporated under reduced pressure, the residue dissolved in dioxane (100 ml) and concentrated hydrochloric acid (3 ml) and lyophilized. The process was repeated to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-2,2-diaminopropane hydrochloride in quantitative yield, which was used without further purification. E. The product from Part D was dissolved in tetrahydrofuran (100 ml) and treated with triethylamine (2.5 g, 24 mmole), followed by cyclopentanecarbonyl chloride (1.75 g, 13.2 mmole). The reaction mixture was stirred at room temperature for 5 hours, filtered and the filtrate evaporated under reduced pressure. The residue was purified by chromatography on silica gel to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-N'-(cyclopentanecarbonyl)-2,2-diaminopropane, which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. F. The product from Part E was hydrogenated in the usual manner in glacial acetic acid (100 ml) over 10% palladium on carbon. After lyophilization and relyophilization from water several times, N-(L-aspartyl)-N'-(cyclopentanecarbonyl)-2,2-diaminopropane was obtained in quantitative yield. Sweetness=50-100×sucrose EXAMPLE 21 N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylcyclopentanecarbonyl)-R-1,1-Diaminopropane [Compound I, R=CH.sub.2 CH.sub.3, R'=H, R"=2,2,5,5-tetramethylcyclopentyl] A. D-α-Amino-n-butyric acid (5.0 g, 48.5 mmole) was dissolved in dimethylformamide (50 ml), treated with chlorotrimethylsilane (6.15 ml, 48.5 mmole) and the mixture stirred at room temperature for 1 hour. Meanwhile, N.sup.α-benzyloxycarbonyl-β-benzyl-L-aspartic acid ( 15.73 g, 45.1 mmole) was dissolved in dimethylformamide (50 ml), cooled to -15° C. and treated with N-methylmorpholine (4.84 ml, 44.1 mmole), followed by isobutyl chloroformate (5.72 ml, 44.1 mmole). After 10 minutes' activation, the precooled solution of D-α-amino-n-butyric acid silyl ester was added, followed by a second equivalent of N-methylmorpholine (4.84 ml, 44.1 mmole). The solution was allowed to warm to room temperature, stirred for 4 hours and then acidified (pH 1-2) with aqueous hydrochloric acid. Chloroform was added, the phases separated and the aqueous layer re-extracted with chloroform. The combined organic phases were washed with 1N hydrochloric acid (3×), saturated sodium chloride and dried (MgSO 4 ). The solvent was evaporated under reduced pressure and the residue crystallized from ethyl acetate/hexanes to give N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl-D-α-amino-n-butyric acid (13.3 g), m.p. 150°-152° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. B. The product from Part A (10.0 g, 22.6 mmole) was dissolved in dimethylformamide (50 ml), cooled to -15° C. and treated with N-methylmorpholine (2.48 ml, 22.6 mmole), followed by isobutyl chloroformate (2.93 ml, 22.6 mmole). After 4 minutes' activation at -15° C., 1-hydroxybenzotriazole ammonium salt (3.84 g, 24.9 mmole) was added as a solid and the mixture stirred at -15° C. for 45 minutes. The reaction mixture was allowed to warm to room temperature slowly, stirred for 4 hours and then diluted with water and chloroform. The phases were separated and the aqueous phase re-extracted with chloroform. The combined organic extracts were washed with 1N hydrochloric acid (3×), saturated aqueous sodium bicarbonate (3×), saturated sodium chloride and dried (MgSO 4 ). The solvent was evaporated under reduced pressure and the solid residue recrystallized from ethyl acetate/hexanes to give N.sup.α -benzylocarbonyl-β-benzyl-L-aspartyl-D-α-amino-n-butyramide (7.5 g), m.p. 170° -171° C., which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. C. The product from Part B (5.0 g, 11.3 mmole) was dissolved in aqueous acetonitrile (1:1, v/v, 100 ml) and treated with iodobenzene bis(trifluoroacetate) (5.85 g, 13.6 mmole). The reaction mixture was stirred at room temperature for 5 hours and evaporated to dryness under reduced pressure. The residue was redissolved in dioxane (50 ml), excess concentrated aqueous hydrochloric acid added, and the solution re-evaporated several times and finally lyophilized from dioxane to give N-(N.sup.α -benzyloxycarbonyl-β-benzyl-L-aspartyl)-R-1,1-diaminopropane hydrochloride in quantitative yield which was used without further purification. D. The product from Part C was dissolved in tetrahydrofuran (25 ml) and treated with 2,2,5,5-tetramethylcyclopentanecarbonyl chloride (2.56 g, 13.6 mmole), followed by triethylamine (3.46 ml, 24.9 mmole). The mixture was stirred at room temperature and the reaction monitored by TLC. When reaction was complete (approximately 5 hours), ethyl acetate and water were added, the phases separated and the aqueous phase re-extracted with ethyl acetate. The combined organic phases were washed with 1M aqueous sodium bicarbonate (2×), 2N hydrochloric acid (3×), saturated sodium chloride and dried (MgSO 4 ). The solvent was evaporated under reduced pressure and the residue recrystallized from ethyl acetate/hexanes to give N-(N.sup.α -benzyloxycarbonyl-α-benzyl-L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-R-1,1 diaminopropane (4.4 g) which was homogeneous by TLC. The nmr spectrum of the product was consistent with the assigned structure. E. The product from Part D (4.0 g) was hydrogenated in the usual manner in glacial acetic acid (100 ml) over 10% palladium on carbon. After lyophilization and relyophilization from water several times, N-(L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopentanecarbonyl)-R-1,1-diaminopropane was obtained in quantitative yield, m.p. 164° C. dec. Sweetness=200-300×sucrose. EXAMPLE 22 Stability of N-(L-Aspartyl)-N'-(2,2,5,5-Tetramethylcyclopentanecarbonyl)-R-1,1-Diaminoethane Sweetener The stability of the title sweetener (Example 14) was studied at 90° C. and pH 7.0 and 3.0 in 0.01M phosphate buffer. The disappearance of the compound under these conditions was monitored by quantitative HPLC measurements, under the following conditions: column: Lichrosorb RP-18; flow rate: 1.5 ml/min.; isocratic acetonitrile (17%) in 0.01M triethylammonium phosphate buffer, pH 4.5. The results of these studies are summarized in Table 2. From these data the half-life of this compound at both pH 3.0 and pH 7.0 is estimated to be a minimum of 20 years at room temperature (25° C.). TABLE 2______________________________________Stability of N--(L-Aspartyl)-N'--(2,2,5,5-Tetramethyl-cyclopentanecarbonyl)-R-1,1-DiaminoethaneSweetener at pH 7.0 and 3.0 Percent Sweetener RemainingTime pH 7.0 pH 3.0______________________________________1 hour 99.6 98.93 hours 98.7 96.58 hours 97.0 92.41 day 92.4 83.04 days 81.0 58.2______________________________________ Sweetness Evaluation The following is an outline of the "sip and spit" method of blind evaluation used to evaluate the sweetness of the compounds of the invention. Samples were prepared by dissolving a given amount of the sweetener (e.g. 40 mg in 100 ml) in water or coffee. The sweetener concentration was chosen on the basis of preliminary taste evaluation in which the order of magnitude of sweetness was somewhat established. In addition to the experimental sample, three other samples of sucrose were prepared, their concentrations being chosen to bracket the estimated sweetness of the compound being tested. Samples were presented to an expert taste panel for evaluation. The selected judges were asked to evaluate each sample for sweetness intensity by sipping the solution and spitting and to rank the samples in accordance with descending order of sweetness. The average rank of the experimental sample was computed and the equivalent concentration of sucrose was estimated. The relative sweetness was calculated from this data. If the experimental product was ranked lowest or highest, the experiment was repeated using different sucrose concentrations. In addition to being sweeteners, the compounds of the present invention are also useful as flavor potentiators. This is confirmed by the following tests: Flavor Potentiating--Tomato Sauce To commercial spaghetti sauce, 3 ppm of the following were added: 1. Compound Example 1 2. Compound Example 14 3. Saccharin The sauces were mixed, heated and evaluated hot by an expert panel for flavor level on a scale of 0=none to 8=very strong. The panel also received a blind control product (with nothing added). The results are summarized below: ______________________________________Sample Flavor Level______________________________________Control 6.0Compound Example 1 6.7*Compound Example 14 7.0*Saccharin 5.7______________________________________ *Significant at the 95 percent confidence level. These data clearly indicate that these compounds act as flavor enhancers and that this property is not related to their sweetness properties. Flavor Potentiating--Mouthwash To a commercial mouthwash preparation, the following compounds were added at the 1.5 ppm level: 1. Compound Example 1 2. Compound Example 14 In addition, a control (unaltered product) was included. An expert panel was asked to gargle with the mouthwash for 15 seconds and evaluated the flavor intensity immediately and 3 minutes after gargling on a scale of 0=none to 8=very strong. The results are outlined below: ______________________________________ 1 minute 3 minutes______________________________________Control 5.7 2.2Example 14 6.7* 3.0*Example 1 6.0 3.0*______________________________________ *Significant at the 95 percent confidence level. These data clearly establish the flavor enhancing properties of the compounds of the invention. While the invention has been described with respect to particular compounds and methods of producing the compounds, it is apparent that variations and modifications of the invention can be made.

Compounds of the formula: ##STR1## wherein n is 0 or 1, R is lower alkyl (substituted or unsubstituted), R' is H or lower alkyl, and R" is a branched alkyl, alkyl-cycloalkyl, cycloalkyl, polycycloalkyl (poly=2 or more, fused or non-fused), phenyl or alkyl-substituted phenyl, and physiologically acceptable cationic and acid addition salts thereof, which compounds are potent sweeteners. These derivatives of gem-diaminoalkanes are many times sweeter than sugar and are free from undesirable flavor qualities. Furthermore, they possess an unanticipated high degree of solubility compared with known synthetic sweeteners. In addition, the compounds possess high stability so that they can be used in all types of beverages and in conventional food processing. Sweetening compositions and sweetened edible compositions of these compounds are also provided.

RELATED APPLICATION The present application claims the benefit of U.S. provisional application 60/597,836, filed Dec. 21, 2005. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to ventilation systems in breathing apparatuses, such as anesthesia apparatuses, and in particular to a ventilation system with a mechanical ventilation system combined with a manual ventilation system. The invention provides a breathing apparatus and also a method for controlling a breathing apparatus, especially an electronic expiration valve in the apparatus. The invention also concerns software products for controlling a breathing apparatus. 2. Background and Prior art When patients are subjected to anesthesia there is usually a transition from ventilation by spontaneous breath, via a phase of manually controlled ventilation by means of a manual breathing bag over to mechanically controlled ventilation, and vice versa when the patient is taken out of anesthesia. A direct transition from spontaneous to mechanical ventilation is considered to be too harsh for the patient and it is important to closely monitor the patient's response to the anesthesia. A human operator executing manually controlled ventilation with a direct contact between the breathing bag and the lungs of the patient is more sensitive to the conditions and the reactions of the patient than the mechanical ventilation system and can adjust anesthesia parameters in a smother and safer way. Also during mechanical ventilation operators sometimes want to switch over to a phase of manually controlled ventilation in order to check the condition of the patient, for example in connection with a change in the composition of an anesthetic gas or in connection with distribution of an anesthetic agent. Anesthesia apparatuses are therefore usually provided with a manual ventilation system in parallel with an automatic mechanical ventilation system, and a ventilation selection switch for selecting between the manual and the mechanical ventilation system. Although having tubing, valves and other components in common in a breathing circuit connected to the lungs of a patient, the manual and the mechanical ventilation systems are basically separate systems with separate pressure control valves designed for different purposes and functions. In the manual ventilation system an important control valve is the adjustable pressure limit valve, commonly called APL valve. The APL valve has the function to limit the pressure of breathing gas that can occur in the breathing circuit during manual ventilation. Traditionally, the APL valve is provided with a spring that exerts pressure on a diaphragm that seals off a vent passage against a valve seat. When the pressure exceeds the spring force, the APL valve opens to vent excess gas into an evacuation system. The valve is adjusted by compressing the spring with a screw mechanism so that the level of the compressed spring force corresponds to the wanted pressure limit. FIG. 2A-FIG . 2 C show schematically pressure and flow characteristics in a breathing circuit, with a prior art APL valve drawn as graphs of pressure and flow parameters over time in an exemplifying case of operation. FIG. 2A shows the system pressure in the breathing circuit Psys over time t, with the indicated level APL that is preset on the adjustable pressure limit valve. FIG. 2B shows the compression rate of the manual bag over time t, which for example would correspond to or can be described as the change rate in the volume of the manual bag (time derivative of bag volume). FIG. 2C shows the flow of gas Qout over time that is let out from the system in this instance via the APL valve. FIG. 2C also shows the flow Qpat over time to and from the patient. In FIG. 2C , the flow level Qf is the flow level of the fresh gas flow, which usually is a selectable and adjustable constant flow. Thus, in the time interval from 0 to T 1 the patient inspires a part Qpat of the fresh gas flow Qf and the rest of the fresh gas flow builds up the pressure Psys until the APL pressure level is attained at T 1 . At T 1 the APL valve opens and lets out a gas flow corresponding to the fresh gas flow level Qf, and at the same time the flow to the patient ceases. The manual bag is now filled at the APL pressure level. At T 2 the operator compresses the manual bag which results in an increase in the flow Qout from the breathing circuit since the APL pressure level is already attained. No gas flow to the patient is induced by the bag compression from T 2 to T 4 , which rather has the purpose of adjusting the volume in the manual bag by pressing out superfluous fresh gas from it. At T 4 the compression of the manual bag is also released and the patient starts an expiration phase that lasts until T 5 . At T 5 an inspiration phase begins. At T 6 the operator starts manual bag compression and induces an increased gas flow Qpat to the patient until T 7 . At T 7 the APL pressure is attained whereupon the flow Qpat to the patient ceases and the outlet pressure Qout starts and lasts until T 8 . At T 8 the manual bag compression is released and the patient starts an expiration phase that lasts until T 9 during which the outlet flow Qout ceases and the manual bag is filled with the gas expired from the patient. In FIG. 2C the changes in the flow curves Qpat and Qout coincide at T 1 and T 7 , respectively, but for visibility reasons the flow curves are drawn with a gap in between. Another valve type commonly used in manual ventilation is the Berner valve described in U.S. Pat. No. 3,780,760. FIG. 3A-3C show in a similar way the characteristics of such a prior art Berner valve. FIG. 3A shows the system pressure in the breathing circuit Psys over time t, with the indicated level PBern that is preset on the Berner valve for a pressure level to be maintained as long as there is no compression of the manual bag. FIG. 3B shows the compression rate of the manual bag over time t. FIG. 3C shows the flow of gas Qout over time that is let out from the system in this instance via the Berner valve. FIG. 3C also shows the flow Qpat over time to and from the patient. In FIG. 2C , the flow level of the fresh gas flow is indicated as Qf. Thus, in the time interval from 0 the patient inspires a part Qpat of the fresh gas flow Qf until the Psys attains the PBern pressure level, whereupon the Berner valve opens and lets out a flow Qpat. The flow to the patient ceases until T 1 where compression of the manual bag starts and the Berner valve is mechanically triggered to allow a pressure that exceeds the PBern pressure level. From T 1 to T 2 a relatively high flow Qpat flows to the patient and from T 2 it decreases to and remains at the lower fresh gas flow level Qf as the operator holds the manual bag at a constant volume until T 3 . At T 3 the operator releases the bag compression and an expiration phase is started, which results in a flow Qpat from the patient to the manual bag followed by an increase up to Qf level in the outlet flow Qout from the breathing circuit. In FIG. 3C the indicated area between the curves Qout and Qpat corresponds to the gas volume in the bag. At T 5 the pressure level PBern is attained and maintained until T 6 . At T 6 the manual bag is compressed, this time to less degree than the previous compression, and again the pressure Psys increases and there is again a two step first high then lower flow Qpat to the patient. At T 8 an expiration phase starts and proceeds with the same pattern as before. With such a Berner valve, there is a risk that the pressure increases to a too high a level with an entailing risk for injuries on the patient, such as barotraumas. Further, if the fresh gas flow Qf exceeds a mechanical trigger level, there is that the fresh gas flow Qf is mistakenly interpreted as a breath. When the mechanical ventilation mode is set, the APL valve or the Berner valve is no longer a part of the breathing circuit. The mechanical ventilation system operates, in the absence of the APL valve or corresponding valve, with an expiration valve for venting excess gas into the evacuation system. In prior art breathing apparatuses the expiration valve is electronically controlled not only to limit the maximum pressure that should occur in the breathing circuit but also to ensure a minimum pressure in the breathing circuit. This minimum pressure is commonly known as the positive end expiratory pressure PEEP and is important to ensure that the lungs of a patient always to some extent are filled with breathing gas in order not to collapse and be completely deflated. The expiration valve is therefore usually called a PEEP valve. The PEEP valve is flexibly operated via the normal user interface of the breathing apparatus and is usually controlled by means of a control computer program realizing a set of predetermined rules adapted to the requirements of the mechanical ventilation mode. The manual ventilation system of such breathing apparatuses is less flexible and does not allow for very accurate control of the pressure in the breathing circuit. There is therefore a need for improvements in the manual ventilation system of breathing apparatuses having both a manual and an automatic mechanical ventilation system. There are different examples of prior art showing breathing apparatuses with manual and mechanical ventilation systems. WO 2004/067055 A2 shows an example of an open ventilation system of the type described above with a manual ventilation system, an automatic mechanical ventilation system and a ventilation selection switch to select between the manual and the mechanical systems. This piece of prior art is directed to such a ventilation system in which the number of components that must be autoclaved are reduced. The use of a CO 2 absorber, an APL valve or Berner valve is eliminated. A selection valve for connecting either of the manual or the mechanical ventilation system is provided outside the patient circle. The gases from the patient are prevented from returning to the manual bag in order to eliminate the need for autoclaving the manual bag. The automatic mechanical ventilation system and the manual ventilation system have separate expiration valves for the outlet of exhalation gas to atmosphere. In the manual ventilation mode fresh inhalation gas is input to the manual bag via a bag filling valve that is devised with an adjustable bias spring in order to allow a gas flow to the bag dependent on a differential pressure between the inhalation gas source and the manual bag. This bag filling valve has the function to limit the pressure in the manual bag. When the manual bag is manually compressed breathing gas flows via an inhalation conduit through a patient input branch of a Y-piece connected to the airways of the patient. In the exhalation phase, exhalation gas from the patient flows through a patient output branch of the Y-piece via an expiration valve selector that in the manual ventilation mode is open for evacuation of exhalation gas through a manual expiration valve to atmosphere. The maximum pressure of the manual bag is controlled independently of the pressure in the airways of the patient and exhalation gas is simply let out through the manual ventilation expiration valve, and therefore there is no need for an APL valve or a Berner valve in this piece of prior art. In the mechanical ventilation mode, fresh inhalation gas flows past the manual bag branch, which is closed by means of the ventilation selection switch, to the patient via the Y-piece in the same manner. In the exhalation phase, exhalation gas flows via the expiration valve selector that in the mechanical ventilation mode is open for evacuation of exhalation gas through an automatic ventilation expiration valve. A separately controlled automatic ventilation mode PEEP valve is provided in the mechanical ventilation system. U.S. Pat. No. 5,471,979 discloses an example of a breathing circuit that is coupled in a circle system and arranged for re-use of anesthetic gases that are not absorbed by the patient. This piece of prior art shows an entirely mechanical ventilation system and there is neither any manual bag nor any APL valve. SUMMARY OF THE INVENTION An object of the present invention is to improve the manual ventilation system of a breathing apparatus having a manual ventilation system and an automatic mechanical ventilation system. There are the following aspects of the problem: To enable a more accurate and flexible control of the manual expiration valve function. To enable remote control of the manual expiration valve function. To achieve a simpler and less costly breathing apparatus. To improve the pressure conditions in the manual bag under certain breathing gas flow conditions, To enable realization of different modes of valve characteristics. According to the present invention the problem is solved by coupling, in a manual ventilation mode, the manual ventilation system to the electronically controlled expiration valve of a mechanical ventilation system so as to control the pressure in the breathing circuit during manual ventilation. The electrically controlled expiration valve is controlled according to a set of predetermined control rules that are adapted to manual ventilation mode requirements. The mechanical APL or Berner valve of prior art manual ventilation systems is thus substituted by the expiration valve of the automatic ventilation system and a specific manual ventilation mode expiration control device. The invention provides an improved control of the manual expiration valve function and thereby also achieves a higher level of patient safety since a high pressure level can be maintained with more accuracy. So, for example, the risk for barotraumas that exists with a Berner valve is eliminated. Thus, the number of complex/expensive valves are reduced compared to the prior art. The inventive concept also provides a method for controlling a breathing apparatus wherein an electronic expiration valve is controlled during the mechanical ventilation mode as well as during the manual ventilation mode of the apparatus. The control of the expiration valve can be implemented by means of a software product for the breathing apparatus comprising control rules, which when executed in the apparatus enable control of the expiration valve during manual ventilation. The invention enables the realization of different and adjustable pressure and flow characteristics of the breathing circuit by controlling the expiration valve in accordance with selectable schemes embodied in the control rules. This has the further effect that manual ventilation valves can be eliminated from the breathing apparatus. According to a further aspect, the invention enables remote control of the manual expiration valve function. The invention makes it possible to maintain a certain adjustable pressure in the manual bag in the manual ventilation mode. This improves the tactile properties of the manual bag since the operator can adjust the pressure such that he has a convenient palpable contact with the lungs of the patient via the manual bag. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic drawing of a ventilation system, in accordance with embodiments of the invention. FIG. 2A to 2C show a schematic illustration of pressure and flow characteristics in a breathing circuit provided with a prior art APL valve. FIG. 3A to 3C show a schematic illustration of pressure and flow characteristics in a breathing circuit provided with a prior art Berner valve. FIG. 4A to 4C show a schematic illustration of pressure and flow characteristics in a breathing circuit provided with an electronically controlled APL valve in accordance with embodiments of the invention. FIG. 5 shows a schematic drawing of a ventilation system, in accordance with embodiments of the invention, FIG. 6 shows a schematic drawing of a ventilation system, in accordance with embodiments of the invention. FIG. 7 shows a schematic drawing of a ventilation system, accordance to prior art. DESCRIPTION OF THE PREFERRED EMBODIMENTS To illustrate the differences between the invention, especially the embodiments in FIGS. 5 and 6 , and prior art FIG. 7 illustrates a known configuration. The configuration in FIG. 7 includes a mechanical and a manual ventilation system that selectively by means of a manual ventilation valve 80 can drive breathing gas in a breathing circuit. The breathing circuit includes a patient 1 connector to a CO 2 -absorber 16 , one way valves, and the circle is connected to the manual ventilation valve and also to a vaporizer 21 by means of which fresh gas from gas supply units 20 A-C can be supplied to the circle. During mechanical ventilation, driving gas is supplied from gas sources through selection valves 86 A, B to a bag in bottle unit 85 driving breathing gas inside the bag to and from the breathing circle, via the manual ventilation valve 80 . The pressure of the breathing gas is controlled during expiration in that the driving gas flow through a PEEP valve 240 . Excess gas, in the breathing circuit, is released through a POP-off valve in the bag in the bag-and-bottle unit 85 , and further to an evacuation system. During manual ventilation a manual bag 50 is used to drive breathing gas to and from the patient via the manual ventilation 80 valve and the patient circle. An APL-valve 140 is arranged limiting the pressure from the bag, said APL-valve is a mechanical valve, comprising a manually adjustable turning knob and a spring loaded valve. Excess gas is released through the APL-valve to an evacuation system. FIG. 1 shows schematically, a breathing circuit coupled in a circle system with a mechanical ventilation system 53 and a manual ventilation system 54 configured in accordance with embodiments of the present invention The airways of a patient 1 are connected to a patient branch line 2 of a Y-piece 4 in a circular tubing system with an inspiration branch line 6 provided with a one-way inspiratory valve 8 and an expiration branch line 10 provided with an one-way expiratory valve 12 . In one embodiment a pressure sensor 74 is provided in the patient branch line of the Y-piece 4 . After the one-way expiratory valve 12 , in a clockwise direction along the circle system, there is a common expiration and inspiration line 14 for the delivery of inspiration gas to the patient and evacuation of expiration gas from the patient coupled to the breathing circle at a junction 15 . Further along the circle system the tubing passes through a CO 2 absorber 16 and after the absorber there is gas supply branch line 18 provided to feed fresh inhalation gas into the circle system from a fresh inhalation gas source 20 A, 20 B and coupled to the breathing circle at a junction 19 . After the junction 19 there is a vaporizer 21 devised for vaporizing gas components in the flow of inspiration gas to the patient. In the exemplifying breathing circuit the vaporizer should be an injection type vaporizer in order to work properly with the mechanical ventilation system as well as with the manual ventilation system. A gas analyzer 23 is provided to analyze gas contents with an input of sample gas just before the one-way inspiratory valve 8 and an output of the sample gas just after the one-way inspiratory valve 8 . A pressure sensor 70 is provided between the one-way inspiratory valve 8 and the output of the sample gas The common expiration and inspiration line 14 is provided with an adsorption filter 26 devised for adsorption and desorption of anesthetic and respiration gases to or from the patient. At the distal side (from the perspective of the patient) of the adsorption filter 26 the common expiration and inspiration line 14 is coupled at a junction 24 to a first output branch line 52 from a selection valve 22 , here in the shape of a bypass valve. A second output branch 52 of the selection valve 22 is coupled to the fresh gas supply line 18 . At an input side, the selection valve 22 is coupled to an input line 28 leading from the fresh inhalation gas source 20 A, 20 B. The selection valve 22 is devised to select the flow route for the fresh inhalation gas via the supply branch line 18 or via the common expiration and inspiration line 14 passed the adsorption filter 26 into the breathing circle. In this example there are two different gases in the inhalation gas source, more specifically Oxygen O 2 in the inhalation gas source 20 A which is coupled to an O 2 inspiration valve 30 that in its turn is connected to the selection valve input line 28 at a junction 34 . Similarly, there is Nitrous oxide N 2 O in the inhalation gas source 20 B which is coupled to an N 2 O inspiration valve 32 that also is coupled to the selection valve input line 28 at the junction 34 . The O 2 inspiration valve 30 and the N 2 O inspiration valve 32 are devised for adjusting the inlet flow and the proportions of the respective gases into the input line 28 . Only O 2 and N 2 O are shown, but air can also be used as is common in the art. In the embodiment of the invention shown in FIG. 1 the selection valve is a bypass valve 22 which has the function of selecting fresh inhalation gas flow either through the first output branch 51 or through the second output branch 52 of the selection valve 22 . Thus, with the selection valve being actuated to a first flow selection mode the fresh inhalation gas is enabled to flow to the patient via the common expiration and inspiration line 14 and through the adsorption filter 26 , or via the supply branch line 18 then bypassing the adsorption filter 26 as well as the CO 2 absorber 16 . An evacuation line 36 is connected to the common expiration and inspiration line 14 and to the mentioned first output branch line 52 at the junction 24 . The evacuation line 36 leads via a flow meter 38 and a pressure sensor 76 to an expiration valve 40 that is devised to control output of evacuated gas flow from the breathing system to a scavenging system 42 or to the atmosphere. A manual ventilation line 46 is connected to the evacuation line 36 at a junction 44 . The manual ventilation line 46 is provided with a manual ventilation valve 48 and leads to a manual bag 50 devised for manual ventilation. In one embodiment there is a pressure sensor 72 provided on the manual bag side of the manual ventilation valve 48 . The mechanical ventilation system 53 and the expiration valve 40 as well as other components are preferably parts of a per se known mechanical ventilator with a ventilation control system 56 . The ventilation control system 56 comprises a user input/output interface 58 with command input means and display means of a per se known type. In a further development of the invention, the interface may also be provided with remote control means for remote control of the manual expiration valve functions or characteristics. The remote control function may for example be realized in a per se known manner as shown in EP1426966, where an anesthetic machine is provided with remote control for controlling alarms and transitions between mechanical ventilation and manual ventilation. Also in a per se known manner, the ventilation control system 56 comprises mechanical ventilation control means 60 usually comprising specifically designed computer program code for controlling the operation of the mechanical ventilation system 53 and its components via a symbolically shown control line 62 . The mechanical ventilation control means 60 enables vent of breathing gas from the mechanical ventilation system according to a first set of predetermined control rules for controlling the expiration valve 40 in accordance with mechanical ventilation mode requirements. In effect, the expiration valve is in this connection controlled to open or close at predefined pressure levels that occur in the tubing system. Typically the control rules realize pressure control functions such as a PEEP valve function and the like. Usually a PEEP valve is closed during inspiration and controls the pressure level, and flow, during expiration. The ventilation control system 56 further comprises a manual ventilation control means 64 . The a manual ventilation control means 64 is devised to control the expiration valve 40 via the symbolically shown control line 66 according to a second set of predetermined control rules and enable mechanical ventilation features adapted to manual ventilation mode requirements. In the manual ventilation mode, the manual ventilation valve 48 is actuated to an open position in order to allow gas flow in the manual ventilation line 46 to and from the manual ventilation bag 50 , and the manual ventilation control means 64 is activated to control the expiration valve 40 . The effect of this is that the same expiration valve 40 is used for the manual ventilation system as well as for the mechanical ventilation system, but is controlled according to different sets of control rules. Switching over from mechanical to manual ventilation mode, and vice versa, involves actuating the manual ventilation valve 48 to enable the selected ventilation mode as well as selecting the corresponding ventilation control mode on the user input/output interface 58 of the ventilation control system 56 . When the manual ventilation control mode is selected on the ventilation control system 56 , the mechanical ventilation mode functions for the expiration valve 40 are disabled. The manual ventilation control mode is in different embodiments adapted to different manual ventilation mode requirements. For this purpose the manual ventilation control means 64 comprises different subsets of predetermined manual ventilation control rules. In one embodiment, the manual ventilation control rules are adapted to control the expiration valve ( 40 ) to keep a standby pressure level Pstb in the tubing system of the breathing circuit, in order to maintain a predetermined degree of gas volume content in the manual bag. The idea is to keep the manual bag filled with breathing gas to such an extent and with such a pressure that there is a palpable contact with the gas pressure in the lungs of the patient from the manual bag as it is operated by a human operator. In this control mode it is enabled that the patient can breathe spontaneously to and from the manual bag, while excessive gas is let out via the expiration valve. FIG. 4A-4C illustrates the characteristics of embodiments of the invention in a manner similar to that of the previously described FIGS. 2-3 , and reference is made below to FIG. 4 . As with the previously explained FIG. 2C the changes in the flow curves Qpat and Qout coincide at certain times, and similarly for visibility reasons the flow curves in FIG. 4C are drawn with a gap in between. FIG. 4A-FIG . 4 C show schematically pressure and flow characteristics in a breathing circuit, with an electronically controlled expiration valve operated in the manual control mode drawn as graphs of pressure and flow parameters over time in an exemplifying case of operation. FIG. 4A shows the system pressure in the breathing circuit Psys over time t, with the indicated pressure levels Pman, Pman 1 , Pman 2 , Pstb and Pmin that are devised to be preset by means of the manual ventilation control means. These pressure levels are explained below. FIG. 4B shows the compression rate of the manual bag over time t, which as described above for example would correspond to or can be described as the change rate in the volume of the manual bag, i.e. the time derivative of the bag volume. FIG. 4C shows the flow of gas Qout over time that is let out from the system in this instance via the APL valve. FIG. 4C also shows the flow Qpat over time to and from the patient. In FIG. 4C , the flow level Qf is the selectable and adjustable flow level of the fresh gas flow. Thus, in the time interval from 0 the patient inspires a part Qpat of the fresh gas flow Qf until the Psys attains a first pressure level, which may be a standby pressure level Pstb or a minimum pressure level Pmin, whereupon the expiration valve 40 is opened to let out a flow Qpat. The flow to the patient ceases until T 1 where compression of the manual bag starts. Thus, when a manually induced breath shall be induced, the operator compresses the manual bag at time T 1 such that the pressure and/or flow characteristics in the breathing circuit changes during the time interval T 1 to T 2 , which is detected by the control system with the aid of a suitable sensor, for example pressure sensor 76 and/or flow meter 38 . If the detected change in pressure and/or flow characteristics matches a predetermined first pattern, the expiration valve ( 40 ) is controlled to enable a predetermined maximum pressure level corresponding to a desired manual ventilation pressure level Pman in the breathing circuit. With the triggering event devised to be a quick compression of the manual bag, the predetermined first pattern of the pressure and/or flow characteristics in the breathing circuit would preferably comprise an increase in pressure corresponding to a predetermined pressure increase rate starting from a predetermined minimum pressure level that may correspond to the standby pressure level Pstb or some other selected minimum pressure level. From T 1 to T 2 a relatively high flow Qpat flows to the patient and from T 2 it ceases when the expiration valve 40 is opened for an outlet flow Qout corresponding to the fresh gas flow level Qf as the operator holds the manual bag at a constant volume until T 3 . The manual ventilation pressure level is typically higher than the standby pressure Pstb, and thus the expiration valve ( 40 ) is controlled to close until the manual ventilation level is attained at T 2 . The pressure in the breathing circuit then rises with the compression action on the manual bag until the manual ventilation pressure is attained at time T 2 and the patient receives an induced breath. The expiration valve 40 is then controlled to keep the pressure at this level throughout the induced breath during the time interval from T 2 to T 3 , and to open if the pressure level is exceeded. At T 3 the operator releases the bag compression and an expiration phase is started, which results in a flow Qpat from the patient to the manual bag followed by an increase up to Qf level in the outlet flow Qout from the breathing circuit. In FIG. 4C the indicated area between the curves Qout and Qpat corresponds to the gas volume in the bag. In this mode the manual ventilation control rules are thus further adapted to control the expiration valve ( 40 ) to allow a predetermined minimum pressure level in the breathing circuit Pmin. This minimum pressure level Pmin may coincide with the standby pressure level Pstb or may be a different selected level that in one embodiment is adjustable via a selection input means during manual ventilation. The purpose is, as described above, to enable a suitable pressure in the manual bag. When the induced breath is terminated at time T 3 , i.e. when the compression of the manual bag ends, the expiration valve is controlled such that the pressure in the tubing system returns to the predetermined minimum level at time T 4 . Thus, at T 4 the pressure level Pstb/Pmin is attained and maintained until T 5 . The patient has an expiration phase during the time interval from T 3 to T 5 , and as illustrated in FIG. 4 the operator gives at T 6 a following manually induced breath with less bag compression during the time interval T 5 to T 8 . Again the pressure Psys increases and there is again a two step first high then lower flow Qpat to the patient. The operator can in this mode thus continue to give manually assisted breathing by compressing the manual bag while maintaining a certain pressure in the breathing circuit as well as in the manual bag. When expiration phases start and the manually induced inspiration ends at time T 3 and T 8 respectively, the expiration valve is controlled to open or close such that the pressure in the breathing circle returns to the standby pressure level. This is preferably achieved such that the second set of predetermined control rules are adapted to control the expiration valve ( 40 ) to attain the predetermined standby pressure level Pstb in response to a detected predetermined second pattern of the pressure and/or flow characteristics in the breathing circuit. This predetermined second pattern preferably comprises a decrease in pressure corresponding to a predetermined pressure decrease rate that occurs when the operator releases the manual bag at time T 3 and T 8 and the bag is allowed expand. In one embodiment the inventive concept is implemented to realize an APL (Adjustable Pressure Limit) valve that operates with two different pressure levels as described above. The second set of predetermined control rules are in this embodiment adapted to control the expiration valve ( 40 ) to enable and attain a predetermined first, high pressure level Pman in the breathing circuit in response to a detected predetermined first pattern of the pressure and/or flow characteristics in the breathing circuit that occurs when an operator starts to compress the manual bag. Similarly, the second set of predetermined control rules are adapted to control the expiration valve ( 40 ) to enable a second, lower pressure level Pmin that is above the atmospheric pressure in response to a detected predetermined second pattern of the pressure and/or flow characteristics in the breathing circuit that occurs when the operator releases the compression of the manual bag. This thus has the effect that the operator of the breathing apparatus can switch between the lower and the higher pressure levels by compressing and releasing the manual bag, respectively. In a further developed variety the second set of predetermined control rules are adapted to control the expiration valve ( 40 ) to enable pressure variations in the breathing circuit around the first and/or second pressure levels within predetermined pressure variation intervals, for example between Pman 1 and Pman 2 as illustrated in FIG. 4A . With a suitable selection of pressure variation intervals above and below the respective first and/or second pressure level(s), this variety has the effect that the patient is enabled to breathe spontaneously at the higher pressure as well as at the lower pressure. The second set of predetermined control rules are preferably further adapted to control the expiration valve ( 40 ) to allow a predetermined maximum pressure level in the breathing circuit in response to a command signal received from a command signal input means. In this control mode there is no minimum pressure level higher than the atmosphere and the pressure and/or flow characteristics are thus similar to that of a breathing circuit provided with a traditional APL valve as described in above with reference to FIG. 3 . The invention enables a flexible selection of valve control modes. A general embodiment is devised such that the second set of predetermined control rules are adapted to control the expiration valve ( 40 ) to enable predetermined pressure characteristics that depend on detected pressure and/or flow characteristics in response to a command signal received from a command signal input means. For example, the control rules can be adapted such that the predetermined pressure characteristics correspond to those of a Berner valve as described in above with reference to FIG. 3 . In a further embodiment, the control means are devised to trigger a change from a mechanical ventilation mode to a manual ventilation mode in response to a detected change in pressure and/or flow characteristics that matches a predetermined pattern, for example a certain pressure change rate. The effect of this is that an operator can trigger the change from a mechanical ventilation mode to a manual ventilation mode for example by means of a quick compression of the manual bag that results in a first pattern of the pressure and/or flow characteristics in the breathing circuit detected by the control means, enter into a manual ventilation mode and proceed with manual ventilation. The return from the manual ventilation mode to the mechanical ventilation mode may be triggered for example in response to a detected predetermined time interval without any detected significant pressure changes in the manual bag that similarly results in a second pattern of the pressure and/or flow characteristics in the breathing circuit detected by the control means. Pressure changes in the manual bag that occur during the time interval and that are not to be taken for manual ventilation action can for example come from the operator touching or tactilely test compressing the manual bag for diagnostic purposes. Another origin of non-triggering pressure changes may be the spontaneous breathing of the patient. It is also enabled that the patient can breath spontaneously into the manual bag, and it is not necessary to ventilate mechanically during parts of the process of anaesthetizing or awakening the patient. For these purposes a pressure sensor 72 is provided close to or in the manual bag, since when the breathing apparatus is set in the mechanical ventilation mode the manual ventilation valve 48 is closed and other pressure sensors in the system are not possible to use for detecting pressure conditions of the manual bag. The invention can for example be realized by providing a per se known ventilator 52 with an existing expiration valve 40 with computer program code for realizing the manual ventilation control means 64 , and with the tubing connected to a circle system and a manual bag via a manual ventilation valve 48 as described above. Two different configurations of a breathing apparatus, in the form of anesthetic machines, where the invention is implemented, are shown in FIGS. 5 and 6 , respectively. The pressure in the breathing circuits in FIGS. 5 and 6 is controlled in accordance with the first and second set of rules as described above and in the claims below. The patient breathing circle is the same in the different configurations shown in FIGS. 5 and 6 , comprising an inspiration and an expiration branch, respectively. As in the apparatus in FIG. 1 there is a patient Y-piece 4 for a patient connected to an inspiration branch line 6 and an expiration branch line 10 . In the expiratory flow direction, from the Y-piece, the expiration branch line includes a one-way valve 12 and is further connected to a junction 15 connecting the expiration branch line to a common inspiration and expiration line 14 , and also to the inspiration branch line 6 . The inspiration branch line is provided with, in the inspiratory flow direction starting from the junction 15 , a carbon dioxide absorber 16 , a junction 19 , a one-way inspiration valve 8 and further connected to the Y-piece for the patient. Junction 19 connects the inspiration branch line (and the breathing circle) to a vaporizer 21 via a fresh gas branch line 18 A. The vaporizer is further connected via branch line 18 B to gas sources 20 A, 20 B and 20 C, supplying air, O 2 and N 2 O, so that in the flow direction the fresh gas supply sources is connected via the vaporizer to the breathing circle at junction 19 , between the carbon dioxide absorber 16 and the inspiratory one-way valve 8 . The gas sources 20 A-C is connected, or disconnected, by means of supply valves 81 , 82 , 83 , for N 2 O, O 2 and air, to the fresh gas supply line 18 A via a junction 84 . To supply anesthetics to the breathing circle and further to the patient one, or at least one, of the gas sources supply gas via its respective supply valve 81 - 83 to the vaporizer and further to the breathing circle and to the patient as is common in anesthesia machines. These configurations can also include a gas analyzer, for example in the inspiration branch, and include pressure sensors at Y-piece and in the evacuation line as described in connection to FIG. 1 . The common inspiration and expiration line 14 is, in the embodiments, provided with a flow meter 17 . The configurations in FIGS. 5 and 6 differ in the driving of the breathing gas in the patient breathing circle, but both configurations include a common expiration valve 40 for manual and mechanical ventilation in an evacuating line 36 . This expiration valve 40 is used to control the pressure level in expiration and inspiration branch of the patient breathing circle. The same expiration valve 40 is used by the manual ventilation as well as by the mechanical ventilation system, but is controlled according to different first and second sets of control rules. Both implementations have a “bag in bottle” 85 to drive the breathing gas in the patient circle. This bag in bottle 85 is, as is usual, provided with a, so called, pop-off valve 89 , releasing excess gas from the breathing circuit to an evacuation system. In FIG. 5 the driving gas in the mechanical ventilation system is provided to the outside side of the bag in bottle. The expiration valve 40 controls the pressure of the driving gas by regulating the flow of the driving gas through the expiration valve to evacuation, and the pressure in the breathing circle is controlled by the pressure of the drive gas by means of the bag in bottle. Gas sources (O 2 and air) are connected via respective supply valves 86 A, 86 B and further to a junction 87 connecting the gas sources to the bag in bottle 85 and the expiration valve 40 via a one-way valve 88 and a junction 89 . In this way the gas sources provide driving gas, during mechanical ventilation, to the bag driving the breathing gas inside the bag and which driving gas pressure is adjusted by, means of controlling, the expiration valve 40 . The manual ventilation bag 50 is connected to the evacuation line 36 including the expiration valve 40 via the junction 90 . Between the bag and the junction 90 is provided a manual ventilation valve 48 for selecting manual ventilation. The junction 90 connects the manual ventilation bag 50 to the expiration branch 36 with the expiration valve 40 and to the breathing circle via a selection valve 80 and the common inspiration and expiration line 14 . Thus the expiration valve 40 controls the pressure provided by the manual bag 50 to the breathing gas flow in the breathing circuit. The selection valve 80 arranged in the common inspiration and expiration line 14 selectively connects the bag in the bag in bottle 85 and the manual ventilation bag 50 to the breathing gas circle. Thus, the manual ventilation system, driven by the manual bag, is connected to the breathing circle providing gas flow to and from the circle and excess gas through expiration valve 40 controlling the pressure by controlling the flow of breathing gas, or supplied fresh gas to the breathing circuit. In FIG. 6 both the manual ventilation system and mechanical ventilation system drive the breathing gas by providing driving gas on the outside of the bag in the bag in bottle, and thus driving the breathing gas inside the bag to and from the breathing circle. In FIG. 6 the gas sources, that provide driving gas, are also connected via respective supply valves 86 A, 86 B to the outside of the bag in the bag in bottle, via a junction 87 that also connects the driving gas to the expiration valve 40 via a one-way valve 88 , similar to the apparatus in FIG. 5 . The manual system is arranged different since the manual bag is arranged to provide driving gas, supplied from the gas sources, to the outside of the bag in the bag in bottle. As shown in FIG. 6 the manual bag is connected to the bag via junction 92 to driving gas line between junction 87 and one-way valve 88 . The control rules are different in the mechanical mode and in the manual mode, the expiration valve is the same. The breathing apparatuses in FIGS. 1 , 5 and 6 adjust the pressure level in the breathing circuit according to these rules, by controlling the electronic expiration valve 40 . FIG. 1 illustrates control means 60 , 64 in the control system 56 that controls the expiration valve. The apparatuses in FIGS. 5 and 6 suitably also includes control means, for example including a control unit such as a computer, to adjust the expiration valve, but this control unit is not shown in the Figs. Thus, the ventilator in FIGS. 5 and 6 also include a ventilation control system comprising means for controlling mechanical and manual ventilation and a user input/output interface with command input means and display means of a per se known type. The ventilation control system comprises computer program code for controlling the operation of the mechanical ventilation and manual ventilation, enables the electronic expiration valve to open or close at pre-defined pressure levels and thereby limit the pressure in the breathing circuit, according to a first set of predetermined control rules during mechanical ventilation mode, controlling pressure such as a PEEP valve function, and according to a second set of predetermined control rules during manual ventilation enabling and adapting mechanical ventilation features for manual ventilation mode requirements. The configurations include the manual ventilation valve 48 , the opening of which allow gas to flow to the manual ventilation bag 50 (via line 46 ) and activates the manual ventilation mode and, thus, activating the control of the electronic expiration valve 40 in accordance with the second set of rules adapted for manual ventilation requirements. As in FIG. 1 the same expiration valve 40 is used for the manual ventilation system as well as for the mechanical ventilation system, but is controlled according to different sets of control rules. Switching over from mechanical to manual ventilation mode, and vice versa, involves actuating the manual ventilation valve 48 to enable the selected ventilation mode as well as selecting the corresponding ventilation control mode on the user input/output interface of the ventilation control system. When the manual ventilation control mode is selected on the ventilation control system, the mechanical ventilation mode functions for the expiration valve 40 are disabled. The mechanical ventilation system, comprising driving means, i.e. gas supply selection valves 30 , 32 , 86 A, 86 B, and the expiration valve 40 controls the mechanical ventilation. The manual system, comprising the manual bag 50 , as driving means, and the expiration valve 40 is used to control the manual ventilation. In accordance with FIG. 1 the pressure level in the breathing circuit where controlled by controlling the flow of breathing gas through expiration valve 40 during both mechanical and manual ventilation. In accordance with FIG. 5 the pressure level in the breathing circuit is controlled by controlling the flow of breathing gas through expiration valve 40 during manual ventilation, and by controlling the flow of driving gas through expiration valve 40 during mechanical ventilation. In accordance with FIG. 6 the pressure level in the breathing circuit is controlled by controlling the flow of driving gas through expiration valve 40 during both mechanical and manual ventilation. Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted heron all changes and modifications as reasonably and properly come within the scope of their contribution to the art.

A breathing apparatus for ventilating the lungs of a patient with breathing gas, has: a breathing circuit configuration; a mechanical ventilation system; a manual ventilation system provided with a manual ventilation bag; a manual ventilation valve for enabling manual ventilation of breathing gas from the breathing circuit; a pressure sensor devised to detect the pressure level in the breathing circuit; an electronically controlled expiration valve ( 40 ) that in a mechanical ventilation mode is controlled to control the pressure level in the breathing circuit according to a first set of predetermined control rules adapted to mechanical ventilation mode requirements; said electronically controlled expiration valve in a manual ventilation mode being coupled to enable ventilation of breathing gas from the breathing circuit by means of the manual ventilation system according to a second set of predetermined control rules adapted to manual ventilation mode requirements. In a method for controlling a breathing apparatus, an electronic expiration valve is controlled during the mechanical ventilation mode as well as during the manual ventilation mode of the apparatus. The control of the expiration valve can be implemented by means of a software product for the breathing apparatus embodying programming instructions as control rules, which, when executed in the apparatus, enable control of the expiration valve during manual ventilation.

FIELD OF THE INVENTION AND RELATED ART [0001] The present invention relates to a developing apparatus, in particular, a developing apparatus which forms a visible image (image formed of toner) by developing an electrostatic image formed on an image bearing member with the use of an electrophotographic image forming method. A developing apparatus, such as the above described one, can be integrated as a part of an image forming apparatus, or a part of a process apparatus removably mountable in the main assembly of an image forming apparatus. [0002] As examples of an image forming apparatus, an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer, etc.), a facsimile apparatus, a wordprocessor, a multifunction printer capable of performing two or more of the functions of the preceding image forming apparatuses, etc., may be included. [0003] A process cartridge is a cartridge in which an electrophotographic photosensitive member, and at least one among a charging means, a developing means, and a cleaning means, for example, are integrally disposed so that they can be removably mountable in the main assembly of an image forming apparatus. [0004] There have been known various methods used by a developing apparatus of an image forming apparatus, such as a copying machine, a printer, a facsimile apparatus, etc., which uses an electrophotographic process. One of these developing methods is the nonmagnetic single-component developing method. [0005] FIG. 11 shows a developing apparatus 100 , which uses the nonmagnetic single-component developing method. The developing apparatus 100 is of the contact type. It uses nonmagnetic single-component developer. The developing apparatus 100 in this embodiment has a housing 101 , which has a toner storage chamber 110 and a development chamber 111 . The toner storage chamber 110 stores toner T, which is nonmagnetic single-component toner. The development chamber 111 has a development roller 112 , a toner supply roller 113 , and a blade 114 . The developer roller 112 is a developer bearing member, and is made up of a metallic shaft and a layer of electrically conductive rubber coated on the peripheral surface of the metallic shaft in a manner to wrap the development roller 112 . The toner supply roller 113 is a member which supplies the development roller 112 with developer. It is made up of a metallic shaft, and a layer of sponge placed on the peripheral surface of the metallic shaft in a manner to wrap the metallic shaft. The blade 114 is a regulating member. It is made up of a piece of metallic plate. Designated by a referential numeral 116 is a photosensitive drum, which is an image bearing member. It is rotated in the direction indicated by an arrow mark A. The development roller 112 is positioned in parallel to the photosensitive drum 116 so that its peripheral surface is placed in contact, or virtually in contact, with the peripheral surface of the photosensitive drum 116 , forming thereby a developing portion G. [0006] The toner in the toner storage 110 is conveyed into the development chamber 111 by a toner conveying member 115 , which is made up of a flexible blade (blades). The toner T in the development chamber 111 is supplied to the development roller 112 by the toner supply roller 113 , which coats the peripheral surface of the development roller 112 with toner, forming a layer of toner on the peripheral surface of the development roller 112 . Then, the layer of toner on the peripheral surface of the development roller 112 is regulated by the regulating blade 114 in thickness so that the amount of the toner, per unit area of the peripheral surface of the development roller 112 , becomes proper. As the toner is coated on the peripheral surface of the development roller 112 by the toner supply roller 113 , the toner particles are given a proper amount of electrical charge by friction. [0007] The layer of toner on the development roller 112 is moved by the rotation of the development roller 112 through the regulating portion H, in which the regulating blade 14 is in contact with the peripheral surface of the development roller 112 . Thereafter, the layer of toner is conveyed to the developing portion G, that is, the area in which the peripheral surface of the development roller 112 is in contact (virtually in contact) with the peripheral surface of the photosensitive drum 116 . In the developing portion G, the toner particles in the layer of toner adhere to the electrostatic latent image on the peripheral surface of the photosensitive drum 116 , which has been formed through the charging and exposing processes. As a result, the latent image turns into a visible image. [0008] The toner particles (development residual toner particles) remaining on the peripheral surface of the development roller 112 , that is, the toner particles on the peripheral surface of the development roller 112 , which did not adhere to the peripheral surface of the photosensitive drum 116 , are recovered by the toner supply roller 113 . In order to ensure that the development residual toner particles on the development roller 112 are efficiently recovered, the toner supply roller 113 is rotated in such a direction that in the area of contact F between the development roller 112 and toner supply roller 113 , the peripheral surface of the toner supply roller 113 moves in the opposite (counter) direction from the moving direction of the development roller 112 . That is, referring to FIG. 11 , the development roller 112 rotates in the clockwise direction indicated by an arrow mark C, and the toner supply roller 113 rotates in the same direction as the development roller 112 (clockwise direction indicated by arrow mark D). Thus, the peripheral surface of the development roller 112 and the peripheral surface of the toner supply rollers 113 intensely rub against each other in the area F of contact, making it possible to recover the development residual toner particles. [0009] It has been known to apply to the toner supply roller 13 , such voltage (toner supply bias) that is the same in polarity as toner, and is greater in absolute value than that applied to the development roller 112 , as disclosed in Japanese Laid-open Patent Application H06-194944. The application of such voltage is effective to reliably supply the development roller 12 with toner. Therefore, it is effective to prevent the formation of defective images, more specifically, images which are abnormally low in density, and/or faint, which is attributable to the problem that the development roller 12 is unsatisfactorily supplied with toner, even when a substantial number of high density images have to be continuously formed. [0010] Further, providing a difference in potential level between the development roller 112 and toner supply roller 113 , by applying toner supply bias as described above, makes it possible to supply the development roller 112 with only the toner particles which are normal in polarity. Therefore, it stabilizes the developing apparatus in the amount of the electrical charge of the toner on the development roller 112 , and therefore, prevents the formation of defective images, for example, images which are abnormal in density, images suffering from fog, and the like. [0011] However, the structural arrangement for the developing apparatus 100 shown FIG. 11 is unsatisfactory for the purpose of achieving a substantially higher level of image quality than that achievable by the structural arrangement for a developing apparatus in accordance with the prior art, in particular, regarding fog. [0012] In the case of the structural arrangement for the developing apparatus 100 shown in FIG. 11 , the upstream edge (toner spewing portion Fa) of the area of contact F between the development roller 112 and toner supply roller 113 , in terms of the rotational direction of the development roller 112 is the top edge of the area of contact F. Therefore, the toner particles spewed out of the toner spewing portion Fa hang over the toner spewing portion Fa. That is, the toner particles which were not supplied to the development roller 112 become stagnant in the adjacencies of the toner spewing portion Fa. In other words, the toner particles, which are hanging over the toner spewing portion Fa are those which were not supplied to the development roller 112 even though toner supply bias was applied. Therefore, these toner particles are not normal in polarity (reversal in polarity), and/or smaller in the amount of electrical charge (weakly charged toner particles) than the toner particles which were coated on the development roller 112 . [0013] With these toner particles being present in the adjacencies of the development roller 112 , in particular, hanging over the development roller 112 , they are gradually conveyed into the regulating portion H by the rotation of the development roller 112 . Thus, the development roller 112 is supplied with these toner particles, in addition to the toner particles supplied by the toner supply roller 113 . Therefore, the developing apparatus 100 sometimes becomes unstable in the amount of the electrical charge of the toner on the development roller 112 , in spite of the desire to keep the developing apparatus 100 stable in terms of the abovementioned aspect. In other words, the effect of the application of the toner supply bias is prevented from becoming manifest. [0014] Further, the regulating blade 114 is a piece of SUS plate, one of the end portions of which is bent in the shape of a letter L. The amount by which toner was allowed to remain coated, per unit area of the peripheral surface of the development roller 112 , before the layer of toner on the development roller 112 is moved into the developing portion G, is regulated by placing the bend of the regulating blade 114 in contact with the peripheral surface of the development roller 112 . This regulating method has been widely known. [0015] Structuring the developing apparatus 100 as described above, that is, structuring the developing apparatus 100 so that the bend of the regulating blade 114 is placed in contact with the peripheral surface of the development roller 112 , causes the portion (NE) of the regulating blade 114 , which is between the edge 114 a of the blade 114 and the area of contact H, to extend from the area of contact H into the development chamber 111 , creating thereby the following problems: [0016] That is, the portion NE of the regulating blade 114 , that is, the portion of the regulating blade 114 , which extends into the development chamber 111 , acts as a guide which aggressively guides the toner particles which are in the area between the portion NE and development roller 112 , into the area of contact H. Therefore, even if toner supply bias is applied to the toner supply roller 113 to supply the development roller 112 with only the toner particles which are normal in polarity, the toner particles which are not normal in polarity are also guided into the area of contact H, along with the toner particles which are normal in polarity. Thus, the developing apparatus 100 sometimes becomes unstable in the amount of the electrical charge of the toner on the development roller 112 , on the downstream side of the area of contact H, in terms of the rotational direction of the development roller 112 . SUMMARY OF THE INVENTION [0017] The primary object of the present invention is to provide a developing apparatus which supplies its developer bearing member with only the developer particles which are normal in polarity, being therefore stable in the amount of the electrical charge of the developer on the developer bearing member. [0018] Another object of the present invention is to provide a developing apparatus which does not cause an image forming apparatus to form an image suffering from defects, such as fog, attributable to the instability in the amount of the electrical charge of the developer on the development roller, and therefore, enables the image forming apparatus to reliably form satisfactory images for a long period of time. [0019] Another object of the present invention is to provide a developing apparatus in which developer is reliably supplied to its developer bearing member by its developer supplying member. [0020] Another object of the present invention is to provide a developing apparatus which does not cause an image forming apparatus to form an image which is abnormally low in density, being therefore faint, even when a substantial number of high density images are continuously formed. [0021] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 is a schematic sectional view of the image forming apparatus in the first embodiment of the present invention, showing the general structure of the apparatus. [0023] FIG. 2 is a schematic sectional view of the developing apparatus in the first embodiment of the present invention, showing the general structure of the apparatus. [0024] FIG. 3 is a schematic drawing which shows the toner movement in the toner supplying portion. [0025] FIG. 4 is a schematic sectional view of a developing apparatus in accordance with the prior art, showing the positioning of the developer roller, toner supply roller, and blade in the development chamber, which results in the toner accumulation on the development roller. [0026] FIG. 5 is a schematic sectional view of the developing in the first embodiment of the present invention, showing the positioning of the developer roller, toner supply roller, and blade in the development chamber of the developing apparatus. [0027] FIG. 6 is a schematic sectional view of a developing apparatus structured so that its regulating portion has the NE portion. [0028] FIG. 7 is a schematic sectional view of a developing apparatus in which toner re-circulates in the small area in the adjacencies of the area from which toner is spewed, showing the positioning of the development roller, toner supply roller, and blade of the developing apparatus. [0029] FIG. 8 is a schematic drawing of an apparatus used for measuring the amount of charge which the toner on the development roller has. [0030] FIG. 9 is a schematic sectional view of the second and third comparative developing apparatuses, showing the general structure of the apparatuses. [0031] FIG. 10 is a schematic sectional view of the fourth comparative developing apparatus, showing the general structure of the apparatus. [0032] FIG. 11 is a schematic sectional view of a conventional developing apparatus, which uses nonmagnetic single-component developer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0033] Hereinafter, the developing apparatuses in accordance with the present invention will be described in more detail with reference to the appended drawings. Embodiment 1 [0034] FIG. 1 is a schematic sectional view of the image forming apparatus in the first embodiment of the present invention, and shows the general structure of the apparatus. The image forming apparatus 200 in this embodiment is a color laser printer of the transfer type, which employs one of the known electrophotographic processes. It also employs a charging system of the contact type, and a development system which uses single-component developer. The image forming apparatus 200 , that is, the printer in this embodiment, is capable of forming and outputting a full-color image on a sheet of recording medium S, such as a sheet of paper, OHP sheet, etc., in accordance with pictorial information it receives from an external host apparatus (unshown) connected thereto so that information can be exchanged between it and host apparatus. [0035] The image forming apparatus 200 in this embodiment, which is capable of outputting a full-color image, employs four drums, which are juxtaposed in parallel, being therefore sometimes referred to as an image forming apparatus of the in-line type. More concretely, the image forming apparatus 200 has multiple image forming means, that is, four image forming portions P (Pa, Pb, Pc, and Pd) which form yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. The images formed by the image forming portions P are temporarily transferred in layers onto an intermediary transfer belt 20 (intermediary transfer member), and then, are transferred together onto a sheet of recording medium S, for example, a sheet of paper. The intermediary transfer belt 20 is supported, being thereby stretched, by a driver roller 21 and a support roller 22 , and is driven in the direction indicated by an arrow mark B. [0036] The image forming portions P (Pa, Pb, Pc, and Pd) are the same in structure. Each image forming portion P has an image bearing member, which is an electrophotographic photosensitive member 1 ( 1 Y, 1 M, 1 C, and 1 K), which is in the form of a drum (which hereafter may be referred to as photosensitive drum); the image forming apparatuses Pa, Pb, Pc, and Pd have photosensitive drums 1 Y, 1 M, 1 C, and 1 K, respectively. Each image forming portion P has a charge roller 2 ( 2 Y, 2 M, 2 C, and 2 K) as a charging means, and a laser beam scanning apparatus 3 ( 3 Y, 3 M, 3 C, and 3 K) as an exposing means, which is in the adjacencies of the peripheral surface of the photosensitive drum 1 . The charge roller 2 and exposing apparatus 3 form an electrostatic latent image on the photosensitive drum 1 . Also disposed in the adjacencies of the peripheral surface of the photosensitive drum 1 are a developing apparatus 4 ( 4 Y, 4 M, 4 C, and 4 K) as a developing means, and a cleaning apparatus 5 ( 5 Y, 5 M, 5 C, and 5 K) as a cleaning means for removing the toner remaining on the photosensitive drum 1 . The developing apparatus 4 develops the electrostatic latent image on the photosensitive drum 1 , into a visible image (image formed of toner, which hereafter will be referred to as toner image). [0037] In this embodiment, the abovementioned photosensitive drum 1 , charge roller 2 , developing apparatus 4 , and cleaning apparatus 5 , which make up the image forming portion P, are integrally placed in a cartridge, making up a process cartridge 8 ( 8 a , 8 b , 8 c , and 8 d ), which is replaceably mountable in the main assembly 200 A of the image forming apparatus 200 through a process cartridge mounting-and-removing means (unshown). Thus, if the developing apparatus 4 of the process cartridge 8 in the main assembly 200 A reaches the end of its service life, for example, runs out of toner, the process cartridge 8 can be replaced with another process cartridge 8 (for example, a brand-new process cartridge). [0038] The image forming apparatus 200 employs four process cartridges 8 , that is, process cartridge 8 Y (which uses yellow toner), 8 M (which uses magenta toner), 8 C (which uses cyan toner), and 8 K (which uses black toner), which are juxtaposed in parallel, in the direction parallel to the circulatory direction of the intermediary transfer belt 20 . [0039] The image forming sequence of the image forming apparatus 200 is as follows: First, the peripheral surface of the photosensitive drum 1 is uniformly charged by the charge roller 2 , in the image forming portion P. Then, a latent image, which reflects the pictorial signals inputted from a controller, is formed on the uniformly charged portion of the peripheral surface of the photosensitive drum 1 by the exposing apparatus 3 . This latent image is developed into a toner image by the developing apparatus 4 . This image forming sequence is carried out in each image forming portion P. [0040] The four monochromatic toner images, different in color, are transferred (primary transfer) onto the intermediary transfer belt 20 by transfer rollers 9 ( 9 Y, 9 M, 9 C, and 9 K) as transferring means, in the primary transferring portions T 1 (T 1 a , T 1 b , T 1 c , and T 1 d ), effecting thereby a single full-color image on the intermediary transfer belt 20 . Then, the four monochromatic toner images, which effected a single full-color image, are transferred together onto the recording medium S, in the second transferring portion T 2 where a transfer roller 23 , which is a secondary transferring means, is disposed. Regarding the recording medium S, multiple sheets of recording mediums S are stored in a sheet feeder cassette 30 . As an image forming operation begins, the multiple sheets of recording medium S are sent one by one from the sheet feeder cassette 30 by a recording medium conveyance roller 32 , which is a recording medium conveying means, to the secondary transferring portion T 2 in which the transfer roller 23 is located. [0041] After the transfer of the full-color toner image onto the recording medium S, the recording medium S is conveyed to a fixing apparatus 7 , in which the toners images (full-color image) are fixed to the recording medium S. Then, the recording medium S is discharged from the image forming apparatus. Meanwhile, the transfer residual toner particles, that is, the toner particles remaining on the peripheral surface of the toner image transfer, is removed by the cleaning apparatus 5 ( 5 a , 5 b , 5 c , and 5 d ). [0042] Next, referring to FIG. 2 , the general structure of the developing apparatus 4 in this embodiment will be described. The developing method employed by the developing apparatus 4 is of the contact type. It uses nonmagnetic single-component developer. [0043] The developing apparatus 4 in this embodiment has a housing 41 , which has a toner storage chamber 10 and a development chamber 11 . [0044] The toner storage chamber 10 stores toner T. It has a toner conveying member 15 , which is a flexible blade. The toner conveying member 15 is rotated in the direction indicated by an arrow mark in FIG. 2 , conveying thereby the toner in the toner storage chamber 10 to the development chamber 11 while stirring the toner. [0045] There are a development roller 12 , a toner supply roller 13 , and a regulating blade 14 , in the development chamber 11 . The development roller 12 is a developer bearing member, and is rotated in the direction indicated by an arrow mark C. The toner supply roller 13 is a member which coats the development roller 12 with developer. It is rotated in the direction indicated by an arrow mark D. The regulating blade 14 is a member which regulates the amount by which developer is allowed to remain coated on the peripheral surface of the photosensitive drum 1 , per unit area, after the developer is coated on the peripheral surface of the photosensitive drum 1 . [0046] The development chamber 11 in this embodiment is located on top of the toner storage chamber 10 . There is an opening 42 between the development chamber 11 and toner storage chamber 10 , allowing the toner in the housing 41 to move between the toner storage chamber 10 and development chamber 11 . As the toner conveying member 15 is rotated, the toner T in the toner storage chamber 10 is conveyed, as if being flipped up, into the development chamber 11 through the opening 42 , as indicated by an arrow mark 44 . [0047] The development chamber 11 is provided with a toner storage 43 , which stores the toner conveyed from the toner storage chamber 10 . The developing apparatus 4 is structured so that the toner supply roller 13 is partially or fully enclosed in the toner storage 43 . The toner supply roller 13 is placed in contact with the development roller 12 . It is rotated in such a direction that in the area of contact F (coating portion) between the toner supply roller 13 and development roller 12 , the peripheral surface of the toner supply roller 13 moves in the direction opposite (counter) to that in which the peripheral surface of the development roller 12 moves. That is, in the area of contact F, the peripheral surface of the development roller 12 moves downward (direction of gravity), whereas the peripheral surface of the toner supply roller 13 moves upward (direction opposite to direction of gravity). In other words, in terms of the rotational direction of the toner supply roller 13 , the downstream edge of the area of contact F is roughly straight above the upstream edge of the area of contact F. [0048] The toner in the toner storage 43 is conveyed to the area of contact F between the toner supply roller 13 and development roller 12 by the rotation of the toner supply roller 13 , to be coated on (supplied to) the development roller 12 . When the toner is coated on the peripheral surface of the development roller 12 by the toner supply roller 13 , the toner is charged by the friction between the toner and development roller 12 . The toner supply roller 13 also scrapes away, in the area of contact F, the toner remaining on the peripheral surface of the development roller 12 after the development of a latent image. [0049] It is in the development chamber 11 that the blade 14 is disposed as a regulating member, being kept pressed against the peripheral surface of the development roller 12 . After the toner T is coated on the peripheral surface of the development roller 12 , the layer of toner T on the development roller 12 is regulated in thickness, while being given electrical charge, by the blade 14 . As a result, a thin layer of toner T is formed on the peripheral surface of the development roller 12 . [0050] The development roller 12 is positioned so that its peripheral surface is kept pressed against the peripheral surface of the photosensitive drum 1 , forming thereby a developing portion G, in which the contact pressure between the development roller 12 and photosensitive drum 1 has a preset value. The development roller 12 is rotated so that in the area of contact G, its peripheral surface moves in the same direction as the moving direction of the peripheral surface of the photosensitive drum 1 , with the presence of a preset amount of difference between its peripheral velocity and that of the photosensitive drum 1 . [0051] The thin toner layer formed on the peripheral surface of the development roller 12 by the blade 14 is conveyed by the rotation of the development roller 12 to the area of contact G between the development roller 12 and photosensitive drum 1 , in which the latent image on the peripheral surface of the photosensitive drum 1 is developed. The toner particles remaining on the peripheral surface of the development roller 12 , that is, the toner particles which were not used for the development of the latent image are removed from the peripheral surface of the development roller 12 by the aforementioned toner supply roller 13 . [0052] As the development roller 12 and toner supply roller 13 rotate in the abovementioned directions, respectively, pressure is generated on the upstream side of the area of contact G, in terms of the rotational direction of the toner supply roller 13 . Thus, this force pushes the toner T in the toner storage 43 , into to the opening 42 , along with air, and falls back into the toner storage chamber 10 . Thus, the toner T in the toner storage 43 does not stagnate in the toner storage 43 . That is, the body of toner T in the toner storage 43 is continuously replaced by the next body of toner, which is conveyed into the toner storage 43 from the toner storage chamber 10 ; toner is circulated through the toner storage 43 . [0053] The development roller 12 employed by the developing apparatus 4 in this embodiment is a semiconductive elastic roller. It is provided with an elastic layer, and is 16 mm in external diameter. The material for the semiconductive elastic layer is a soft rubber or a foamed substance, such as silicone rubber, urethane, etc., in which electrically conductive substance, such as carbon, has been dispersed, and the volume resistivity of which is in a range of 10 2 ohm.cm-10 10 ohm.cm. In some cases, it is formed of a combination of the abovementioned substances. [0054] The toner supply roller 13 is an elastic roller, which is 16 mm in external diameter. Its elastic surface layer is formed of electrically conductive foamed substance (conductive sponge). It is kept pressed against the development roller 12 so that the amount of its apparent intrusion into the development roller 12 , in the area of contact F, is 1.5 mm. [0055] The blade 14 is a piece of plate spring formed of SUS. It is kept in contact with the peripheral surface of the development roller 12 , being elastically bent in curvature, so that a preset amount of contact pressure is maintained between the blade 14 and development roller 12 , in the area of contact H. [0056] In this embodiment, −350 V and −550 V are applied to the development roller 12 and toner supply roller 13 , respectively. To the blade 14 , −550 V is applied. Incidentally, the potential level to which the photosensitive drum 1 is charged by the charging apparatus 2 is −550 V. [0057] The developer used by the developing apparatus 4 in this embodiment is nonmagnetic single-component toner, which is negatively chargeable. [0058] The process speed of the image forming apparatus in this embodiment, that is, the peripheral velocity of the photosensitive drum 1 , is 150 mm/sec, whereas the peripheral velocity of the development roller 12 is 180 mm/sec. [0059] At this point in time, what characterizes this embodiment, more specifically, the method for supplying the development roller 12 with only the normally charged toner particles, and the structural arrangement for carrying out this method, will be described. [0060] First, the voltage to be applied to the toner supply roller 13 will be described. [0061] In this embodiment, the voltage (toner supply bias) applied to the toner supply roller 13 is greater in absolute value than the voltage applied to the development roller 12 . The voltage applied to the development roller 12 is the same in polarity as the polarity to which toner is charged. More specifically, to the development roller 12 , −350 V is applied, and to the toner supply roller 13 , −550 V is applied. [0062] That is, to the toner supply roller 13 , such voltage that is the same in polarity as the developer (toner), and provides a difference in voltage (−200 V) between the toner supply roller 13 and development roller 12 , is applied. In other words, the voltage applied to the toner supply roller 13 is set so that its polarity is the same as the normal polarity to which the developer is chargeable, being therefore the same as the voltage applied to the development roller 12 , and also, that its absolute value is greater than that of the voltage applied to the development roller 12 . [0063] Referring to FIG. 3 , therefore, it is possible to coat the development roller 12 with only the normally (negatively) charged toner particles. That is, it is possible to prevent the positively charge toner particles, and the toner particles, which are normal (negative) in polarity, but, are insufficient in the amount of electrical charge, from adhering to the development roller 12 . [0064] Next, the positioning of the development roller 12 , toner supply roller 13 , and blade 14 , will be described. [0065] By applying toner supply bias as described above, it can be ensured that the development roller 12 is supplied with only the normally charged toner. [0066] However, in a case where the developing apparatus 4 is structured so that the toner supply roller 13 is positioned on top of the development roller 12 , as shown in FIG. 4 , for example, the following problem occurs: [0067] That is, it is possible that while the portion of the peripheral surface of the development roller 12 , which is in the area of contact F (coating area) between the development roller 12 and toner supply roller 13 , is moved from the area of contact F to the area of contact H (regulating portion) between the development roller 12 and regulation blade 14 , the toner particles in the body of toner T in the adjacencies of the development roller 12 will settle on (and adhere to) the toner layer on the peripheral surface of the development roller 12 , and be conveyed to the regulating portion H. In other words, it is possible that the toner particles, which have not been properly charged, will be conveyed to the regulating portion H, and coated on the peripheral surface of the development roller 12 . [0068] Thus, in the case of the developing apparatus 4 in this embodiment, its development roller 12 , toner supply roller 13 , and blade 14 are positioned so that as a given portion of the peripheral surface of the development roller 12 moves into the area between the coating portion F, that is, the area of contact between the development roller 12 and toner supply roller 13 , and the regulating portion H, that is, the area of contact between the development roller 12 and blade 14 , it becomes roughly parallel to the direction of gravity (vertical direction), as shown in FIG. 5 . That is, the development roller 12 and toner supply roller 13 are positioned so that while a given portion of the peripheral surface of the development roller 12 is moving through the area between the coating portion F and regulating portion H, it remains roughly vertical. In other words, while a give portion of the peripheral surface of the development roller 12 is in the area between the coating portion F and regulating portion H, it remains below the horizontal plane which coincides with the rotational axis of the toner supply roller 13 . [0069] With the provision of this structural arrangement, should toner particles which are insufficient in the amount of charge, and/or toner particles which are reverse in polarity, adhere to the peripheral surface of the development roller 12 , they would be peeled away from the peripheral surface of the development roller 12 by their own weight, because there is no electrostatic attraction between them and the peripheral surface of the development roller 12 . Therefore, not only is the development roller 12 not supplied with an excessive amount of toner by the toner supply roller 13 , but also, only the toner particles supplied by the toner supply roller 13 , that is, the toner particles which are normal in polarity and amount of electrical charge, remain on the peripheral surface of the development roller 12 . [0070] Lastly, the regulating blade 14 will be described. [0071] The toner particles spewed out of the toner storage 43 by the pressure generated in the adjacencies of the coating portion F by the toner supply roller 13 , and/or toner particles which fell from the development roller 12 , are carried to the adjacencies of the blade 14 by the air movement (wind) or the like caused by the rotation of the development roller 12 , or the like. [0072] Referring to FIG. 6 , if the developing apparatus 4 is structured so that the edge 14 a of the regulating blade 14 extends beyond the area of contact H (regulating portion) between the development roller 12 and blade 14 (that is, if developing apparatus 4 is structured so that portion NE is created), the portion NE of the blade 14 functions a toner guide, making it possible for the toner in the adjacencies of the blade 14 to be conveyed to the regulating portion H and coated on the peripheral surface of the development roller 12 . The NE portion is the portion of the blade 14 , which is extending beyond the area of contact between the blade 14 and development roller 12 . [0073] In order to prevent the toner in the adjacencies of the blade 14 from being guided to the regulating portion H by the NE portion, the developing apparatus 4 in this embodiment is structured so that only the edge 14 a of the regulating blade 14 contacts the development roller 12 (that is, contact only by edge) to regulate the toner layer on the peripheral surface of the development roller 12 in terms of the amount per unit area. With the employment of this structural arrangement, the toner particles floating in the adjacencies of the blade 14 are not guided into the regulating portion H. Therefore, only the toner particles coated on the development roller 12 by the toner supply roller 13 are moved into the regulating portion H. In other words, only the toner particles which have just been satisfactorily charged to the normal polarity enter the regulating portion H, and are coated on the peripheral surface of the development roller 12 . [0074] To summarize, the developing apparatus 4 in this embodiment is structured so that the toner supply bias is applied to the toner supply roller 13 ; the toner supply roller 13 and development roller 12 are positioned so that while a given portion of the peripheral surface of the development roller 12 is moved between the coating portion F and regulating portion H by the rotation of the development roller 12 , it faces downward (in the direction parallel to direction of gravity); and the regulating blade 14 contacts the peripheral surface of the development roller 12 only by its edge 14 a . Therefore, it is possible to ensure that the development roller 12 is supplied with only the toner particles which are normal in polarity and amount of electrical charge. [0075] Regarding the positioning of the toner supply roller 13 relative to the development roller 12 , the toner supply roller 13 is desired to be positioned as shown in FIG. 5 . That is, the toner supply roller 13 is desired to be positioned so that the downstream edge Fa of the area of contact F (coating portion) between the toner supply roller 13 and development roller 12 , in terms of the rotational direction of the development roller 12 , coincides with, or is below, the horizontal plane H 13 which includes the rotational axis 013 of the toner supply roller 13 . [0076] With the toner supply roller 13 and development roller 12 positioned as described above, even if a certain mount of toner is spewed into the air by the pressure generated by the rotation of the toner supply roller 13 , in the coating portion F, the spewed toner does not settle on the toner supply roller 13 . [0077] In a case where the developing apparatus 4 is structured so that the toner supply roller 13 is positioned diagonally below the development roller 12 , for example, as shown in FIG. 7 , the same body of toner is repeatedly sent back to the coating portion F; in other words, once a body of toner is moved into an area I, it is continuously recirculated in the area I, and therefore, prematurely deteriorates, creating thereby problems, such as the formation of a foggy image, fusion of toner to the blade 14 , etc. [0078] In this embodiment, however, the developing apparatus 4 is structured as described above (as shown in FIG. 5 ). Therefore, the toner does not continuously recirculate in the area I, and therefore, does not prematurely deteriorate. In other words, the developing apparatus 4 in this embodiment can make developer last longer than a developing apparatus in accordance with the prior art. [0079] The inventors of the present invention comparatively studied the structure of the developing apparatus 4 in this embodiment, and the structure of a conventional developing apparatus, that is, a developing apparatus in accordance with the prior art. [0080] The developing apparatus 4 in this embodiment and a conventional developing apparatus were compared in terms of the amount (Q/M) of electrical charge, per unit amount of toner on the peripheral surface of the development roller 12 , on the downstream side of the regulating portion H, and the amount of fog of an image. <Method for Measuring Amount of Electrical Charge of Toner> [0081] The amount of electrical charge of the toner on the peripheral surface of the development roller 12 is measured with the use of the following method: [0082] That is, it is measured with the use of a Faraday cage shown in FIG. 8 . The Faraday cage is a double-walled cylindrical container made up of two concentric cylindrical walls, that is, an internal cylindrical wall, and an external cylindrical wall, which are insulated from each other. Placing a substance, which is an amount Q of electrical charge, in the internal cylinder creates the same effects as the presence of a metallic cylinder, which is Q in the amount of electrical charge, because of electrostatic induction. The amount of this induced electrical charge is measured by a Keithley 616 Digital Electrometer. Then, the obtained amount (Q) of the Faraday cage is divided by the value of the weight M of the body of toner in the internal cylinder, obtaining thereby the value of (μC/g). The value is used as the amount of electrical charge of the toner on the aforementioned portion of the peripheral surface of the development roller 12 . The toner on the peripheral surface of the development roller 12 is directly caught by a filter by suction. <Method for Measuring Amount of Fog> [0083] The amount of fog was obtained with the use of a Reflection Densitometer TC-6DS (product of Tokyo Denshoku Co., Ltd.). More specifically, it is obtained by subtracting the reflection density (%) of a solid white image formed on a sheet of recording paper, from the reflection density (%) of a plane sheet of recording paper which belongs to the same lot as the sheet of recording paper on which the solid white image was formed. [0084] Next, the comparative developing apparatuses will be described regarding their structure. <Comparative Developing Apparatus 1 > [0085] The first comparative developing apparatus was the same in structure as the developing apparatus 4 in this embodiment. The first comparative developing apparatus is different from the developing apparatus 4 in this embodiment in that in the case of the first comparative developing apparatus, the toner supply bias, which characterizes the first embodiment of the present invention, is not applied to the toner supply roller 13 , and therefore, the toner supply roller 13 and development roller 12 are the same in potential level. <Comparative Developing Apparatus 2 > [0086] The second comparative developing apparatus is different in structure from the developing apparatus 4 in this embodiment. That is, referring to FIG. 9 , the second comparative developing apparatus is structured so that the toner spewing portion F of the coating portion F faces upward. That the toner spewing portion F faces upward means that in the coating portion F, the peripheral surface of the toner supply roller 13 moves downward. This structural arrangement does not meet concur with one of the features of the developing apparatus 4 in this embodiment, which characterizes the present invention, that is, “while a given portion of the peripheral surface of the development roller 12 moves between the coating portion F and regulating portion G, it remains facing downward”. While a given portion of the peripheral surface of the development roller 12 is facing downward, it is below the horizontal plane which coincides with the rotational axis of the toner supply roller 13 . <Comparative Developing Apparatus 3 > [0087] The third comparative developing apparatus is the same in structure as the second comparative developing apparatus. However, in the case of this comparative developing apparatus, the “toner supply bias” is not applied. <Comparative Developing Apparatus 4 > [0088] Referring to FIG. 10 , in terms of the positioning of the development roller 12 and toner supply roller 13 , the fourth comparative developing apparatus is the same as the developing apparatus 4 in this embodiment. However, in the case of the fourth comparative developing apparatus, the blade 14 extends beyond the area of contact H between the blade 14 and development roller 12 ; in terms of the direction in which the blade 14 extends, the edge portion 14 a of the blade 14 is beyond the area of contact H between the blade 14 and development roller 12 . Unlike the abovementioned one of the features of the developing apparatus 4 in the first embodiment of the present invention, which characterizes the present invention, it is not by the edge 14 a that the blade 14 of the fourth comparative developing apparatus is not placed in contact with the development roller 12 . That is, the blade 14 extends beyond the point of contact between the blade 14 and development roller 12 ; the portion (NE) of the blade 14 , which is between the edge 14 a of the blade 14 and the area of contact H between the blade 14 and development roller 12 , extends into the development chamber 11 . Thus, the portion of the blade 14 , which is near the edge 14 a of the blade 14 , is not in contact with the development roller 12 . [0089] Next, the results of the abovementioned comparative studies will be described. The results of the comparative studies are summarized in Table 1. [0090] All of the four comparative developing apparatuses are lower in the amount of the electrical charge of the toner on the peripheral surface of the development roller 12 , and also, are worse in terms of fog, than the developing apparatus 4 in this embodiment, regardless of the difference in structure. [0091] Based on the results of comparison between the structure of the developing apparatus 4 in this embodiment, and that of the first comparative developing apparatus, the following may be inferred: Not only did the application of the toner supply bias ensure that only the toner particles which are normal in the polarity of their electrical charge are supplied to the development roller 12 , but also, increased the amount by which the toner particles are electrically charged. Therefore, the developing apparatus 4 in this embodiment was better in terms of fog than the comparative developing apparatuses. [0092] The effectiveness of the toner supply bias is evident from the results of comparison between the developing apparatus 4 in this embodiment, and the second and third comparative developing apparatuses. Incidentally, in terms of the amount of electrical charge of toner and the severity of fog, the second comparative developing apparatus is not much different from the third comparative developing apparatus. [0093] In the case of the second comparative developing apparatus structured as shown in FIG. 9 , the toner spewing portion Fa is on the top side of the area of contact between the toner supply roller 13 and development roller 12 , allowing thereby the spewed toner to hang over the peripheral surface of the development roller 12 and settle on the peripheral surface of the development roller 12 . Thus, these tone particles, that is, the toner particles which have not been electrically charged, are sent into the regulating portion H by the rotation of the development roller 12 , and some of them remain coated on the peripheral surface of the development roller 12 . Thus, even if the toner supply bias is applied to ensure that only the toner particles which are normal in polarity and amount of electrical charge are supplied to the development roller 12 , the toner supply bias has little effect upon the amount of the electrical charge which the toner particles on the development roller 12 have on the downstream side of the area of contact H, in terms of the rotational direction of the development roller 12 . [0094] Further, it became evident from the comparison between the structure of the developing apparatus 4 in this embodiment and that of the fourth comparative developing apparatus that the state of contact between the blade 14 and development roller 12 also has a large amount of effect upon the amount of fog and the amount of electrical charge of toner on the development roller 12 , on the downstream side of the area of contact H. [0095] In the case of the structure of the developing apparatus 4 in this embodiment, the blade 14 is in contact with the peripheral surface of the development roller 12 by its edge 14 a . However, in the case of the structure of the fourth comparative developing apparatus, the blade 14 is in contact with the peripheral surface of the development roller 12 by its belly portion, and therefore, the portion NE of the blade 14 , which extends beyond the area of contact H between the blade 14 and development roller 12 , guides toner into the regulating portion H. [0096] In the case of the fourth comparative developing apparatus, the toner particles spewed from the toner spewing portion Fa are floating in the adjacencies of the blade 14 . These toner particles are those which were not supplied to the development roller 12 , and are unsatisfactory in the amount of electrical charge, and also, are reverse in polarity. These toner particles reach the adjacencies of the blade 14 by riding the wind (air flow) generated by the rotation of the development roller 12 . In addition, the portion NE of the blade 14 guides these toner particles into the regulating portion H, in which they are coated on the peripheral surface of the development roller 12 . Therefore, the effects of the toner supply bias are nullified. This is thought to be why the fourth comparative developing apparatus is smaller in the amount of toner charge, on the downstream side of the regulating portion H, and inferior in terms of fog than the developing apparatus 4 in this embodiment. [0097] The inventors of the present invention presumed that as long as the amount of fog of an image is no more than 1.5%, the fog dose not create any problem in terms of image quality, whereas if the amount of fog of an image is no less than 2.0%, the fog is conspicuous, and therefore, the image falls outside the tolerable range in terms of quality. In other words, in order for an image to be thought to be high in quality, the amount of its fog is desired to no more than 1.5%. [0000] TABLE 1 Spewing Supply Blade Q/M Fog portion bias contact (μC/g) (%) Embodiment Dwn Y Edge 40 1.4 Comp. Ex. 1 Dwn N Edge 33 2.5 Comp. Ex. 2 Up Y Edge 36 2.0 Comp. Ex. 3 Up N Edge 34 2.4 Comp. Ex. 4 Dwn Y NE 31 2.8 [0098] The comparative studies described above revealed the following: [0099] In order for the structure of a developing apparatus to concur with the structural features of the developing apparatus 4 in this embodiment, which characterizes the present invention, it is important that the developing apparatus is structured so that the toner supply bias is applied; the toner supply roller 13 and development roller 12 are positioned so that while a given portion of the peripheral surface of the development roller 12 moves through the range between the coating portion F and regulating portion H, it faces downward; and the blade 14 contacts the peripheral surface of the development roller 12 by its edge. This structural arrangement stabilizes a developing apparatus in terms of the amount of the electrical charge of the toner on the development roller 12 , on the downstream side of the area of contact between the blade 14 and development roller 12 in terms of the rotational direction of the development roller 12 , and also, is effective to prevent the formation of an image suffering from fog. As described above, the developing apparatus 4 in this embodiment is structured so that the toner spewing portion Fa is level with, or below, the horizontal plane H 13 which coincides with the rotational axis 013 ( FIG. 5 ) of the toner supply roller 13 . Therefore, it does not occur that the toner particles in the adjacencies of the downstream (upstream) edge of the area of contact between the toner supply roller 13 and development roller 12 , in terms of the rotational direction of the development roller 12 (toner supply roller 13 ), continuously recirculates in the abovementioned adjacencies. Therefore, it does not occur that toner abnormally deteriorates in the adjacencies of the downstream edge of the area of contact between the toner supply roller 13 and development roller 12 . Therefore, the above described effects of the structural arrangement for a developing apparatus lasts for a long period of time. [0100] As described above, the developing apparatus 4 in this embodiment is structured so that: [0101] (1) voltage which is the same in polarity as the toner, and is different in potential level from the voltage applied to the development roller 12 , is applied to the toner supply roller 13 , so that difference in potential level is provided between the toner supply roller 13 and development roller 12 ; [0102] (2) the development roller 12 and toner supply roller 13 are positioned so that while a given portion of the peripheral surface of the development roller 12 is moved by the rotation of the development roller 12 through the range between the downstream edge Fa of the area of contact between the development roller 12 and toner supply roller 13 , in terms of the rotational direction of the development roller 12 and the area of contact H (regulating portion) between the development roller 12 and regulating blade 14 , it faces downward; [0103] (3) the regulating blade 14 is in contact with the peripheral surface of the development roller 12 by its edge 14 a , and the downstream edge Fa of the area of contact F between the development roller 12 and toner supply roller 13 , in terms of the rotational direction of the development roller 12 , is level with, or lower than the horizontal plane H 13 which coincides with the rotational axis 013 of the toner supply roller 13 . [0104] With the developing apparatus 4 structured as described above, only the toner particles which are satisfactory in terms of the amount of electrical charge are supplied to the development roller 12 . Therefore, only the toner particles which are normal in polarity and satisfactory in the amount of electrical charge are coated on the development roller 12 , and therefore, the developing apparatus 4 is stable in the amount of the electrical charge of the toner on the development roller 12 , on the downstream side of the regulating portion H. Further, these effects of the structural arrangement for a developing apparatus last for a long period of time. Thus, the developing apparatus 4 in this embodiment can prevent the problems, such as the formation of an image which is suffering from fog, and/or abnormal in density, which occurs when a developing apparatus is unstable in the amount of the electrical charge of the toner on its development roller. [0105] In this embodiment, the difference in potential level between the toner supply roller 13 and development roller 12 was set to 200 V. However, it does not need to be set to this value. That is, it may be varied according to the electrical resistances of the components of the developing apparatus (developing apparatus 4 , in particular), and the characteristics of the toner used by the developing apparatus 4 . [0106] Also in this embodiment, a piece of SUS plate was used as the blade 14 . However, the material for the blade 14 does not need to be limited to SUS plate. For example, it may be a piece of metallic plate coated with resin. Further, regarding the voltage to be applied to the blade 14 , in this embodiment, such voltage that provides 200 V of difference in potential level between the blade 14 and development roller 12 was applied to the blade 14 . This setup, however, may be modified. [0107] Further, this embodiment was described with reference to the developing apparatus 4 (developing means), which is an integral part of the process cartridge 8 which is removably mountable in the main assembly 200 A of the image forming apparatus 200 . However, the present invention is also compatible with a developing apparatus that is an integral part of a process cartridge, which is removably mountable in the main assembly 200 A of the image forming apparatus 200 , but, does not have a photosensitive member. It is also compatible with a developing apparatus that is an integral portion of the main assembly 200 A of the image forming apparatus 200 . [0108] Further, in the embodiment described above, the image forming apparatus was a color image forming apparatus. However, the application of the present invention is not limited to a color image forming apparatus. For example, the present invention is applicable to a monochromatic image forming apparatus as well. [0109] Further, this embodiment was described with reference to the color image forming apparatus which employs the intermediary transfer medium, that is, the intermediary transfer belt 20 . However, the present invention is also applicable to a color image forming apparatus structured so that a color image is effected by directly transferring in sequence the toner images formed on the multiple photosensitive drums 1 in the image forming portions P (PY, PM, PC, and PK), one for one, onto the recording medium S, instead of the intermediary transfer belt 20 , while the recording medium S is conveyed through the image forming portions P, one after another, by the recording medium conveying belt. An image forming apparatus, such as the above described one, that is, the so-called image forming apparatus of the direct transfer type, which directly transfer an image from a photosensitive member to the transfer medium S, is well-known to the people in this business, and therefore, will not be described in detail here. [0110] According to the present invention, a developing apparatus is structured so that only the developer particles which are normal in polarity and amount of electrical charge, are supplied to the developer bearing member, in order to prevent the formation of images suffering from such an image defects as fog, which occurs when the developing apparatus becomes unstable in the amount of the electrical charge of the developer on the developer bearing member. Therefore, an image forming apparatus in accordance with the present invention can continuously form satisfactory images for a long period of time. [0111] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. [0112] This application claims priority from Japanese Patent Application No. 029719/2007 filed Feb. 8, 2007, which is hereby incorporated by reference.

A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer; a developer feeding member, contactable to the carrying member, for supplying the developer to the carrying member, the developer feeding member is rotatable in a direction of peripheral movement opposite a peripheral movement of the carrying member at a contact portion relative to the developer feeding member, wherein a direction the peripheral movement of the developer feeding member at the contact portion is substantially upward; and a regulating member for regulating an amount of the developer carried on the carrying member, the regulating member having a free end portion contacted to the carrying member; wherein the developer feeding member is supplied with a voltage which is different from a potential of the developer member toward a regular charging polarity of the developer, and wherein the carrying member is provided with a surface facing substantially downward, in a range from a downstreammost point of the developer member in the contact portion with respect to a rotational direction of the carrying member to a contact portion between the carrying member and the regulating member.

This application is a continuation of U.S. Ser. No. 13/854,895 and claims priority from Ser. No. 09/716,052 filed Nov. 17, 2000, issued as U.S. Pat. No. 6,976,216. FIELD OF INVENTION This invention relates to use of dedicated audio/video control keys on computing devices that execute programs for playing audio or video works. BACKGROUND Since compact disc drives were added to personal computers many years ago, personal computers have been used for playing first audio and then video works of authorship. The common implementations use either a mouse or a standard text keyboard to control the playout software. If a mouse is used, images of buttons for some of the customary playout control functions (play, stop, pause, fast forward, rewind, skip to next or last track, volume, mute, and change channel) are displayed on the screen. The mouse controls cursor movement, and a click of the mouse when the cursor is over a button causes the playout software to control the playout accordingly. If a standard text keyboard is used, keys of the keyboard will be selected for each of the control functions listed above, such as “P” for play and right and left arrows for fast-forward and rewind. The audio/video playout control software is typically loaded to the computing device from a transportable disc or may be downloaded across a network for installation or may be embedded in a markup language page such as with use of a Java applet or ActiveX control embedded in an HTML page which is transparent to the user and requires little to no action by the user to install or begin execution of the software. Users of computer systems to play audio/video works can add remote control devices such as those commonly used for televisions or for audio stereo systems to allow control of the playout of audio/video works from anywhere in the same room. Radio or infrared receiving devices for such remote controls can be added to an input port on the computer, such as a USB (Universal Serial Bus) port. Then, a specialized audio/video work playout program is added which includes instructions to receive keystroke data through the port and interpret said data in order to recognize remote control key presses. This allows the remote key presses to effect audio/video playout according to which key is pressed. As audio/video playout programs became commonplace on personal computers, it became desirable to be able to control a wide variety of audio/video control programs that are designed for text keyboard input using a hand-held remote. To accomplish this, special software (sometimes called a “wedge”) can be installed on the computer to control communications through the port, receive keystroke data from the remote control, translate the keystroke data to standard text keystroke data such as “P” for play, and provide the standard keystroke data to the operating system which provides it to the playout control software. Thus, with the remote control added to the computer system and the special control software installed, the remote control can simulate keystrokes at the text keyboard to control audio/video playout control software designed for receiving text keyboard input. Then the user can control the audio/video playout control software using either the text keyboard or the remote control. There are two serious deficiencies with this system. First, the system can no longer use for their original intended purpose the standard text keys that are used to indicate audio/video playout control. For example, a playout control program that uses “P” to indicate “pause playout” or left and right arrows to indicate “previous audio/video work” or “next audio/video work” are not able to use these same keys to allow the user to type a music artist or song name into an edit box. Second, the translator program must be tailored to work with differing varieties of audio/video playout programs, all of which use differing keys to represent each playout control action. Newer operating systems, such as Microsoft's Windows 2000, address these problems by creating a standard set of key codes that are passed to applications when a playout control key is pressed. These standard key codes are used specifically for keyboards or other input devices with dedicated keys for playout control purposes. This method carries the advantage that any application can be easily made to recognize playout control key presses. This approach still suffers from deficiencies because the operating system delivers each playout control key press event to software programs in the same way that a text keyboard key event would be delivered. Specifically, if a user presses a key when several software programs are running, the operating system must determine which one of those applications is to receive the notification of key-press, or “key event”. The existing approach is to send key press information only to the application window with which the user is actively interacting. This approach makes sense for most applications, but audio/video playout control applications—in particular, audio player programs—are an exception. It is a common occurrence to simultaneously execute an audio/video playout program and another program that demands user input, such as a word processor. Typically the audio/video playout program is run in the background because it requires less user attention to operate. However, because existing systems send keystrokes to the foreground program, the user must explicitly select the audio/video program to be the foreground program (usually by moving the mouse over the audio/video playout program window and clicking the mouse), before being able to send audio/video playout key-press events to the audio/video playout program. This adds an additional, inconvenient and unnecessary step to audio/video playout program operation. The requirement that the user must specifically select the audio/video playout control application to perform audio/video playout control is particularly confusing to the user when presented with a web page that consists of a markup language with one or more embedded applications. In this case, though the user is presented with what appears to be a single web application, it is in reality a conglomerate of one or more applications as well as text, graphics, and user interface items such as checkboxes or text boxes where one may provide input using the keyboard or mouse. On the web page, in order to control the audio/video playout application, the user must select the portion of the web page that displays the playout application to place it in the “foreground” before being able to press a playout control key that will control the embedded audio/video playout program. Furthermore, if the user were to click on any other web page constituents, the playout application would no longer receive keyboard events, preventing the user from using the dedicated audio/video keys to control audio/video playout. In modern operating systems, where multiple computer programs may operate concurrently as one or more “windows” on a screen, or as one or more “child” windows of a web browser, standard keyboard-press events are communicated by the operating system to the window that has the “keyboard focus” (is in the “foreground”). The keyboard focus is typically assigned by the user to a window by placing the mouse cursor over a window and clicking a mouse button. If the assigned window is a window where the user can type text, often a flashing text cursor can be seen in the window that has the keyboard focus. Windows that do not have flashing text cursors typically indicate visually that they have the keyboard focus by changing the color of the application's primary window's title bar. On existing computers equipped with a common (text) keyboard as well as dedicated keys for audio/video playout control (sometimes on a wireless hand-held remote), such dedicated audio/video control key-presses are communicated to the application window that has the keyboard focus, just as are standard key presses. Alternatively, the operating software delivers audio/video key events only to a specialized set of programs customized for the device. SUMMARY This invention comprises systems that enable a software program to receive audio/video key events without requiring the user to explicitly direct the keyboard focus to the playout program. The invention simplifies the user interface because it allows audio/video playout buttons to control a web-embedded audio/video player even if the user has not explicitly set the keyboard focus within the web page to that audio/video player. Note that though the figures in this document indicate that the audio/video playout window is visible to the user at all times, it is a common technique to hide a program window by specifying dimensions of zero width and zero height for the program's window. In this case, the inventions as described are still effective, and indeed more important because the user has no clear way to set the keyboard focus to the application by using the mouse or keyboard. The invention includes methods that allow a computer user to communicate audio/video key events to applications that do not have a window in the foreground. This is accomplished by creating two keyboard focuses: one for regular text input and a second for audio/video keyboard input. By having two separate keyboard focuses, the user may assign the audio/video keyboard focus to any playout program that may be running in the foreground or background on the computer. The user may then set the text keyboard focus to any other computer program, without affecting the placement of the audio/video keyboard focus. Furthermore, the user may reassign the audio/video keyboard focus to another executing playout program at any time. Additionally, the user may enter a default mode, whereby the audio/video focus window is the same as the text keyboard focus window. This frees the user from thinking about multiple keyboard focuses when their usage is not required. Another shortcoming of existing systems that is addressed by this invention is the need for playout programs to be able to determine whether the user has pressed a playout control key on a keyboard that is typically used at short range (such as a typing keyboard) or on a keyboard that is typically used at long range (such as a hand-held remote). This is desirable because a program may be better suited to different modes of operation when the user presses audio/video control buttons on a hand-held remote. For example, it is desirable to temporarily display text in an enlarged font if the user presses buttons on a hand-held remote, because presumably the user is operating the computer from a distance that makes regular screen text viewing difficult. This is accomplished by delivering, along with key event notification data, an indication of whether the key was pressed on a short-range keyboard or a long-range keyboard. Alternatively, a new set of distinct codes may be used to identify each long-range keyboard key. The invention is most useful on computers equipped with specialized keyboards that have audio/video playout keys or on computers that have an auxiliary audio/video keyboard (“handheld remote”) to control audio/video playout programs. However, many of the embodiments described are useful on computer systems with playout programs that use regular text keys (“P” for Play, “S” for Stop, “Up Arrow” for Volume Up) that are dedicated to controlling audio/video playout. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a web browser displaying typical web page constituents. FIG. 2 is a top view of a hand-held keypad whose keys consist only of audio/video playout control keys. FIG. 3 is a top view of a traditional keyboard with the addition of specialized audio/video playout control keys. FIG. 4 is a diagram of program window hierarchy on a modern operating system “desktop” display. FIG. 5 . is a diagram of the communications between a “wedge server” program that is added to an operating system to enable an auxiliary audio/video keyboard focus, and the “event client” programs that receive audio/video key events from the wedge program by the Microsoft COM protocol. DETAILED DESCRIPTION It is common to create a web page that is composed by a markup language and/or scripting language that specifies the arrangement of web page “constituents”: text, images, hyperlinks, keyboard or mouse input boxes, audio/video works, and embedded applications such as Java applets or ActiveX controls. FIG. 1 shows a block diagram of an example web page 13 as displayed in a web browser display window 10 . For the purposes of the present invention, a web browser is any computer application that interprets a data set in a generalized form suitable for interpretation by many different computer systems to create a display to a user, and a web page is such a data set in any generalized form, including a frame. A web browser is typically designed to interpret human-readable markup languages that describe the arrangement of web page constituents and present said arrangement to the computer user. Such markup language web pages are often sourced from a server computer over a computer network such as the Internet, using HTTP protocol, but other transmission protocols may be used, and web pages may originate from other places such as a storage device in the computer on which the web browser is executing. The markup language described is preferably HTML but it can be any sequence of human readable computer instructions that are interpreted by a web browser to specify the arrangement of both useful information or entertainment and embedded computer programs (Java applets/ActiveX controls). Such currently known markup languages include SGML (Standard Generalized Markup Language), WML (Wireless Markup Language), HDML (Handheld Device Markup Language), and Extensible Markup Language (XML). Other similar languages, some of which are not called “markup” languages, are in development and still more will be developed in the future. For purposes of the present invention, the essential function of the markup language is that it allows an executable program, whether compiled or interpreted or semi-compiled to non human-readable byte-code which is then interpreted, to be loaded by the web browser as a constituent of a web page, and to automatically execute on the device without requiring attention or action by the user while the user is receiving information desired by the user from the web browser. The information typically includes visually displayed information including text, but that is not an essential component for purposes of this invention. The information could be entirely auditory, such as music or spoken words. Markup languages are often accompanied by scripting languages such as JavaScript, JScript, VBScript, or ECMAScript that are human-readable instructions interpreted by the web browser/operating system in order to affect how each web page constituent appears and behaves as a function of time and as a function of user input such as keyboard and mouse movement or clicks. Such scripting languages are often used to coordinate the visual display or operation of the constituents of a web page. This is preferably done using the DOM (Document Object Model) whose essential function is to provide a standard definition of the relationships of various web page constituents and to provide a nomenclature that scripting languages may use to access them. Other similar languages, some of which are not called “scripting” languages, are in development and still more will be developed in the future. For the purposes of the invention, the essential function of the script program is to cause programs on the client machine to detect and respond to keystrokes or mouse clicks that are sent to the web browser, web page, or web page constituents, and to operate on web page constituents in order to change their appearance, keyboard focus, or if they are embedded programs, to communicate messages to the programs. It is common to imbed into a web page an audio/video playout program such as the Microsoft Media Player ActiveX control or RealPlayer ActiveX control. This allows the user to hear or view an audio/video work within the context of the web page without opening a separate application window for the audio/video player program. Sometimes the player program will allow the user to control playout by dedicating certain keys as playout control keys such as pressing the letter “P” to pause or pressing the up or down arrows to increase or decrease volume. Traditional keyboard keys are usually used for these functions because most computers and operating systems do not have specialized keys and corresponding key codes for audio/video playout control. However, it is expected that playout programs will be designed to respond to such specialized keys as they become commonplace on keyboards, as in FIG. 3 , or as auxiliary hand-held keypads, as in FIG. 2 . On computers and operating systems that do not have specialized audio/video control keys, it is common to add a specialized wireless keypad to a computer, and add a specialized program to receive data from said wireless keypad and translate it into the traditional keystrokes which are sent to an audio/video playout application in order to effect the desired playout control. In the preferred embodiment of this invention, the keypad is an infrared remote such as those used to control traditional home entertainment electronics, and the infrared signals are translated to digital codes that are sent to a personal computer through the USB port. However, the remote may alternatively use radio frequency communication to transmit key press information, and the means of communication to a PC may be the serial port, IEEE 1394 port, IrDA port, ISA (Industry Standard Architecture) bus, PCI (Peripheral Component Interconnect) bus, BlueTooth, 802.11, or any other communications port or bus, including those that are still under development or may be developed in the future. Regardless of whether the audio/video playout program detects traditional key events, or specialized audio/video key events, existing operating systems deliver both types of key events to the playout program in the same manner. That is, the window that has the keyboard focus will be the sole window to receive key events. Optionally, the application window with keyboard focus may choose to pass key press events to its “parent” window—the window in which the application window resides. Common operating systems adopt the notion of child windows and parent windows, as shown in FIG. 4 . The topmost window is typically called the “Desktop” window 19 and application displays 40 , 44 have primary windows 41 , 45 that are the child windows of the desktop window 19 . In FIG. 4 , the desktop window 19 is the parent to two child application windows 41 , 45 . Furthermore, any child windows, such as 41 and 45 may act as the parent windows to their own child windows. Windows 42 and 43 are child windows to the parent window 41 . Windows 46 and 47 are child windows to the parent window 44 . In this document, a parent window and its child windows (and their child windows, etcetera) will be referred to collectively as a “window family” designated by the name of the parent. An essential function of this window hierarchy is to provide a clear sequence that describes how user input events, such as key presses or mouse clicks, are processed by applications. When a child window has the keyboard focus, it is the first window to receive key events from the operating system. This window then has the option to pass the key event to its parent window. The parent window may then act on the key event, sometimes by passing the event to its parent. In the preferred embodiment, the operating system is Microsoft Windows 2000, but the invention applies to all operating systems that implement the same parent-child window hierarchy and share this system of key event propagation. Most audio/video playout control programs exist as stand-alone applications. That is, they have their own primary application window 41 , 45 . This means that even if the application has a child window that has the keyboard focus, the parent window will receive key press notification from the child window as long each as child window passes key press events up to its parent window. To allow dedicated audio/video playout keys to function at all times, existing playout programs consist of only a primary application window or they ensure that every user-selectable child window passes playout control key events to its parent. Then the primary application window, when receiving key events, will always affect audio/video playout. In this way, as long as one of the application's windows has the keyboard focus, the desired playout control will occur as a result of playout key presses. Web Page Embedded Playout Programs This technique becomes less effective when the audio/video playout program is not a stand-alone application, but instead is embedded in a web page. As shown in FIG. 1 , a web page embedded program window 50 is a child window of the web page window 13 . This means that, unless the window of the web page embedded program has the keyboard focus, or one of its child windows has the keyboard focus, the embedded program will not receive keyboard events. For example, in the preferred embodiment, the web browser is Microsoft's Internet Explorer 5.5. In this web browser, when a web page is first opened, the web page window 13 automatically receives the keyboard focus. Since the embedded audio/video playout program window 50 is a child window of the web page window 13 , it will not receive any key press events. This can be confusing to a user if the web page presents an audio/video work as the central constituent of the web page. Even for users who understand that the embedded programs must have the keyboard focus to receive key press events, it is inconvenient for the user to have to select the audio/video application in order to control playout using key presses. Web pages often consist of text, graphics, or hyperlinks that the user may want to click, for example to select text for copying, or to follow a hyperlink. This clicking action will cause the web page window 13 to receive the keyboard focus, and keyboard key events will no longer be delivered to the embedded application. This is particularly inconvenient for the users who may inadvertently set the keyboard focus to a window that is not the audio/video player application, and then step away from the computer and attempt to perform playout control using a hand-held remote keypad. Beyond the inconvenience, it may in fact be impossible or extremely difficult for the user to set the keyboard focus to the player program window 50 due to the fact that some web pages may choose to hide the player program window 50 from the user by setting its height and width dimensions to zero or some small number. In order to solve this problem, two solutions are presented. 1. Embedded Program or Associated Script Frequently Requests Keyboard Focus In a first embodiment of the invention, as shown in FIG. 1 , the web-embedded audio/video application is the only web page constituent that needs to process and respond to key events. In this case, the embedded player includes instructions to continuously request they keyboard focus from the operating system/web browser. The rate is preferably slow enough to ensure minimized processor usage, but high enough to ensure lively user interface responsiveness, such as between 100 Hz and 1 Hz in an Intel Pentium processor running at 300 MHz. In this manner, even if the user clicks on a part of the desktop window 19 or a part of the web page window 13 outside of the audio/video program window 50 , the keyboard focus will quickly be redirected to the proper program window 50 . There may, in fact be other embedded programs on this web page which are capable of receiving the keyboard focus by user-specification. However, as long as those programs do not need to react to keyboard input, it is not a problem for the user if the keyboard focus is immediately reassigned to the audio/video playout program window. While some operating systems and web browsers, such as Windows 2000 and Internet Explorer 5.5, allow the embedded application itself to obtain the keyboard focus by request, it is also possible to use a scripting language to cause the web browser to set the keyboard focus to a specific web page constituent. Thus, in a preferred embodiment, the JavaScript language instructs the web browser to set the keyboard focus to the embedded audio/video program window 50 on a continual basis. Note that in this solution, the embedded application does not include instructions that may affect its keyboard focus relative to other web page constituents. Instead, the web browser, by interpreting the web page markup and scripting languages, will set the keyboard focus to the appropriate web page constituent. This is preferred because keyboard focus instructions are not included in the embedded program. This enables the same program to be used in a wide variety of web pages, allowing the web page composer freedom to determine with a script how and if the embedded audio/video application should have the keyboard focus. In this manner, the same audio/video application can be utilized on a wide number of web pages under different usage scenarios. 2. Browser and all Constituents Instruct Audio/Video Control Program The above solution has a drawback when there are other web page constituents besides a playout control program to which the user may want to intentionally assign the keyboard focus. For example, in FIG. 1 , a web page may incorporate a search function where the user may type in to a key entry window 101 that is a child window of the web page window 13 rather than the window of the playout control program. In this arrangement, it would be undesirable to continuously assign the keyboard focus to the playout control program window 50 because the user may want to place the keyboard focus in the text box window 101 in order to type in, for example, the title of an audio/video work that the user would like to see or hear. In this case, a better approach is to write scripting language instructions that instruct the browser to use a window within its window family to intercept and interpret key events intended for web page constituents that are not part of the embedded audio/video player program. If the web browser were capable of redirecting key events that are directed to any child window of the browser window to an embedded program, it would be sufficient to use a script to cause the browser to simply capture all key events to all web page constituents, and redirect key events resulting from audio/video control key events to the audio/video player window 50 . However, for security reasons, known web browsers do not allow scripting programs or embedded applications to communicate key or mouse events to other web page constituents (which is how a redirection of a key event would be done). The solution of this invention is to place within the embedded audio/video control program a means for the scripting language to control playout by accessing “methods” of the audio/video program which are made available to the scripting language by way of the Document Object Model specification. The preferred implementation uses the JavaScript language to cause the browser to use one of the browser family windows to capture all key events, then detect whether each key event is from an audio/video control key and, in the event that it is, to activate the corresponding audio/video control action by calling the available methods of the web-embedded application. However, although contemporary browsers are able to intercept key events sent to regular web page constituents such as text boxes, they are unable to intercept key events that are delivered directly by the operating system to web embedded programs which may have their own windows within the browser family of windows and may request the keyboard focus. In this case, each web embedded program on the web page that may have the keyboard focus must be written to detect audio/video control key events and then notify the web-embedded audio/video player to perform the corresponding playout control action via the DOM method described above. Use of Uncommon Text Key Codes An important extension of the invention for both of the above embodiments addresses the problem that most existing web browsers and operating systems do not have specialized key codes for audio/video playout control keys. In this case, existing audio/video playout programs use traditional keys, such as “P” for play, “S” for stop, etc. to control playout. Another reason to use such keys is that browsers and scripting languages of present operating systems may not yet be capable of processing audio/video control keys. However, using traditional keyboard buttons to control audio/video playout presents problems for the embodiments presented above. This is because these keys may be needed to indicate input into another web page constituent, such as a text box, for purposes other than playout control. If a playout control key is pressed while entering text data, playout control will inadvertently be activated. An extension to the invention solves this problem by using key codes that the browser and scripting language can process, but that would not normally be used when typing into a text box. The following table is an example of such key codes: Playout Control Substitute Character ASCII Button Representation Code PLAY { 123 STOP } 125 PAUSE | 124 VOLUME UP {circumflex over ( )} 94 VOLUME DOWN — 95 REWIND < 60 FAST FORWARD > 62 Thus, a JavaScript program can intercept these keys when typed into a text box and perform the corresponding playout control action using the Document Object Model to access the playout program. As described above, any other embedded program designed to receive text input should be written to receive the input from the browser in the form of a DOM command rather than key events from the operating system so that these unusual characters will not appear as text in the program. Alternatively, the script program should cancel the key event, if possible, to ensure that it is not also interpreted as a key that is intended for the text box. Otherwise the character will appear in the box and confuse the user. Using such non-traditional key characters for playout control might at first be considered confusing to the user. However, the intention of this invention is for it to be used in conjunction with a specialized “wedge” program that interfaces with the audio/video playout control keyboard and translates each detected key-press to the key events in the table above. Thus, the user does not need to remember these specialized key codes. Instead the user simply presses a playout control key, which is translated to the proper key code and delivered to the window that has the keyboard focus. A problem that arises here is that a web page composer may wish to embed an audio/video playout program that does not detect specialized keys such as those presented in the above table but nevertheless can obtain the keyboard focus if selected by the user. Such as program would be designed to work with non-key event controls as described above. If such a program were used with the above system and the user were to explicitly set the keyboard focus to the audio/video playout program and then press a playout control key, nothing would happen. The playout program would not recognize these keys, and contemporary web page script programs cannot intercept key events directed to embedded programs. A solution to this problem is to write the web page script such that if the audio/video playout window receives the keyboard focus, the script will immediately reassign the keyboard focus to the web page window 13 so that the above described processes can take over. Control of Audio/Video Keyboard Focus Whether Inside or Outside of a Web Browser. Unfortunately, none of the above embodiments solves the problem of a user wanting to enter text input in one program window, and send audio/video keyboard input to a different program window without changing the text keyboard focus. For example (see FIG. 5 ), the user may want to execute a word processing program 70 in the foreground, and at the same time execute audio/video playout programs in background windows 72 , 73 . A user might work at the computer using the word processor program, but occasionally step away from the computer and desire to use an audio/video control keypad to control a background audio/video playout program. Or one user may be word processing on the computer while a cohort controls a background audio/video playout program using a hand-held remote. The following embodiments of the invention allow the audio/video keyboard focus to be set to any number of computer program windows. This is accomplished by treating the audio/video keyboard focus as a separate keyboard focus that is not set in the same way as the text keyboard focus. In the following embodiments, any number of computer programs can receive the audio/video keyboard focus without requiring reassignment of the text keyboard focus. Such programs may be embedded in a web page 73 or they may execute as applications 72 that are independent of a web browser. In these embodiments, one program may have the audio/video keyboard focus, while another program maintains the text keyboard focus. Thus, audio/video control key events are delivered to a single audio/video playout program 72 or 73 , and text keystrokes are delivered in the common way to the foreground window 70 that has the text keyboard focus. 3. Multiple Keyboard Focuses Added to Existing Operating Systems For security reasons, modern operating systems such as Windows 2000 do not allow programs to send key events to any window except the foreground window, nor do they allow programs to change the text keyboard focus between executing programs. Additionally, operating systems that have key event codes for audio/video control keys deliver such event codes to the window with the keyboard focus. Thus, to communicate audio/video control key events to a window that does not have the keyboard focus, it is necessary to deliver audio/video key events by another means. In a preferred embodiment, Microsoft's Component Object Model (COM) is used for auxiliary key event delivery. However, other inter-process communication methods, such as shared memory, pipes, sockets, CORBA, RMI, or Microsoft's general-purpose window message passing, may be used instead. In existing computers with audio/video keyboards, the wedge program receives information from the audio/video key hardware and translates that information into key events that are delivered to the operating system, which in turn delivers the key events to the window that has the keyboard focus. In this embodiment of the invention, as shown in FIG. 5 , to deliver key events to various program windows, the wedge program 71 uses Microsoft COM 74 . First, the wedge program must know which programs are able to receive audio/video key events (herein referred to as “event client” programs 72 , 73 ). Since there may be any number of such programs, at startup each event client uses the COM architecture to locate and register its existence with the wedge “server” program 71 . In this way, the wedge server 71 can keep track of all programs that are capable of receiving audio/video key events. An important part of this registration process is that the client program 72 , 73 provides the wedge server with information (sometimes called a “reference”, “handle”, or “pointer”) that allows the wedge server 71 to find and pass key event information to the event client program 72 , 73 . By keeping a reference to every program that needs to receive audio/video key events, the wedge server 71 can deliver key events to any one of these known key event clients 72 , 73 . Similarly, an event client program 72 , 73 notifies the wedge server when it would like to be removed from the list of event client programs. This is typically done when the event client program terminates execution. Alternatively, the wedge server may remove the event client from its list upon detecting that the event client program is no longer executing. When an audio/video key is pressed, only one of the event client programs is notified of the key event, and this program is considered to have the “audio/video keyboard focus”. This simplifies the user interface by ensuring that a single audio/video key-press controls only one audio/video playout program at a time. Accordingly, there must be a means of specifying which program is to receive the audio/video keyboard focus. The default behavior is for the audio/video keyboard focus to be assigned to the same window that has the text keyboard focus. That is, when the user sets the text keyboard focus to a program window, that program window also receives the audio/video keyboard focus. This is a desirable default behavior because it frees the user from having to think about the assignment of the audio/video keyboard focus most of the time. However, the user may override this default behavior in order to set the audio/video keyboard focus to a window other than the window with the text keyboard focus. To implement the above method, the wedge server 71 in default mode sends audio/video key events to the operating system, which passes them to the window with the text keyboard focus. When the user selects a particular window to retain the audio/video keyboard focus (for example, by mouse-clicking on a designated button in that window), the wedge server uses the COM protocol to pass audio/video key events to the application specified by the user, regardless of which application window in the foreground has the text keyboard focus. There are several user interfaces that can allow the user to specify which window is to retain the audio/video keyboard focus. One method is for each event client program to present the user with a mouse-clickable button that, when activated, causes the event client 72 , 73 to notify the wedge server 71 program that audio/video key events should be delivered only to that event client program. However, this method has the drawback that a malicious event client program may notify the wedge server that it is to hold the audio/video keyboard focus even if the user has not requested this behavior. An alternative user interface eliminates this problem by having the user interact with the wedge server 71 program window in order to specify which program is to receive the audio/video keyboard focus. Each event client program, when registering its existence with the wedge server, specifies a word or phrase that identifies the program to the user (preferably, the word or phrase in the program's main window title bar). The user then observes the wedge server 71 window which displays a list of programs that may hold the audio/video keyboard focus. The user indicates which one of these programs is to hold the audio/video keyboard focus by moving the mouse over the corresponding identifying phrase and clicking the mouse. Regardless of the user interface presented to the user, when the user specifies a window to hold the audio/video keyboard focus, any other window that presently has the audio/video keyboard focus immediately loses the focus in favor of the more recently specified window. Also, there is a user interface means for the user to specify that the audio/video focus should return to the default mode where the audio/video keyboard focus is the same as the text keyboard focus. This can be accomplished several ways, such as including a mouse-clickable button in the wedge server 71 window that causes the server to enter the default mode. Or the same user interface that is used to specify the selection of the audio/video focus may be used to turn off the focus to that window. That is, if the user selects a window for the audio/video keyboard focus that already has the focus, this is interpreted as a desire to turn the focus off of that window, and enter the default mode. Thus, according to the above methods, the user may turn the audio/video keyboard focus on or off for any audio/video key event client program, and only one such application may hold the audio/video keyboard focus at any time. 4. Multiple Keyboard Focuses Built into an Improved Operating System It is common for text keyboard focus and key event processing to be built into the operating system so that another program running on the operating system cannot maliciously change text keyboard focus from the user's specification. In the embodiment described above, the wedge server and event client programs are not built into the operating system, thus they are subject to interference from other programs. Furthermore, the above embodiment requires significant work on the part of playout program developers in order to ensure that their programs comply with the wedge server event delivery architecture. Also, the above embodiment requires special registration methods to allow the wedge server program to gain a reference to each application that may receive audio/video key events. In contrast, the operating system is responsible for loading computer programs, thus it already has a means of finding and passing information to all executing programs. Thus, in a preferred embodiment, the audio/video keyboard focus is incorporated directly into the operating system, so that neither the user, nor another program may inadvertently or intentionally misdirect the delivery of audio/video key events or the assignment of the audio/video keyboard focus. In this preferred embodiment, audio/video key events are delivered in a similar manner as regular text keyboard events. This means that programs running on the operating system require minimal additional programming effort in order to interpret audio/video key events, since they can use the same software architecture as regular key event processing. Audio/video keyboard focus selection is built into the operating system to prevent malicious programs from changing the audio/video focus to a window that was not specified by the user. In contrast to existing operating systems, the audio/video keyboard focus behaves in the manner described by the previous embodiment. That is, by default the audio/video keyboard focus follows the text keyboard focus. However, the user may set the audio/video keyboard focus to another computer program. For example, in Microsoft Windows the text keyboard focus can be set by moving the mouse over a program window and clicking the left mouse button. If the right button is clicked, a “pop-up” window displays various actions to perform on that window (such as minimize, close, or maximize). One of such options could be to hold the audio/video keyboard focus. Alternatively, just as most programs include mouse clickable buttons in their title bars in order to minimize, maximize or close the window, an additional button may be included to turn on or off the audio/video focus to that window. Or a special key or combination of keys (such as Ctrl-Alt-Insert) may be pressed while the desired window is in the foreground, which causes the foreground window to hold the audio/video focus if another window is subsequently assigned the text keyboard focus. Alternatively, a special key or combination of keys may be reserved to cycle through all executing computer programs that can receive the audio/video focus, where each time the special key is pressed, the next executing program is assigned the audio/video focus (perhaps indicated visually by a different color window border). This particular approach is most usefully applied using the keys on a hand-held keypad so that the audio/video focus can be selected from a distance without using the mouse or text keyboard. Distinction Between Local Key Presses and Remote Key Presses Contemporary computer systems may include either a keyboard designed for short-range (local) usage (such as a traditional text keyboard as in FIG. 3 ) or a keyboard designed for long-range (remote) usage (such as a hand-held remote as in FIG. 2 ) or both such keyboards. Systems with such dual keyboard capabilities make no attempt to indicate to audio/video playout programs whether a key press occurred on a short-range keyboard versus a long-range keyboard. This is valuable information to a playout program, because a different mode of operation may be desirable depending on which keyboard is being used. For example, a video playout program may automatically enter a full-screen mode if it detects that the user has pressed a key on a long-range (remote) keyboard. Or an audio playout program may temporarily display a large on-screen indicator (more easily viewable from a distance) of the audio output volume if a volume adjustment key is pressed on a long-range keyboard. Rather than requiring the user to notify a program to increase its display size if a long-range keyboard is being used (as would be done on common systems), it is better if the program is notified with each key-press whether the key originated from a short-range or long-range keyboard. This is accomplished by adding just one bit to each key event message. A “one” bit indicates that the key originated from a long-range keyboard, and a “zero” bit indicates that the key originated from a short-range keyboard. Alternatively, an entirely new set of key codes may be used for each key on a long-range keyboard, if those keys exist in duplicate on short-range keyboards. In this manner, the user may easily switch between short-range keyboard use and long-range keyboard use, and the playout program is notified of this change by each new key press. There are several ways to improve a computer program's user interface if the program is able to detect the difference between local versus remote key presses. For example, the user may run a video playout program that displays a video clip in a window. When a remote key press is detected, the program enlarges the video to occupy the entire screen to make long-range viewing easier. This is done until a local key press is detected, and the playout program returns to its original size and location on the screen. Or a user may run an audio playout program that normally displays its volume setting in a small graphical indicator. When the user presses a remote button to change the volume, the program displays a large, full-screen volume indicator that can be seen from large distances. This indicator is displayed for a programmable amount of time (for example 0.5 to 5 seconds) in order to allow the user to see the volume setting. After this pre-programmed time elapses, the program no longer displays the large volume indicator, so that other on-screen graphics may be viewed more easily. This same method can be employed when the user presses buttons to fast-forward or rewind an audio/video clip. In this case, the on-screen indicator is a large horizontal “progress bar” whose degree of opaqueness indicates the current point of playout in the clip. That is, if the song is halfway through playout, the progress bar is half opaque, and the other half is the screen's background color. The above described embodiments of the invention are only examples. Many other embodiments are possible. The scope of the invention should not be limited to the above embodiments but should only be limited by the following claims:

Computer software allowing enhanced control of the playout of audio/video works on a computer system. In various embodiments, the software allows key events from dedicated audio/video keys, whether part of a full sized keyboard or on a hand held remote, to control the actions of an audio/video playout program without requiring the user to direct the key event focus of the operating system to the audio/video playout program. Also, the invention distinguishes between key presses from a local, full sized keyboard and key presses from a remote keyboard so that the audio/video playout program can enlarge its screen display when a key event is received from the remote keyboard. In one embodiment, the invention constantly instructs the operating system to move the focus to the audio/video playout program. In another embodiment, if the focus is received by any of various windows in a display, software associated with the window forwards to the audio/video playout program any key events received from audio/video keys. In a third embodiment, audio/video key event data is routed to the audio/video playout program by a method that does not use the key event features of the operating system, such as by using a key board wedge server program to serve key events to audio/video client programs. In a fourth embodiment, the operating system is modified so that it has two separate focuses, one for a text keyboard and a second focus for audio/video keys.

FIELD OF THE INVENTION [0001] This disclosure relates to the field of communication, and in particular to a cloud service consuming method, a cloud service message packet, a cloud service broker and a cloud system. BACKGROUND OF THE INVENTION [0002] As a new method for sharing the infrastructure, cloud computing can connect huge system pools to provide various IT services. [0003] Cloud computing can be usually classified as broad cloud computing and narrow cloud computing. In the above, the broad cloud computing means the delivery and usage pattern of services, and it means getting the needed services through the network according to demand and in an easily extendable way. Such services can be services related to IT, software and internet, and also can be any other services. [0004] At present, as the capability and interface between cloud computing are incompatible, when a cloud service requester (consumer) needs to use the cloud service, the cloud service requester has to send a request to different cloud service providers in order to get the cloud service information of the cloud service providers. If the cloud service provider is unable to provide the cloud service requested by the consumer, the consumer still needs to send a request to other cloud service providers to get the cloud service information till a cloud service provider that can provide the cloud service requested by the consumer. For example, if the consumer needs to use the cloud service provided by Google, but the consumer does not know that such cloud service is available in Google, and then the consumer first requests Amazon for the cloud service. At this moment, as Amazon is unable to provide the cloud service for the consumer, so the consumer can only respectively send a request to other cloud service providers till send a request to Google. It is thus clear that such cloud service access way is inconvenient for the consumer to request and use the cloud service. Also, as the consumer needs to send requests to different cloud service providers for many times, the system resources are wasted, and the system efficiency is low. SUMMARY OF THE INVENTION [0005] This disclosure provides a cloud service consuming method, a cloud service message packet, a cloud service broker and a cloud system, to solve the problems of wasted system resources and low system efficiency caused as the consumer needs to send requests to different cloud service providers for many times. [0006] According to one aspect of this disclosure, a cloud service consuming method is provided, comprising: a cloud service broker receiving a cloud service consumer request sent by a cloud service requester; and the cloud service broker returning a cloud service consumer response to the cloud service requester. [0007] Preferably, the step that the cloud service broker receiving the cloud service consumer request sent by the cloud service requester comprises: the cloud service broker receiving a cloud service consuming interface message packet sent by the cloud service requester, wherein the message packet carries the cloud service consumer request, and the cloud service consumer request comprises cloud service information requested by the cloud service requester; and the step that the cloud service broker returning a cloud service consumer response to the cloud service requester comprises: the cloud service broker returning a cloud service consuming interface message packet to the cloud service requester, wherein the message packet carries the cloud service consumer response used for indicating cloud service information provided by the cloud service broker, and the cloud service information comprises information of cloud computing services and/or resources provided by a cloud service provider that is selected and/or adapted by the cloud service broker for the cloud service requester. [0008] Preferably, the cloud service requester accesses and/or controls the cloud service provided by the cloud service provider through the cloud service broker, and the accessing and/or controlling of the cloud service provided by the cloud service provider comprises at least one mode of: creating, reading, updating, deleting, executing, copying, moving, selecting and collecting. [0009] Preferably, the cloud service consuming interface message packet comprises information of one of: request information and response information. [0010] Preferably, the cloud service consuming interface message packet is transmitted in at least one mode of: Hyper Text Transport Protocol (HTTP) format, Session Initiation Protocol (SIP) format, Representational State Transfer (REST) format, Simple Object Access Protocol (SOAP) format, Extensible Markup Language (XML)-based Hypertext Markup Language Version 5 (XHTML5) format, Application Programming Interface (API) format, and specific command format. [0011] Preferably, the information contents of the cloud service consuming interface message packet are described in at least one of the following formats: XML, JavaScript Serialized Object Notation (JSON) and specific format. [0012] According to another aspect of this disclosure, a cloud service consuming interface message packet is also provided and applied in information interaction of cloud service consuming between a cloud service broker and a cloud service requester, comprising information of one of: request information and response information. [0013] Preferably, the request information comprises information of at least one of: session information, Infrastructure as a Service (IaaS) information, Data Storage as a Service (Daas) information, Platform as a Service (PaaS) information, and Software as a Service (SaaS) information. [0014] Preferably, the response information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, and SaaS information. [0015] Preferably, the cloud service consuming interface message packet is transmitted in at least one mode of: HTTP, SIP, REST, SOAP, XHTML5, API, and specific command format. [0016] Preferably, the information contents of the cloud service consuming interface message packet are described in at least one format of: XML format, JSON format and specific format. [0017] According to still another aspect of this disclosure, a cloud service broker is also provided, comprising: a cloud service consuming interface module, configured to realize the cloud service consuming between the cloud service requester and the cloud service broker, comprising: a receiving module, configured to receive a cloud service consumer request sent by the cloud service requester; and a feedback module, configured to send a cloud service consumer response to the cloud service requester, wherein the cloud service consumer response comprises cloud service information provided by the cloud service broker. [0018] Preferably, the receiving module is configured to receive a cloud service consuming interface message packet sent by the cloud service requester, wherein the message packet carries the cloud service consumer request, and the cloud service consumer request comprises the cloud service information requested by the cloud service requester; and the feedback module is configured to return a cloud service consuming interface message packet to the cloud service requester, wherein the message packet carries the cloud service consumer response used for indicating the cloud service information provided by the cloud service broker, and the cloud service information comprises information of cloud computing services and/or resources provided by a cloud service provider that is selected and/or adapted by the cloud service broker for the cloud service requester. [0019] Preferably, the cloud service consuming interface message packet comprises request information and response information. [0020] Preferably, the request information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, and SaaS information; and the response information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, and SaaS information. [0021] Preferably, the cloud service consuming interface message packet is transmitted in at least one mode of: HTTP format, SIP format, REST format, SOAP format, XHTML5 format, API format, and specific command format; and information contents of the cloud service consuming interface message packet are described in at least one format of: XML format, JSON format and specific format. [0022] According to yet another aspect of this disclosure, a cloud system is also provided, comprising: a cloud service requester, configured to send a cloud service consumer request to a cloud service broker, wherein the cloud service consumer request comprises cloud service information requested by the cloud service requester; and receive a cloud service consumer response returned by the cloud service broker, wherein the cloud service consumer response comprises cloud service information provided by the cloud service broker; and the cloud service broker, comprising: a cloud service publishing interface module, configured to subscribe to information of cloud computing services and/or resources provided by a plurality of cloud service providers; a cloud service consuming interface module, configured to provide a consuming interface for the cloud service requester to access the cloud service provider; a cloud service processing module, configured to process the cloud service consumer request of the cloud service requester; a cloud service adapting module, configured to adapt the cloud computing services and/or resources provided by the cloud service provider to the cloud service requester according to the cloud service consumer request; and the cloud service provider, configured to publish the cloud service information of the cloud service to the cloud service broker, and provide the cloud service needed by the cloud service requester. [0023] Preferably, the cloud service consuming interface module comprises: a receiving module, configured to receive the cloud service consumer request sent by the cloud service requester, wherein the cloud service consumer request comprises the cloud service information requested by the cloud service requester; and a feedback module, configured to send the cloud service consumer response to the cloud service requester, wherein the cloud service consumer response comprises the cloud service information provided by the cloud service broker. [0024] In this disclosure, the cloud service broker uniformly receives the consumer request from the cloud service requester, and selects and adapts the cloud computing service and/or resource of the proper cloud service provider for the cloud service requester according to the cloud service information of the cloud service provider that the cloud service broker obtained or subscribed to. Therefore, the cloud service requester only needs to send a request once to the cloud service broker to realize the corresponding cloud service access. The problem that the cloud service requester sending cloud service requests for many times causes wasted system resource and low system efficiency is avoided. The utilization ratio of system resources is effectively improved, and the system efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS [0025] Drawings described herein are provided for further understanding of this disclosure and form one part of the application. The exemplary embodiments of this disclosure and descriptions thereof are used for explaining this disclosure and do not constitute improper limit to this disclosure. In the drawings: [0026] FIG. 1 illustrates a usage scenario diagram of a cloud service broker according to the embodiment of this disclosure; [0027] FIG. 2 illustrates a step flow chart of a cloud service consuming method according to the embodiment of this disclosure; [0028] FIG. 3 illustrates a step flow chart of another cloud service consuming method according to the embodiment of this disclosure; [0029] FIG. 4 illustrates a signaling flow chart of the cloud service consuming method according to the embodiment shown in FIG. 3 ; [0030] FIG. 5 illustrates a structure block diagram of a cloud service broker according to the embodiment of this disclosure; and [0031] FIG. 6 illustrates a structure block diagram of a cloud system according to the embodiment of this disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS [0032] This disclosure will be described in details hereinafter with reference to drawings and embodiments. It should be noted that embodiments in the application and features in the embodiments can be combined with each other if there is no conflict. [0033] With reference to FIG. 1 , a usage scenario diagram of a cloud service broker according to the embodiment of this disclosure is illustrated. [0034] The cloud service broker (also called cloud service gateway) provides brokering services for various cloud service providers, and cloud provided by the cloud service providers can be private cloud, community cloud, public cloud or hybrid cloud. The cloud service broker can provide services including but not limited to arbitration service, proxy service, monitoring service, transition service, porting service, control service, deployment service, shielding service, permutation service, security service and synthesis service or the like between various cloud service providers (cloud computing service providers) such as private cloud, community cloud, public cloud or hybrid cloud and cloud service requesters (consumers) such as WEB service, application or user (enterprise user and individual consumer). The cloud service broker can abstract the incompatible capabilities and interfaces between different cloud computing services, and provide public, open and standard brokering services for consumers. It can solve the problem of incompatibility between different cloud platforms/cloud computing services, provide optimal one-stop services for consumers, and fully meet the demands of consumers. [0035] As shown in FIG. 1 , the cloud service broker is located between the cloud service requesters and the cloud service providers. Cloud service requesters such as WEB service, application or user (enterprise user and individual consumer) can access the cloud computing services and/or resources provided by the cloud service providers such as private cloud, community cloud, public cloud or hybrid cloud through the cloud service broker. It can be that the cloud service broker itself is not a cloud computing platform, and the cloud service broker also can be implemented by the cloud computing technology. [0036] The cloud service broker gets information of various cloud computing services and/or resources provided by the cloud service providers through the cloud service publishing function, and stores the information. The cloud service broker selects and/or adapts the cloud computing services and/or resources provided by the proper cloud service providers for the cloud service requesters, so that the cloud service requesters do not have to access different cloud service providers for many times. Thus, on one hand, the cloud service broker provides convenience for the cloud service requesters to use the cloud services, and on the other hand, it also provides a uniform management and usage platform for cloud service information provided by the cloud service providers. [0037] Through the cloud service publishing function, the cloud service broker can subscribe to information of the cloud computing services and/or resources published and supported by the cloud service providers such as private cloud, community cloud, public cloud or hybrid cloud. The cloud service providers such as private cloud, community cloud, public cloud or hybrid cloud can publish a notification of information of the cloud computing services and/or resources supported by themselves to the cloud service broker. [0038] Through the cloud service consuming function, the cloud service broker can, according to the consuming request of the cloud service requesters, select and/or adapt information of the cloud computing services and/or resources published and supported by the cloud service providers such as private cloud, community cloud, public cloud or hybrid cloud. [0039] With reference to FIG. 2 , a step flow chart of a cloud service consuming method according to embodiments of this disclosure is illustrated, comprising the following steps. [0040] S 202 : A cloud service broker receives a cloud service consumer request sent by a cloud service requester; and [0041] the cloud service consumer request comprises cloud service information requested by the cloud service requester, for example, the request for usage of cloud storage service or the like. [0042] S 204 : The cloud service broker returns a cloud service consumer response to the cloud service requester. [0043] In the above, the cloud service consumer response comprises cloud service information provided by the cloud service broker. That is, the cloud service broker has selected and/or adapted the information of the cloud computing services and/or resources provided by a proper cloud service provider for the cloud service requester. The cloud computing services and/or resources provided by the proper cloud service provider can be real cloud computing services and/or resources of the cloud service provider, and also can be virtual cloud computing services and/or resources, i.e., the cloud computing services and/or resources of the cloud service provider processed by the cloud service broker (such as the services described hereinafter: the proxy service, transition service, porting service, shielding service, permutation service and synthesis service). [0044] According to the cloud service consumer request, the cloud service requester accessing and/or controlling the cloud services provided by the cloud service provider through the cloud service broker can include at least one of the following operation ways: creating, reading, updating, deleting, executing, copying, moving, selecting, collecting or the like. Through the above operations, different demands of the cloud service requester on cloud services are effectively met. [0045] In the related technologies, when the cloud service requester needs cloud services, the cloud service requester can need to access different cloud service providers for many times. As a result, the system resources are wasted, and the system efficiency is low. Through this embodiment, the cloud service broker selects and/or adapts a proper cloud service provider for the cloud service requester according to the stored cloud service information of various cloud service providers, so that the cloud service requester can avoid accessing different cloud service providers for many times. The system resources are effectively saved, and the system efficiency is improved. [0046] The embodiment of this disclosure provides a cloud service consuming interface message packet, which is used by the cloud service requester to access the cloud service. [0047] The cloud service consuming interface message packet is transmitted by using at least one of the following ways: HTTP, SIP, REST, SOAP, XHTML5, API, and specific command. The information contents of the cloud service consuming interface message packet are described in at least one of the following formats: XML, JSON and other specific formats. [0048] The cloud service requester can carry an XML message packet, a JSON message packet or message packets in other specific formats in ways of HTTP, SIP, REST, SOAP, XHTML5, API and specific command, to access and/or control the cloud service and/or resource information provided by the cloud service provider through the cloud service broker. [0049] Further, the cloud service requester accessing and/or controlling the cloud services provided by the cloud service provider through the cloud service broker can include at least one of the following operation ways: creating, reading, updating, deleting, executing, copying, moving, selecting, collecting or the like. When the cloud service requester adopts HTTP, POST, GET, PUT, DELETE, COPY, HEAD, MKCOL, MOVE, OPTIONS or the like can be used. [0050] The specific protocol interface method of the cloud service consuming interface message packet is as follows. [0051] The cloud service consuming interface message packet csb-consumer comprises elements such as request and response. [0052] In the above, <csbconsumer> is a root element, comprising sub-elements such as <CloudServiceRequest> and <CloudServiceResponse>. [0053] (1) Sub-element <CloudServiceRequest> is a cloud service consumer request element, through which the cloud service requester (consumer client) initiates a consumer request to the cloud service broker, comprising one or more of the following attributes and sub-elements: [0054] sub-element: <session-info>, session information of the cloud service requester consuming the cloud service resources through the cloud service broker; [0055] sub-element: <IaaS>, Infrastructure as a Service (IaaS) information of the cloud service; [0056] sub-element: <DaaS>, Data Storage as a Service (DaaS) information of the cloud service; [0057] sub-element: <PaaS>, Platform as a Service (PaaS) information of the cloud service; and [0058] sub-element: <SaaS>, Software as a Service (SaaS) information of the cloud service. [0059] (2) Sub-element <CloudServiceResponse> is a cloud service consumer response element, through which the cloud service broker returns a consumer response to the cloud service requester, comprising one or more of the following attributes and sub-elements: [0060] attribute: status codes, indicating the response statuses, such as 200: OK, 400: syntax error, 408: resources cannot be found, 409: resources cannot be updated, 410: resources cannot be removed, 420: unsupported attribute or element; [0061] attribute: reason; [0062] sub-element: <session-info>, session information of the cloud service requester consuming the cloud service resources through the cloud service broker; [0063] sub-element: <IaaS>, IaaS information of the cloud service; [0064] sub-element: <DaaS>, DaaS information of the cloud service; [0065] sub-element: <PaaS>, PaaS information of the cloud service; and [0066] sub-element: <SaaS>, SaaS information of the cloud service. [0067] In the above, [0068] (A)<session-info> is a session information element, and specifically is session information of the cloud service requester consuming the cloud service resources through the cloud service broker. The cloud service requester can monitor the life cycle that the cloud service broker consumes the cloud service resources. <session-info> is initially returned when <CloudService Response> responds successfully, and <CloudServiceRequest> uses <session-info> to process the session information of the cloud service resources. <session-info> comprises: [0069] sub-element: <session-id>, cloud service resource session identifier associated with the cloud service requester and the cloud service broker; [0070] sub-element: <seq>, sequence number; [0071] sub-element: <expires>, activated duration of the cloud service resources, in unit of second; only used for <CloudServiceResponse>; and [0072] sub-element: <action>, requested actions: update: update the session, remove: remove the session; only used for <CloudServiceRequest>. [0073] (B)<IaaS> is an infrastructure as a service information element, comprising one or more of the following common attributes and sub-elements: [0074] <compute>: computing resource sub-element, comprising architecture (CPU architecture) attribute, cores (CPU cores) attribute, hostname attribute, speed (CPU speed) attribute, memory attribute, status attribute (the status of the computing resource), and comprising the supported operations of start, stop, restart and suspend; [0075] <Network>: network resource sub-element, comprising vlan 802.1q identity attribute, label attribute (label-based vlan), address attribute (network address), gateway attribute (gateway address), allocation attribute (address allocation mechanism), and comprising the supported operations of down and up; [0076] <Storage>: storage resource sub-element, comprising size attribute (size of drive), status attribute (status of storage resources), and comprising the supported operations of backup, offline, online, resize and snapshot; and [0077] <Virtualization>: virtualization sub-element, comprising attributes and sub-elements such as DiskSection (disk information), NetworkSection (network information), DeploymentOptionSection (deployment option information), VirtualSystemCollection (virtual system collection information), VirtualSystem (virtual system information), OperatingSystemSection (operating system information), InstallSection (system install information), ResourceAllocationSection (resource allocation information) and StartupSection (system startup information) and corresponding executed operations. [0078] (C)<DaaS> is a data storage as a service information element, comprising one or more of the following common attributes and sub-elements: [0079] <DataObject>: data object sub-element, comprising metadata, mimetype, objectURI (universal resource identifier), objectID, parentURI, domainURI, capabilitiesURI, Location, value and the like, and comprising the supported operations of create, read, update, delete and the like; [0080] <Container>: container sub-element, comprising metadata, objectURI, objectID, parentURI, domainURI, capabilitiesURI, location, exports interface protocol (Open Cloud Computing Interface (OCCI) interface, internet Small Computer System Interface (iSCSI) protocol, Network File System (NFS), and Fiber Channel over Ethernet (FCoE) protocol), snapshots, children and the like, and comprising the supported operations of create, read, update, delete and the like; [0081] <Domain>: domain sub-element, comprising metadata, objectURI, objectID, parentURI, domainURI, capabilitiesURI, location, children or the like, and comprising the supported operations of create, read, update, delete and the like; [0000] <Queue>: queue sub-element, comprising metadata, objectURI, objectID, parentURI, domainURI, capabilitiesURI, queueValues, location or the like, and comprising the supported operations of create, read, update, delete and the like; and [0082] <Capabilities>: capabilities sub-element, comprising cloud storage system-wide capabilities, storage system metadata capabilities, data system metadata capabilities, data object capabilities, container capabilities, domain capabilities and queue object capabilities, and comprising the supported operation of read. [0083] (D)<PaaS> is a platform as a service information element, comprising one or more of the following common attributes and sub-elements: [0084] <Distributed file system>: distributed file system sub-element; [0085] <Distributed database>: distributed database sub-element; [0086] <Distributed cache>: distributed cache sub-element; [0087] <Distributed computing schedule>: distributed computing schedule sub-element; [0088] <Session>: session sub-element; and [0089] <Messaging>: messaging sub-element. [0090] (E)<SaaS> is a software as a service information element, and SaaS can comprise one or more of the following common attributes and sub-element contents: [0091] communication services, such as short message service, multimedia message service, presence service, chat service, voice call service, video call service, one number service, coloring ring back tone (CRBT), multimedia conference service, and call center service; [0092] location services, such as location service and landmark service; content services, such as video share service, file share service and content sharing service; [0093] enterprise application services, such as custom resource management service, document management service, business intelligence service, and collaboration service; [0094] common services, such as authentication service, temporary storage service, poll/voting service, tag service, contacts service, redirect service and calendar service; and [0095] socialization services, such as blog service, Facebook service and Twitter service. [0096] All of the embodiments of this disclosure can employ the above cloud service consuming interface message packet to realize the access of cloud services. The cloud service requester and the cloud service broker interact with each other by using the above cloud service consuming interface message packets, so that the system compatibility is effectively improved. [0097] With reference to FIG. 3 , a flow chart of another cloud service access method according to embodiments of this disclosure is illustrated, comprising the following steps. [0098] S 302 : A cloud service broker receives a cloud service consumer request sent by a cloud service requester, and the cloud service consumer request can be carried in the cloud service consuming interface message packet. [0099] The specific message format contents are as follows: [0000] Client- > CSB (consumer request) ------------------------------------------ HTTP POST or SIP INVITE Message packet: csb-consumer Content-type: application/csb-consumer+xml <?xml version=“1.0” encoding=“UTF-8” standalone=“yes”?> <csbconsumer version=“1.0” xmlns=“urn:ietf:params:xml:ns:csb-consumer”> <CloudServiceRequest> <session-info> <session-id>0GX1jCYZ8WBa</session-id> <seq>1</seq> </session-info> <IaaS> <compute> <architecture>......</architecture> <cores >......</cores> <hostname>......</hostname> <speed>......</speed> <memory>......</memory> <status>......</status> </compute> <Network> <vlan>......</vlan> <label>......</label> <address>......</address> <gateway>......</gateway> <allocation>......</allocation> </Network> <Storage> <size>......</size> <status>......</status> </Storage> <Virtualization> <DiskSection>......</DiskSection> <NetworkSection>......</NetworkSection> <DeploymentOptionSection>......</DeploymentOptionSection> <VirtualSystemCollection> <VirtualSystem> <OperatingSystemSection>......</OperatingSystemSection> <InstallSection>......</InstallSection> </VirtualSystem> <ResourceAllocationSection>......</ResourceAllocationSection> <StartupSection>......</StartupSection> </VirtualSystemCollection> </Virtualization> </IaaS> <DaaS> <DataObject> <metadata>.....</metadata> <objectURI>.....</objectURI> <objectID>.....</objectID> <parentURI>.....</parentURI> <domainURI>.....</domainURI> <capabilitiesURI>.....</capabilitiesURI> <Mimetype>.....</Mimetype> <value>.....</value> <Location>.....</Location> </DataObject> <Container> <metadata>.....</metadata> <objectURI>.....</objectURI> <objectID>.....</objectID> <parentURI>.....</parentURI> <domainURI>.....</domainURI> <capabilitiesURI>.....</capabilitiesURI> <Location>.....</Location> <exports>.....</exports> <snapshots>.....</snapshots> <children>.....</children> </Container> <Domain> <metadata>.....</metadata> <objectURI>.....</objectURI> <objectID>.....</objectID> <parentURI>.....</parentURI> <domainURI>.....</domainURI> <capabilitiesURI>.....</capabilitiesURI> <children>.....</children> <Location>.....</Location> </Domain> <Queue> <metadata>.....</metadata> <objectURI>.....</objectURI> <objectID>.....</objectID> <parentURI>.....</parentURI> <domainURI>.....</domainURI> <capabilitiesURI>.....</capabilitiesURI> <queueValues>.....</queueValues> </Queue> </DaaS> <PaaS> <Distributed file system> ................................................. </Distributed file system> <Distributed database> ................................................. </Distributed database> <Distributed cache> ................................................. </Distributed cache> <Distributed computing schedule> ................................................. </Distributed computing schedule> <session> ................................................. </session> < Messaging > ................................................. </ Messaging > </PaaS> <SaaS> <Custom Resource Management> ................................................. </Custom Resource Management> <Video share> ................................................. </Video share> <File share> ................................................. </File share> <Short Message Service> ................................................. </Short Message Service> <Multimedia Message Service> ................................................. </Multimnedia Message Service> </SaaS> </CloudServiceRequest> </csbconsumer> [0100] S 304 : The cloud service broker selects the proper cloud computing services and/or resources and the relative service logic and function modes, and executes the cloud service operation. [0101] S 306 : The cloud service broker adapts the cloud services and/or resources provided by the cloud service provider. [0102] S 308 : The cloud service broker returns a consumer response to the cloud service requester, and the cloud service consumer response can be carried in the cloud service consuming interface message packet. [0103] The specific message format contents are as follows: [0000] Client < - CSB (consumer response) ------------------------------------------ 200 OK Message packet: csb-consumer Content-type: application/csb-consumer+xml <?xml version=“1.0” encoding=“UTF-8” standalone=“yes”?> <csbconsumer version=“1.0” xmlns=“urn:ietf:params:xml:ns:csb-consumer”> <CloudServiceResponse reason=“Resource found” status=“200”> <session-info> <session-id>0GX1jCYZ8WBa</session-id> <seq>1</seq> <expires>3600</expires> </session-info> <IaaS>  .................. </IaaS> <DaaS>  .................. </DaaS> <PaaS>  .................. </PaaS> <SaaS>  .................. </SaaS> </CloudServiceResponse> </csbconsumer> [0104] The signaling flow of the cloud service access method in the embodiment is as shown in FIG. 4 , comprising the following steps. [0105] S 402 : A cloud service requester sends a cloud service consumer request to a cloud service broker; and the cloud service consumer request can be sent through the cloud service consuming interface message packet. [0106] In the above, the cloud service consumer request comprises the cloud service information requested by the cloud service requester. [0107] S 404 : The cloud service broker returns a cloud service consumer response to the cloud service requester; the cloud service consumer response can be returned through the cloud service consuming interface message packet. [0108] In the above, the cloud service consumer response comprises cloud service information provided by the cloud service broker. That is, the cloud service broker has selected and/or adapted the information of the cloud computing services and/or resources provided by a proper cloud service provider for the cloud service requester. The information of the cloud computing services and/or resources provided by the proper cloud service provider can be real cloud computing services and/or resources of the cloud service provider, and also can be virtual cloud computing services and/or resources, i.e., cloud computing services and/or resources of the cloud service provider processed by the cloud service broker (such as the proxy service, transition service, porting service, shielding service, permutation service and synthesis service). [0109] With reference to FIG. 5 , a structure block diagram of a cloud service broker according to embodiments of this disclosure is illustrated, comprising: [0110] a cloud service publishing interface module 502 , configured to subscribe to the information of the cloud computing services and/or resources provided by a plurality of cloud service providers; a cloud service consuming interface module 504 , configured to provide a consuming interface for the cloud service requester to access the cloud service provider; a cloud service processing module 506 , configured to process the cloud service consumer request of the cloud service requester; and a cloud service adapting module 508 , configured to adapt the cloud computing services and/or resources provided by the cloud service provider to the cloud service requester according to the cloud service consumer request. [0111] In the above, the cloud service consuming interface module 504 is configured to realize the cloud service consuming between the cloud service requester and the cloud service broker, comprising: a receiving module 5042 , configured to receive a cloud service consumer request sent by the cloud service requester, wherein the cloud service consumer request comprises cloud service information requested by the cloud service requester; and a feedback module 5044 , configured to send a cloud service consumer response to the cloud service requester, wherein the cloud service consumer response comprises cloud service information provided by the cloud service broker, that is, the cloud service broker has selected and/or adapted the information of the cloud computing services and/or resources provided by a proper cloud service provider for the cloud service requester. The cloud computing services and/or resources provided by the proper cloud service provider can be real cloud computing services and/or resources of the cloud service provider, and also can be virtual cloud computing service and/or resource information, i.e., cloud computing service and/or resource information of the cloud service provider processed by the cloud service broker (such as the proxy service, transition service, porting service, shielding service, permutation service and synthesis service). [0112] Preferably, the receiving module 5042 is configured to receive a cloud service consuming interface message packet sent by the cloud service requester, wherein the message packet carries the cloud service consumer request, and the cloud service consumer request comprises cloud service information requested by the cloud service requester. The feedback module 5044 is configured to return a cloud service consuming interface message packet to the cloud service requester, wherein the message packet carries the cloud service consumer response used for indicating cloud service information provided by the cloud service broker, i.e., the cloud computing services and/or resources provided by a cloud service provider that is selected and/or adapted by the cloud service broker for the cloud service requester. [0113] Preferably, the cloud service consuming interface message packet comprises request information or response information. In the above, the request information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, or SaaS information. And, the response information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, or SaaS information. [0114] Preferably, the cloud service consuming interface message packet is transmitted in at least one of the following ways: HTTP, SIP, REST, SOAP, XHTML5, API, or specific command. The information contents of the cloud service consuming interface message packet are described in at least one of the following formats: XML, JSON or other specific formats. [0115] With reference to FIG. 6 , a structure block diagram of a cloud system according to embodiments of this disclosure is illustrated, comprising: a cloud service requester 602 , a cloud service broker 604 and a cloud service provider 606 . [0116] In the above, the cloud service requester 602 is configured to send a cloud service consumer request to a cloud service broker 604 , wherein the cloud service consumer request can be carried in the cloud service consuming interface message packet and it comprises cloud service information requested by the cloud service requester; and receive a cloud service consumer response returned by the cloud service broker 604 , wherein the cloud service consumer response is carried in the cloud service consuming interface massage packet and it comprises cloud service information provided by the cloud service broker 604 , that is, the information of cloud computing services and/or resources provided by a proper cloud service provider that the cloud service broker has selected and/or adapted for the cloud service requester. The cloud computing services and/or resources provided by the proper cloud service provider can be real cloud computing services and/or resources of the cloud service provider, and also can be virtual cloud computing service and/or resource information, i.e., cloud computing service and/or resources information of the cloud service provider processed by the cloud service broker (such as the proxy service, transition service, porting service, shielding service, permutation service and synthesis service). [0117] In the above, the cloud service broker 604 comprises: a cloud service publishing interface module 6042 , configured to subscribe to the information of the cloud computing services and/or resources provided by a plurality of cloud service providers; a cloud service consuming interface module 6044 , configured to provide a consuming interface for the cloud service requester 602 to access the cloud service provider 606 ; a cloud service processing module 6046 , configured to process the cloud service consumer request of the cloud service requester 602 ; and a cloud service adapting module 6048 , configured to adapt the cloud computing services and/or resources provided by the cloud service provider 606 to the cloud service requester 602 according to the cloud service consumer request. [0118] In the above, the cloud service consuming interface module 6044 comprises: a receiving module 60442 , configured to receive a cloud service consumer request sent by the cloud service requester 602 , wherein the cloud service consumer request comprises cloud service information requested by the cloud service requester 602 ; and a feedback module 60444 , configured to send a cloud service consumer response to the cloud service requester 602 , wherein the cloud service consumer response comprises cloud service information provided by the cloud service broker 604 . [0119] In the above, the cloud service provider 606 is configured to publish its cloud service information to the cloud service broker 604 , and provide the cloud service requested by the cloud service requester 602 . [0120] Preferably, the cloud service consuming interface message packet comprises request information or response information. In the above, the request information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, and SaaS information; and the response information comprises information of at least one of: session information, IaaS information, DaaS information, PaaS information, and SaaS information. [0121] Preferably, the cloud service consuming interface message packet is transmitted by using at least one of the following ways: HTTP, SIP, REST, SOAP, XHTML5, API, and specific command. The information contents of the cloud service consuming interface message packet are described in at least one of the following formats: XML, JSON and other specific formats. [0122] Obviously, those skilled in the art should understand that the above modules or steps of this disclosure could be achieved through general calculating devices. They can be concentrated in a single calculating device or distributed in a network formed by multiple calculating devices. Optionally, they can be achieved by program codes that can be executed by calculating devices. Thus, they can be stored in storage devices to be executed by calculating devices. Under certain situation, the shown or described steps can be executed according to an order different from the above order. Or, they can be achieved by respectively making them into many integrated circuit modules or by making multiple modules or steps among them into a single integrated circuit module. In this way, this disclosure is not limited to combinations of any specific hardware and software. [0123] Above contents are only preferred embodiments of this disclosure and are not used for limiting this disclosure. For those skilled in the art, this disclosure can have various alternations and changes. Any modifications, equivalent replacements and improvements within the spirit and principle of this disclosure should be contained within the protection scope of this disclosure.

This disclosure discloses a cloud service consuming method, a cloud service message packet, a cloud serviced broker and a cloud system. Wherein, the cloud service consuming method comprises: a cloud service broker receives a cloud service consumer request sent by a cloud service requester (S202); the cloud service broker returns a cloud service consumer response to the cloud service requester (S204). Through this disclosure, the problems of wasted system resource and low system efficiency caused as the cloud service requester sends cloud service requests for many times are avoided, the utilization ratio of system resources is effectively improved, and the system efficiency is improved.

This application is a division of application Ser. No. 13/988,742, filed May 21, 2013, which was the U.S. national stage entry of international application Ser. No. PCT/EP2011/070558, filed Nov. 21, 2011. BACKGROUND OF THE INVENTION The invention relates to an ultrasonic welding device for welding cables, for example strands. The invention also relates to a mobile ultrasonic welding apparatus. Cables here are understood to be cables having one or more strands and also individual wires or electrically conductive lines. However, it is possible, in principle, for a cable to be a terminal, i.e. a rigid electrical connection. In the case of known devices of this type, ultrasonic vibration is introduced parallel to a welding surface, wherein a compacting force is exerted simultaneously in a direction perpendicular thereto, for example via a compacting or abutment surface. A compacting or welding space, in which the welding material is compressed, i.e. compacted, before and during the welding operation, is typically provided here. In particular for welding strands, it is necessary, for the purpose of achieving a durable weld, for the individual wires to be compressed by a comparatively large force during welding. During the welding operation, on account of the compacted welding material moving in relation to one another, the ultrasonic vibration results in the parts being connected, i.e. in welding taking place. In a large number of industrial applications, in particular in the automobile industry, there is a need for it to be possible for already installed and/or difficult-to-access parts to be connected by means of ultrasonic welding. For example, in the case of the production of cable harnesses for vehicles, these being prefabricated on a board, the individual cables, in some cases, can be raised merely by approximately 4 cm. In particular, there is also increasingly the need to use ultrasonic welding to connect not just copper, but also materials which oxidize to a pronounced extent, for example aluminum. For this purpose, it is necessary for the highest possible level of power to be introduced into the welding region, in order to create a durable welding connection despite the oxide layer. DE 10 2007 026 707 B3 discloses a device for connecting aluminum strands in an electrically conductive manner. A sonotrode here has a welding surface which is in direct contact with the aluminum strand. The sonotrode, which vibrates in its longitudinal direction, subjects the strands, in the longitudinal direction thereof, to ultrasonic vibration, and therefore the strands are welded to one another. For this purpose, the strands have to be arranged in the longitudinal direction of the sonotrode, which requires a large amount of space and presupposes that the parts which are to be welded allow for a corresponding arrangement in the first place. EP 0 143 936 B1 proposes, for space-saving welding purposes, that a welding or compacting space of a device should be formed perpendicularly to the longitudinal axis of the sonotrode, and therefore it is also the case that the parts which are to be welded can be arranged perpendicularly to the sonotrode axis. However, the parts here are subjected to the ultrasonic vibration transversely to the compacting space, and thus transversely to their longitudinal direction, as a result of which only a low level of effective power is introduced. It is thus barely possible to effect metal welding of, for example, strands, in particular those made of aluminum. WO 95/23668 A1 proposes to excite a sonotrode head to perform simultaneous longitudinal and torsional vibrations, wherein the vibration energy is taken off at the circumference. This makes it possible to arrange a compacting space perpendicularly to the sonotrode axis and, nevertheless, for the parts which are to be welded to be subjected to the ultrasonic vibration in their longitudinal direction up to a certain degree. However, it has been found that, on account of the design and excitation of the sonotrode, configuration of the compacting space requires high outlay in design terms and comparatively large tolerances. It is also possible, during the welding of strands, for ultrasonic vibrations introduced transversely to the strand direction to have an adverse effect on the welding since these vibrations disrupt the compacted arrangement of the wires (individual wires “roll”, rather than rub), as a result of which it is also the case that the vibrations can become less effective in the longitudinal direction. Similarly, miniaturizing the sonotrodes is limited by design, since the dimensions of the oblique slots of the converter which are necessary for generating the torsional vibration cannot fall below a certain minimum level. Not least is the design of the slots complex and therefore costly. SUMMARY OF THE INVENTION It is therefore an object of the invention to avoid the disadvantages of the prior art and to provide, in particular, a versatile ultrasonic welding device which is of straightforward design and allows space-saving, efficient and durable welding, in particular on a cable harness. The device here should also make it possible, in particular, to weld strands made of copper and of aluminum. It is also an object of the invention to provide a mobile welding apparatus. The object is achieved according to the invention in that the device for welding metal parts by means of ultrasound comprises a sonotrode with a sonotrode head, which can be excited by a vibration generator to perform torsional vibrations in relation to a torsion axis. A welding surface is arranged circumferentially here on the sonotrode head, as seen in relation to the torsion axis. An anvil with a compacting surface is also present, it being possible for this to be arranged opposite the welding surface of the sonotrode, in a fixed state in relation to the same. In the case of an opposite arrangement, the welding surface and the compacting surface delimit a compacting space, provided for accommodating parts which are to be welded, in a direction perpendicular to the torsion axis. The invention is distinguished in that the sonotrode is designed, and coupled to the vibration generator, such that the sonotrode as a whole can be excited to perform torsional vibration with a negligibly small longitudinal-vibration component. In other words, the vibration generator is designed for generating longitudinal vibrations and is arranged perpendicularly to the torsion axis, wherein the vibration generator is in contact with a torsion vibrator, on which the sonotrode is fitted in a rotationally fixed manner, at a radial distance from the torsion axis, in particular tangentially. Since, according to the invention, the sonotrode as a whole can be made to perform torsional vibration, the longitudinal-vibration component, which is barely avoidable in practice, can be reduced to a negligibly low level. A negligibly small longitudinal-vibration component is understood here, and herein below, to mean a longitudinal-vibration component which has a longitudinal amplitude which is less than 1% of the torsional operating amplitude, preferably less than 0.5%. It has even been found that, in practice, the device according to the invention achieves amplitudes for the longitudinal-vibration component which are only approximately 0.2% of the operating amplitude. On the one hand, this results in largely all the vibration energy fed by the vibration generator being available in the torsional vibration of the sonotrode, and therefore optimum power transmission takes place even in the case of welding material being arranged perpendicularly to the torsion axis. On the other hand, an operating region of the sonotrode, in the present case the sonotrode head with welding surface formed thereon, describes a well-defined rotary movement without any significant deflection in the longitudinal direction. Adjacent fixed or displaceable parts of the device can therefore be respectively installed on, and pushed onto, the sonotrode head with considerably lower tolerances, without account having to be taken of any vibration amplitudes occurring in the longitudinal direction. In particular the compacting or welding space, which is delimited on one side by the welding surface of the sonotrode can be delimited in a comparatively precise manner by it being possible for delimiting elements to be arranged in very close proximity to the sonotrode head even in the direction of the torsion axis. This makes it possible, for example, to prevent the situation where particularly fine wires, during the compacting operation in the compacting space, can enter into gaps between delimiting elements of the compacting space and get caught there. The vibration generator of the device according to the invention, this generator also being referred to in the art as a converter, is therefore advantageously designed for generating longitudinal vibrations and is arranged perpendicularly to the torsion axis of the sonotrode. Such vibration generators are in widespread use, and it is therefore possible to use cost-effective standard components. Since the vibration generator is arranged perpendicularly and in a laterally offset manner in relation to the torsion axis, it is possible to use suitable, direct or indirect, coupling to the sonotrode to convert the longitudinal vibration of the generator into torsional vibration of the sonotrode as a whole. It is also conceivable for two or more vibration generators to interact with the sonotrode in order to generate the torsional vibration, wherein these generators are then cyclically controlled, for example alternately, depending on their arrangement and/or number. In order to excite the torsional vibration of the sonotrode, the vibration generator preferably interacts with the sonotrode via a torsional vibrator, which is coupled to the sonotrode in respect of torsional vibration. The torsional vibrator may be designed, for example, as an axial body which is arranged coaxially in relation to the torsion axis and at one end region of which the sonotrode is fastened in a rotationally fixed manner. For fastening on the torsional generator, the sonotrode is preferably screw-connected thereto. In the case of known screw connections between sonotrodes and torsional vibrators, a blind hole with an internal thread is formed on a respective fastening end side both of the sonotrode and of the torsional vibrator. The sonotrode is screw-connected to the torsional vibrator via a grub screw on either side. The difficulty with such a screw connection, however, is that of aligning the sonotrode in respect of rotation about the longitudinal axis, since it is necessary for the sonotrode to be able to rotate during fastening. In the present case, however, the sonotrode preferably has a one-sided screw connection, in the case of which advantageously a fastening screw is screwed into the torsional vibrator in the direction of the torsion axis so as to be supported on the sonotrode from the sonotrode head. For this purpose, the sonotrode preferably has, in the longitudinal direction, a central countersunk hole which is accessible from the sonotrode head and, in the direction of the fastening end side, has a longitudinally continuous bore on the floor of the countersunk hole. It is thus possible for a screw to be screwed longitudinally through the bore, from the sonotrode head, into the internal thread on the torsional vibrator and for the sonotrode to be fastened on the torsional vibrator. A screw head can be arranged in the countersunk hole and supported on a floor of the countersunk hole. This makes it possible for alignment of the sonotrode in respect of rotation to be straightforwardly predetermined, and fixed by virtue of the screw being tightened. In particular there is no need for the sonotrode to be rotatable in relation to the torsional vibrator during the fastening operation. It goes without saying that the screw connection can, of course, also take place in the reverse order, i.e. the countersunk hole is formed for access from a rear longitudinal end of the torsional vibrator in the longitudinal direction thereof and the internal thread is formed in the sonotrode. In this case, the screw connection takes place from the torsional vibrator into the internal thread of the sonotrode, wherein the screw head is supported in the countersunk hole on the torsional vibrator. It likewise goes without saying that this fastening principle (screw connection on one side) of the sonotrode on the torsional vibrator is also advantageous as an aspect in its own right and can be used for other sonotrodes. A region at a longitudinal end of the axial-body-design torsional vibrator which is located opposite the fastening region of the sonotrode may be provided, for example, for contact with the vibration generator. For vibration-isolated mounting on a housing of the device, the axial body can be supported on the housing, for example, in a known manner in a vibration node of the excited vibration mode. In order to excite the torsional vibration in the torsional vibrator and the sonotrode, which is connected thereto, an activator of the vibration generator is in contact with the torsional vibrator, preferably at a radial distance from the torsion axis. It is particularly straightforward to achieve contact in a region tangential to the cross section of the torsional vibrator. Since the activator is in contact with the torsional vibrator at a radial distance from the torsion axis, the torsional vibrator is subjected to a torque about the torsion axis. It is thus readily possible for the longitudinal vibration, which can be picked up at the activator, to be converted directly into torsional vibration of the torsional vibrator. Since the vibration generator is arranged perpendicularly to the torsion axis, the torsional vibrator is subjected only to a torque about the torsion axis, without any longitudinal force components. The torsion axis preferably coincides with a longitudinal axis of the sonotrode. It is advantageous here for the sonotrode to be designed in an axis-symmetrical manner in relation to the longitudinal axis, and this therefore means that there is no unbalance in relation to the torsion axis. In the case of a torsional vibrator, the latter is preferably likewise designed in an axis-symmetrical manner in relation to its longitudinal axis, wherein the longitudinal axis coincides with the torsion axis. In a preferred embodiment, the sonotrode head protrudes in a flange-like manner, transversely to the torsion axis, at a free end of the sonotrode. The flange-like sonotrode head advantageously has, in the longitudinal direction, two plane-parallel surfaces oriented transversely to the torsion axis. A distance between the surfaces in the direction of the torsion axis here defines a thickness of the sonotrode head. It is advantageous here for the welding surface to extend over the entire longitudinal dimension, i.e. the thickness of the sonotrode head. As a result, on the one hand, the welding surface, irrespective of the rest of the design of the sonotrode, may be arranged at largely any desired radial distance from the torsion axis. On the other hand, the entire thickness of the flange can be used for vibration transmission at the welding surface. The flange may therefore be of comparatively thin design. In a preferred embodiment, the flange-like sonotrode head comprises two lugs which are formed symmetrically in a direction transverse to the torsion axis and of which at least one has the welding surface on the circumference. The vibrating mass of the sonotrode head can thus be reduced further in relation to a completely annular flange. In a modification, it is possible for the two lugs to have a welding surface on the circumference, and therefore, when the one welding surface is worn, the sonotrode can be rotated through 180 degrees in relation to the torsion axis, in order to arrange the other welding surface for use at the compacting or welding space. For this purpose, the sonotrode may have a fastening means which allows it to be fastened on the torsional vibrator in a removable manner and in various positions. It goes without saying that it is also possible, for other designs of the sonotrode head, to provide a plurality of welding surfaces which can be arranged for use at the compacting or welding space by virtue of the sonotrode being fastened in various rotary positions on the torsional vibrator. In a further preferred embodiment, the sonotrode head therefore preferably comprises generally at least two or more, preferably four, welding surfaces formed on the circumference. The compacting space is delimited preferably by an outer lateral slide and an inner lateral slide in the direction of the torsion axis. The lateral slides therefore define a length of the compacting space in the longitudinal direction, i.e. in the direction of the torsion axis. The compacting space here is preferably designed to be continuous, and to open outward, in a direction perpendicular to the torsion axis. It is thus possible for the welding material, e.g. one or more cables, to be arranged in the compacting space in a direction transverse to the torsion axis. It is advantageous, in particular in the case of fixed lateral slides, for the compacting space to be delimited by the lateral slides on either side of the welding surface of the sonotrode, and for the sonotrode head to be arranged, at least in part, in an interspace between the lateral slides. It is preferable here for a distance between the lateral slides in the direction of the torsion axis to correspond to a dimension of the sonotrode head in this direction. The aforementioned dimensional correspondence is understood in the framework of a tolerance which ensures free torsional vibration of the sonotrode head. Such an arrangement is made possible for the first time by the excited torsional vibration with negligible longitudinal-vibration component of the sonotrode head according to the invention. Otherwise, on account of the longitudinal-vibration amplitude, the lateral slides would have to be spaced apart from the sonotrode head and/or corresponding apertures would have to be present, and these could give rise to possibly undesired free spaces between the sonotrode head and lateral slide. It is preferred here for the outer lateral slide to be arranged in front of the sonotrode head, as seen in the direction of the torsion axis, and to fully cover over preferably an end side of the sonotrode. Since the outer lateral slide fully covers over the sonotrode head, the latter is outwardly protected against mechanical effects. The outer lateral slide may be of comparatively thin design here, and therefore the compacting space can be moved close up to the welding material in the axial direction. In particular in the case of an embodiment with longitudinally fixed lateral slides, it is advantageous for the inner lateral slide and the outer lateral slide to be arranged such that they can be jointly displaced in relation to the sonotrode in a direction perpendicular to the torsion axis. For this purpose, for example a longitudinal guide which is oriented transversely to the torsion axis is formed, and the lateral slides can be displaced in a guided manner thereon. It is thus possible for the sonotrode head to be arranged in the interspace between the lateral slides by virtue of the lateral slides being displaced to a more or less pronounced extent. The inner lateral slide and the outer lateral slide here are advantageously mounted jointly on a carriage, which is guided such that it can be displaced in relation to the sonotrode perpendicularly to the torsion axis, and therefore, during displacement of the carriage, the sonotrode head can be introduced into the interspace between the lateral slides or moved out of the same. It goes without saying that it is also the case that just one of the lateral slides can be mounted on the carriage, while the other is fixed in a direction perpendicular to the torsion axis. In an embodiment which may possibly be preferred, it is possible for at least one of the lateral slides to be designed such that it can be displaced in the direction of the torsion axis. For this purpose, the lateral slide preferably has an aperture which essentially, i.e. within the framework of a tolerance necessary for the vibration of the sonotrode, leaves free a region of a projection of the sonotrode head in the direction of the torsion axis, in particular in the region of the welding surface. This means that the at least one lateral slide can be displaced into a length region of the sonotrode head and/or the welding surface thereof, wherein a lateral-slide inner surface, which is directed toward the compacting space, follows the welding surface, with the smallest possible gap therebetween. The lateral slide can thus be displaced towards the other lateral slide in the torsion-axis direction and therefore makes it possible to reduce the dimension of the compacting space in the direction of the torsion axis. In particular it is possible, in this case, for the dimension of the compacting space in this direction to be reduced irrespective of the longitudinal dimension of the sonotrode head. It is preferably the outer lateral slide which can be displaced in the longitudinal direction, while the inner lateral slide is arranged in a longitudinally fixed position. The lateral slide which can be displaced in the longitudinal direction need not be displaceable here in the radial direction in relation to the torsion axis. In this case, it is possible for the anvil to strike longitudinally, for example by way of an end side, against the inner surface of the at least one lateral slide, this inner surface being directed toward the compacting space, in order for the compacting space to be closed off fully in the radially outward direction. When the at least one lateral slide is displaced in the direction of the torsion axis, the anvil can correspondingly be displaced along with it. It is also conceivable, in principle, for just the inner lateral slide or for the two lateral slides to be configured so as to be displaceable in the direction of the torsion axis. These variants, however, usually involve a higher level of outlay. It is advantageous for the at least one lateral slide to be mounted directly or indirectly on a device-mounted displacement guide such that it can be displaced in the direction of the torsion axis, wherein preferably an electric drive, in particular with a spindle drive, is present for displacement purposes. The drive can use, for example, a spindle drive to act on a displacement body which is guided on the device-mounted displacement guide, and to which the lateral slide is connected rigidly directly or indirectly. It goes without saying that the displacement can also take place pneumatically, hydraulically or via other drives. It is advantageous for the anvil to be mounted on the carriage or on one of the lateral slides, in particular on the inner lateral slide, such that the anvil can be displaced transversely to the torsion axis together with said lateral slides, wherein the anvil is arranged such that it can be displaced in the direction of the sonotrode during displacement of the carriage or of the lateral slide. It is preferable here for the anvil to be arranged such that it can be displaced, in addition, in a direction parallel to the torsion axis, and therefore the anvil can be moved into an extended position, in which it projects beyond the lateral slide and the abutment or compacting surface of the anvil is located opposite the welding surface of the sonotrode. In addition, the anvil is also advantageously displaceable into a retracted position, in which it terminates in the longitudinal direction with the lateral slide, and therefore the compacting space is accessible in order for welding material to be introduced. It is preferable for the anvil, in the extended position, to close off the compacting space fully outward in a direction perpendicular to the torsion axis. In other words, the anvil, in the extended position, fully spans the distance between the lateral slides, i.e. a length of the compacting space. The anvil thus forms, together with the lateral slides, a jaw-like unit in respect of displacement in a direction transverse to the torsion axis. In particular, it is thus possible, with the anvil extended, for the volume of the compacting space for compacting the welding material to be uniformly reduced in the radial direction by virtue of the anvil being lowered. In the case of the lateral slide being additionally displaceable in the direction of the torsion axis, it is also possible to reduce a dimension of the compacting space in this direction, in order to achieve the most uniform possible reduction in the volume of the compacting space. It goes without saying that it is also conceivable to have other variants in which the anvil is mounted, for example, in a pivotable manner or the lateral slides are fixed in relation to the sonotrode and the anvil can be displaced, in the interspace between the lateral slides, in the direction of the welding surface. These variants, however, may have the disadvantage that they involve comparatively high outlay in design terms and/or are difficult to handle in practice. On account of the welding space being accessible in a space-saving manner, the device according to the invention, in particular all of the embodiments thereof described above, can advantageously be used in mobile welding apparatuses. The invention therefore also covers a mobile welding apparatus which has a device according to the invention. Such apparatuses are connected to a separate supply unit preferably via a supply line, the separate supply unit preferably comprising a generator for supplying the welding apparatus with electric current or an air-pressure generator for supplying it with compressed air. The supply unit advantageously also comprises a control computer, wherein, for example, an operating panel, also with a screen, is formed on the mobile welding apparatus. In this case, the user can operate the supply unit directly on the mobile welding apparatus. The supply line preferably combines all the necessary connections between the supply unit and the mobile welding apparatus in a single line. Such mobile welding apparatuses are particularly suitable for use with welding material which, for example, is already installed and/or fixed in some other way and is no longer able to be fed to a stationary welding apparatus. It is precisely in this area that the device supplied according to the invention for space-saving, efficient and durable ultrasonic welding proves to be particularly advantageous. It is usually the case here that the supply unit is of stationary design, whereas the mobile welding apparatus can be moved largely freely. However, it is also conceivable for the supply unit to be provided on a mobile base, and therefore it can be moved closer to the operating region, in which the mobile welding apparatus can then be used to carry out welding at various locations. Mobile welding apparatuses are understood to mean, for example, welding tongs or other designs which users can carry and guide up to the welding material. Also conceivable are designs which are retained, for example, on a weight-compensating suspension means and are only guided by the user. Furthermore, it is also possible to have a fastening device or a stand on the mobile welding apparatus, the fastening device or stand allowing the welding apparatus to be respectively temporarily fastened or propped up in an operating region during welding. In order to be handled by a user, mobile welding apparatuses typically comprise handles formed on the outside of the housing. According to the invention, the compacting/welding space is arranged on the end side in a direction transverse to a longitudinal direction of the device or of the sonotrode. In the case of a mobile welding apparatus according to the invention, it is therefore preferred for a handle to be arranged in a front region, on an upper side of the apparatus, in a direction transverse to the longitudinal axis of the device. This allows reliable handling when the apparatus is moved up to the welding material by way of the front end side, largely in its longitudinal direction. It goes without saying that, depending on the position of the welding material, the apparatus can also be moved up to the welding material in other directions. In addition, it is advantageous here for a further handle to be provided in a region at a rear longitudinal end of the apparatus. If the converter, which is arranged perpendicularly to the torsion/longitudinal axis, is oriented downward, it is possible for a housing casing of the converter to be designed advantageously as a gun-handle-like grip and thus to form a rear grip. Further advantageous embodiments and combinations of features of the invention can be gathered from the following detailed description and claims below. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which are used to explain the exemplary embodiment, schematically: FIG. 1 shows an oblique view, in perspective, of a device according to the invention; FIG. 2 shows a front view of an operating region of the device along a longitudinal axis; FIG. 3 a shows a side view of the device in a standby position; FIG. 3 b shows a side view of the device in a compacting/welding position; FIG. 4 shows the sonotrode and converter in an arrangement for the device according to the invention; FIG. 5 shows an oblique view, in perspective, of a further embodiment of a device according to the invention; FIG. 6 shows a partial outer view of a sonotrode head with an outer lateral slide of the device from FIG. 5 ; FIG. 7 shows a partial side view of the device according to FIG. 5 ; FIG. 8 a shows a schematic diagram of the compacting space of the device according to FIG. 1 ; FIG. 8 b shows a schematic diagram of the compacting space of the device according to FIG. 5 ; and FIG. 9 shows a partial sectional view of a sonotrode fastening on the torsional vibrator. It is basically the case in the figures that like parts are provided with like designations. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an oblique view, in perspective, of a device 1 according to the invention. The device 1 has, at a front longitudinal end 5 , an operating region, at which a compacting or welding space 8 is formed. A vibration generator or converter 9 is arranged in an end region at a rear longitudinal end 6 of the device 1 , and the activator 9 . 1 of the generator or converter is connected to a torsional vibrator 4 of the device 1 . The converter 9 here is oriented perpendicularly to the torsion axis B. A direction in which the converter 9 extends is referred to here, and herein below, by “upward” and, correspondingly, the opposite direction is referred to by “downward”. It goes without saying that this assignment of terms is selected by way of example in accordance with the embodiment described here. It is, of course, also conceivable to have other embodiments, in which the converter 9 may be oriented, for example, “downward” or “to the side”. A plane C therefore refers, herein below, to a vertical plane, which comprises the longitudinal axis A and the torsion axis B and is oriented in the upward/downward direction. The converter 9 is parallel, and laterally offset in relation, to said plane C. The torsional vibrator 4 is designed as an elongate axial body, of which the longitudinal axis coincides with a torsion axis B and corresponds to the longitudinal axis A of the device 1 (see also FIG. 4 ). The torsional vibrator 4 is arranged in, and mounted on, a carrier 7 of the device 1 (see FIG. 2 , clamping ring 4 . 1 ). A rear longitudinal end of the torsional vibrator 4 , this end being directed away from the operating region, projects beyond the carrier 7 in the longitudinal direction A. In an end region at the rear longitudinal end of the torsional vibrator, the activator 9 . 1 of the converter 9 is in contact tangentially with the torsional vibrator 4 . Provided at a front longitudinal end of the carrier 7 , this end being directed toward the operating region, is a carrier plate 11 which is arranged perpendicularly to the longitudinal axis A and on the front side of which is arranged a longitudinal guide 12 , which is provided in the upward/downward direction, perpendicularly to the longitudinal axis A and torsion axis B, and has two parallel rails which are symmetrical in relation to the plane C. Between the rails, the carrier plate 11 contains a through-passage 11 . 1 through which, fastened on the end side of the torsional vibrator 4 , a sonotrode 3 projects forwards into the operating region. A carriage 13 is mounted on the rails 12 such that it can be guided in a displaceable manner in a direction perpendicular to the torsion axis B (the carriage not being illustrated in FIG. 1 ; see, for example, FIG. 2 ). On an underside of the carrier 7 , two linearly acting activators 14 . 1 and 14 . 2 are arranged perpendicularly to the longitudinal axis A and are supported on the carrier 7 via carrier elements 7 . 1 and 7 . 2 . The activators 14 . 1 and 14 . 2 can each expand in their longitudinal direction, (e.g. by being subjected to the action of compressed air) and can thus each exert a force in a direction perpendicular to the longitudinal axis A. Arranged between the activators 14 . 1 and 14 . 2 is a driver element 15 , which projects forward through the aperture 11 . 1 in the carrier plate 11 and engages with coupling action in the carriage 13 . If the upper activator 14 . 1 , which is arranged closer to the carrier 7 , is actuated, this results in the driver element 15 being subjected to a downward force, as a result of which the carriage 13 is also displaced downward. Conversely, the carriage 13 is subjected to an upward force via the driver element 15 if the lower activator 14 . 2 is actuated. The carriage 13 here has an aperture 13 . 1 , through which the sonotrode 3 can pass without obstruction in any displacement position of the carriage 13 (see FIG. 2 ). A head 3 . 1 of the sonotrode 3 is arranged in front of the carriage 13 , as seen in the longitudinal direction. The carriage 13 has arranged on it, above the sonotrode 3 , an inner lateral slide 16 , which has a through-passage 16 . 1 in the longitudinal direction A directly above the sonotrode head 13 . 1 . The through-passage 16 . 1 contains an anvil 18 which, guided in a longitudinal guide 10 , can be extended and retracted through the through-passage 16 . 1 via an actuator 19 , which acts in the longitudinal direction A. On a side which is directed toward the sonotrode head 3 . 1 , the anvil 18 has an abutment surface or compacting surface 18 . 1 . Both the actuator 19 and the longitudinal guide 10 , as well as the anvil 18 , are mounted on the carriage 13 and are also displaced when the carriage 13 is displaced. Likewise mounted on the carriage 13 is an outer lateral slide 17 , which is fastened on the carriage 13 via two carrying bolts 17 . 1 and 17 . 2 , which project in the direction of the carrier 7 . The outer lateral slide 17 here is arranged in front of the sonotrode head 3 . 1 , as seen in the longitudinal direction A, and is spaced apart from the inner lateral slide 16 in the longitudinal direction 1 . The outer lateral slide 17 fully covers over the sonotrode head 3 . 1 on the end side. The sonotrode head 3 . 1 has two wings 3 . 2 and 3 . 3 , which protrude in a flange-like manner and extend upward ( 3 . 2 ) and downward ( 3 . 3 ). The upwardly projecting wing 3 . 2 here is arranged between the outer lateral slide 17 and the inner lateral slide 16 , wherein a welding surface 3 . 4 is formed circumferentially on an upper side of the wing 3 . 2 . Along with the welding surface 3 . 4 of the sonotrode head 3 . 1 , regions of the mutually facing inner surfaces of the lateral slides 16 and 17 which are arranged by the welding surface 3 . 4 delimit three sides of the compacting space 8 . The anvil 18 is arranged in a displaceable manner on the inner lateral slide 16 such that, in the extended state, it is adjacent to the outer lateral slide 17 , wherein the compacting surface 18 . 1 is located opposite the welding surface 3 . 4 of the sonotrode 3 . With the anvil 18 extended, the compacting space 8 is thus annularly enclosed in the plane C. In the direction perpendicular to the plane C, the compacting space 8 is open on either side, and therefore welding material can pass transversely through the compacting space 8 . FIG. 2 shows a front view of the operating region 5 of the device 1 along the longitudinal axis A. For the sake of priority, the illustration does not include the outer lateral slide 17 , in order to give a free view of the sonotrode head 13 . 1 . The sonotrode head 13 . 1 is of largely lozenge-shaped design in plan view, this giving rise to the upwardly and downwardly projecting wings 3 . 2 and 3 . 3 , respectively. The sonotrode head 3 . 1 is designed symmetrically in relation to the torsion axis B, and this therefore avoids any unbalance in relation to torsional vibration. An upper end of the sonotrode head 3 . 1 , i.e. the upwardly projecting wing 3 . 2 , is flattened (cropped lozenge shape) and formed into the welding surface 3 . 4 , which is arranged circumferentially in relation to the torsion axis B. The downwardly projecting wing 3 . 3 is flattened correspondingly, wherein, depending on the embodiment of the device 1 , a second (replacement) welding surface 3 . 5 may be formed. In the arrangement illustrated, this latter welding surface is not in a functional position, but, for example in the case of the sonotrode 3 being fitted in a rotatable manner on the torsional vibrator 4 , can be rotated into the position of the welding surface 3 . 4 . This may be expedient, in particular, when the welding surfaces are subjected to rapid wear and have to be exchanged. Above the welding surface 3 . 4 , the inner lateral slide 16 is designed as a crossbar-like element arranged largely perpendicularly to the plane C. The lateral slide 16 here is fastened in a groove which is formed correspondingly on the carriage 13 . The anvil 18 , arranged in the longitudinal guide 10 , can be seen on the lateral slide 16 , through the through-passage 16 . 1 . The abutment or compacting surface 18 . 1 is formed on an underside of the anvil 18 , said underside being directed toward the welding surface 3 . 4 . Two further apertures 13 . 2 and 13 . 3 are formed on the carriage 13 level with the torsion axis B or the longitudinal axis A of the device 1 , these further apertures being provided for accommodating, and retaining, the carrying bolts 17 . 1 and 17 . 2 of the outer lateral slide 17 . FIG. 2 further shows the converter 9 being arranged laterally, in a manner in which it is offset in relation to the plane C and which allows the activator 9 . 1 to be in tangential contact with the torsional vibrator 4 in order to excite the torsional vibration. FIG. 3 a shows a side view of the device 1 , wherein, for the sake of clarity, the carrier 7 has been omitted from the illustration. The illustration of FIG. 3 a shows the device 1 in a standby state. The lower actuator 14 . 2 has been expanded and the upper actuator 14 . 1 has been collapsed, and therefore the driver element 15 , arranged therebetween, has been displaced upward. The coupling to the carriage 13 means that the latter has been carried along by the driver element 15 and has likewise been displaced upward. The anvil 18 is fully retracted into the through-passage 16 . 1 , and therefore an end surface of the anvil 18 terminates with the inner surface of the inner lateral slide 16 , said inner surface being directed toward the outer lateral slide 17 . The compacting space 8 is thus open in the upward direction, as a result of which welding material, for example strands or other cables, can be introduced into the compacting space 8 and arranged on the welding surface 3 . 4 of the sonotrode 3 . FIG. 3 b corresponds to the illustration of FIG. 3 a , although the device 1 is in a compacting/welding position. The anvil 18 has been extended forward, out of the through-passage, in the longitudinal direction A, and therefore its end side strikes against an inner surface of the outer lateral slide 17 , said inner surface being directed toward the inner lateral slide 16 . The compacting surface 18 . 1 of the anvil 18 is arranged opposite the welding surface of the sonotrode head 3 . 4 . The compacting space 8 is thus fully closed off in the upward direction by the anvil 18 . In the welding position, in addition, the carriage 13 has been displaced downward. This is achieved by the upper actuator 14 . 1 having been expanded and the lower actuator 14 . 2 having been collapsed. The driver element 15 is thus moved downward, away from the carrier 7 , and carries along the carriage 13 , which is displaced downward in the longitudinal guide 12 . Together with the carriage 13 , it is also the case that the lateral slides 16 , 17 , fitted thereon, and the anvil 18 (as well as the actuator 19 and longitudinal guide 10 ) are lowered downward in relation to the carrier 7 . The sonotrode 3 , mounted on the carrier 7 , and the torsional vibrator 4 remain in a fixed location in relation to the carrier 7 . This gives rise to the carriage 13 , with components fitted thereon, being displaced relative to the sonotrode 3 . The lateral slides 16 and 17 and anvil 18 here form a U-shaped compacting jaw, which at least partially encloses the sonotrode head 3 . 1 and is displaced in relation to the same during transfer into the welding position. The sonotrode head 3 . 1 , or the wing 3 . 2 of the sonotrode head 3 . 1 , enters into the interior space enclosed by the U shape. The interior space of the U shape and the wing 3 . 2 of the sonotrode head 3 . 1 are dimensioned here such that the wing 3 . 2 virtually completely fills the interior space in the longitudinal direction A. It goes without saying that a tolerance which allows for free torsional vibration of the sonotrode head 3 . 1 is provided here. During transfer into the welding position, in particular also the compacting surface 18 . 1 of the anvil 18 is displaced in the direction of the welding surface 3 . 4 . The welding material (not illustrated), which is present in the compacting space 8 , is compacted between the compacting surface 18 . 1 and welding surface 3 . 4 and, depending on the force exerted by the actuator 14 . 2 , pressed against the welding surface 3 . 4 . The torsional vibration of the sonotrode 3 can thus be introduced into the welding material via the welding surface 3 . 4 of the sonotrode head 3 . 1 . The welding material is preferably compacted by a first force prior to the excitation of the torsional vibration in the sonotrode 3 . When the welding operation is initiated, i.e. when the torsional vibration of the sonotrode is excited, the welding material may thus continue to be subjected to the action of the first force or be subjected to the action of a second, e.g. greater force. For removal of the welding material, the device 1 is moved back into the standby state, i.e. the carriage 13 is displaced upward again and the anvil 18 is retracted, as a result of which the compacting space is open once again in the upward direction. FIG. 4 shows the sonotrode 3 , the torsional vibrator 4 and the converter 9 in an arrangement for the device according to the invention. A front end side of the sonotrode 3 is terminated by the sonotrode head 3 . 1 . Along the torsion axis B or longitudinal axis of the sonotrode 3 , the sonotrode extends rearward to a region 3 . 6 , in which it is connected to the torsional vibrator 4 . The torsional vibrator 4 here is designed as an elongate axial body, of which the longitudinal axis coincides with the longitudinal axis of the sonotrode 3 and with the torsion axis B. The torsional vibrator 4 , at a longitudinal position behind the sonotrode 3 , is enclosed by the clamping ring 4 . 1 , which forms a bearing for the torsional vibrator, at which the torsional vibrator is supported on the carrier 7 . The clamping ring 4 . 1 here is typically arranged in a vibration node of the excited torsional-vibration mode, in order to avoid transmission of vibrations to the carrier 7 and thus also to other components of the device 1 . Behind the clamping ring 4 . 1 , i.e. at a longitudinal position of the torsional vibrator 4 which is located opposite the sonotrode 3 , as seen in relation to the clamping ring 4 . 1 , the actuator 9 . 1 of the laterally offset converter 9 is in contact with the torsional vibrator 4 tangentially to a circumference of the torsional vibrator 4 and perpendicularly to the longitudinal axis or to the torsion axis B. FIG. 5 shows a further embodiment of the device 1 ′ according to the invention. In a manner similar to the device 1 , a compacting or welding space 8 ′ is formed at a front longitudinal end 5 ′. Two converters 9 a and 9 b are present at a rear longitudinal end 6 ′, each being in contact, on opposite sides, with an axial-body-design torsional vibrator 4 ′ and by way of an activator 9 a . 1 and 9 b . 1 . The converters 9 a and 9 b here are arranged perpendicularly to a torsion axis B′, which is defined by the torsional vibrator 4 ′. A longitudinal axis A′ of the device 1 ′ coincides here with the torsion axis B′. A sonotrode 3 ′ (not visible in FIG. 5 ; see, for example, FIG. 6 ) is fastened on the torsional vibrator 4 ′ in the direction of the front longitudinal end 5 ′. A sonotrode head 3 . 1 ′ of the sonotrode 3 ′ is arranged in the longitudinal region of the compacting space 8 ′ and delimits the latter radially, in the direction of the torsion axis B′, by way of a lateral welding surface 3 . 4 ′. A gun-like handle 30 is formed on an underside of the device 1 ′ and allows a user to hold the device 1 ′. The handle 30 has an actuating element 30 . 1 , by means of which a welding operation can be initiated. The compacting space 8 ′ is delimited on the end side by an outer lateral slide 17 . 2 ′, which is part of a lateral-slide unit 17 ′ (see FIG. 7 ), which is mounted in the device 1 ′ such that it can be displaced in the direction B′. The lateral-slide unit 17 ′, furthermore, comprises a slide carrier 17 . 1 ′, to which the outer lateral slide 17 . 2 ′ is fixed. The slide carrier 17 . 1 ′ is arranged in front of the sonotrode head 3 . 1 ′, as seen in the direction of the torsion axis B′, and extends in the direction perpendicular to B′. The compacting space 8 ′ is delimited on the inside in relation to B′, i.e. in the direction of the longitudinal end 6 ′, by an inner lateral slide 16 ′, on which an anvil 18 ′ is mounted such that it can be displaced in the direction B′. FIG. 6 shows a partial view of the device 1 ′ in the region of the sonotrode head 3 . 1 ′, wherein, for the sake of clarity, the slide carrier 17 . 1 ′ has not been included in the illustration. The sonotrode head 3 . 1 ′ has four wings 3 . 2 ′ protruding radially in a flange-like manner. The wings 3 . 2 ′ here are arranged in a crosswise manner at right angles in relation to one another. The welding surface 3 . 4 ′ which delimits the compacting space 8 ′ is formed laterally on an upwardly projecting wing 3 . 2 ′ which is directed toward the compacting space 8 ′. The welding surface 3 . 4 ′ here has channels which are oriented parallel to the torsion axis B and ensure good transmission of the sonotrode vibrations to the welding material compacted in a compacting space 8 ′. The rest of the wings 3 . 2 each bear an identical welding surface 3 . 5 ′. Depending on the rotary position of the sonotrode 3 ′ on the torsional vibrator 4 ′, it is optionally possible for any of the welding surfaces 3 . 5 ′ to be assigned to the compacting space 8 ′. The inner lateral slide 16 ′ is arranged behind the welding surface 3 . 4 ′, as seen in the direction of the torsion axis B′, and delimits the compacting space 8 ′ in the rearward direction. The outer lateral slide 17 . 1 ′ is arranged opposite the inner lateral slide 16 ′, as seen in the direction B′. The lateral slide 17 . 1 ′ has an aperture 17 . 3 ′ which, as seen in the direction of the torsion axis B′, corresponds to a projection of the wing 3 . 2 ′ which bears the welding surface 3 . 4 ′-wing 3 . 2 ′ with welding surface 3 . 4 ′ is thus essentially aligned with the aperture 17 . 3 ′. The aperture 17 . 3 ′ allows the lateral slide 17 . 2 ′ to be displaced in the direction of the lateral slide 16 ′ for the purpose of compacting the welding material in the compacting space 8 ′, in the direction of the torsion axis B′ via the welding surface 3 . 4 ′. The aperture 17 . 3 ′ here is dimensioned such that there is sufficient space for the torsional vibration of the sonotrode 3 ′ if the wing 3 . 2 ′ with the welding surface 3 . 4 ′ is arranged, at least in part, in the aperture 17 . 3 ′. The aperture 17 . 3 ′, in addition, has longitudinal ribbing which complements the welding surface 3 . 4 ′. The small vibration amplitudes thus make it possible for the lateral slide 17 . 2 ′ to extend comparatively closely to, with just a small gap from, the welding surface 3 . 4 ′. As can be seen from (the bottom of) FIG. 7 , the lateral slide 17 . 2 ′ is connected rigidly, via the slide carrier 17 . 1 ′, to a slide carriage 17 . 5 ′, which is mounted on a displacement guide 25 of the device 1 ′, beneath the sonotrode 3 ′. The displacement guide 25 here comprises device-mounted guide elements 25 . 1 , on which a rail 25 . 2 , which is fixed to the slide carriage 17 . 5 ′, is mounted such that it can be guided in a displaceable manner in the direction of the torsion axis B′, or in the present case also in the longitudinal direction A′. The slide carrier 17 . 1 ′, which is not illustrated in FIG. 6 , extends from the slide carriage 17 . 5 ′ in the direction of the lateral slide 17 . 2 ′, in doing so spanning the sonotrode head 3 . 1 ′ on the end side (see FIG. 7 ). FIG. 7 shows the device 1 ′ in a side view in which some concealing elements have been removed. For reasons of clarity, FIG. 7 does not illustrate a central carrier body of the device 1 ′, the components of the device 1 ′ such as, for example, the torsional vibrator 4 ′ being fastened and/or mounted on said carrier body directly or indirectly via a clamping ring 4 . 1 ′. Screws designated by X serve for anchoring the corresponding component on the carrier body. Such components anchored on the carrier body are also referred to as being “device-mounted”. The guide elements 25 . 1 , which are arranged largely beneath the sonotrode 3 ′, as seen in relation to B′, are anchored on the carrier body via the screws X. The guide rail 25 . 2 is mounted in the guide elements 25 . 1 such that it can be displaced in the direction of the torsion axis B′. The slide carriage 17 . 5 ′ is fastened rigidly on the rail 25 . 3 . A motor 21 is mounted on the device via screws X essentially behind the slide carriage 17 . 5 ′, as seen in direction B′. Via a spindle 21 . 1 , the slide carriage 17 . 5 ′ can be displaced in the displacement guide, in direction B′, by the motor 21 . The slide carrier 17 . 1 ′ is fastened rigidly on the end side of the slide carriage 17 . 5 ′. In front of the sonotrode head 3 . 1 ′, as seen in direction B′, the slide carrier 17 . 1 ′ extends into a region by the compacting space 8 ′, where the outer lateral slide 17 . 2 ′ is fastened rigidly on the slide carrier 17 . 1 ′. It is thus possible for the motor 21 to displace the lateral slide 17 . 2 ′ in direction B′ toward the inner lateral slide 16 ′ or away from the same. It is therefore possible for a longitudinal dimension of the compacting space 8 ′ to be reduced for compacting purposes (or increased for the purpose of freeing the welding material). The anvil 18 ′ is designed such that, in the extended state, it follows a displacement of the lateral slide 17 . 2 ′. This ensures that, during the compacting operation, the compacting space 8 ′ is closed off fully in the radially outward direction in any displacement position of the lateral slide 17 . 2 ′. The lateral slide 16 ′ is mounted on a carriage 13 ′ such that it can be displaced in a direction perpendicular to the torsion axis B′, and therefore it can be displaced radially in the direction of the torsion axis B′ or away from the same. Actuators 14 . 1 ′ and 14 . 2 ′ for displacing the carriage 13 ′ are arranged beneath the sonotrode 3 ′ (i.e. largely opposite the lateral slide 16 ′, as seen in relation to B′) and are fixed to the carrier body by screws X. In contrast to the end-side longitudinal guide 12 of the device 1 for the carriage 13 , the functionally largely corresponding longitudinal guide 12 ′ for guiding the carriage 13 ′ is arranged on either side of the sonotrode 3 ′, as seen in relation to B′. The carriage 13 ′ comprises, on either side, an outer plate 13 . 1 ′, which operatively connects the lateral slide 16 ′, via screws Y, to a driver element 15 ′ arranged between the actuators 14 . 1 ′ and 14 . 2 ′. The plates 13 . 1 ′ are each fastened rigidly on runners 12 . 1 ′ of the longitudinal guide 12 ′. The runners 12 . 1 ′ are guided in a displaceable manner on guide rails 12 . 2 ′, which are arranged perpendicularly to B′ and are mounted on the device via screws X (in FIG. 7 , elements of the longitudinal guide 12 ′ are illustrated only on the side which is hidden from view. During the compacting operation, the actuators 14 . 1 ′ and 14 . 2 ′ act on the driver element 15 ′ such that the carriage 13 ′, and thus also the lateral slide 16 ′, is displaced downward in the direction of the sonotrode 3 ′. A compacting surface 18 . 1 ′ of the extended anvil 18 ′ is moved here in the direction of the welding surface 3 . 4 ′. The inner lateral slide 16 ′ and the anvil 18 ′, which is mounted thereon, thus essentially corresponding, in functional terms, to the corresponding elements of the device 1 . FIGS. 8 a and 8 b show a schematic sectional view of the compacting space 8 or 8 ′, respectively, of the devices 1 and 1 ′, respectively. FIG. 8 a shows the compacting space 8 of the device 1 . The compacting space 8 is delimited by the lateral slides 16 and 17 in the direction of the torsion axis B. Said slides are spaced apart from one another, in the direction of B, in a fixed longitudinal position such that there is just enough space for the sonotrode head 3 . 1 in between. The two lateral slides 16 and 17 are arranged rigidly on the carriage 13 , which can be displaced relative to the sonotrode head 3 . 1 in a direction perpendicular to B. During the compacting operation, the two lateral slides 16 and 17 , at a fixed longitudinal distance apart, are jointly lowered in the direction of the torsion axis B, wherein the extended anvil 18 is lowered, by way of its compacting surface 18 . 1 , onto the welding surface 3 . 4 . During the compacting operation, there is therefore a reduction only in the dimension of the compacting space 8 in a direction perpendicular to B. A longitudinal dimension in the direction of B is predetermined by the sonotrode head 3 . 1 . FIG. 8 b shows the compacting space 8 ′ of the device 1 ′. The compacting space 8 ′ is delimited by the lateral slides 16 ′ and 17 . 2 ′ in the direction of the torsion axis B. Whereas the lateral slide 16 ′ is arranged in the fixed longitudinal position, as seen in the direction of B′, adjacent to the welding surface 3 . 4 ′ of the sonotrode head 3 . 1 ′, the lateral slide 17 . 2 ′ can be displaced in the direction of B′, above the welding surface 3 . 4 ′, toward the lateral slide 16 ′. The lateral slide 16 ′ here is arranged rigidly on the carriage 13 ′, which can be displaced relative to the sonotrode head 3 . 1 ′ in a direction perpendicular to B′. During the compacting operation, the lateral slide 16 ′ is lowered in the direction of the torsion axis B′, wherein the extended anvil 18 ′, which is mounted on the lateral slide 16 , is lowered, by way of its compacting surface 18 . 1 ′, onto the welding surface 3 . 4 ′. During the compacting operation, in addition, the lateral slide 17 . 2 ′ is displaced in the direction of the lateral slide 16 ′. This can take place at the same time as, or sequentially in relation to, the operation of lowering the lateral slide 16 ′. The anvil 18 ′ here is displaced along in the direction B′ and can thus close off the compacting space 8 ′ fully in the upward direction. During the compacting operation, there is therefore a reduction in the dimension of the compacting space 8 ′ both in a direction perpendicular to B′ and in the direction of B′, in particular irrespective of a corresponding dimension of the sonotrode head 3 . 1 ′. FIG. 9 shows, schematically, a partial cross-sectional view along the torsion axis B (or B′) through the sonotrode 3 (or 3 ′) and the torsional vibrator 4 (or 4 ′). The sonotrode 3 here from the direction of the sonotrode head 3 . 1 , has a countersunk hole 3 . 6 , which extends in the direction B essentially over the entire length of the sonotrode 3 . At a fastening end 3 . 7 of the sonotrode 3 , the countersunk hole 3 . 6 is terminated by a floor 3 . 8 . The floor 3 . 8 contains a continuous bore 3 . 9 , which runs in direction B and is open on an end-side fastening surface 3 . 10 . The sonotrode 3 butts, by way of the fastening surface 3 . 10 , against a complementary fastening surface 4 . 2 on the torsional vibrator 4 . The torsional vibrator 4 has an internal thread 4 . 4 in an inner bore 4 . 3 . The sonotrode 3 is fastened on the torsional vibrator 4 by way of a screw 26 , which is arranged in the countersunk hole 3 . 6 . The screw 26 extends through the bore 3 . 9 and is screwed into the internal thread 4 . 4 by way of an external thread 26 . 1 . A screw head 26 . 2 here is supported on the floor 3 . 8 of the countersunk hole 3 . 6 . This gives rise to a particularly straightforward, front-access means of fastening the sonotrode 3 on the torsional vibrator 4 or, possibly, directly on a converter, wherein the sonotrode 3 can be straightforwardly aligned in respect of rotation about B and can then be fixed in this position.

A device for ultrasonically welding metal parts includes a sonotrode whose head can be excited by a vibration generator to produce vibrations. The sonotrode is connected to the vibrator with a screw connection provided on one side of the sonotrode. The sonotrode head may have at least one welding surface relative to the torsion axis on the circumference side. An anvil having a counter/compacting surface may be arranged opposite the welding surface of the sonotrode in a stationary position. The welding surface and the compacting surface may delimit a compaction space to receive parts to be welded. The entire sonotrode may be excited to produce torsional oscillation with a negligibly small longitudinal vibration component.

BACKGROUND OF THE INVENTION The present invention relates to devices for the separation of mixtures of hot materials such as partially molten metals or molten metal compounds and metal mixtures with slag by passing them through a centrifugal separation chamber in a rotary separator drum, and more particularly to an improved method and apparatus for the continual separation of metal slag mixtures which can be used in a continual operating refining process. Centifugal apparatus for the separation of materials has been known in the art, shown for example, in German Pat. No. 80041 issued Apr. 18, 1894. The utilization of centrifugal drums for the separation of molten metals and metal slag mixtures is basic in principle and can be effective and advantageous, and while attempts have been made to utilize the centrifugal separation principle in the continuous metal smelting industry, difficulties have been encountered which have prevented it from being successful. It is essential in a continously operating metallurgical plant that the separating stage which is at the end of the complete process must be completely satisfactory and be capable of continual operation, or the entire process will fail. One of the requirements is that the separation device be completely reliable and sturdy and simple in maintenance and repair and can operate under heavy loads with heavy materials in heat environments, and with corrosive materials. In the separation stages in a continuous metal recovery process, one of the steps has been to heat the separator so that when centifugal separation was used, the centrifugal drum was heated before it was placed into operation substantially to the operating temperature required and was held at that temperature level during operation. Maintaining external parts at a predetermined temperature, created difficulties in that some of the parts were not particularly adapted to high temperature, and it was difficult to maintain drives and bearings, and further this resulted in the consumption of heat energy and required insulation or the encountering of heat losses. In other operations, oxidation of the metal or metal compounds had to be avoided, and because of the deleterious effect of exposure to air, attempts were made to produce an inert gas zone or a buffering gas environment to protect the surface of the materials from the harmful influence of the cold or of the oxidizing circulating air. The problems have been increased by the fact that good separation of different heavy constituents often requires that the products be subjected to contact with the wall of the centrifugal vessel over a long period of time and that all materials be carried on the centrifuging wall for a relatively uniform time period. It is accordingly an object of the invention to provide an improved centrifugal separator which is capable of continuous operation in a metallurgical refining system and which avoids disadvantages of the prior art encountered because of cooling of the material during separation and because of exposure of the materials to air with resultant temperature loss or resultant oxidation. A feature of the invention is to provide a centrifugal drum which rotates about an axis of rotation and wherein a flame conducting pipe is coaxially arranged within the drum extending from the outlet end to the inlet end and wherein the pipe is provided with openings for the outlet of hot flame gases which are directed in continual contact with the material within the drum in a flow path that insures heating of the material and prevents exposure to air. The flame gases are arranged to sweep over the entire surface of the material located in the vessel. A further feature of the invention provides that the flame conducting pipe or shell is supported so as to rotate with the centrifugal drum and is provided with an end wall opposite the inlet to the centrifugal drum which provides as a distributing and deflecting device for the material being charged into the drum, and the deflected material all engages the wall at the beginning end and is immediately subjected to the sweeping flame gases for its full travel along the length of the interior drum surface. The charging material is accelerated additionally by its engagement with the end distribution wall, and is uniformly directed onto the outer wall of the rotating drum. This insures longer contact with the separating wall of the drum and prevents charging material from disrupting material already on the wall of the drum and being separated. The distributing wall, being part of the flame shell, is heated so that there is no loss in temperature of the entering material. A further feature of the invention is arrangement at the outlet end of the drum for channeling the flame gases out of the drum for continuous complete circulation therein. At the discharge end, the drum has a circular baffle which extends radially and performs a dual function of regulating the amount of lighter material which flows out of the drum, and also guides the flames radially inwardly to pass out of the drum. The lighter weight slag material and flames fow out through the same passage without interfering with the fuel supply and burner which are centrally located in a coaxial position. Another advantage of the invention lies in an arrangement wherein a mounting is provided which supports the flame shell within the drum and which also supports the conduits for conducting the separated materials from the drum. The supports are in the form of hollow arms which serve as conduits for the separated heavier material leaving the drum and the hollow arms are constructed so as to also conduct flames emerging from the drum so that the flame gases are in contact with the surface of the heavier separated material as it flows away from the drum. The hollow arms extending radially outwardly are positioned so that centrifugal force carries the separated material away and has a ventilating effect on the hot flame gases aiding in the effective circulation through the drum and away from the drum. This arrangement also continues to protect the heavier separated material maintaining it blanketed with hot flame gases and maintaining its temperature. Other advantages, objects and features, as well as equivalent methods and structures which are intended to be covered herein, will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments in the specification, claims and drawing, in which: DRAWINGS FIG. 1 is a vertical sectional view taken through a separator constructed and operating in accordance with the principles of the present invention; and FIG. 2 is a fragmentary vertical sectional view of a lower end of a separator illustrating a modified structure. DESCRIPTION As illustrated in FIG. 1, a centrifugal separator drum 1 is shown having a separation chamber therein. The drum may be operated in various positions, but preferably is operated for rotation about a vertical axis, and is provided with support bearings for mounting the drum for rotation. For this purpose, the drum 1 has an elongate coaxial neck end 4 on which is fitted a pulley 6 to receive belts, not shown, for driving the drum in rotation. The neck end is carried in the inner race of a ball bearing assembly 5 with the outer race being supportively mounted. The separator is positioned with the hollow neck 14 receiving a supply spout 8 which tapers to a smaller end for supplying a flow of material as indicated by the arrowed line 7. This flow of material may be provided from a continuous operating plant mechanism, such as a metallurgical processing unit having an output such as a hot mixture of metal and slag. The charging material enters the inlet end through the spout 8 and is thrown outwardly as it enters to the wall 12 of the shell and passes downwardly as indicated by the heavy arrowed lines 18 and 18' toward the outlet end of the drum. At the outlet end, the drum has an inwardly turned flanged end providing a circular opening through the heavier material flows as indicated by the arrowed line 19. The lighter weight separated material flows out through a central ring 10 as indicated by the broken arrowed line 20. Collectors for receiving the separated material may be provided of a nature which will be recognized by those skilled in the art, and such structures as shown for example, in our copending application, Case No. P-76320, Ser. No. 680,673, Filed Apr. 27, 1976. The ring 10 may be supported by circumferentially separated radial support struts. The arrangement of the ring and outlet will be apparent to those versed in the art from the foregoing description as will modifications thereof, and an arrangement of such structure is shown for example, in German Pat. No. 661,703. In accordance with the invention, a heating or flame shell 14 is positioned coaxially within the centrifugal separation chamber. This shell 14 is open at its lower end, receives a flame from a burner 15, and has radially outwardly opening ports 17 at its upper end for flow of the flame gases outwardly through the openings and down along the walls in the path indicated by the broken lighter weight arrowed lines. At the upper end of the flame shell is an end wall 16 which may have a conical projection at its center for deflecting and distributing the charging material outwardly as it flows into the chamber. The end wall, of course, will be heated so that contact of the charging material with the end wall will not reduce its temperature, and material will not freeze or cling to the wall. As the flame gases flow along the outer wall while the material is being separated, they completely blanket the material protecting it from engagement with air and oxidation. The flames are channelled inwardly and axially outwardly at the lower end of the separator chamber, and the ring 10 has an outwardly flared collar 13 at its upper edge. The outer edge of this collar catches the lighter separated slag material and channels it inwardly to flow downwardly. The collar also aids in channelling the direction of the flame gases guiding them coaxially outwardly in contact with the exiting slag. The central flame tube 14 is supported on spaced radial struts 21 secured between the base of the tube and the ring 10. The ring, as above stated, is also supported by spaced struts shown at 21' which are secured to the inwardly flanged end 9 of the drum 1. The entry portion of the drum is indicated by the double arrowed line 2, and the discharge portion of the drum is indicated by the zone of the double arrowed line 3. The burner 15 may be provided with a control for increasing or decreasing the flame and the amount of flame gases circulated in through the flame distribution tube 14 in accordance with the material being separated and the quantity of material being handled. The thin walled flame tube 14 will be heated to the temperature of the gases so that the material being separated will be heated both by contact with the gases and by radiation from the wall of the tube 14. FIG. 2 provides an arrangement where the discharging flame gases are maintained in contact with the heavier phase of the separated material. In the structure shown therein, 1' presents a rotating centrifugal drum. A flame tube 14' is mounted coaxially within the drum with a flame arrangement similar to that shown in FIG. 1 A coaxial ring 10' is positioned at the lower end of the drum to rotate therewith, and has a flared collar at its upper end. The ring 10' provides an annular passage for the flow of separated slag, and the flow of flame gases axially downwardly. Outwardly of the ring 10' is an annular space for the flow of the heavier separated material. The flame tube 14' and the ring 10' are supported by circumferentially separated radially outwardly extending hollow spokes 22, 22' and 22". These spokes have upwardly facing openings 23a, 23'a and 23"a, which receive the heavier separated phase flowing downwardly and conduct it outwardly through the discharge openings 23, 23' and 23". The inner ends of these spokes at 22a, 22'a and 22"a are open to the inside of the flame tube 14' so that a certain small amount of the flame gases passing upwardly in the tube can flow laterally outwardly. These bypassed flame gases will blanket the surface of the heavier phase flowing outwardly through the hollow spokes, and will maintain the heat of the separated material and protect its surface to prevent exposure to the air.

A method and apparatus for centrifugal separation of hot materials such as molten metals and slag including feeding the metal and slag mixture into a rotational separator drum having a center inlet at one end and coaxial outlets at the other end, a burner shell within the center of the drum chamber having radial outlet holes and a burner therein with the flame gases flowing outwardly through the radial outlet holes and over the surface of the material being separated heating the material and the flame gases being conducted out the outlet end for continual circulation.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for the fragmentation, sterilization, separation, and recovery of recyclable materials from solid waste, such as solid municipal waste, as well as other bio mass materials. The solid waste material is introduced into a rotatable, “kiln-like” pressure vessel with the infusion of a controlled amount of fluid, preferably steam, where it is subjected to elevated temperatures and pressures and mechanical forces exerted within the vessel. Jets of high pressure fluid are used to induce a cutting/agitation action on the waste material as it moves through the pressure vessel. 2. Description of Related Art Great quantities of solid waste materials, particularly municipal solid waste (MSW), are generated and collected regularly in both rural and urban areas of the United States and other developed countries. Suitable disposal methods are required for such waste. The customary solutions for the disposal of such solid waste materials has been to either deposit them into landfills or to separate the inorganic and organic components and incinerate the organic components, either directly, or in the form of fuel derived from the organic components. However, such disposal methods are becoming increasingly expensive and/or environmentally undesirable. Processing of municipal solid waste (MSW) to produce solid fuel products suitable for combustion in steam boilers of electric power plants is known and in commercial use. However, such solid fuel products have serious disadvantages, including an undesirably high moisture content, a high ash content and relatively low heat value. Improvements and innovations in solid waste treatment processes are needed because of the growing economic and environmental needs to recycle and reuse as much of the increasing amounts of municipal solid waste (MSW) material that are produced. Consequently, the patent literature has been replete with various disclosures concerning MSW management, offering all sorts of methods and techniques to deal with this exploding waste management problem. One type of technology that is of particular interest for the separation and recovery of municipal waste components is an in-vessel technology that utilizes a pressure vessel for holding the waste where it is rotated, pressurized, and heated with steam while simultaneously being mechanically agitated and moved through the vessel by an extruding action. The extruding action is achieved by a rotatable extruder mechanism in the pressure vessel that forces the solid waste material through one or more constricted areas at the discharge end of the pressure vessel. Such a method, and some of its variations, are disclosed in U.S. Pat. Nos. 4,342,830; 4,450,495; 4,844,351; 5,190,944; and 5,361,994 all to Holloway and all of which are incorporated herein by reference. While some of the above methods have met with varying degrees of technical and commercial success, they still suffer from inherent problems. For example, in-vessel treatment has become well known in the art and affords some advantage over landfilling and incinerating, but it is very time and labor intensive. It generally does not lead to the cost-effective or efficient recovery of the utilizable inorganic components of a typical municipal solid waste material. Therefore, “pre-process” classification, segregation and removal of the inorganic portions (metals, plastics, glass, etc.) of the municipal solid waste to be treated is usually necessary. These classification and separation techniques are well known in the art, such as trommel separation or size classification of solid components, air classification systems for plastics, spectrographic segregation for glass, and magnetic and eddy current separation for ferrous and non-ferrous metals. The utilization of conventinoal in-vessel composting methodology, without some form of “pre-process” classification and removal of these inorganic components, contaminates the inorganic components during treatment making the recovery of such components more difficult and substantially depreciating their value. Other difficulties incumbent upon in-vessel treatment of solid waste include the protracted length of time the waste material must remain in the vessel (residence time) for treatment to be completed; and the relatively high moisture content of the end-product. This high moisture content inhibits the separation of the organic components from the inorganic components and necessitates additional drying of the end-product material for further processing. Additional drying is particularly difficult in the in-vessel processes that introduce a relatively high volume of moisture into the vessel in order to fluidize the material. These noted deficiencies are overcome by the practice of the present invention that eliminates the need for any “pre-process” classification of the mixed municipal solid waste and does not instill any extraneous or unnecessary water into the system. The moisture content of the end-product exiting the vessel of the present invention will not exceed 30%, preferably it will not exceed 20%, by weight. The present process has the additional advantage of producing an end-product from biomass that is relatively dry and readily utilizable for numerous products, including a fuel product. The present invention also has the advantage of sterilizing the inorganic components of municipal solid waste and rendering such components readily recoverable from the waste stream because of the removal of labels and coatings from them. SUMMARY OF THE INVENTION The objectives of the present invention are to provide an apparatus and method for the facile and cost-effective recovery of the majority of recyclable components in solid waste, preferably municipal solid waste. The objectives of this invention will also provide a method for the processing of other segregated bio-mass feed stocks, such as bagasse, greenwaste, and the like. This is accomplished through rapid fractionalization of the organic components, along with the sterilization and preparation of the inorganic components for recovery. The sterilization and preparation of the inorganic components is accomplished without any pre-process handling or segregation of inorganic components from organic components of the solid waste. In accordance with the present invention there is provided an apparatus for the separation and recovery of recyclable material from solid waste material, which apparatus comprises a cylindrical vessel that is capable of being rotated about its longitudinal axis and capable of withstanding elevated pressures, said vessel comprising: a) an exterior wall surface, b) an interior wall surface, c) a first axial end, d) a second axial end, b) a chamber for receiving waste material to be treated said chamber defined by said interior wall surface and said first axial end and said second axial end, said chamber being sealed against pressure loss within said vessel, c) an inlet at said first axial end and an outlet at said second axial end, d) a feed assembly sealingly connected to said cylindrical vessel at said inlet for feeding solid waste material into said chamber, e) a flight assembly comprised of one or more flights secured to said interior wall surface and projecting radially inwardly from said interior wall surface such that its radial inner edge projects radially inwardly no more than about 80% of the distance from said interior wall surface to said longitudinal axis of said vessel, said flight assembly extending along said interior wall surface in a helical pattern from about said first axial end to about said second axial end, f) a primary tube secured to each of one or more of said flights of said flight assembly along substantially the entire length of said flight, said tube being sealingly and rotatably connected to a source of high pressure fluid, said tube having a plurality of orifices disposed along its length, said orifices being of a predetermined sizes that are sufficient to allow for the injection of jets of high pressure fluid into said chamber. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an elevational view of a preferred process vessel in accordance with the present invention. FIG. 2 is a side view of a preferred air lock barrel component of a preferred breech-type feed assembly suitable for use in the instant invention. FIG. 3 is a side view of a preferred air lock cylinder component of the breech-type feed assembly of the present invention. FIGS. 4A, 4 B, and 4 C show the breech-type feed assembly in three loading positions. FIG. 4A shows the feed assembly in position to be loaded with waste material to be treated. FIG. 4B shows the feed assembly after loading and after being slid into the pressure vessel chamber. FIG. 4C shows the feed assembly in position wherein the waste material is dumped in the pressure vessel. FIG. 5 is an elevational view of a preferred pressure vessel of the present illustrating the helical flight embodiment. FIG. 6 is a partial cross-sectional view of the pressure vessel of FIG. 4 taken along line 5 — 5 showing the embodiment of the present invention relating to the sparger line in relation to the helical flight. DETAILED DESCRIPTION OF THE INVENTION The practice of present invention on solid waste material, such as a municipal solid waste, accomplishes, inter alia, the following: a) fractionalization, fragmentation, and reduction of: i) the cellulosic components (long-chain and/or cross-linked, insoluble carbohydrates) of the organic portion of mixed municipal solid waste and other biomass material, into its base component parts of cellulosic fiber (short-chain carbohydrates); ii) assorted minerals and trace metals; iii) water; iv) fats, oils or other lipids; b) the denaturing and fragmentation of the proteinaceous portions of the organic components; c) the reduction of the moisture content of the treated waste; and d) the sterilization and preparation of the inorganic components of such waste materials. This is accomplished as a result of the fractionalization and hydrolyzation of the organic constituents by subjecting the solid waste material to heat, pressure, and the cutting/agitating action of jets of high pressure fluid, preferably forced steam, and more preferably alternating steam and air into the chamber of a rotating pressure vessel. The mixing and homogenization of the waste material is accomplished in several ways. For example, it is accomplished by the rotation of the vessel, the physical action of the helical flight assembly, and the cutting and agitating forces exerted by the jets of high pressure fluid that are emitted from orifices disposed along a tubular member (sparger line) and optionally its laterals that will be described in detail below with reference to FIGS. 5 and 6. Thus, the solid waste material, during treatment, continuously churns and agitates during its flight through the vessel, thus shortening the treatment time needed to reach the desired end products. Processing of mixed municipal solid waste in accordance with the present invention results in the sterilization and preparation of the inorganic components (including glass, metals and insoluble organic constituents such as rubber, plastics, and synthetics, etc.), thereby enhancing recoverability of these inorganic components and increasing their value as end products. Vapor and water discharge from the vessel, and the moisture content of the discharged end-product material, is controlled by use of positive pressure vacuum for recovering moisture and vapor from the vessel as well as from the material being processed. The resulting effluent end-product, or discharge, is captured in a collection vessel (not shown) for subsequent filtration of solid particulate. The recovered water can be recirculated as process make-up water to a boiler. The particulate matter recovered from such discharge can be returned to the pressure vessel for further processing. Feedstock of municipal solid waste, or other biomass, is introduced and discharged from the apparatus on a “semi-continuous” basis, preferably by use of a breech-type load mechanism, also referred to herein as breech-type feed or unloading assembly, by means of rotating connectors and air-lock systems that will be described in more detail below with reference to FIGS. 2, 3 , and 4 . The solid waste material that is preferred for treatment in accordance with the present invention is municipal solid waste that will typically include both: (a) an organic portion such as agricultural and forestry wastes, foods, paper, plastics, fabrics, and wood residues; and (b) an inorganic portion such as concrete pieces, bricks and other fired clays, glass, metals, stones, synthetics, etc. It is preferred that the weight percentage of the organic portion of the untreated municipal solid waste material be at least about 30 wt %, more preferably about 40-80 wt. %, based on the total weight of the waste material. The table below shows the composition of typical dry municipal solid waste (MSW) as determined by the Environmental Protection Agency. Composition of Municipal Solid Waste Organics 74.0%  Ferrous Metals 7.5% Non-Ferrous Metals 1.5% Glass 10.0%  Plastics 5.0% Non-Organics 2.0% Referring now to the Figures hereof, FIG. 1 depicts a preferred apparatus of the present invention. The preferred apparatus includes a cylindrical pressure vessel 1 having an exterior wall surface 3 , an interior wall surface 5 , a first axial end 16 , and a second axial end 22 . Although the cylindrical pressure vessel can be of any suitable diameter and length, it is preferred that it's diameter be from about 10% to about 15% of its length. The overall length of the pressure vessel 1 can be any suitable length that will allow for an effective residence time of waste material in the pressure vessel for a predetermined rate of vessel rotation and process conditions, including temperature and pressure. The overall length of the pressure vessel will typically be from about 80 to 120 feet. The chosen ratio between diameter of the vessel and its length is of course not critical and will depend on such things as the amount of helical pitch and the frequency (tip to tip) of the flight geometry, which will be described below with reference to FIG. 5 . The pressure vessel can be fitted with at least one access manway 32 , or port, with sealable covers. FIG. 1 shows two manways 32 that are preferably located near each axial end of the pressure vessel and opposed from each other. Manways are well known the art and they are typically die formed dome-type manhole frames and covers with saddles (or repads) rolled to fit the diameter of the pressure vessel or reinforced pipe nipples with flanges. The manways are provided to allow a workman to enter the pressure vessel when not in use for such purposes as cleaning, unplugging, and repair. It is within the scope of this invention that the pressure vessel contain one or more observation ports (not shown) set in the wall of the vessel to allow one to observe the waste material during treatment. Pressure vessel 1 is mounted for rotation about its longitudinal axis 2 . Rotation of the vessel can be caused by any suitable means known in the art FIG. 1 shows one preferred embodiment wherein the rotation is provided by a drive assembly that is comprised of a pair of trunnions 10 that also serve as stiffening braces and that are concentrically welded around the periphery of the vessel. The trunnions rest on two sets of wheels 12 (only one wheel of each set is shown). The wheels can be constructed form any suitable material, such as a metal or polymer composition, including elastomers and the like. It is preferred that the wheels be of an elastomeric material, such as rubber tires. The wheels 12 are set in suitable supporting structures, such as pillow blocks 14 . FIG. 1 also shows sets of roller bearings 13 for supporting each set of wheels to ease rotation. Rotation is accomplished by use of a motor 4 having an output gear 6 in meshed relationship with spur-type, or gear-type ring 8 secured around the periphery of the vessel. Rotation of the vessel can also be achieved by directly causing the wheels to rotate, which will then cause the vessel to rotate. Pressure vessel 1 is caused to rotate about its longitudinal axis at a predetermined rotation speed, that can be readily varied. It is preferred that the waste material being processed be rotated an effective number times during its trip through the pressure vessel. By effective number of times we mean that minimum number of times needed to establish an effective residence time of the material in the pressure vessel. By effective residence time, we mean that minimum amount of time needed for the sterilization of the inorganic component and sufficient fractionalization, fragmentation, and denaturing of the organic material component aided by the cutting/agitation action of jets of high pressure fluid. For example, it order to obtain a desirable effluent product, the long chain carbohydrates of organic materials need to be broken into smaller chain carbohydrates. The precise residence time is of course dependent on such things as the nature of the material being treated, the amount of heat supplied by steam, the moisture content of the material being treated, and the pitch of the flights. Typically, the residence time will be from about 30 to 90 minutes, preferably from about 40 to 70 minutes. The number of revolutions of the vessel for any given waste material moving through the vessel, will typically be not less than about 300 revolutions, preferably not less than about 320 revolutions, and more preferably not less than about 340 revolutions. It is within the scope of the invention that the rotation of the vessel be reversible. First and second axial ends 16 and 22 , respectively, of pressure vessel 1 can be any suitable geometric configuration. Although they can merely be composed of a flat metal plate, it is preferred that they be tapered. It is more preferred that they be flanged domes or conical heads, most preferably 2:1 semi-elliptical heads. It is also within the scope of this invention that the taper of the axial end closures be provided by a concentric reducer defined by the interior wall of the axial end section of the pressure vessel, with or without a flat plate end member. While the angle of incline, or taper, is not critical, it will preferably be from about 0° to 90°, more preferably from about 30° to 75°, and most preferably from about 45° to about 65°. The length of the conical head, if used, is not critical, but it will preferably be approximately {fraction (1/16)} th of the length of the pressure vessel. In FIG. 1, first axial end closure member 16 terminates with a flange 18 , which is preferably a forged steel weld neck pressure vessel flange that is known in the art. This cone and flange is mated to a stationary feed, or hopper, tube 20 having a port 21 by means of an air lock assembly and rotating mounting assembly (not shown). Tube 20 will also contain a fitting 7 for receiving a suitable line for introducing fluid, such as steam and air into the pressure vessel. It is preferred that the wall of tube 20 be jacketed so that the fluid can be introduced through the jacket and through nipple, or fitting 31 of air lock barrel 36 (FIG. 2) which will be in fluid communication with tube 70 (FIG. 6 ). One type of “air lock” system suitable for use herein is one that is well known in the art and that typically includes a pair of separate pressurizable chambers. The preferred “air-lock” system for use herein is a breech-type system that will be described below when describing the feed assembly illustrated in FIGS. 2, 3 and 4 hereof. FIG. 1 also shows loading hopper 30 in association with port 21 . It is to be understood that a hopper need not be used in the practice of the present invention. The only requirement is that a structure be provided so that the solid waste material to be treated can be fed into inlet port 21 by any suitable technique. For example, the waste material can merely be shoveled or dumped into port 21 . Alternatively, a suitable hose can be connected to port 21 so that the waste material can be pumped through port 21 and into the feed assembly. Stationary extension tube 29 is also provided to allow for containment of the air lock piston when in charging mode and which will described below with reference to FIG. 4 . Second axial end 22 of the vessel, which is preferably fitted with a conical head or a 2:1 semi-elliptical head and a flange 23 and stationary discharge tube 24 which is similar to 18 and 20 respectively, at the feed end of the pressure vessel. Discharge rotating tube 24 includes at least one discharge port 27 . The system for feeding the waste material into the pressure vessel can be any suitable feed system, and such systems are well known in the art. For example, it can be comprised of the system taught in U.S. Pat. No. 5,190,226, and incorporated herein by reference, that teaches the use of an “air-lock” system comprised of a pair of separate pressurizable chambers. A preferred feed system is a breech-load feed assembly such as the one depicted in FIGS. 2, 3 , and 4 hereof. Such a system, which is more typically used for feeding munitions into guns, includes a ram, or bolt 34 (FIGS. 1 and 4 ), a fixed air lock barrel 36 and a slidable and rotatable air lock piston 44 (FIGS. 2 and 3 respectively). Air lock barrel 36 contains a forward section 38 and an aft section 47 . The forward section 38 is comprises an opening, or port, 42 that faces downwardly to allow the waste material to be dropped into the pressure vessel during loading. Aft section 47 also contains an opening, or port, 43 that faces upwardly to allow waste material to be fed into the chamber 46 of air lock piston 44 . Air lock barrel 36 is sealingly secured within the vessel structure for the first axial end 16 to the end of extension pipe 29 (FIG. 1 ). Port 42 of air lock barrel 36 will be facing downwardly and within the vessel chamber to allow waste material to be loading into the vessel from chamber 46 of air lock piston 44 . Port 43 will be disposed in an upwardly direction under port 21 to allow waste material to be fed into chamber 46 of air lock piston 44 . Air lock piston 44 contains a forward section 39 and an aft section 41 , the forward section of which contains chamber 46 . Air lock piston 44 is slidable along its longitudinal axis and is also rotatable. Air lock piston 44 contains a chamber 46 in its forward section 39 for receiving and transporting waste material into said pressure vessel. The dimensions of chamber 46 will be substantially the same as the opening of ports 42 and 43 to allow for non-restricted loading and unloading of waste material. It is within the scope of this invention that the dimensions of said opening of said chamber 46 be smaller than the opening of either one or both of ports 42 and 43 . Air lock piston 44 also contains at least one primary seal ring 48 that is capable of sealing the piston periphery and preventing steam from escaping during vessel loading. Air lock piston 44 also contains intermediate seals 49 that can also serve as wipers. Additional tash wipers (not shown) can also fitted onto the air lock piston 44 to protect the seal rings. In operation, the ram 34 (FIGS. 1 and 4A) is first slid backward from the vessel along its longitudinal axis and suitably rotated so that chamber 46 of air lock piston 44 is positioned underneath port 21 of feed tube 20 . The waste material WM to be treated is passed from the charging hopper 30 into the port 21 and into chamber 46 of air lock piston 44 . After filling chamber 46 , the air lock piston 44 is advanced longitudinally to the primary seal 48 so that chamber 46 is within forward section 38 of air lock barrel 36 (FIG. 4 B). Piston 44 is then rotated so that chamber 46 aligns substantially with port 42 of air lock barrel 36 , thus venting chamber 46 to the internal pressure of the pressure vessel and causing the waste material to be dumped into the pressure vessel (FIG. 4 C). It is preferred that the ram be hollow to provide a passage for steam inlet piping into the vessel. It is within the scope of this invention that the loading of waste material into pressure vessel 1 be performed either while the vessel is rotating or when it is at rest. It will be understood that the loading of the vessel can take place by first pushing piston 44 so that chamber 46 is within the forward section 38 of air lock barrel 36 . The piston can then be rotated so that chamber 46 is aligned with port 42 to allow the waste material to dump into the pressure vessel. Once the waste material is in the pressure vessel, it is moved toward the discharge axial end while being subjected to mechanical forces generated by flight assembly 60 (FIG. 5 and 6 ). Referring now to FIG. 5, flight assembly 60 is shown and is preferably comprised of at least one, and more preferably at least two helical flights 60 A and 60 B. Each flight will be in the form of one or more blade structures secured to and radially projecting inwardly from the interior wall surface 62 of pressure vessel 1 toward its longitudinal axis of the vessel. The use of the word blade herein also includes the word vane. Each flight that comprises the flight assembly can be a single continuous blade or discontinuous blade segments, disposed along a predetermined helical path from about the first axial end to about the second axial end of said vessel. It is preferred that each flight be comprised of a continuous blade from about one axial end of the vessel to about the other axial end. The flight assembly will radially project inwardly toward the longitudinal axis of the vessel to an effective depth. That is, it will project radially inwardly toward the longitudinal axis of the vessel to such a depth that will be effective to agitate and move the material from about the feed axial end of the vessel to about the discharge axial end. The depth to which each flight will project radially inwardly will typically be no more than about 80%, preferably no more that about 60%, and more preferably no more than 30%, of the distance from the interior wall surface 5 to the longitudinal axis 2 . The frequency of the flights, as measured from tip end to tip end, will be spaced a pretermined distance apart, which distance will be preferably closer toward the discharge axial end of the pressure vessel. Typically, the distance between tip to tip of the helical flight will be from about 12 to 18 inches. The helical flights will typically be comprised of steel plate of at least ½ inch in thickness. The flights should vary in helical pitch progressing from a greater pitch at the charging end of the vessel to a lesser pitch at the discharge end of the vessel. The frequency of the flights will also vary from a frequency that produces a “throw” of the material being treated of approximately twelve to fifteen inches at the charging end to a “throw” of about six to nine inches at the discharge end. By “throw” we mean the longitudinal distance the waste material will be moved with each rotation of the vessel. Turning now to FIG. 6, which is a cross-sectional view of said flight assembly along line 5 — 5 of FIG. 5, a tube 70 (sparger line) is shown and is secured to at least one flight of the flight assembly. Tube 70 is provided, along its length, with a plurality of orifices 61 . Tube 70 provides agitation and cutting from jets of high pressure fluid that are emitted through orifices 61 disposed along its length. It is preferred that the sparger line be welded onto the radially interior edge of the one or more flights. It is within the scope of this invention that the sparger line be secured at any location along the side surfaces of the flight(s) and not just the preferred radially interior edge. The orifices disposed along the length of the sparger line will preferably vary in diameter from approximately {fraction (1/16)} th inch to about ⅛ th inch to provide the injection locations for jets of high pressure fluid, preferably steam or alternating steam and air. The jets of fluid are forced directly into the waste material as it moves through the vessel. The sparger line can also be fitted with laterals, or branching, tubulars 64 (FIG. 6) that are substantially perpendicular to the sparger line. The laterals will vary in length from ¼ to ¾ of the distance from the sparger to the interior wall surface of the vessel. It is also preferred that the lateral be spaced approximately 12 inches to 24 inches apart, preferably about 16 inches to 20 inches apart along the length of the sparger line. It is also preferred that the laterals be alternated between the feed side of the flight to the discharge side of the flight. A plurality of orifices 65 will also be disposed along the length of the laterals, which orifices will preferably be of varying diameters. It is preferred that the diameters of the orifices of the laterals be from approximately ⅛ th inch to {fraction (1/16)} th of an inch. The orifices, particularly those of the sparger line, are preferably directed medially and from perpendicular to approximately 45° along the vessel's longitudinal axis in the direction toward the discharge axial end of the vessel. The orifices of the laterals are preferably directed distally and from parallel of the flight to approximately 45° from parallel in direction of the opposing flight. The varying diameters of the orifices 61 and 65 are preferably randomly selected in order to ensure that the amount of “head pressure” of steam being emitted from the individual orifices varies to ensure homogenization results. It is preferred that the orifices be located in such a way that they direct the jets of high pressure fluid toward the interior wall surface 5 of pressure vessel 1 . It is also preferred that they be within 90°, preferably within 60°, from the side surface 67 of the flight. It is within the scope of this invention that the sparger contain orifices that point toward the center, or longitudinal axis, of the pressure vessel. At least an effective number of orifices, of an effective diameter, are provided at effective distances apart. That is, the orifices should be of sufficient number and size such that the pressure of the fluid being injected through the orifices is of sufficient force to provide a cutting/agitation action on the waste material being treated. The orifices will extend along the length of the sparger line so that at least 50%, preferably at least 75%, and more preferably at least about 90% of the length of vessel receives jets of high pressure fluid. It is preferred that the orifices that direct the jets of fluid toward the interior wall surface of the vessel be of greater diameter than the orifices that direct the jets of fluid toward the center of the vessel. For example, the orifices that direct the high pressure fluid back toward the interior wall surface can have a diameter of about {fraction (1/16)} inch, whereas the orifices that direct the high pressure fluid toward the center of chamber of the pressure vessel can be about {fraction (1/125)} inch. The end of each sparger line nearest the charging end of the pressure vessel will be sealingly and rotatably connected to a source of high pressure fluid, preferably steam and air. It is more preferred that it be fluidly connected to fitting 31 of air lock barrel 36 . The steam and air will be delivered to the vessel through a suitable manifold structure. One preferred type of connection is a centrally mounted tee (not shown) for attachment to a rotating swivel joint (not shown) steam supply system, which connections and systems are well known in the art. In operation, the waste material is moved through the pressure vessel by the helical flight assembly 60 during rotation of the vessel. During its movement through the pressure vessel, the waste material is subjected to the cutting and agitation action of the jets of high pressure fluid that are injected through the orifices of the sparger line and optionally laterals. It is preferred that the pressure vessel be operated within a temperature range from about 250° F. to about 300° F., more preferred is a temperature of about 260° F. to about 280° F. It is also preferred that the operating pressure in the vessel be from about 30 to about 70 psig, more preferred is a pressure of about 40 to 60 psig. Charging of the waste material into the pressure vessel is stopped when a predetermined effective volume of the vessel is occupied by the waste material. By effective volume we mean that the waste material should occupy enough of the vessel volume to make the process economically profitable and to have enough waste material to be cut, agitated and efficiently moved through the vessel at a sufficient treatment, or residence time. Effective volume also means that not too much waste material is fed into the vessel so that the movement of the material through the vessel would be impeded. It is preferred that the waste material occupy no more than about 40 vol. % of the pressure vessel chamber. Treatment of the waste material continues as the waste material moves through the vessel by continuing to subject the material to the jets of high pressure fluid and the rotation of the vessel. The high pressure fluid, as previously mentioned, is preferably selected from steam and dry, heated air. It is also preferred that the injection of steam and dry, heated air be alternated. That is, it is preferred to inject steam into the vessel for a predetermined period of time, followed by the injection of dry, heated air for a predetermined period of time, then the injection of steam, then a final treatment of heated dry air. A typical non-limiting steam/air cycle will be injecting steam first for period of time from about 15 to 25 minutes, followed by the injection of air for about 20 to 35 minutes, followed by another treatment of steam from about 15 to 25 minutes, followed by injection of air for about 15 to 25 minutes. It is also within the scope of this invention that steam alone, without the injection of dry, heated air, be used throughout the treatment. During treatment, the pressure vessel continues to rotate and jets of high pressure fluid continues to be injected through the sparger line, and optionally laterals, to maintain an effective cutting/agitation action. If additional steam is required, it can be introduced into the pressure vessel by any appropriate means. When the waste material reaches the end closure member 22 it is squeezed back toward the charging end of the vessel. This causes any paper (cellulose) that was insufficiently broken down and processed during its movement through the vessel to be torn apart by compression and sheer action of the resulting indirect extrusion to complete the treatment process. The desired level of treatment is reached when the desired end products are produced, which end products will have a moisture level substantially reduced from the virgin feed solid waste material. The moisture content of the waste material is monitored as it moves through the vessel. For example, virgin waste material will typically contain greater than 30 wt. % water, more typically greater than about 40 wt. % water. As previously stated, the moisture level of the desired end products will preferably be no greater than about 20 wt. %. Also, it is within the skill of those in the art to know that a certain residence time is needed in the pressure vessel for a given temperature and pressure and moisture content to sufficiently fractionalize, fragment, and denature the organic components and to sterilize the inorganic components. It is within the scope of this invention that additional reagents be introduced into the pressure vessel along with the preferred fluids, steam and air. Non-limiting examples of such additional reagents include surfactants and dispersing agents. After a solid waste material has reached the desired level of treatment, the treated waste material is removed from the vessel either while it is rotating, preferably when it comes to rest. The end-product material can be removed from the vessel by any suitable means. A preferred means would be to use the preferred breech-load (unload) system as described above for charging the vessel. For example, an air lock barrel and air lock piston, as illustrated in FIGS. 2, 3 , and 4 hereof can be used to unload the waste material from the pressure vessel after treatment. The pressure vessel can also be fitted with one or more “pop-off” type pressure release valves (not shown) that function as control mechanisms to ensure that the pressure generated inside of the vessel does not exceed operating parameters. The pressure vessel can also be fitted with multiple “quick connect” type nipples (also not shown) mounted 180° opposed from said pop-off valves, and preferably at the discharge end of the vessel. These “quick connect” type nipples will provide a means to remove vapor, particulate, condensate, and moisture by use of vacuum to maintain the desired level of each during treatment. The resulting liquid effluent product of the practice of this invention can be drawn from the vessel at intervals throughout treatment in order to remove excess moisture from the processed material during processing. This liquid effluent can be drawn from the vessel and collected in a collection tank (not shown), then passed through a sand (or equivalent) filter and then through a reverse osmosis (or equivalent) filtration system as is known in the art. The solid, or particulate matter, from the filtration step can be recycled back to the pressure vessel. The water can also be routed back into a boiler as make-up water for the production of steam, as is known in the art. It is preferred that the pressure vessel be inclined along its longitudinal axis slightly off of the horizontal and sloping downward from the charging end of the vessel to the discharge end of the vessel. This will enhance the movement of the waste material through the vessel. While, not critical, the degree of slope, off of true horizontal, will preferably be not more than about 4°. Practice of the present invention will result in an end-product material comprised of a cellulosic pulp that is relatively dry and contains no more than about 30 wt. %, and preferably no more than about 20 wt. % of moisture. The end-product material will also contain inorganic components that are relatively clean (i.e. labels removed from glass containers, paint and coatings removed from metal containers, and plastic items that are easily segregated and recoverable). The end-product material is preferably then conveyed (by means that are well known in the art) from the discharge end of the pressure vessel to a rotating trommel for straining and segregation of the cellulosic pulp from the other components that are then sent to separation, size classification and recovery equipment for separation and collection of the inorganic components. The waste materials can be separated in the trommel by means of screens that include a first screen material having larger openings than a second screen that is mounted in spaced relation with the first screen layer. Separation is efficiently accomplished in the trommel since the organic waste material is more fluid while heated and pressurized. The cellulosic pulp is then further dried by any suitable means, such as by use of air, a fluidized bed dryer, a barometric dryer, or other suitable drying techniques that are well known in the art. The resultant carbohydrate/cellulosic pulp may then be used for any number of commerical applications, such as a clean-burning fuel source, stock for animal feeds, base material for composite building material products, acoustical or insulating material, or composting or fill material. The carbohydrate/cellulosic pulp product may also be biochemically converted to methane or ethanol. The residence and/or cycle time, temperature and pressure control, fluid injection amount and time cycle, vacuum pressure and time cycle, and rotational speed, duration and direction, and operation of the rotating sleeve/ram inlet and discharge systems can all be controlled by a programmable logic control (PLC) system to maintain each variable within the designed operational parameters. It is also within the scope of this invention that adjustment of the operational parameters (residence time, steam injection amount and timing, rotational speed, and vacuum pressure and timing) be used to allow for operational adjustments sufficient to adapt to varying imput conditions. Such input conditions include, but are not limited to the constituency of the feed waste material, such as from high organic content feedstocks like bargasse or newprint or green waste, to the variations in mixed municipal solid waste. For example, variations in the composition of a mixed municipal solid waste will occur during rainy or dry collection periods. Incumbent upon the invention is the manner that both pressurized steam and heated, dry air are introduced into the vessel, and thereby instilled into the material being processed, in the preferred alternating manner, thereby limiting any extraneous moisture from being introduced into the vessel. The present invention contemplates that a manifold or similar gathering mechanism be used for conducting both steam from a boiler system and heated, dry air for introduction into the vessel. The dry air may be, for example, collected from a reservoir tank that accepts pressurized air that may have been, for example, pre-heated by any suitable means. Non-limiting suitable means include use of a heater coil (such as electric) or use of a heat exchanger utilized in connection with the recovery of the pressurized steam from the pressure vessel during operation, or by a combination thereof, or by any other suitable means know by those having skill in the art.

The invention relates to apparatus and method for the treatment of recyclable materials from solid waste. The material is introduced into a pressure vessel where it is heated and shredded. Fluid jets within the vessel produce a cutting/agitating action on the waste material as it flows through the vessel.

TECHNICAL FIELD The disclosure relates to a small fuse and a method of manufacturing the same. More particularly, the disclosure relates to a small fuse and a method of manufacturing the same, in which the small fuse is mounted on a printed circuit board (PCB) of an electronic product such that a fusing element provided in the small fuse is melted to prevent parts on the PCB from being damaged by shutting off current when over current is applied to the PCB, thereby preventing circuits of the PCB from being damaged. BACKGROUND ART In general, higher voltage may be applied to electronic products, such as communication devices connected to telephone circuits, when surge current caused by induction lightning is applied to the electronic products or telephone lines make contact with power lines. For this reason, a fuse used in the communication device must have time lag characteristics to endure against the surge current caused by the induction lightning as well as current blocking characteristics to block current causing malfunction of the communication device. Recently, as the size of devices has become reduced, the current blocking characteristics and the time lag characteristics are required for the surface-mount type small fuse. The conventional small fuse includes a base, a pair of lead wires extending by passing through the base while being spaced apart from each other, a fusing element for connecting ends of the lead wires to each other, and a cover coupled with the base to receive the fusing element and the lead wires therein. The fusing element and the lead wires are made from an alloy of copper and tin so that they have flexibility so as to be bent easily. The base and the cover are individually manufactured by using thermoplastic resin and then coupled with each other to define a space therebetween to receive the fusing element and end portions of the lead wires adjacent to the fusing element. The small fuse is mounted on the PCB of the electronic product through the lead wires extending out of the base and the fusing element of the small fuse is melted when the over current is applied to the PCB, thereby protecting circuits of the PCB. SUMMARY OF THE INVENTION However, the conventional small fuse represents following disadvantages. Since the size of the small fuse is determined according to the size of the cover and the base, the size of the cover and the base must be minimized to reduce the size of the small fuse such that the size of the electronic product employing the small fuse can be reduced. However, if the size of the cover and the base is reduced, the size of the space formed between the cover and the base to receive the fusing element is also reduced. Thus, if the lead wires adjacent to the fusing element are bent due external impact applied thereto while the base is being coupled with the cover, the fusing element makes contact with an inner wall of the cover. In this case, the cover made from the thermoplastic resin may be damaged by heat generated from the fusing element, so that the small fuse may malfunction. In this regard, it is very difficult to minimize the size of the small fuse. Accordingly, it is an aspect of the disclosure to provide a small fuse, which can be easily manufactured in a small size without degrading the reliability of the product, and a method of manufacturing the same. Additional aspects and/or advantages of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure. The foregoing and/or other aspects of the disclosure are achieved by providing a small fuse comprising a base, a pair of lead wires extending by passing through the base while being spaced apart from each other, a fusing element interconnecting end portions of the lead wires adjacent to the base, and a cover including thermosetting resin and coupled with the base to receive the fusing element and the lead wires adjacent to the base. The cover is integrally coupled with the base through an injection molding process. The base is formed with a perforation hole positioned corresponding to the fusing element and an interior of the cover is communicated with an exterior of the cover through the perforation hole. The base may include thermosetting resin. The cover is individually formed and coupled with the base. The base may include thermoplastic resin. The cover has a hollow box shape having one end being open and is press-fitted with the base such that the open end of the cover surrounds an outer peripheral surface of the base, and the base restricts deformation of the cover when the base is coupled with the cover. The base is provided at the outer peripheral surface thereof with contraction grooves to induce contraction of the base. The cover has a hollow box shape having one end being open and is press-fitted with the base such that the open end of the cover surrounds an outer peripheral surface of the base, and the open end of the cover is screw-coupled with the outer peripheral surface of the base. The fusing element makes contact with an inner wall of the cover when the lead wires are inclined toward the inner wall of the cover. According to another aspect, there is provided a method of manufacturing a small fuse having a base, a pair of lead wires extending by passing through the base while being spaced apart from each other, a fusing element interconnecting end portions of the lead wires adjacent to the base, and a cover including thermosetting resin and coupled with the base to receive the fusing element and the lead wires adjacent to the base, the method comprising installing the lead wires connected to each other by the fusing element on the base and integrally forming the cover with the base through an injection molding process by injecting thermosetting resin molten material into a cavity of a mold in a state in which the fusing element and a portion of the base adjacent to the fusing element are exposed to an interior of the cavity of the mold. The base is formed with a perforation hole positioned corresponding to the fusing element, the cavity is communicated with an exterior of the base through the perforation hole, and air is injected into the cavity through the perforation hole to prevent the thermosetting resin molten material from approaching to the fusing element. The mold is formed with injection ports to inject the thermosetting resin molten material and the injection ports are arranged to prevent the thermosetting resin molten material from being directly injected toward the fusing element. ADVANTAGEOUS EFFECTS As described above, according to the small fuse and the method of manufacturing the same of the disclosure, the cover made from thermosetting resin is coupled with the base to receive the fusing element therein, so that the cover can be prevented from being damaged by the fusing element even if the fusing element makes contact with the inner wall of the cover due to size reduction of the cover. Accordingly, the small fuse can be manufactured in a small size without degrading the reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS These and/or other aspects and advantages of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: FIG. 1 is a front sectional view showing the structure of a small fuse according to one embodiment; FIG. 2 is a side sectional view showing the structure of a small fuse according to one embodiment; FIG. 3 is a sectional view showing a preparation step in the manufacturing process for a small fuse according to one embodiment; FIG. 4 is a partially sectional view showing an injection molding step in the manufacturing process for a small fuse according to the one embodiment; FIG. 5 is a front sectional view showing the structure of a small fuse according to another embodiment; FIG. 6 is a side sectional view showing the structure of a small fuse according to another embodiment; and FIG. 7 is a top sectional view showing the structure of a small fuse according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the embodiments of the disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements. The embodiments are described below to explain the disclosure by referring to the figures. As shown in FIGS. 1 and 2 , a small fuse A includes a base 10 , a pair of lead wires 20 extending by passing through the base 10 while being spaced apart from each other, a fusing element 30 for connecting ends of the lead wires 20 to each other, and a cover 40 coupled with the base 10 to receive the fusing element 30 and the lead wires 20 therein. The fusing element 30 and the lead wires 20 are made from an alloy of copper and tin so that they have flexibility so as to be bent easily. The base 10 and the cover 40 receive the fusing element 30 therein in such a manner that particles generated when the fusing element 30 is melted can be prevented from scattering toward other parts on the PCB adjacent to the small fuse A, thereby preventing peripheral devices from being damaged when the fusing element 30 is melted. The fusing element 30 can be welded to the ends of the lead wires 20 . The small fuse A is mounted on the PCB of the electronic product through the lead wires 20 extending out of the base 10 and the fusing element 30 of the small fuse A is melted when the over current is applied to the PCB, thereby protecting circuits of the PCB. The lead wires 20 can be soldered to the PCB when the small fuse A is mounted on the PCB. Meanwhile, the small fuse A according to the present embodiment can be manufactured in a small size without degrading the reliability of the product due to the material property of the cover 40 , which will be described below in more detail. According to the small fuse A of the present embodiment, the cover 40 has a hollow box shape, in which one end of the cover 40 , that is, a bottom portion of the cover 40 is open. In order to allow the small fuse A to have a small size, an internal space of the cover 40 has a small size to the extent that the fusing element 30 makes contact with an inner wall of the cover 40 if the lead wires 20 are inclined to the inner wall of the cover 40 . Since the cover 40 substantially receives the fusing element 30 therein, if the internal space of the cover 40 is reduced, the whole size of the cover 40 can be reduced. If the whole size of the cover 40 is reduced, the size of the base 10 , which is coupled with the cover 40 , can also be reduced, so that the whole size of the small fuse A can be reduced. For reference, the virtual line shown in FIG. 2 represents the fusing element 30 making contact with the inner wall of the cover 40 due to deformation of the lead wires 20 . If the internal space of the cover 40 has a small size so that the fusing element 30 makes contact with the inner wall of the cover 40 when the lead wires 20 are inclined to the inner wall of the cover 40 , the fusing element 30 makes contact with the inner wall of the cover 40 if external impact is applied to the lead wires 20 adjacent to the fusing element 30 while the base 10 is being coupled with the cover 40 or before the base 10 is coupled with the cover 40 . Thus, the cover 40 is damaged by heat generated from the fusing element 30 , so the product reliability of the small fuse A may be degraded. According to the present embodiment, however, the cover 40 is made from thermosetting resin having superior heat-resistant property, so that the cover 40 is not deformed by the heat generated from the fusing element 30 . Therefore, the product reliability of the small fuse A may not be degraded even if the fusing element 30 makes contact with the cover 40 . Although thermosetting resin has superior heat-resistant property as compared with thermoplastic resin, the thermosetting resin represents high rigidity and low flexibility so that the thermosetting resin may be easily broken. Thus, the cover 40 including the thermosetting resin may be easily broken when external impact is applied thereto while the cover 40 is being coupled with the base. To solve this problem, according to the present embodiment, the cover 40 is integrally coupled with the base 10 through injection molding. FIGS. 3 and 4 show the manufacturing procedure for the small fuse A according to the present embodiment. In order to manufacture the small fuse A according to the present embodiment, a pair of lead wires 20 connected to each other through the fusing element 30 are installed on the base 10 as shown in FIG. 3 , and the cover 40 is integrally formed with the base 10 through the injection molding process by injecting thermosetting resin molten material 40 a into a cavity 100 a of a mold 100 in a state in which the fusing element 30 and a portion of the base 10 adjacent to the fusing element 30 are exposed to the interior of the cavity 100 a of the mold 100 as shown in FIG. 4 . The cavity 100 a is open toward the base 10 such that the fusing element 30 and the portion of the base 10 adjacent to the fusing element 30 can be introduced into the cavity 100 a . Injection ports 110 are formed in the mold 100 in opposition to the base 10 such that the thermosetting resin molten material 40 a can be injected into the cavity 100 a through the injection ports 110 . Therefore, according to the present embodiment, the thermosetting resin molten material 40 a for forming the cover 40 directly makes contact with the surface of the base 10 when forming the cover 40 through the injection molding process. Thus, the cover 40 can be integrally formed with the base 10 as the thermosetting resin molten material 40 a is dried, so that the cover 40 can be prevented from being broken although the cover 40 is made from the thermosetting resin which can be easily broken. If the base 10 comes into contact with the thermosetting resin molten material 40 a used for forming the cover 40 , the base 10 may be damaged by the thermosetting resin molten material 40 a having the high temperature. Thus, the base 10 is made from the thermosetting resin having superior heat-resistant property. In addition, if the thermosetting resin molten material 40 a is injected into the cavity 100 a of the mold 100 in a state in which the fusing element 30 has been introduced into the cavity 100 a of the mold 100 , the thermosetting resin molten material 40 a may stick to the fusing element 30 so that the melting performance of the fusing element 30 may be degraded. In this regard, the thermosetting resin molten material 40 a is prevented from approaching to the fusing element 30 during the injection molding process. To this end, the base 10 is formed with a perforation hole 11 through which the cavity 100 a is communicated with the outside of the base 10 . In addition, when the thermosetting resin molten material 40 a is injected into the cavity 100 a of the mold 100 , high-pressure air is sprayed toward the fusing element 30 through the perforation hole 11 to prevent the thermosetting resin molten material 40 a from approaching to the fusing element 30 . Since the fusing element 30 is installed corresponding to the center of the base 10 , the perforation hole 11 is located at the center of the base 10 corresponding to the position of the fusing element 30 in order to prevent the thermosetting resin molten material 40 a from approaching to the fusing element 30 . Arrows with solid lines shown in FIG. 4 indicate the injection direction of the thermosetting resin molten material 40 a , and arrows with dotted lines indicate the air supply direction. A gap may not be formed between the base 10 and the cover 40 if the cover 40 is integrally formed with the base 10 through the injection molding. Thus, the perforation hole 11 may substitute for the gap formed between the base and the cover in the conventional small fuse. That is, the perforation hole 11 may serve as a discharge path for explosive pressure occurring when the fusing element 30 is melted during the use of the small fuse A, so that the small fuse A can be stably used. If air having excessive pressure is introduced into the cavity 100 a through the perforation hole 11 , the thermosetting resin molten material 40 a may not be easily injected into the cavity 100 a . In this regard, the injection pressure of the thermosetting resin molten material 40 a introduced into the cavity 100 a is higher than the pressure of air introduced into the cavity 100 a through the perforation hole 11 by 10 HPa to 20 HPa. In addition, in order to effectively prevent the thermosetting resin molten material 40 a from approaching to the fusing element 30 , the injection ports 110 are positioned corresponding to outer sides of the fusing element 30 such that the thermosetting resin molten material 40 a may not be directly injected toward the fusing element 30 . In order to uniformly maintain the injection pressure in a state in which the injection ports 110 are located at outer sides of the cavity 100 a , other than the center of the cavity 100 a , a plurality of injection ports 110 are formed in the mold 100 such that the thermosetting resin molten material 40 a can be simultaneously injected to plural portions of the cavity 100 a while preventing the thermosetting resin molten material 40 a from being directly injected toward the fusing element 30 . FIGS. 5 and 6 show the structure of a small fuse B according to another embodiment. In this embodiment, the cover 40 of the small fuse B is made from thermosetting resin. This embodiment is different from the previous embodiment in that the cover 40 and the base 10 are individually formed through the injection molding and then coupled with each other. In addition, the base 10 is made from thermoplastic resin having superior flexibility than the thermosetting resin to prevent the cover 40 from being broken while the cover 40 is being coupled with the base 10 . In more detail, according to the present embodiment, the cover 40 has a hollow cylindrical shape having one end being open and the base 10 has a disc shape having predetermined thickness. The cover 40 is coupled with the base 10 in such a manner that the open end of the cover 40 surrounds an outer peripheral surface of the base 10 . That is, the outer peripheral surface of the base 10 is screw-coupled into the open end of the cover 40 such that the cover 40 can be securely coupled with the base 10 while preventing the cover 40 from being broken when the cover 40 is coupled with the base 10 . To this end, a female screw 41 is formed at an inner peripheral surface of the open end of the cover 40 and a male screw 12 is formed at the outer peripheral surface of the base 10 . In addition, explosive pressure occurring when the fusing element 30 is melted can be discharged through a fine gap formed between the female screw 41 and the male screw 12 . According to still another embodiment, as shown in FIG. 7 , a small fuse C includes the cover 40 made from thermosetting resin and the base 10 made from thermoplastic resin. According to this embodiment, different from the previous embodiment, the cover 40 is coupled with the base 10 through the press-fitting scheme. That is, according to the present embodiment, the cover 40 has a hollow box shape having one end being open and the open end of the cover 40 surrounds the outer peripheral surface of the base 10 when the cover 40 is coupled with the base 10 . At this time, the outer peripheral surface of the base 10 is press-fitted into the open end of the cover 40 . In order to prevent the open end of the cover 40 from being expanded, contraction grooves 13 are formed at the outer peripheral surface of the base 10 to induce contraction of the base 10 when the cover 40 is coupled with the base 10 . The contraction grooves 13 are formed along the outer peripheral surface of the base 10 while being spaced apart from each other by a predetermined distance. Each contraction groove 13 is open toward the outside of the base 10 to induce contraction of the outer peripheral surface of the base 10 when the cover 40 is coupled with the base 10 . According to the small fuse C of the present embodiment, deformation of the cover 40 can be absorbed by the contraction grooves 13 , thereby preventing the cover 40 made from the thermosetting resin from being broken when the cover 40 is coupled with the base 10 . The contraction grooves 13 may have various shapes to the extent that they can restrict the deformation of the cover 40 . In the case of the small fuse C according to the present embodiment, explosive pressure occurring when the fusing element 30 is melted can be discharged through the contraction grooves 13 . Similar to the small fuse A, the small fuses B and C can also be manufactured in the small size without degrading the reliability of the product due to the material property of the cover 40 . Although few embodiments of the disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Disclosed are a small fuse and a method of manufacturing the same. A cover made from thermosetting resin is coupled with is a base to receive a fusing element therein. The fusing element does not cause damage to the cover even if the fusing element makes contact with an inner wall of the cover due to size reduction of the cover.

BACKGROUND OF THE INVENTION This invention relates to power plant operations, and, more particularly, to an approach for removing particulate matter from a flue gas stream produced in a fossil fuel power plant, especially a coal-fired power plant. In a fossil fuel power plant, a fuel is burned in air to produce a flue gas. The flue gas heats water in a boiler to generate steam, which turns a turbine to produce power. After passing through various apparatus, the flue gas is exhausted through a stack to the atmosphere. The flue gas of certain fossil fuels (i.e. coal) includes solid particulate matter and a variety of gaseous contaminants. The maximum permissible emission levels of the particulate matter and gaseous contaminants are set by laws and regulations. The maximum emission levels are typically far less than the amounts present in the flue gas as it is produced, and various types of gas treatment apparatus are usually provided to reduce the particulate matter and gaseous contaminants in the flue gas before it leaves the stack. In many power plants, particulate matter in the gas stream is removed by electrostatic precipitation. An electrostatic charge is applied to the particulate matter in the flue gas, and the flue gas passes between charged electrodes. The particulate matter is deposited upon the electrode having the opposite charge to that of the particulate and is later removed. The fuel typically contains from about 0.2 percent to about 6 percent sulfur, which at least in part oxidizes to sulfur dioxide during combustion. A small part of the sulfur dioxide further oxidizes to sulfur trioxide. Since the combustion air and the fuel also contain moisture, the flue gas contains water vapor. The sulfur trioxide and water vapor in the flue gas react to produce sulfuric acid, which deposits upon the particulate matter. The sulfuric acid deposited upon the particulate matter imparts a degree of electrical conductivity to the particulate and promotes the electrostatic precipitation process. If the fossil fuel contains too little sulfur, so that there is a deficiency of sulfur trioxide, and thence sulfuric acid in the flue gas, the electrostatic precipitator may not function properly because of the high electrical resistivity of the particulate. It is therefore known to add sulfur trioxide from an external source to the flue gas produced from burning low-sulfur fossil fuels. See, for example, U.S. Pat. No. 3,993,429. In the '429 sulfur trioxide conditioning system, sulfur is burned to form sulfur dioxide, which is passed over a catalyst to achieve further oxidation to sulfur trioxide. The sulfur trioxide is injected into the flue gas flow upstream of the electrostatic precipitator. The amount of injected sulfur trioxide is controlled by varying the amount of sulfur that is burned. Other similar sulfur trioxide systems, which have been successfully used commercially, include a system which starts with a sulfur dioxide feedstock, which is vaporized and then catalytically converted to sulfur trioxide. Sulfur trioxide injection systems, such as illustrated in the '429 patent, work well and are widely used. In some instances, however, there are drawbacks: high equipment capital costs; a constant supply of sulfur or sulfur dioxide feedstock is required, and this feedstock must be safely handled; the several components of the burning, catalyzing, and injecting system must be kept in good working order; there is a substantial power consumption associated with the process; when the plant or system goes into stand-by condition, the system, at least from the converter forward, must be purged to prevent excessive corrosion of the system and/or blockage of the probe nozzles; the injection arrangement must be operative over a range of boiler operating conditions in a manner that appropriate mixing is achieved prior to the flue gas stream entering the precipitator; because the conversion of the newly produced SO 2 to SO 3 is not always 100% efficient, trace amounts of excess SO 2 may be produced; in many instances, significant runs of hot gas insulated duct-work must be included, together with complicated and costly manifold assemblies; and the like. U.S. Pat. No. 5,011,516 describes an alternate approach to the types of systems illustrated in the '429 Patent, and teaches an arrangement wherein a slip stream of flue gas is drawn from the main flow and passed over a catalyst. A portion of the sulfur dioxide in the slip stream is oxidized to sulfur trioxide, and the slip stream is merged back into the main flue gas flow. While of interest, this approach has major drawbacks when implemented. System thermal efficiency is reduced because less heat is recovered. There is typically insufficient mixing of the slip stream with the main flow at the point where they rejoin, due to an insufficient pressure differential. Moreover, the '516 patent does not disclose any approach which permits control of the amount of sulfur trioxide produced, responsive to variations in the sulfur content of the fuel and changes in other operating parameters. A patent to a related approach, U.S. Pat. No. 3,581,463, suggests using a fan to draw a portion of the hot gas flow into the slip stream, but gives no further details as to how the amount of sulfur trioxide can be controlled. One can imagine that valving could be added to the slip stream to control its total flow, but such valves are complex, expensive, and difficult to build. U.S. Pat. No. 5,320,052, which is assigned to the same assignee as is this invention, provides an improvement over the approaches discussed above and includes a catalytic converter support adapted to be disposed across at least a portion of the cross-section of the main duct, and a catalyst for the oxidation of sulfur dioxide to sulfur trioxide is supported on the catalyst support. This system further includes a mechanical adjustment means for selectively adjusting the amount of surface area of the catalyst which is exposed to the flow of flue gas in the main duct. While it is believed that the '052 system is an advance over the prior art discussed hereinabove, several problems and/or deficiencies exist, for example: structural modifications to the duct, which are required in a retrofit and/or new installed FGC system of this sort, is expensive and may be difficult to achieve in many instances; mechanical complexity, with a resultant potential for breakdown; because the efficiency of the catalyst in converting SO 2 to SO 3 is dependent to a great degree on the temperature of the flue gas passing thereby, the amount of catalyst surface area required is relatively substantial and may result in a significant back pressure being created, which in turn may result in a decrease on power plant efficiency; and the like. There is therefore a need for an improved approach to sulfur trioxide conditioning of flue gas streams. The present invention fulfills this need, and further provides related advantages. SUMMARY OF THE INVENTION The present invention provides an apparatus and method for sulfur trioxide conditioning of flue gas streams produced by fossil fuel power plants. This approach permits a selectively controllable amount of sulfur trioxide to be created and added to the flue gas stream. The apparatus used to accomplish the sulfur trioxide addition is simple and rugged, and readily controlled to precisely vary the sulfur trioxide addition. There is no sulfur burning apparatus or supply of sulfur required. No slip stream is taken from the flue gas stream, and no associated variable-speed fan or valving is used to achieve controllability. No additional sulfur dioxide is added to the flue gas stream with the sulfur trioxide addition. There is no difficulty in mixing the sulfur trioxide into the flue gas stream. No cumbersome or difficult to maintain equipment is required. No significant back-pressure is caused by the system of the present invention. Only a relatively minor modification to the duct work is required for the present invention. In accordance with the invention, a sulfur trioxide conditioning system is provided for use in a fossil fuel-burning facility having a main duct for transporting sulfur dioxide-containing flue gas from a boiler, through a heat recovery apparatus, and to particulate removal equipment, such as an electrostatic precipitator, for subsequent discharge through a stack. The sulfur trioxide conditioning system includes catalytic converter means for converting a portion of the sulfur dioxide in the flue gas to sulfur trioxide. The catalytic converter means includes a catalyst support adapted to be disposed across at least a portion of the cross section of the main duct, and a catalyst for the oxidation of sulfur dioxide to sulfur trioxide supported on the catalyst support. The conditioning system further includes selectively variable temperature modifying means in communication with the catalyst support to selectively vary the temperature of at least portions of the catalyst, to in turn vary the amount of catalytic conversion of sulfur dioxide, in the flue gas passing thereby, to sulfur trioxide. The temperature modification means operates independently of the temperature of the flue gas. The temperature modification means may be operable to heat or to cool the catalyst. A means for heating the catalyst can include, for example, an electrical heater within, or on, the catalyst support. A means for cooling the catalyst can include, for example, a coolant conduit within the catalyst support and a source of a coolant that is passed through the coolant conduit. The temperature modification means can include either a means for heating, and/or a means for cooling. The catalyst may be placed at a location in the flue gas duct corresponding to a maximum operating catalyst temperature than might ever be required, and then selectively cooled by passing coolant through internal conduits. No heating will ever be required. The catalyst chamber can alternatively be located at a location corresponding to the coolest temperature required for the catalyst, and only a means for heating provided. Or anywhere in between, depending upon design parameters and desires. The temperature modification means adjusts the catalyst temperature to a preselected level. The extent of the catalytically aided reaction is typically a strong function of the temperature of the catalyst. The present approach directly adjusts the catalyst temperature to that required to achieve the desired extent of reaction of the flue gas passing over the catalyst. The approach of the invention is particularly effective in controlling the extent of reaction where a relatively small amount of the reactive component of the flue gas is to be catalytically converted. In the case of the conversion of SO 2 to SO 3 to produce sulfuric acid, only a few percent of the SO 2 is typically converted. The heating or cooling of the catalyst, as required, is highly effective in precisely controlling the extent of conversion. The present invention provides an advance in the art of flue gas conditioning. Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic depiction of a fossil fuel power plant incorporating the principles of the present invention; FIG. 2 is a schematic graph of catalyzed chemical reaction conversion as a function of catalyst temperature; FIG. 3 is a perspective view of the interior of a honeycomb-style catalyst chamber with a coolant conduit therein; and FIG. 4 is a perspective view of the interior of a plate-style catalyst chamber with a heating element thereon. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 schematically illustrates a fossil fuel burning power plant 20 utilizing the apparatus and method of the present invention. Briefly, the power plant includes a boiler 22, which receives a flow of fuel from a fuel inlet 24 and a flow of preheated fresh combustion air from a preheated air conduit 26. The fuel introduced through the fuel inlet 24, mixed with preheated fresh air, introduced through the air conduit 26, is combusted to produce flue gas 28. The flue gas 28 heats water flowing in boiler tubes 30 and converts it to steam, and the steam is supplied to a turbine/generator 32 which produces electrical power. The flue gas 28 flows from the boiler 22 through an outlet flue gas conduit 34 to a catalyst portion or chamber 36. The catalyst chamber 36 includes a catalyst support 38, of any suitable configuration, and catalyst 40 supported thereon. The catalyst 40, which is operative for promoting a chemical reaction to convert a portion of the SO 2 in the flue gas stream to SO 3 , may be any of several types of catalysts. Any suitable catalyst may be used for the oxidation of sulfur dioxide to sulfur trioxide (i.e. vanadium oxide, alkali metal pyrosulfates,and alkali metal oxides); however, for purposes of reducing the amount of catalyst required, and hence the potential back pressure and energy requirements, a precious metal catalyst is preferred. The catalyst is typically applied to the catalyst support 38 by a wash and pressure drop for typical applications should not exceed 5", and preferably 2", of water gage coat technique. The preferred SO 2 /SO 3 catalyzed reaction will serve as the basis for the following discussion, but the invention is not so limited. The catalyst chamber 36 further includes temperature modification means 42 for modifying the temperature of at least a portion of the catalyst, to be different than that of the flue gas 28. The means for modifying 42 is preferably disposed within the catalyst support 38, or otherwise in communication with the surface thereof. The means for modifying may be selected to heat the catalyst 40 to a temperature, preferable at least 50° F. greater than that of the flue gas 28, or to cool the catalyst 40 to a temperature below that of the flue gas 28. Further details of the various approaches to the means for modifying will be presented subsequently. After leaving the catalyst chamber 36, the flue gas 28 passes through heat exchanger 44 that transfers heat from the flue gas 28 to the incoming fresh air in the air conduit 26. The cooled flue gas passes to a device for removing particulates therefrom, here illustrated as an electrostatic precipitator 46. Alter the removal of particulate matter, the flue gas passes to an exhaust gas stack. At some point downstream of the location of the catalyst chamber 36, there may be provided an instrument to assess the extent of the catalytic conversion reaction catalyzed by the catalyst 40. In one preferred case, a resistivity monitor 48 may measure the resistivity of the flyash passing thereby. The resistivity of the flyash is one of the key factors which determine the efficiency of an electrostatic precipitator. The determination of the sulfur trioxide content of the flue gas, after it passes by the flue gas conditioning system of the present invention, is another way of assessing the effectiveness of the flue gas conditioning system of the present invention. On the other hand, the extent of the reaction may also be assessed by its effect on the performance of other parts of the pollution control system, for example, an opacity measurement at the stack exit, the current within the precipitator 46, gas temperature, and the like. The degree of heating or cooling of the catalyst 40 by the means for modifying 42 may be controlled by a resistivity measurement from the monitor 48, or an indirect measurement from the electrostatic precipitator 46, or otherwise. A control signal 50 from either the monitor 48 or the electrostatic precipitator 46, or otherwise (i.e. boiler operating conditions) is received by a controller 52. The controller 52 determines whether greater or less temperature modification is required, and sends a command signal 54 to a modifying control 56. The modifying control 56 alters the flow of a modifier 58 from a source 60 to the means for modifying 42, thereby completing the control loop. This discussion of a power plant is intended to be highly schematic in nature and to provide the information necessary to understand, practice, and enable the present invention. In an operating power plant there are typically many other systems that are not shown here. The present invention is compatible with such other systems and may be used with them. FIG. 2 depicts the conceptual origin of the present invention. The extent of a catalyzed reaction is, in many cases, strongly dependent upon the temperature of the catalyst 40 in the catalyst chamber 36. The higher the temperature of the catalyst, the greater the extent of completion of the reaction, preferably, the catalyst is active in the conversion of SO 2 to SO 3 at a temperature of substantially no less than 500° F. In the preferred case, the conversion of SO 2 to SO 3 in the presence of a catalyst proceeds further to completion at higher temperatures of the catalyst. In a preferred embodiment, the increase in the efficiency of the catalyst 40 for the conversion of SO 2 to SO 3 is at least 200% over the range from the temperature of the flue gas passing by the catalyst 40, to 100° F. higher. FIG. 2 illustrates such a preferred case wherein it is indicated that for a 50° F. rise in catalyst temperature (i.e. from 600° F. to 650° F.), the conversion efficiency of the catalyst rises from approximately 2% to 8%. In practice, the preferred range of conversion of SO 2 to SO 3 is from 0 to 20%, and even more preferred is from 0 to 10%, and is proportional, respectively, to the adjustment in the temperature of catalyst 40. The present invention involves no moving parts inserted into the flue gas stream, and no alteration of the flow of the flue gas stream. Only the temperature of the catalyst is changed, thereby changing the extent of the catalyzed reaction. In the preferred approach, the temperature of the catalyst is changed from the "inside" by altering the temperature of the catalyst support 38, rather than from the "outside" by changing the temperature of the flue gas. (The temperature of the catalyst could also be changed by external radiation, for example, but in this event the temperature of the catalyst is changed, not that of the flue gas.) As it passes over the catalyst, the temperature of the flue gas can change to a minor degree, as the contact time between flue gas and the catalyst is relatively short. Moreover, in the preferred embodiment only a relatively small conversion of SO 2 to SO 3 , on the order of 0.5 to 5 percent, is required, so there will be a relatively minor temperature change imparted to the flue gas as it flows through the catalyst chamber 36. It is not necessary in most cases that the means for modifying 42 the temperature of the catalyst 40 achieve a uniform heating or cooling of the catalyst 40. The means for modifying may heat some portions of the catalyst 40 more than others, so that different regions of the catalyst 40 operate at different locations on the curve of FIG. 2. This operating condition is perfectly acceptable, and reflects the normal operating mode. Since there is a feedback controller 52 that controls the flow of the modifier 58 to achieve a particular result, any temperature variations will be accounted for by the control system. In some cases it may be desirable to achieve a uniform temperature throughout the catalyst 40, and in that case great care can be taken to design a uniform heating or cooling system. FIG. 1 shows a single heating or cooling system for the catalyst chamber 36. There may be provided both a heating and a cooling system for the catalyst chamber if desired. However, for most cases it is possible to design the catalyst chamber such that only a single heating or cooling system is required. In one case, the catalyst chamber 36 is located relatively far upstream in the conduit 34 (close to the boiler 22) so that the flue gas is at a relatively high temperature as it enters the catalyst chamber 36. In this arrangement, the location of the catalyst chamber is selected so that it will never be necessary to heat the catalyst, within the operating limits of the power plant. Only a cooling system for the catalyst will be thence be required. On the other hand, the catalyst chamber 36 may be located further downstream in the conduit 34, so that the flue gas has cooled somewhat before it enters the catalyst chamber 36. The location of the catalyst chamber is selected so that it will never be necessary to cool the flue gas within the operating parameters of the power plant. In this case only a heater for the catalyst will be required. Either of the above described arrangements are acceptable, depending upon the design criteria, cost of energy, availability of coolant, system capital costs visa vis running costs (which may vary from plant to plant), and the like. FIGS. 3 and 4 depict a cooling system and a heating system for the catalyst, respectively. In FIG. 3, a honeycomb-style catalyst support 70 has catalyst 72 on the surfaces 74 thereof. A coolant conduit 76 passes through the interior of the catalyst support 70. A coolant such as water is the modifier 58 of FIG. 1, the source 60 is a water source, and the modifying control 56 is a water flow valve. The flow of water through the conduit 76 cools the surfaces 74 and thence the catalyst 72 by conduction. FIG. 4 illustrates a plate-style catalyst support 80, with catalyst 82 on the surfaces 84 thereof. A heating element 86 such as a resistor is carried by plate 80. Electrical current through the resistor is the modifier 58 of FIG. 1, the source 60 is an electrical current source, and the modifying control 56 is a current control such as a variable resistor. The heat produced by the electrical resistance in the heating element 86 heats the surfaces 84 and thence the catalyst 82 by conduction. Further description of the heating elements 86, and the support 80 therefore are not required, for electrically heated support arrangements are readily commercially available and are well known (i.e. see U.S. Pat. No. 5,213,780, which illustrates a heated catalytic surface to maximize catalytic NOx reduction). It is to be noted that the catalytic surface itself can be configured to maximize the surface presented to the flowing flue gas stream, such as using corrugations, or the like. It is envisioned that a number of supports 80 would be positioned within the duct 34, the actual number being dependent on a variety of design factors (i.e. the total surface area of catalyst required, the depth of the supports 80, the amount of conversion required, the type of fuel burned, the flue gas temperature passing thereby, the catalyst selected, and the like). FIGS. 3 and 4 illustrate two preferred types of catalyst supports and their respective cooling and heating means. Other types of catalyst supports can similarly be used, and in each case any operable type of heating and cooling means can be used. Heating could also be accomplished by a diverted flow of high-temperature flue gas, but that approach requires valving and modification of the flue gas stream, a generally less desirable alternative. In addition to the embodiments illustrated in FIGS. 3 & 4, it is to be understood that existing elements within the duct 34, and even portions of the duct 34, can be used as supports 38 for the catalyst 40, so long as they have surfaces exposed to the flow of flue gas 28. In this regard, is envisioned that known turning vanes within the duct 34 may be utilized for supports for catalyst in a manner as is taught by the invention herein. Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

A method and apparatus for the selective control of the sulfur trioxide concentration in flue gases, to enhance the ash removal efficiency of electrostatic precipitators, which includes supporting a catalyst in the path of the flue gas, positioning temperature modifying means in communication with the catalyst, passing the flue gas by the catalyst and selectively varying the temperature of the catalyst, with the temperature modifying means, to vary the amount of catalytic conversion of SO 2 in the flue gas to SO 3 .

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a wrench, and more particularly to a wrench that can be operated in a limited space and convenient in use. [0003] 2. Description of Related Art [0004] With reference to FIG. 13 , a first conventional wrench has a body ( 50 ) and a head ( 51 ). The head ( 51 ) is pivotally mounted on the body ( 50 ) and has a ratchet hole ( 52 ) defined in the head ( 51 ). When the wrench is in use, the ratchet hole ( 52 ) is mounted around a nut ( 40 ) and the body ( 50 ) is rotated. Because the head ( 51 ) of wrench is pivotally mounted on the body ( 50 ), the wrench could be used in a limited space. However, when the angle formed between the head ( 51 ) and the body ( 50 ) is near a right angle, to rotate the wrench is difficult. Furthermore, when the user wants to rotate nuts in different sizes, to replace a different head ( 50 ) is necessary. [0005] With reference to FIGS. 14 and 15 , a second conventional wrench comprises a body ( 60 ), two heads ( 61 ), two pins ( 62 ) and two springs ( 62 ). The body ( 60 ) has a distal end, a proximal end and two through holes ( 600 ). The two through holes ( 600 ) are respectively defined through the distal end and the proximal end. The two heads ( 61 ) are mounted on the distal end and the proximal end of the body ( 60 ). The two springs ( 63 ) are respectively mounted inside the through holes ( 600 ). The two pins ( 62 ) are respectively mounted through the heads ( 61 ) and the through holes ( 600 ) in the body ( 60 ). When such wrench is in use, the heads ( 61 ) of the wrench could be rotated in a limited space. However, when the angle between the head ( 61 ) and the body ( 60 ) is near a right angle, to rotate the wrench is difficult. [0006] To overcome the shortcomings, the present invention tends to provide a wrench to mitigate the aforementioned problems. SUMMARY OF THE INVENTION [0007] The primary objective of the present invention is to provide a wrench that can be used in a limited space and convenient in use. [0008] A wrench has a body, a head and at least one pivotal device. The body has two arms separately formed on a distal end of the body and a mounting recess formed between the two arms. Each arm has a hole defined through the arm. The head is rotatably and replaceably mounted inside the mounting recess and has a driving hole defined through the head and two pivotal holes defined in the outer surface of the head and facing the holes in the body. The at least one pivotal device is movably mounted between the body and the head for holding the head. [0009] When the wrench is in use, the body may be rotated at various angles relative to the head, so that the wrench could be used in a limited space and is convenient in use. Furthermore, the head may be conveniently replaced depending on a user's needs. [0010] Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 is a perspective view of a first embodiment of a wrench in accordance with the present invention; [0012] FIG. 2 is an exploded perspective view of the wrench in FIG. 1 ; [0013] FIG. 3 is a side view in partial section of the wrench in FIG. 1 ; [0014] FIG. 4 is an operational perspective view of the wrench in FIG. 1 ; [0015] FIG. 5 is an operational side view in partial section of the wrench in FIG. 1 ; [0016] FIG. 6 is a perspective view of a second embodiment of a wrench in accordance with the present invention; [0017] FIG. 7 is a side view in partial section of the wrench in FIG. 6 ; [0018] FIG. 8 is an operational side view in partial section of the wrench in FIG. 6 when the head of the wrench is changed; [0019] FIG. 9 is a perspective view of a third embodiment of a wrench in accordance with the present invention; [0020] FIG. 10 is a side view in partial section of the wrench in FIG. 9 ; [0021] FIG. 11 is an operational side view in partial section of the wrench in FIG. 9 when the head of the wrench is changed; [0022] FIG. 12 is an exploded perspective view of a fourth embodiment of a wrench in accordance with the present invention; [0023] FIG. 13 is perspective view of a first conventional wrench in accordance with the prior art; [0024] FIG. 14 is an exploded perspective view of a second conventional wrench in accordance with the prior art; and [0025] FIG. 15 is a perspective view of the conventional wrench in FIG. 14 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0026] To solve the shortcomings of the conventional wrench, the present invention intends to provide a wrench that can be used in a limited space and is convenient in use. The wrench of the present invention has a body, a head pivotally mounted on the body and at least one pivotal device connected between the body and the head. [0027] With reference to FIGS. 1 to 3 , a first embodiment of a wrench ( 10 ) in accordance with the present invention has a body ( 11 ), a head ( 20 ) and a pivotal device ( 30 A). [0028] The body ( 11 ) is elongated and has a thickness, a proximal end, a distal end ( 12 ), two arms ( 121 ), a handle ( 13 ) and a mounting recess ( 14 ). The arms ( 121 ) are extended on the distal end ( 12 ) of the body ( 11 ) and forms the mounting recess ( 14 ) between the arms ( 121 ). Each arm ( 12 ) has a free end, a holding surface ( 1211 ) and a hole ( 15 A). The holding surface ( 1211 ) is formed on the arm ( 121 ) and faces to the holding surface ( 1211 ) on the other arm ( 12 ). The two holding surfaces ( 1211 ) are paralleled to each other. The handle ( 13 ) is mounted on the proximal end of the body ( 11 ). The hole ( 15 A) is defined through the arm ( 121 ) and is near the free end of the arm ( 121 ). The two holes ( 15 A) are aligned with each other. [0029] The head ( 20 ) has an octagonal cross section and is pivotally and replaceable mounted inside the mounting recess ( 14 ) in the body ( 11 ). The head ( 20 ) has a thickness, an outer surface, a driving hole ( 21 ), multiple arc protrusions ( 211 ) and two pivotal holes ( 23 ). The thickness of the head ( 20 ) is the same as that of the body ( 11 ). The driving hole ( 21 ) is defined through the head ( 20 ) and has an inner surface. In a preferred embodiment, the driving hole ( 21 ) may be, but not limited to a hexagon hole for holding a nut or a threaded pin directly. The multiple arc protrusions ( 211 ) are formed on the inner surface of the driving hole ( 21 ) for holding a nut or a threaded pin securely. The two pivotal holes ( 23 ) are defined in the outer surface and are respectively corresponding to the holes ( 15 A) in the arm ( 121 ) of the body ( 11 ). [0030] The pivotal device ( 30 A) is mounted between the body ( 11 ) and the head ( 20 ) for holding the head ( 20 ) in the mounting recess ( 14 ). The pivotal device ( 30 A) may be two threaded pins, each threaded pin has a distal end and a post ( 31 A). The post ( 31 A) is formed on the distal end of the threaded pin. The two threaded pins are respectively mounted through the holes ( 1 5 A) and into the pivotal holes ( 23 A), so that the head ( 20 ) will be pivotally mounted inside the recess ( 14 ) in the body ( 11 ). [0031] With reference to FIGS. 4 and 5 , when the wrench ( 10 ) in accordance with the present invention is in use, the driving hole ( 21 ) in the head ( 20 ) is mounted around a nut ( 40 ) and the body ( 11 ) is rotated to rotate the nut ( 40 ) with the head ( 20 ). Because the head ( 20 ) is pivotally mounted with the body ( 11 ), therefore, the angle between the body ( 11 ) and the head ( 20 ) may be adjusted for using in a limited space. When the wrench ( 10 ) is used in a very limited space, the body ( 11 ) may become perpendicular to the head ( 20 ) and the body ( 11 ) is still convenient for use. [0032] When the head ( 20 ) of the present wrench ( 10 ) is replaced, the pivotal device ( 30 A) is removed firstly with a tool. Therefore, the post ( 31 A) of each threaded pin is escaped from the pivotal hole ( 23 ) and the head ( 20 ) can be replaced. [0033] With reference to FIGS. 6 and 7 , a second embodiment of a wrench ( 60 ) in accordance with the present invention is shown. The wrench ( 60 ) has a body, a head ( 20 B) and two pivotal devices ( 30 B). The way to assemble the body and the head ( 20 B) is same as foregoing described. The differences are described as follows. [0034] Each arm ( 121 B) has an outer surface. Each hole ( 15 B) defined in the arm ( 121 B) has an inner thread ( 15 1 B) near the outer surface of the arm ( 121 B). [0035] The head ( 20 B) has two pivotal holes ( 23 B) defined in the outer surface of the head ( 20 ) and corresponding respectively to the holes ( 15 B) in the arms ( 121 B). [0036] The two pivotal devices ( 30 B) are respectively mounted between the arms ( 121 B) and the head ( 20 B) for pivotally holding the head ( 20 B) between the arms ( 121 B). Each pivotal device ( 30 B) has a holder ( 31 B), a pivotal rod ( 32 B), a spring ( 33 B) and a resilient tab ( 34 B). The holder ( 31 B) has an outer threaded portion ( 311 B) and is mounted inside the holes ( 15 B) and screwed with the inner thread ( 151 B) in the corresponding hole ( 15 B). The pivotal rod ( 32 B) is mounted inside the corresponding hole ( 15 B) and held by the holder ( 31 B). The pivotal rod ( 32 B) has an enlarged end ( 321 B). The enlarged end ( 321 B) extends into a corresponding pivotal hole ( 23 B) in the head ( 20 B). The spring ( 33 B) is mounted around the pivotal rod ( 32 B) and abuts the enlarged end ( 321 B) and the holder ( 31 B). The resilient tab ( 34 B) is mounted on a corresponding arm ( 121 B) and has a distal end and a proximal end. The proximal end of the resilient tab ( 34 B) is mounted on the corresponding arm ( 121 B), and the distal end of the resilient tab ( 34 B) is mounted with the holder ( 31 B). [0037] With reference to FIG. 8 , when the head ( 20 B) is replaced, the resilient tabs ( 34 B) are pressed to pull the enlarged ends ( 321 B) of the pivotal devices ( 30 B) moving inside the holes ( 15 B) and escaping from the pivotal holes ( 23 B). Therefore, the head ( 20 B) will not be held by the pivotal devices ( 30 B) and will be replaced without a hand tool. [0038] With reference to FIGS. 9 and 10 , a third embodiment of a wrench in accordance with the present invention is shown. The wrench of the third embodiment is almost the same as the first embodiment, but differs in the followings. [0039] The arms ( 121 C) have a first hole ( 15 C) and a second hole ( 15 D) respectively defined through the arms ( 121 C) and near the distal end of the arms ( 121 C). The first hole ( 15 C) is a threaded hole, and the second hole ( 15 D) is a through hole and has an inner surface, a diameter ( 151 D) and a threaded portion ( 152 D). The threaded portion ( 152 D) is defined near the outer surface of the arm ( 121 C). [0040] The pivotal devices ( 30 C) are mounted between the head and the body and have a first pivotal device ( 30 C) and a second pivotal device ( 30 D). The first pivotal device ( 30 C) is a threaded pin and is mounted inside the first hole ( 15 C). The first pivotal device ( 30 C) has an inner end, an outer end, a post ( 31 C) and an enlarged head ( 32 C). The post ( 31 C) is formed on the inner end. The enlarged head ( 32 C) is formed on the outer end of the threaded pin ( 30 C) and has a pattern formed on the enlarged head ( 32 C) for preventing slipping. The post ( 31 C) extends into the recess ( 14 C) between the two arms ( 121 C) and is mounted inside the pivotal hole ( 23 C) in the head ( 20 C). The second pivotal device ( 30 D) is mounted inside the second hole ( 15 D) and has a ball ( 31 D), a spring ( 32 D) and a threaded post ( 33 D). The ball ( 31 D) is received inside the second hole ( 15 D) and partially extends out of the second hole and into a corresponding pivotal hole. The spring ( 32 D) is mounted inside the second hole ( 15 D). The threaded post ( 33 D) is threaded with the threaded portion ( 152 D) in the second hole ( 15 D) and abuts against the spring ( 32 D). [0041] With reference to FIG. 11 , when the head ( 20 C) is replaced, the first pivotal device ( 30 C) is loosening from holding the head ( 20 C). When the head ( 20 C) is removed, the ball ( 31 D) is pressed into the second hole ( 15 D) and the head ( 20 C) may be replaced. [0042] With reference to FIG. 12 , a fourth embodiment of a wrench in accordance with the present invention is shown. The way to assemble the body and the head may be the same as the first, the second or the third embodiment, but differs in the type of the head. The head ( 20 D) may further comprise a ratchet ( 25 ) mounted on the head ( 20 D). The ratchet ( 25 ) is used for driving a sleeve ( 251 ). [0043] The wrench in accordance with the present invention has the following advantages: [0044] 1. When the wrench is used in a limited space, the body may be rotated to various angles to the head and still convenient for operating the wrench. Therefore, the wrench could be applied in various spaces. [0045] 2. To replace the head is convenient. Because the head is pivotally mounted on the body, and the pivotal device of the wrench is convenient for a user to replace the head of the wrench. Therefore, a user may replace the head conveniently depending on his/her needs. [0046] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of raw material used, shape, size, installing surface and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

A wrench has a body, a head and at least one pivotal device. The body has two arms separately formed on a distal end of the body and a mounting recess formed between the two arms. Each arm has a hole defined through the arm. The head is rotatably and replaceably mounted inside the mounting recess and has a driving hole defined through the head and two pivotal holes defined in the outer surface of the head and facing the holes in the body. The at least one pivotal device is movably mounted between the body and the head for holding the head. When the wrench is in use, the body may be rotated at various angles relative to the head, so that the wrench could be used in a limited space and is convenient in use. Furthermore, the head may be conveniently replaced depending on a user's needs.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a U.S. continuation application under 35 U.S.C. §111(a) claiming priority under 35 U.S.C. §§120 and 365(c) to International Application No. PCT/CN2013/080094 filed on Jul. 25, 2013, which claims the priority benefit of Chinese Patent Application No. 201210299261.9 filed on Aug. 22, 2012, the contents of which are incorporated by reference herein in their entirety for all intended purposes. FIELD OF THE INVENTION [0002] The disclosure relates to a technical field for processing application programs, in particular, to a method and user equipment for managing application programs. BACKGROUND [0003] As the development of software technology, more and more application programs are developed and employed, which enrich and facilitate people's life and work. Usually, a user may select and download a required application program from an application program store or search and download the application program in the web, and then install the downloaded application program into the use equipment. The user may also delete an unwanted application program from the user's user equipment (UE) so that there is enough space for receiving new application programs. [0004] In the prior art, the application program may be deleted according to the following method. When the user long-presses an icon of an application program to be deleted, an icon of a waste bin is displayed in the top or bottom of the display screen. When the user drags the application program into the waste bin, a confirmation message for deletion is popped up. When information for confirming the deletion is received from the user, the application program is deleted. [0005] In the process for implementing this invention, the inventor has noticed at least the following problem in the prior art. For a UE with a screen of 4.3 or larger inches, in the process for deleting the application program by dragging the icon of the application program to the waste bin displayed in the top or bottom of the screen, if the icon of the application program is located in the bottom or top of the screen, the dragging distance is long. In particular, when the user operates by a single hand, the long distance dragging operation is difficult. SUMMARY OF THE INVENTION [0006] In order to solve the problem in the prior art, a method for embodiments of managing application programs and a UE for implementing the method are provided in the disclosure. [0007] In an aspect, a method for managing an application program is provided in an embodiment of the invention. The method comprises: [0008] monitoring a touch event generated when a user touches an icon displayed in a displaying interface; [0009] determining an area of the first icon in the displaying interface when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period; [0010] displaying a second icon in the determined area; [0011] monitoring a moving trace generated when the user drags the first icon and controlling the first icon to move along the moving trace; and deleting the application program corresponding to the first icon by using the application program corresponding to the second icon when the first icon moves to a position of the second icon. [0012] In an embodiment, determining an area of the first icon in the displaying interface comprises: [0013] reading out position information of the first icon in the display interface; [0014] determining a coordinate of a center of the first icon according to the position information; [0015] searching corresponding relationship between areas in the display interface and coordinate intervals according to the determined coordinate of the center of the first icon so as to obtain an area in which the coordinate is located, the searched out area being the area of the display interface in which the first icon is located. [0016] In an embodiment, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0017] determining whether the application program corresponding to the first icon is a third party application program or a local system program; [0018] deleting the application program corresponding to the first icon by the application program corresponding to the second icon when the application program corresponding to the first icon is a third party application program; [0019] preventing deleting the application program corresponding to the first icon by the application program corresponding to the second icon and providing a prompt to the user when the application program corresponding to the first icon is a local system program. [0020] In an embodiment, determining whether the application program corresponding to the first icon is a third party application program or a local system program comprises: [0021] reading out an amending authority for the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon; or [0022] searching a local system program catalogue according to the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the local system program catalogue does not include the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the local system program catalogue includes the application program corresponding to the first icon. [0023] In an embodiment, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0024] locally deleting the application program corresponding to the first icon by the application program corresponding to the second icon; or [0025] isolating the application program corresponding to the first icon into the application program corresponding to the second icon. [0026] In another aspect, a user equipment comprising a first monitoring module, a determining module, a controlled displaying module, a second monitoring module and a deleting module is provided in an embodiment of the invention, in which: [0027] the first monitoring module is configured to monitor a touch event generated when a user touches an icon displayed on a displaying interface; [0028] the determining module is configured to determine an area of the first icon in the displaying interface when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period; [0029] the controlled displaying module is configured to display a second icon in the determined area; [0030] the second monitoring module is configured to monitor a moving trace generated when the user drags the first icon and control the first icon to move along the moving trace; [0031] the deleting module is configured to delete the application program corresponding to the first icon by using the application program corresponding to the second icon when the first icon moves to a position of the second icon. [0032] In an embodiment, the determining module comprises: [0033] a reading unit configured to read out position information of the first icon in the display interface; [0034] a determining unit configured to determine a coordinate of a center of the first icon according to the position information; [0035] a searching unit configured to search corresponding relationship between areas in the display interface and coordinate intervals according to the determined coordinate of the center of the first icon so as to obtain an area in which the coordinate is located, the searched out area being the area of the display interface in which the first icon is located. [0036] In an embodiment, the deleting module comprises: [0037] a determining unit configured to determine whether the application program corresponding to the first icon is a third party application program or a local system program; [0038] a first processing unit configured to delete the application program corresponding to the first icon by the application program corresponding to the second icon when the application program corresponding to the first icon is a third party application program; [0039] a second processing unit configured to prevent deleting the application program corresponding to the first icon by the application program corresponding to the second icon and provide a prompt to the user when the application program corresponding to the first icon is a local system program. [0040] In an embodiment, the determining unit is configured to read out an amending authority for the application program corresponding to the first icon, determine that the application program corresponding to the first icon is a third party application program if the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, and determine that the application program corresponding to the first icon is a local system program if the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon; or [0041] the determining unit is configured to search a local system program catalogue according to the application program corresponding to the first icon, determine that the application program corresponding to the first icon is a third party application program if the local system program catalogue does not include the application program corresponding to the first icon, and determine that the application program corresponding to the first icon is a local system program if the local system program catalogue includes the application program corresponding to the first icon. [0042] In an embodiment, the first processing unit is configured to locally delete the application program corresponding to the first icon by the application program corresponding to the second icon; or [0043] the first processing unit is configured to isolate the application program corresponding to the first icon into the application program corresponding to the second icon. [0044] Technical solutions of embodiments of the invention bring the following advantages. The area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. DESCRIPTION OF THE DRAWINGS [0045] In order to illustrate technical solutions of embodiments of the disclosure more clearly, drawings used in the embodiments are briefly described below. It is obvious that the drawings described below are only some embodiments of the invention. For a skilled in the art, other drawings may be obtained without paying any inventive work based on these drawings. [0046] FIG. 1 is a flow diagram showing a method for managing an application program according to a first embodiment of the invention; [0047] FIG. 2 is a diagram showing a displaying interface of a UE according to a second embodiment of the invention; [0048] FIG. 3 is a diagram showing an area division of the displaying interface of the UE according to the second embodiment of the invention; [0049] FIG. 4 is a diagram showing an area division of the displaying interface of the UE according to the second embodiment of the invention; [0050] FIG. 5 is a flow diagram showing a method for managing an application program according to the second embodiment of the invention; [0051] FIG. 6 is a diagram showing a displaying interface of a UE according to the second embodiment of the invention; [0052] FIG. 7 is a structural diagram showing a UE according to a third embodiment of the invention; [0053] FIG. 8 is a structural diagram showing a UE according to the third embodiment of the invention; [0054] FIG. 9 is a structural diagram showing a UE according to the third embodiment of the invention; [0055] FIG. 10 is a structural diagram showing a terminal according to a fourth embodiment of the invention; [0056] FIG. 11 is a structural diagram showing a terminal according to the fourth embodiment of the invention. DETAILED DESCRIPTION [0057] In order to make the objects, technical solutions and advantages of the invention more apparent, the invention will be further illustrated in details in connection with accompanying figures and embodiments hereinafter. Embodiment I [0058] Referring to FIG. 1 , a method for managing an application program comprises the following steps. [0059] At step 101 , a touch event generated when a user touches an icon displayed on a displaying interface is monitored. [0060] At step 102 , when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period, an area of the first icon in the displaying interface is determined. [0061] At step 103 , a second icon is displayed in the determined area. [0062] At step 104 , a moving trace generated when the user drags the first icon is monitored, and the first icon is controlled to move along the moving trace. [0063] At step 105 , when the first icon moves to a position of the second icon, the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon. [0064] In this embodiment, the area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. Embodiment II [0065] In this embodiment, the display interface of the UE is divided into a plurality of grids. After the UE executes an install program of the application program and finishes installation of the application program, an unoccupied grid among currently unoccupied grids in the display interface is sequentially selected and an icon corresponding to the application program is displayed in the selected grid. According to the embodiment, a position of the grid occupied by the icon may be used as a display position of the icon, and position information of the icon corresponding to each application program in the display interface is recorded. In particular, FIG. 2 shows a display interface of a UE according to the embodiment, which is divided into 16 grids each corresponding to an icon of an application program installed in the UE. Dashed boxes in FIG. 2 are unoccupied grids in the display interface. [0066] In this embodiment, the display interface of the UE may be a touch screen so that the user may delete the application program by touching the icon of the application program displayed in the touch screen. [0067] In the embodiment, the display interface of the UE may be previously divided into areas so that the user may delete the application program conveniently. In particular, the display interface of the UE may be equally divided into a plurality of areas, for example, as shown in FIG. 3 or FIG. 4 in both of which the display interface is divided into four areas A, B, C and D. Accordingly, when the user operates the icon of the application program displayed in the touch screen to delete the operated application program, a newly added icon for deletion may be created and displayed in the area in which the icon of the operated application program is located. The icon for deletion corresponds to an application program for deleting an application program. Thereafter, the user may drag the icon of the application program to the icon for deletion within the same area for deleting the application program. The distance for dragging the icon of the application program to be deleted is reduced, which facilitates the operation. [0068] Based on the above description, a method for managing the application program is provided in the embodiment. The method may be implemented by the UE. As shown in FIG. 5 , the method comprises the following steps. [0069] At step 201 , a touch event generated when a user touches an icon displayed on a displaying interface is monitored. [0070] In the embodiment, when the user touches an icon displayed on a displaying interface in a screen of a terminal, a touch event is generated. In specific implementation, the touch event generated when the user touches the icon displayed in the display interface may be monitored by a preset application program programmed with JavaScript scripting language or a controller in the UE. [0071] At step 202 , when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period, an area of the first icon in the displaying interface is determined. In the embodiment, the predetermined period may be set by software or an operator as 1 s, 2 s or the like, which is not limited herein. [0072] In particular, the area of the first icon in the displaying interface may be determined as follows. [0073] Firstly, position information of the first icon in the display interface is read out. [0074] In the embodiment, the position information of the icon corresponding to the application program is recorded when the application program is installed and executed and the icon of the application program is displayed in a grid divided in the display interface so that the position information of the first icon, such as (2, 3) to (3, 3), is read out from the system when a touch event to the first icon is monitored. [0075] The coordinate of the center of the first icon is determined according to the position information. In particular, the central point of the read out position information may be used as the coordinate of the center of the first icon. For example, the central point (2.5, 2.5) of the read out position information (2, 3) to (3, 3) may be used as the coordinate of the center of the first icon. [0076] According to the determined coordinate of the center of the first icon, an area in which the coordinate is located is obtained by searching corresponding relationship between areas in the display interface and the coordinate intervals. The searched out area is the area in the display interface in which the first icon located. [0077] Specifically, a corresponding relationship between the areas and the coordinate intervals may be listed in Table I. [0000] areas coordinate intervals A (0, 0) to (−3, 3) B (0, 0) to (3, 3)  C  (0, 0) to (−3, −3) D (0, 0) to (3, −3) [0078] When the coordinate of the center of the first icon, such as (2.5, 2.5), is determined, the corresponding relationship between the areas and the coordinate intervals as shown in Table I, and it is determined that the coordinate (2.5, 2.5) is located in the area B. Thus, it is known that the first icon is located in the area B of the display interface. [0079] At step 203 , a second icon is displayed in the determined area. [0080] In specific implementation, the second icon may be created and displayed at an edge of the area in which the first icon is located. In the embodiment, the second icon may be an icon in a form of a waste bin. As shown in FIG. 6 , the second icon is displayed in the area B of the display interface in which the first icon is located. [0081] At step 204 , a moving trace generated when the user drags the first icon is monitored, and the first icon is controlled to move along the moving trace. [0082] At step 205 , when the first icon moves to a position of the second icon, the user is prompted whether to delete the application program corresponding to the first icon. In the embodiment, the user may be prompted whether to delete the application program corresponding to the first icon by popping up a prompt box. [0083] At step 206 , when the user selects to delete the application program corresponding to the first icon, the application program corresponding to the first icon is deleted by the application program corresponding to the second icon. [0084] Specifically, the application program corresponding to the first icon may be deleted by the application program corresponding to the second icon as follows. [0085] Firstly, it is determined whether the application program corresponding to the first icon is a third party application program or a local system program. The third party application program herein refers to an application program which is not programmed officially and can be installed or uninstalled in the UE. Correspondingly, the local system program is an officially programmed application program, which is not allowed to be amended or deleted. [0086] When the application program corresponding to the first icon is a third party application program, the application program corresponding to the first icon is deleted by the application program corresponding to the second icon. [0087] When the application program corresponding to the first icon is a local system program, the application program corresponding to the first icon is not allowed to be deleted and a prompt is provided to the user by popping up a prompt box in the display area of the screen. [0088] Herein, whether the application program corresponding to the first icon is a third party application program or a local system program may be determined as below. [0089] An amending authority for the application program corresponding to the first icon is read out. When the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a third party application program. Otherwise, when the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a local system program. [0090] Alternatively, a local system program catalogue may be searched according to the application program corresponding to the first icon. When the local system program catalogue does not include the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a third party application program. Otherwise, when the local system program catalogue includes the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a local system program. [0091] Herein, the application program corresponding to the first icon may be deleted by the application program corresponding to the second icon as follows. [0092] The application program corresponding to the first icon is locally deleted by the application program corresponding to the second icon. [0093] Alternatively, the application program corresponding to the first icon may be isolated into the application program corresponding to the second icon. [0094] It is noted that, in specific implementation of the embodiment, when the first icon is moved to the position of the second icon, the application program corresponding to the first icon may be deleted directly by the application program corresponding to the second icon without prompting the user whether to delete the application program corresponding to the first icon. [0095] In the embodiment, the area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. Embodiment III [0096] Referring to FIG. 7 , a UE may comprise a first monitoring module 301 , a determining module 302 , a controlled displaying module 303 , a second monitoring module 304 and a deleting module 305 . [0097] The first monitoring module 301 is configured to monitor a touch event generated when a user touches an icon displayed on a displaying interface. [0098] The determining module 302 is configured to determine an area of the first icon in the displaying interface when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period. [0099] The controlled displaying module 303 is configured to display a second icon in the determined area. [0100] The second monitoring module 304 is configured to monitor a moving trace generated when the user drags the first icon and control the first icon to move along the moving trace. [0101] The deleting module 305 is configured to delete the application program corresponding to the first icon by using the application program corresponding to the second icon when the first icon moves to a position of the second icon. [0102] Further, referring to FIG. 8 , the determining module 302 of FIG. 7 may comprise the following units. [0103] A reading unit 3021 is configured to read out position information of the first icon in the display interface. [0104] A determining unit 3022 is configured to determine the coordinate of the center of the first icon according to the position information. [0105] A searching unit 3023 is configured to search corresponding relationship between areas in the display interface and the coordinate intervals according to the determined coordinate of the center of the first icon so as to obtain an area in which the coordinate is located. The searched out area is the area of the display interface in which the first icon is located. [0106] Further, referring to FIG. 9 , the deleting module 305 of FIG. 7 may comprise the following units. [0107] A determining unit 3051 is configured to determine whether the application program corresponding to the first icon is a third party application program or a local system program. [0108] A first processing unit 3052 is configured to delete the application program corresponding to the first icon by the application program corresponding to the second icon when the application program corresponding to the first icon is a third party application program. [0109] A second processing unit 3053 is configured to prevent deleting the application program corresponding to the first icon by the application program corresponding to the second icon and provide a prompt to the user when the application program corresponding to the first icon is a local system program. [0110] Specifically, the determining unit 3051 reads out an amending authority for the application program corresponding to the first icon. When the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a third party application program. Otherwise, when the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a local system program. [0111] Alternatively, the determining unit 3051 may search a local system program catalogue according to the application program corresponding to the first icon. When the local system program catalogue does not include the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a third party application program. Otherwise, when the local system program catalogue includes the application program corresponding to the first icon, it is determined that the application program corresponding to the first icon is a local system program. [0112] Specifically, the first processing unit 3052 may locally delete the application program corresponding to the first icon by the application program corresponding to the second icon. [0113] Alternatively, the first processing unit 3052 may isolate the application program corresponding to the first icon into the application program corresponding to the second icon. [0114] In the embodiment, the area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. [0115] It is noted that the above embodiments are described according to various functional modules when the UE manages the application program as an example. In practice, the above described functional modules may be implemented by different modules as required, i.e., to divide the internal structure of the UE being into different functional modules, to perform some or all of the above described functions. In addition, the UE and the method for managing the application program described above belong to a same concept. The detailed implementation of the UE may refer to the embodiments of the method and thus is omitted here. Embodiment IV [0116] According to the embodiment, a terminal as shown in FIG. 10 is provided. [0117] The terminal 1200 comprises a memory 1201 and at least one processor 1202 . The memory 1201 stores software programs and modules, such as program instructions and modules corresponding to the system desktop of embodiments of the disclosure, and data generated when implementing the management of application program according to the embodiment. The processor 1202 performs various functional application and data processing, i.e., implements functions for managing the application program according to the embodiment, by executing the software programs and modules stored in the memory 1201 . [0118] Herein, the processor 1202 is configured to perform the following operations for managing the application program: [0119] monitoring a touch event generated when a user touches an icon displayed on a displaying interface; [0120] determining an area of the first icon in the displaying interface when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period; [0121] displaying a second icon in the determined area; [0122] monitoring a moving trace generated when the user drags the first icon and controlling the first icon to move along the moving trace; [0123] deleting the application program corresponding to the first icon by using the application program corresponding to the second icon when the first icon moves to a position of the second icon. [0124] Herein, determining an area of the first icon in the displaying interface comprises: [0125] reading out position information of the first icon in the display interface; [0126] determining a coordinate of a center of the first icon according to the position information; [0127] searching corresponding relationship between areas in the display interface and coordinate intervals according to the determined coordinate of the center of the first icon so as to obtain an area in which the coordinate is located, the searched out area being the area of the display interface in which the first icon is located. [0128] Herein, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0129] determining whether the application program corresponding to the first icon is a third party application program or a local system program; [0130] deleting the application program corresponding to the first icon by the application program corresponding to the second icon when the application program corresponding to the first icon is a third party application program; [0131] preventing deleting the application program corresponding to the first icon by the application program corresponding to the second icon and providing a prompt to the user when the application program corresponding to the first icon is a local system program. [0132] Herein, determining whether the application program corresponding to the first icon is a third party application program or a local system program comprises: [0133] reading out an amending authority for the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon; or [0134] searching a local system program catalogue according to the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the local system program catalogue does not include the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the local system program catalogue includes the application program corresponding to the first icon. [0135] Herein, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0136] locally deleting the application program corresponding to the first icon by the application program corresponding to the second icon; or [0137] isolating the application program corresponding to the first icon into the application program corresponding to the second icon. [0138] Preferably, as shown in FIG. 11 , the terminal 1200 also comprises the following units: [0139] an RF (Radio Frequency) circuit 110 , one or more memories 120 formed by computer readable storage media, an input unit 130 , a display unit 140 , a sensor 150 , an audio circuit 160 , a transmission module 170 , one or more central processor 180 , a power supply 190 and etc. [0140] Person skilled in the art will appreciate that the structure of the terminal shown in FIG. 7 puts no limitation to the terminal, which may include more or less components, or combination of the components, or different arrangements of the components. [0141] Herein, the RF circuit 110 may be used for signal reception and transmission in transceving or communicating procedure. In particular, the RF circuit 110 may send downlink information received from a base station to one or more processors 180 and send uplink related data to the base station. Usually, the RF circuit 110 includes, but is not limited to, an antenna, at least one amplifier, a tuner, one or more oscillators, a SIM card, a transceiver, a coupler, an LNA (Low Noise Amplifier), a duplexer, and etc. Further, the RF circuit 110 may be implemented by communication with other devices through wireless communication and network. The wireless communication may use any one of communication standards or protocols, including but not limiting to: GSM (Global System of Mobile communication), GPRS (General Packet Radio Service), CDMA (Code Division Multiple Access), WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution), E-mailing, SMS (Short Messaging Service), and etc. [0142] The memory 120 may be used for storing software programs and modules (such as, software programs and modules for managing applications in the embodiments of the invention), and data generated in the implementation of managing applications for implementing the embodiments. The processor 180 performs various functional applications and data processing by running software programs stored in the memory 120 , so as to manage applications. The memory 120 may mainly comprise a program storing area and a data storing area, wherein the program storing area may store an operating system, at least one required application (such as, audio play function, video play function, and etc.), and the data storing area may store data (such as, audio data, phone directory, and etc.) generated by using the terminal and other data. Further, the memory 120 may include a cache memory, and may also include a non-volatility memory, such as at least one disk memory, a flash, or other volatility solid state storages. Accordingly, the memory 120 may also include a memory controller so as to provide an access from the processor 180 and the input unit 130 to the memory 120 . [0143] The input unit 130 is configured to receive input numeral or character information and generate input from a keyboard, a mouse, a controlling rod, an optical or trace ball related to the user's setting and functional control. In particular, the input unit 130 may include a touch sensitive surface 131 and other input devices 132 . The touch sensitive surface 131 , also named a touch display screen or a touch control pad, collects touch operations of the user on or near the surface itself (e.g., a user operates on or near the touch sense surface 131 by using a finger, a touch pen, and any other suitable object or attachment), and actuates corresponding connecting means according to a preset program. Optionally, the touch sense surface 131 may include a touch detecting device and a touch controller, wherein the touch detecting device detects a touch orientation of the user, detects signals generated by the touch operation, and sends the signals to the touch controller; and the touch controller receives touch information from the touch detecting device, transforms the touch information into touch point coordinates, sends them to the processor 180 , and receives and executes commands sent from the processor 180 . Additionally, the touch sense surface 131 may be implemented as a resistive, capacitive or infra-red surface or surface acoustic wave and etc. Besides the touch sense surface 131 , the input unit 130 may further include other input devices 132 . In particular, the other input devices 132 may include (but not limited to) one or more of the following: a physical keyboard, functional keys (such as, audio volume control button, switch button, and etc.), a trace ball, a mouse, a controlling rod. [0144] The display unit 140 displays information input by the user or information provided to the user, as well as various graphical user interfaces (GUIs) of the terminal 1200 , wherein these GUIs are composed of a graph, a text, an icon, a video or a combination thereof. The display unit 140 may comprise a display panel 141 . Optionally, the display panel 141 may be configured as an LCD (Liquid Crystal Display), an OLED (Organic Light-Emitting Diode), and etc. Furthermore, the touch sensitive surface 131 may cover the display panel 141 . After the touch sensitive surface 131 has detected a touch operation on or near the display panel 141 , the detecting result is sent to the processor 180 to determine the type of a touch event, and then the processor 180 commands the display panel 141 to present corresponding visual output according to the type of the touch event. Although the touch sense surface 131 and the display panel 141 act are shown in FIG. 8 as two independent components to perform input and output, in some embodiments, the touch sense surface 131 and the display panel 141 may be integrated as a signal unit to perform the input and output functions. [0145] The terminal 1200 may further include at least one sensor 150 , such as, an optical sensor, a motion sensor, and other sensors. In particular, the optical sensor may include an ambient light sensor and a proximity sensor, wherein the ambient light sensor adjusts the brightness of the display panel 141 according to ambient light, and the proximity sensor may switch off the display panel 141 and/or background light when the terminal 1200 moves close to an ear of the user. As one kind of motion sensors, a gravity acceleration sensor may detect the amplitude of an acceleration in various directions (usually three axes), detect the amplitude and the direction of the gravity when the terminal is stationary, and be used for identifying the gesture of the phone (such as, a switch between horizontal screen and vertical screen, a related game, calibration of the gesture of the magnetometer) and for identifying vibration (such as, pedometer, knocking) and etc. The terminal 1200 may also be configured to accommodate a gyroscope, a barometer, a hygrometer, a thermometer, an infra-red sensor, and other sensors, the description of which are omitted here. [0146] An audio circuit 160 , a speaker 161 , a microphone 162 may provide audio interface between the user and the terminal 1200 . The audio circuit 160 transforms received audio data into an electrical signal, which is then transmitted to the speaker 161 for outputting the electrical signal. On the other hand, the microphone 162 transforms collected sound signal into an electrical signal, which is then received by the audio circuit 160 and is transformed into audio data, wherein the audio data is output to the processor 180 for processing. Then, the processed audio data is for example sent to another terminal via the RF circuit 110 , or is sent to the memory 120 for further processing. The audio circuit 160 may further include an earphone plug so as to provide communication between an earphone and the terminal 1200 . [0147] WiFi is a short distance wireless transmission technology. The terminal 1200 may facilitate the user to transmit/receive an e-mail, browse a website, access streaming media and etc. through a WiFi module 170 which provides the user with a wireless access to the broadband Internet. Although the WiFi module 170 is shown in FIG. 8 , it is appreciated that it is not a necessary composition of the terminal 1200 . That is, the WiFi module may be omitted according to actual needs without varying the essence of the invention. [0148] The processor 180 is the control center of the terminal 1200 , which utilizes various interfaces and connections for connecting various components of the terminal (such as a cell phone), executes various functions of the terminal 1200 and processes data by performing or implementing software programs and/or modules stored in the memory 120 so as to monitor the whole cell phone functions. Optionally, the processor 180 may include one or more processing cores. Preferably, the processor 180 may integrate an application processor and a modem processor, wherein the application processor mainly operates the operating system, user interfaces, and application programs, and the modem processor mainly operates wireless communication. It is also appreciated that the modem processor may also be not integrated into the processor 180 . [0149] The terminal 1200 may further include a power supply 190 (such as, a battery) for powering various components. Preferably, the power supply 190 may be logically connected to the processor 180 via a power supply management system so that the charging, discharging, power consumption or the like may be managed by the power source management system. The power supply 190 may include one or more DC or AC power supplies, a re-charging system, a power fault detection circuit, a power converter or inverter, a power status indicator and etc. [0150] Although not shown, the terminal 1200 may also include a camera, a Bluetooth module and etc, which are omitted here. [0151] In this embodiment, a terminal is provided, in which the area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. Embodiment V [0152] A readable storing medium is provided in this embodiment. The readable storing medium may be a readable storing medium included in the memory of the above described embodiment, or a separate computer readable storing medium which has not been assembled in the terminal. One or more programs may be stored in the computer readable storing medium and executed by one or more processors for implementing a method for managing an application program. The method comprises the following steps: [0153] monitoring a touch event generated when a user touches an icon displayed in a displaying interface; [0154] determining an area of the first icon in the displaying interface when a touch event corresponding to a first icon is monitored and the monitored event lasts for a predetermined period; [0155] displaying a second icon in the determined area; [0156] monitoring a moving trace generated when the user drags the first icon and controlling the first icon to move along the moving trace; and deleting the application program corresponding to the first icon by using the application program corresponding to the second icon when the first icon moves to a position of the second icon. [0157] Herein, determining an area of the first icon in the displaying interface comprises: [0158] reading out position information of the first icon in the display interface; [0159] determining a coordinate of a center of the first icon according to the position information; [0160] searching corresponding relationship between areas in the display interface and coordinate intervals according to the determined coordinate of the center of the first icon so as to obtain an area in which the coordinate is located, the searched out area being the area of the display interface in which the first icon is located. [0161] Herein, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0162] determining whether the application program corresponding to the first icon is a third party application program or a local system program; [0163] deleting the application program corresponding to the first icon by the application program corresponding to the second icon when the application program corresponding to the first icon is a third party application program; [0164] preventing deleting the application program corresponding to the first icon by the application program corresponding to the second icon and providing a prompt to the user when the application program corresponding to the first icon is a local system program. [0165] Herein, determining whether the application program corresponding to the first icon is a third party application program or a local system program comprises: [0166] reading out an amending authority for the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the amending authority indicates that it is allowed to amend the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the amending authority indicates that it is not allowed to amend the application program corresponding to the first icon; or [0167] searching a local system program catalogue according to the application program corresponding to the first icon, determining that the application program corresponding to the first icon is a third party application program if the local system program catalogue does not include the application program corresponding to the first icon, and determining that the application program corresponding to the first icon is a local system program if the local system program catalogue includes the application program corresponding to the first icon. [0168] Herein, deleting the application program corresponding to the first icon by using the application program corresponding to the second icon comprises: [0169] locally deleting the application program corresponding to the first icon by the application program corresponding to the second icon; or [0170] isolating the application program corresponding to the first icon into the application program corresponding to the second icon. [0171] In this embodiment, a readable storing medium is provided, in which the area of the first icon in the displaying interface is determined, the second icon is displayed in the determined area, and the application program corresponding to the first icon is deleted by using the application program corresponding to the second icon when the first icon moves to the position of the second icon. Since the first icon and the second icon are displayed in the same area, the distance for moving the first icon to the position of the second icon so as to delete the application program corresponding to the first application will not be too long for operation. [0172] The numbers of the above described embodiments are used only for the purpose of description, but not represent preference of the embodiments. [0173] It is anticipated for an ordinary person in the art that all or some of steps in the above embodiments may be implemented by hardware or a program for instructing related hardware. The program may be stored in a computer readable storing medium which may be a read-only memory, a magnetic disk or an optical disk. [0174] The above described embodiments are merely preferred embodiments of the invention, but not intended to limit the invention. Any modifications, equivalent alternations and improvements that are made within the spirit and scope of the invention should be included in the protection scope of the invention.

The present invention provides a method and a user device for managing application. The method includes: detecting the touch event which induced by a user touching icons displayed in a display interface; determining the area of the display interface which the first icon located in, when the touch event corresponding to the first icon is detected and the detected touch event persists a scheduled time; displaying a second icon in the determined area; detecting the movement path which induced by the user dragging the first icon through the application corresponding to the second icon, when the first icon moves into the location of the second icon. The distance of moving the first icon will not be very long and easy to operate, when the first icon is moved into the location of the second icon and the application corresponding to the first icon is deleted.

CROSS-REFERENCE TO PRIOR APPLICATION This is the U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2007/054552 filed Mar. 8, 2007, which claims the benefit of Japanese Application Nos. 2006-062922 filed Mar. 8, 2006 and 2006-062923 filed Mar. 8, 2006, all of which are incorporated by reference herein. The International Application was published in Japanese on Sep. 20, 2007 as WO 2007/105594 A1 under PCT Article 21(2). TECHNICAL FIELD The present invention relates to a hydrogen permeation/separation thin membrane constituted of an Ni—Ti—Nb alloy or Nb—Ti—Ni alloy having high mechanical strength, and thus can be made into a thin membrane having a thickness of 0.07 mm (70 μm) or less, and in which, as a result, hydrogen permeation/separation performance can be significantly improved when applied in practical use due to its thinness. BACKGROUND ART In recent years, high purity hydrogen gas has drawn attention as a fuel gas used in energy systems such as hydrogen fuel cells and hydrogen gas turbines. It is known that the high purity hydrogen gas is produced from a hydrogen-containing source gas such as a mixed gas obtained by electrolyzing water or a mixed gas obtained by steam reforming liquefied natural gas (LNG) due to the following process by employing a high-performance hydrogen purifier like that shown in the schematic diagram in FIG. 5 . The purifier is partitioned into a left-hand chamber and a right-hand chamber by a hydrogen permeation/separation membrane, which is made of a material permeable only to hydrogen and which has a thickness of 0.1 to 3 mm, and is reinforced at the periphery with a frame body made of nickel or the like. A hydrogen-containing source gas inlet tube and an exhaust gas outlet tube are installed in the left-hand chamber, whereas a high purity hydrogen gas outlet tube is installed in the right-hand chamber. A reaction chamber made of a material such as stainless steel is provided at the center of the purifier. The reaction chamber is heated to 200 to 300° C. and the hydrogen-containing source gas is introduced from the inlet tube. While maintaining the internal pressure of the right-hand chamber where the hydrogen separated/purified by the hydrogen permeation/separation membrane is present at 0.1 MPa and the internal pressure of the left-hand chamber where the hydrogen-containing source gas is present at 0.2 to 0.5 MPa, the high purity hydrogen gas is produced by a separation/purification process due to the hydrogen permeation/separation membrane. In addition, the wide use of the abovementioned hydrogen permeation/separation membrane in the chemical reaction processes including the steam reforming process of hydrocarbons and the hydrogenation/dehydrogenation processes such as the reaction between benzene and cyclohexane where hydrogen is selectively transferred is also well known. Moreover, it is also known that the abovementioned hydrogen permeation/separation membrane is constituted from an Ni—Ti—Nb alloy having the following composition (α) and alloy structure (β): (α) a composition consisting of 25 to 45 atomic % of Ni, 26 to 50 atomic % of Ti, and a remainder containing Nb and inevitable impurities (with the proviso that the Ni content is 11 to 48 atomic %); and (β) with respect to a cast thin plate cut out from a cast ingot by electrical discharge machining and having a thickness of 0.1 to 3 mm, an alloy structure which has a eutectic microstructure of a solid solution of Ni in an NbTi phase and a solid solution of Nb in an NiTi phase, and also has a primary NbTi phase (white islands seen in FIG. 4 ) dispersed in the microstructure as shown in the photographs of structures in FIGS. 2 and 4 taken by a scanning electron microscope (magnification: 2500× in FIGS. 2 and 4000× in FIG. 4 ). [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2005-232491 The demands for various chemical reactors with higher performance including the above high-performance hydrogen purifier are extremely high. Accordingly, even higher performance in the hydrogen permeation/separation is required for the hydrogen permeation/separation membrane used as a structural member in the aforementioned reactors. In addition, when the aforementioned hydrogen permeation/separation membrane is used, since it is known that its hydrogen permeation/separation performance generally improves as its membrane thickness is reduced, studies concerning the development of highly strong Ni—Ti—Nb alloy that constitutes the aforementioned hydrogen permeation/separation membrane have been conducted intensively. However, since the Ni—Ti—Nb alloy that constitutes the conventional hydrogen permeation/separation membranes has insufficient mechanical strength, the thickness of the membrane could not be reduced to 0.1 mm or less, and thus satisfactory improvement in the hydrogen permeation/separation performance has currently not been achieved. BRIEF SUMMARY OF THE INVENTION From the abovementioned viewpoints, the present inventors conducted a study in order to achieve the above various chemical reactors with higher performance while particularly focusing on the achievement of a highly strong hydrogen permeation/separation membrane in order to achieve a thin hydrogen permeation/separation membrane, which is a structural member of the reactors, and obtained the following research results. That is, the composition of the aforementioned hydrogen permeation/separation membrane is first specified as Nb of 10 to 47 atomic %, Ti of 20 to 52 atomic %, and a remainder containing Ni and inevitable impurities (with the proviso that the Ni content is 20 to 48 atomic %), and a molten alloy having the aforementioned composition is made into a cast foil material having a thickness of 0.07 mm or less by roll quenching. When this cast foil material is subjected to a refining heat treatment in an inert gas atmosphere or a vacuum atmosphere in order to prevent oxidation and under the condition where the material is heated to and retained at a temperature of 300 to 1100° C. for a predetermined time, the resulting material subjected to the refining heat treatment will have an alloy structure as shown in the structural photograph of FIG. 1 taken by a scanning electron microscope (magnification: 2,500×) where fine particles of an Nb-base solid solution alloy (seen as the white parts in FIG. 1 ) formed of a solid solution of Ni and Ti in Nb are dispersed in a microstructure (seen as the black parts in FIG. 1 ) made of an Ni—Ti(Nb) intermetallic compound formed of a solid solution of an Ni—Ti intermetallic compound, in which part of the Ti is replaced by Nb. The Ni—Ti—Nb alloy having the above alloy structure has an extremely high mechanical strength, and thus when practically applied as a hydrogen permeation/separation membrane, the membrane having a thickness of 0.07 mm or less can be achieved and the membrane exhibits even higher performance in the hydrogen permeation/separation for a long time. Moreover, the present inventors also obtained the following research results. That is, the composition of the aforementioned hydrogen permeation/separation membrane is first specified as Ni of 10 to 32 atomic %, Ti of 15 to 33 atomic %, and a remainder containing Nb and inevitable impurities (with the proviso that the Nb content is 48 to 70 atomic %), and a molten alloy having the aforementioned composition is made into a cast foil material having a thickness of 0.07 mm or less by roll quenching. When this cast foil material is subjected to a refining heat treatment in an inert gas atmosphere or a vacuum atmosphere in order to prevent oxidation under the condition where the material is heated to and retained at a temperature of 300 to 1,100° C. for a predetermined time, the resulting material subjected to the refining heat treatment will have an alloy structure as shown in the structural photograph of FIG. 3 taken by a scanning electron microscope (magnification: 4,000×) where fine particles of an Ni—Ti(Nb) intermetallic compound (seen as the black parts in FIG. 3 ), formed of an Ni—Ti intermetallic compound in which a part of the Ti thereof is replaced by Nb, are dispersed in a microstructure (seen as the white parts in FIG. 3 ) made of an Nb-base solid solution alloy formed of a solid solution of Ni and Ti in Nb. The Nb—Ti—Ni alloy having the above alloy structure ensures excellent performance in hydrogen permeation/separation due to the Nb-base solid solution alloy of the microstructure and also has an extremely high mechanical strength due to the dispersion of the fine particles of the Ni—Ti(Nb) intermetallic compound in the microstructure. Accordingly, when practically applied as a hydrogen permeation/separation membrane, the membrane having a thickness of 0.07 mm or less can be achieved, and the improvement in hydrogen permeation/separation performance due to the achievement of thin membrane together with the excellent hydrogen permeation/separation performance exhibited by the microstructure of the Nb-based solid solution alloy will result in even higher performance in the hydrogen permeation/separation. The present invention is made based on the above research results and provides a hydrogen permeation/separation thin membrane made of an Ni—Ti—Nb alloy characterized in that the Ni—Ti—Nb alloy is a cast foil material obtained by roll quenching and having a thickness of 0.07 mm or less, which has been subjected to a refining heat treatment, and has the following composition (a) and alloy structure (b) (hereafter, this membrane is frequently referred to as a “hydrogen permeation/separation thin membrane (I)”): (a) a composition consisting of 10 to 47 atomic % of Nb, 20 to 52 atomic % of Ti, and a remainder containing 20 to 48 atomic % of Ni and inevitable impurities; and (b) an alloy structure where fine particles of an Nb-base solid solution alloy formed of a solid solution of Ni and Ti in Nb are dispersed in a microstructure made of an Ni—Ti(Nb) intermetallic compound formed of a solid solution of an Ni—Ti intermetallic compound, in which part of the Ti thereof is replaced by Nb. Further, the present invention also provides a hydrogen permeation/separation thin membrane made of an Nb—Ti—Ni alloy characterized in that the Nb—Ti—Ni alloy is a cast foil material obtained by roll quenching and having a thickness of 0.07 mm or less, which has been subjected to a refining heat treatment, and has the following composition (a′) and alloy structure (b′) (hereafter, this membrane is frequently referred to as a “hydrogen permeation/separation thin membrane (II)”): (a′) a composition consisting of 10 to 32 atomic % of Ni, 15 to 33 atomic % of Ti, and a remainder containing of 48 to 70 atomic % of Nb and inevitable impurities; and (b′) an alloy structure where fine particles of an Ni—Ti(Nb) intermetallic compound formed of a solid solution of an Ni—Ti intermetallic compound, in which part of the Ti thereof is replaced by Nb, are dispersed in a microstructure made of an Nb-based solid solution alloy formed of a solid solution of Ni and Ti in Nb. EFFECTS OF THE INVENTION Due to the Ni—Ti(Nb) intermetallic compound in the microstructure having high mechanical strength, the hydrogen permeation/separation thin membrane (I) of the present invention can be made into a thin membrane having a thickness of 0.07 mm or less. In addition, due to the improvement in hydrogen permeation/separation performance owing to the achievement of a thin membrane together with the excellent hydrogen permeation/separation performance exhibited by the Nb-based solid solution alloy that is uniformly dispersed in the microstructure as fine particles, excellent hydrogen permeation/separation performance can be achieved for a long time when the thin membrane is used in various chemical reactors. Further, due to the dispersion of fine particles of an Ni—Ti(Nb) intermetallic compound in the microstructure made of an Nb-based solid solution alloy exhibiting excellent hydrogen permeation/separation performance, the hydrogen permeation/separation thin membrane (II) of the present invention is ensured to have high mechanical strength, and as a result, can be made into a thin membrane having a thickness of 0.07 mm or less. In addition, due to the improvement in hydrogen permeation/separation performance owing to the achievement of thin membrane together with the excellent hydrogen permeation/separation performance exhibited by the microstructure made of the Nb-based solid solution alloy, the thin membrane exhibits even higher performance in the hydrogen permeation/separation for a long time. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph of a structure of an Ni—Ti—Nb alloy constituting a present invention hydrogen permeation thin membrane (I)-19 taken by a scanning electron microscope (magnification: 2500×). FIG. 2 is a photograph of a structure of an Ni—Ti—Nb alloy constituting a conventional hydrogen permeation membrane (I)-8 taken by a scanning electron microscope (magnification: 2500×). FIG. 3 is a photograph of a structure of an Nb—Ti—Ni alloy constituting a present invention hydrogen permeation thin membrane (II)-6 taken by a scanning electron microscope (magnification: 4000×). FIG. 4 is a photograph of a structure of an Ni—Ti—Nb alloy constituting a conventional hydrogen permeation membrane (II)-8 taken by a scanning electron microscope (magnification: 4000×). FIG. 5 is a schematic diagram showing an example of a high-performance hydrogen purifier. Next, the reasons for limiting the composition of an Ni—Ti—Nb alloy constituting the hydrogen permeation/separation thin membrane (I) of the present invention as described above will be explained. (1) Nb The Nb component has the effects as described above. That is, Nb is contained in the Ni—Ti intermetallic compound by replacing a part of the Ti thereof to form the Ni—Ti(Nb) intermetallic compound that constitutes the microstructure so as to improve the performance of the microstructure in hydrogen permeation/separation, and also forms an Nb-based solid solution alloy formed of a solid solution of Ni and Ti in Nb, and is dispersed in the microstructure as fine particles to exhibit excellent hydrogen permeation/separation performance. However, when the Nb content is less than 10 atomic %, the desired excellent hydrogen permeation/separation performance cannot be achieved even when the thickness of the thin membrane is reduced to 0.07 mm or less. On the other hand, when the Nb content exceeds 47 atomic %, it becomes impossible to reliably secure the aforementioned alloy structure. For these reasons, the Nb content is determined to be 10 to 47 atomic %. (2) Ti and Ni The Ti and Ni components have the following effects. That is, Ti and Ni form the Ni—Ti(Nb) intermetallic compound that constitutes the microstructure and improves the mechanical strength of the thin membrane so as to enable the achievement of a thin membrane having a thickness of 0.07 mm or less for practical use, and also forms a solid solution by being incorporated in the Nb-based solid solution alloy and dispersed in the microstructure as fine particles to enhance the mechanical strength of the alloy. However, when either the Ti content is less than 20 atomic % or the Ni content is less than 20 atomic %, the desired mechanical strength cannot be secured for the thin membrane, and thus the thin membrane having a thickness of 0.07 mm or less becomes difficult to be applied for practical use. On the other hand, when either the Ti content exceeds 52 atomic % or the Ni content exceeds 48 atomic %, a reduction in the hydrogen permeation/separation performance cannot be avoided. For these reasons, the Ti content and the Ni content are determined to be 20 to 52 atomic % and 20 to 48 atomic %, respectively. Next, the reasons for limiting the composition of an Nb—Ti—Ni alloy constituting the hydrogen permeation/separation thin membrane (II) of the present invention as described above will be explained. (1′) Nb The Nb component has the effects as described above. That is, Nb forms a microstructure constituted from an Nb-based solid solution alloy that is formed of a solid solution of Ni and Ti in Nb, and exhibits excellent hydrogen permeation/separation performance, and is also contained in the Ni—Ti intermetallic compound by replacing a part of the Ti thereof to form fine particles of the Ni—Ti(Nb) intermetallic compound so as to improve the performance of the fine particles in hydrogen permeation/separation. However, when the Nb content is less than 48 atomic %, it becomes difficult to reliably ensure the aforementioned alloy structure, and thus membrane properties are likely to vary. On the other hand, when the Nb content exceeds 70 atomic %, the proportion of dispersed fine particles of the Ni—Ti(Nb) intermetallic compound declines rapidly. As a result, the mechanical strength of the thin membrane is reduced and it becomes impossible to provide a thin membrane having a thickness of 0.07 mm or less for practical use. For these reasons, the Nb content is determined to be 48 to 70 atomic %. (2′) Ti and Ni The Ti and Ni components have the following effects. That is, Ti and Ni form fine particles of the Ni—Ti(Nb) intermetallic compound dispersed in the microstructure and improve the mechanical strength of the thin membrane so as to enable the achievement of a thin membrane having a thickness of 0.07 mm or less for practical use, and also form a solid solution to be incorporated in the Nb-based solid solution alloy that constitutes the microstructure to enhance the mechanical strength of the alloy. However, when either the Ti content is less than 15 atomic % or the Ni content is less than 10 atomic %, the desired mechanical strength cannot be secured for the thin membrane, and thus the thin membrane having a thickness of 0.07 mm or less becomes difficult to be applied for practical use. On the other hand, when either the Ti content exceeds 33 atomic % or the Ni content exceeds 32 atomic %, a reduction in the hydrogen permeation/separation performance cannot be avoided. For these reasons, the Ti content and the Ni content are determined to be 15 to 33 atomic % and 10 to 32 atomic %, respectively. BEST MODE FOR CARRYING OUT THE INVENTION Next, the hydrogen permeation/separation thin membranes (I) and (II) of the present invention will be described in detail with reference to the following Examples. EXAMPLES <Hydrogen Permeation/Separation Thin Membrane (I)> A highly pure Nb shot material of 99.9% purity, a highly pure Ni shot material of 99.9% purity, and a highly pure Ti sponge material of 99.5% purity, were used as raw materials. These raw materials were blended so as to achieve the proportions shown in Table 1 and they were made into an ingot by arc melting in a highly pure Ar atmosphere. This ingot was cut into a 20 mm square and was charged into a graphite crucible, in which a slit having a dimension of 20 mm (length)×0.3 mm (width) was formed at its bottom. The ingot was remelted in an argon atmosphere under reduced pressure of 0.06 MPa in a high frequency induction heating furnace and the resulting molten alloy was sprayed from the aforementioned slit at an injection pressure of 0.05 MPa onto the surface of a water-cooled copper roll rotating at a roll rate of 20 m/sec to form cast foil materials of the Ni—Ti—Nb alloy all having a plane dimension of 20 m (length)×20 mm (width) but also having individual average thicknesses (the average of thickness measured at 5 arbitrary points) indicated in Table 1. Next, these foil materials were charged into a vacuum furnace and subjected to a refining heat treatment in a vacuum of 10 −2 Pa or less under the conditions where the foil materials were retained at the respective predetermined temperatures within the range of 300 to 1,100° C. for 5 hours followed by the furnace cooling. After the refining heat treatment, the foil materials were cut out into pieces having a plane dimension of 20 mm (width)×60 mm (length) to produce hydrogen permeation/separation thin membranes (I)-1 to (I)-24 of the present invention (hereafter, these membranes are referred to as the present invention hydrogen permeation thin membranes). In addition, for the sake of comparison, conventional hydrogen permeation/separation membranes (hereinafter referred to as the conventional hydrogen permeation membranes) (I)-1 to (I)-10 made of thin plate materials of casting cut outs were produced as follows. A highly pure Nb shot material of 99.9% purity, a highly pure Ni shot material of 99.9% purity, and a highly pure Ti sponge material of 99.5% purity, were used as raw materials. These raw materials were blended so as to achieve the proportions shown in Table 2 and they were subjected to an arc melting process in a highly pure Ar atmosphere and cast to be made into Ni—Ti—Nb alloy ingots having a dimension of 80 mm (diameter)×10 mm (thickness). Thin plate materials all having a plane dimension of 20 mm (width)×60 mm (length) but also having individual average thicknesses (the average of thickness measured at 5 arbitrary points) indicated in Table 2 were cut out from these ingots by electrical discharge machining, thereby obtaining the conventional hydrogen permeation membranes. With respect to the present invention hydrogen permeation thin membranes (I)-1 to (I)-24 and the conventional hydrogen permeation membranes (I)-1 to (I)-10 obtained above, the compositions were measured using an energy dispersive X-ray fluorescence analyzer, and all the results showed substantially the same analysis values as the compositions indicated in Tables 1 and 2. Further, with respect to the present invention hydrogen permeation thin membranes (I)-1 to (I)-24 and the conventional hydrogen permeation membranes (I)-1 to (I)-10 obtained above, the structures were observed using a scanning electron microscope and an X-ray diffractometer. As a result, the present invention hydrogen permeation thin membranes (I)-1 to (I)-24 showed an alloy structure where fine particles of an Nb-based solid solution alloy formed of a solid solution of Ni and Ti in Nb were dispersed in a microstructure made of an Ni—Ti(Nb) intermetallic compound formed of a solid solution of an Ni—Ti intermetallic compound, in which part of the Ti thereof was replaced by Nb, as shown by the alloy structure of the present invention hydrogen permeation thin membrane (I)-19 in FIG. 1 . On the other hand, all the conventional hydrogen permeation membranes (I)-1 to (I)-10 showed an alloy structure where a primary NbTi phase was dispersed in a microstructure made of a eutectic structure of a solid solution of Ni in an NbTi phase and a solid solution of Nb in an NiTi phase, as shown by the alloy structure of the conventional hydrogen permeation membrane (I)-8 in FIG. 2 . Subsequently, a Pd thin film having a thickness of 0.1 μm was formed on both surfaces of the present invention hydrogen permeation thin membranes (I)-1 to (I)-24 and the conventional hydrogen permeation membranes (I)-1 to (I)-10 by deposition using a sputtering method (alternatively, the film may be formed by an electroplating process). The resulting membranes were sandwiched by two copper-made reinforcing frames having a dimension of 20 mm (transverse outer dimension)×60 mm (longitudinal outer dimension)×5 mm (frame width)×0.5 mm (frame thickness) from both sides and the respective permeation membranes were placed in a reaction chamber of a hydrogen permeability evaluation apparatus having the same structure as that of the high-performance hydrogen purifier shown in FIG. 5 while being fixed to the reinforcing frames. The inside of the reaction chamber was heated to 300° C. and hydrogen gas was introduced to the left-hand chamber of the reaction chamber to first set the internal pressure of the left-hand and right hand chambers of the reaction chamber to 0.1 MPa. Then, while maintaining the internal pressure of the right-hand chamber at 0.1 MPa, the internal pressure of the left-hand chamber was increased at a rate of 0.1 MPa per 5 minutes to 0.7 MPa for the present invention hydrogen permeation thin membranes (I)-1 to (I)-7 and the conventional hydrogen permeation membranes (I)-1 to (I)-2, 0.5 MPa for the present invention hydrogen permeation thin membranes (I)-8 to (I)-24 and the conventional hydrogen permeation membranes (I)-3 to (I)-9, and 0.3 MPa for the conventional hydrogen permeation membranes (I)-10. Flow rates of the hydrogen gas permeated (indicated in Tables 1 and 2 as the flow rates of permeated hydrogen at the initial stage) were measured using a gas flow meter at the time point where the membranes were retained for 1 hour under the abovementioned conditions. Further, flow rates of the hydrogen gas permeated were measured at the time point where the membranes were retained for another 20 hours (indicated in Tables 1 and 2 as the flow rates of permeated hydrogen at the later stage) under the same conditions (that is, the membranes were retained under the conditions where the internal pressure of 0.1 MPa in the right-hand chamber, the internal pressure in the left-hand chamber increased to 0.7 MPa, 0.5 MPa, and 0.3 MPa, respectively, from the time point where the membranes were retained under the same conditions for 1 hour). These measurement results are shown in Tables 1 and 2. TABLE 1 Average thickness Flow rate of permeated Composition (atomic %) of cast foil material hydrogen (ml/min) Type Nb Ti Ni (μm) Initial stage Later stage Present (I)-1 10 45 Remainder (45) 28 34 32 invention (I)-2 12 52 Remainder (36) 20 51 48 hydrogen (I)-3 14 38 Remainder (48) 25 48 46 permeation (I)-4 16 42 Remainder (42) 38 34 32 thin (I)-5 18 35 Remainder (47) 26 59 55 membrane (I)-6 19 49 Remainder (32) 29 49 46 (I) (I)-7 20 38 Remainder (42) 32 52 49 (I)-8 23 44 Remainder (33) 42 34 32 (I)-9 25 31 Remainder (44) 39 45 42 (I)-10 27 36 Remainder (37) 41 47 43 (I)-11 28 42 Remainder (30) 31 64 59 (I)-12 29 31 Remainder (40) 42 52 49 (I)-13 31 33 Remainder (36) 54 45 42 (I)-14 32 37 Remainder (31) 47 54 50 (I)-15 34 29 Remainder (37) 43 67 62 (I)-16 35 33 Remainder (32) 40 75 69 (I)-17 37 34 Remainder (29) 44 76 70 (I)-18 39 38 Remainder (23) 40 89 82 (I)-19 40 30 Remainder (30) 38 99 91 (I)-20 41 25 Remainder (34) 59 66 61 (I)-21 43 33 Remainder (24) 53 77 71 (I)-22 44 20 Remainder (36) 46 92 84 (I)-23 45 29 Remainder (26) 56 77 70 (I)-24 47 33 Remainder (20) 68 67 61 TABLE 2 Average thickness of Flow rate of permeated Composition (atomic %) thin plate materials of hydrogen (ml/min) Type Nb Ti Ni casting cut outs (μm) Initial stage Later stage Conventional (I)-1 11 50 Remainder (39) 118 8 8 hydrogen (I)-2 16 42 Remainder (42) 120 19 18 permeation (I)-3 22 39 Remainder (39) 120 14 13 membrane (I)-4 28 40 Remainder (32) 125 14 13 (I) (I)-5 29 31 Remainder (40) 117 15 14 (I)-6 33 39 Remainder (28) 122 14 13 (I)-7 36 30 Remainder (34) 115 15 14 (I)-8 40 31 Remainder (29) 123 16 14 (I)-9 43 31 Remainder (26) 125 11 9 (I)-10 48 26 Remainder (26) 115 13 11 DETAILED DESCRIPTION OF THE INVENTION As shown in Tables 1 and 2, the present invention hydrogen permeation thin membranes (I)-1 to (I)-24 had high mechanical strength secured by the Ni—Ti(Nb) intermetallic compound in the microstructure and could be made into the thin membranes having a thickness of 0.07 mm or less, and thus exhibited excellent hydrogen permeation/separation performance for a long time together with the excellent hydrogen permeation/separation performance exhibited by the Nb-based solid solution alloy dispersed in the microstructure as fine particles, and showed excellent durability (useful life). On the other hand, it is apparent that all the conventional hydrogen permeation membranes (I)-1 to (I)-10 could not be made into the membranes having a thickness of 0.1 mm or less due to their mechanical strength, and thus they had low performance in terms of the hydrogen permeation/separation. <Hydrogen Permeation/Separation Thin Membrane (II)> A highly pure Nb shot material of 99.9% purity, a highly pure Ni shot material of 99.9% purity, and a highly pure Ti sponge material of 99.5% purity, were used as raw materials. These raw materials were blended so as to achieve the proportions indicated in Table 3 and they were made into an ingot by arc melting in a highly pure Ar atmosphere. This ingot was cut into a 20 mm square and was charged into a graphite crucible, in which a slit having a dimension of 20 mm (length)×0.3 mm (width) was formed at its bottom. The ingot was remelted in an argon atmosphere under reduced pressure of 0.06 MPa in a high frequency induction heating furnace and the resulting molten alloy was sprayed from the aforementioned slit at an injection pressure of 0.05 MPa onto the surface of a water-cooled copper roll rotating at a roll rate of 20 m/sec to form cast foil materials of the Nb—Ti—Ni alloy all having a plane dimension of 20 m (length)×20 mm (width) but also having individual average thicknesses (the average of thickness measured at 5 arbitrary points) indicated in Table 3. Next, these foil materials were charged into a vacuum furnace and subjected to a refining heat treatment in a vacuum of 10 −2 Pa or less under the conditions where the foil materials were retained at the respective predetermined temperatures within the range of 300 to 1,100° C. for 5 hours followed by the furnace cooling. After the refining heat treatment, the foil materials were cut out into pieces having a plane dimension of 20 mm (width)×60 mm (length) to produce hydrogen permeation/separation thin membranes (II)-1 to (II)-13 of the present invention (hereinafter, these membranes are referred to as the present invention hydrogen permeation thin membranes). In addition, for the sake of comparison, conventional hydrogen permeation/separation membranes (hereinafter referred to as the conventional hydrogen permeation membrane) (II)-1 to (II)-10 made of thin plate materials of casting cut outs were produced as follows. A highly pure Nb shot material of 99.9% purity, a highly pure Ni shot material of 99.9% purity, and a highly pure Ti sponge material of 99.5% purity, were used as raw materials. These raw materials were blended so as to achieve the proportions indicated in Table 3 and they were subjected to an arc melting process in a highly pure Ar atmosphere and cast to be made into Nb—Ti—Ni alloy ingots having a dimension of 80 mm (diameter)×10 mm (thickness). Thin plate materials all having a plane dimension of 20 mm (width)×60 mm (length) but also having individual average thicknesses (the average of thickness measured at 5 arbitrary points) indicated in Table 3 were cut out from these ingots by electrical discharge machining, thereby obtaining the conventional hydrogen permeation membranes. With respect to the present invention hydrogen permeation thin membranes (II)-1 to (II)-13 and the conventional hydrogen permeation membranes (II)-1 to (II)-10 obtained above, the compositions were measured using an energy dispersive X-ray fluorescence analyzer, and all the results showed substantially the same analysis values as the compositions indicated in Table 3. Further, with respect to the present invention hydrogen permeation thin membranes (II)-1 to (II)-13 and the conventional hydrogen permeation membranes (II)-1 to (II)-10 obtained above, the structures were observed using a scanning electron microscope and an X-ray diffractometer. As a result, the present invention hydrogen permeation thin membranes (II)-1 to (II)-13 showed an alloy structure where fine particles of an Ni—Ti(Nb) intermetallic compound formed of a solid solution of Nb in an Ni—Ti intermetallic compound by replacing part of the Ti thereof were dispersed in a microstructure made of an Nb-based solid solution alloy formed of a solid solution of Ni and Ti in Nb, as shown by the alloy structure of the present invention hydrogen permeation thin membrane (II)-6 in FIG. 3 . On the other hand, all the conventional hydrogen permeation membranes (II)-1 to (II)-10 showed an alloy structure where a primary NbTi phase was dispersed in a microstructure made of a eutectic structure of a solid solution of Ni in an NbTi phase and a solid solution of Nb in an NiTi phase, as shown by the alloy structure of the conventional hydrogen permeation membrane (II)-8 in FIG. 4 . Subsequently, a Pd thin film having a thickness of 0.1 μm was formed on both surfaces of the present invention hydrogen permeation thin membranes (II)-1 to (II)-13 and the conventional hydrogen permeation membranes (II)-1 to (II)-10 by deposition using a sputtering method (alternatively, the film may be formed by an electroplating process). The resulting membranes were sandwiched by two copper-made reinforcing frames having a dimension of 20 mm (transverse outer dimension)×60 mm (longitudinal outer dimension)×5 mm (frame width)×0.5 mm (frame thickness) from both sides and the respective permeation membranes were placed in a reaction chamber of a hydrogen permeability evaluation apparatus having the same structure as that of the high-performance hydrogen purifier shown in FIG. 5 while being fixed to the reinforcing frames. The inside of the reaction chamber was heated to 300° C. and hydrogen gas was introduced to the left-hand chamber of the reaction chamber to first set the internal pressure of the left-hand and right hand chambers of the reaction chamber to 0.1 MPa. Then, while maintaining the internal pressure of the right-hand chamber at 0.1 MPa, the internal pressure of the left-hand chamber was increased at a rate of 0.1 MPa per 5 minutes to 0.3 MPa for all the hydrogen permeation thin membranes of the present invention (II)-1 to (II)-13 and the conventional hydrogen permeation membrane (II)-10, 0.7 MPa for the conventional hydrogen permeation membranes (II)-1 to (II)-2, and 0.5 MPa for the conventional hydrogen permeation membranes (II)-3 to (II)-9. Flow rates of the hydrogen gas permeated (shown in Table 3 as the flow rates of permeated hydrogen at the initial stage) were measured using a gas flow meter at the time point where the membranes were retained for 1 hour under the abovementioned conditions. Moreover, flow rates of the hydrogen gas permeated were measured at the time point where the membranes were retained for another 20 hours under the same conditions (indicated in Table 3 as the flow rates of permeated hydrogen at the later stage). These measurement results are shown in Table 3. TABLE 3 Average thickness Flow rate of permeated Composition (atomic %) of cast foil material hydrogen (ml/min) Type Ni Ti Nb (μm) Initial stage Later stage Present (II)-1 26 26 Remainder (48) 35 79 72 invention (II)-2 17 33 Remainder (50) 61 47 43 hydrogen (II)-3 32 18 Remainder (50) 61 48 43 permeation (II)-4 23 26 Remainder (51) 54 55 50 thin (II)-5 17 30 Remainder (53) 51 61 55 membrane (II)-6 25 22 Remainder (53) 42 74 67 (II) (II)-7 20 25 Remainder (55) 59 55 50 (II)-8 21 20 Remainder (59) 60 58 52 (II)-9 15 25 Remainder (60) 55 65 59 (II)-10 16 22 Remainder (62) 43 86 77 (II)-11 16 18 Remainder (66) 61 65 58 (II)-12 10 22 Remainder (68) 67 76 65 (II)-13 15 15 Remainder (70) 70 76 64 Conventional (II)-1 39 50 Remainder (11) 118* 8 8 hydrogen (II)-2 42 42 Remainder (16) 120* 19 18 permeation (II)-3 39 39 Remainder (22) 120* 14 13 membrane (II)-4 32 40 Remainder (28) 125* 14 13 (II) (II)-5 40 31 Remainder (29) 117* 15 14 (II)-6 28 39 Remainder (33) 122* 14 13 (II)-7 34 30 Remainder (36) 115* 15 14 (II)-8 29 31 Remainder (40) 123* 16 14 (II)-9 26 31 Remainder (43) 125* 18 16 (II)-10 26 26 Remainder (48) 115* 13 11 (In the table, the symbol* indicates “thin plate materials of casting cut outs”) As shown in Table 3, all the present invention hydrogen permeation thin membranes (II)-1 to (II)-13 had high mechanical strength secured by the fine particles of the Ni—Ti(Nb) intermetallic compound dispersed in the microstructure and could be made into the thin membranes having a thickness of 0.07 mm or less. Accordingly, further improvement in the hydrogen permeation/separation performance was achieved, and together with the excellent hydrogen permeation/separation performance exhibited by the Nb-based solid solution alloy in the microstructure, the membranes exhibited even higher performance in the hydrogen permeation/separation for a long time. On the other hand, it is apparent that none of the conventional hydrogen permeation membranes (II)-1 to (II)-10 could be made into the membranes having a thickness of 0.1 mm or less due to their mechanical strength, and thus they had low performance in the hydrogen permeation/separation. INDUSTRIAL APPLICABILITY The hydrogen permeation/separation thin membrane of the present invention is constituted of an Ni—Ti—Nb alloy or Nb—Ti—Ni alloy having high mechanical strength, and can be made into a thin membrane having a thickness of 0.07 mm or less, and thus exhibits excellent hydrogen permeation/separation performance for a long time when applied to practical use. Accordingly, the membrane satisfactorily meets the demands of various chemical reactors with higher performance, in which a hydrogen permeation/separation membrane is used as a structural member. Therefore, the present invention is extremely useful industrially.

A hydrogen permeation/separation thin membrane including a Ni—Ti—Nb alloy. The Ni—Ti—Nb alloy is a cast foil material obtained by roll quenching and a refining heat treatment. The membrane has a thickness of 0.07 mm or less. The Ni—Ti—Nb alloy has the following: (a) a composition consisting of 10 to 47 atomic % of Nb, 20 to 52 atomic % of Ti, and a remainder containing 20 to 48 atomic % of Ni and inevitable impurities; and (b) an alloy structure where fine particles of a Nb-based solid solution alloy, in which Nb forms a solid solution with Ni and Ti in Nb, are dispersed in a basic structure made of a Ni—Ti(Nb) intermetallic compound formed of a solid solution of a Ni—Ti intermetallic compound, in which part of Ti thereof is replaced by Nb.

BACKGROUND OF THE INVENTION [0001] 1. Technical Field [0002] The present invention relates to technology for promoting user convenience in a system in which users share identical networks mutually, enabling simultaneous conversation. More particularly, it relates to technology that makes conversational display easy to view, in a textual conversation system such as IRC (Internet Relay Chat). [0003] In the present invention, “IRC” means a chat system formed by connecting a chat server with a plurality of chat clients on the Internet, and the plurality of chat clients sharing the same virtual space, enabling simultaneous conversation. [0004] Furthermore, “channel” means a virtual space that chat clients share in IRC. A “nickname” utilized in IRC means identifying information for specifying a user. A “topic” means the subject of a channel used in IRC. “Mode” means information that indicates characteristics of a channel utilized in IRC. [0005] 2. Description of Related Art [0006] Text conversation systems (simply “chat systems” below) for conducting conversation using text among information terminals on a network have heretofore been offered. For example, Web chat systems that keep a log of messages that WWW (World Wide Web) servers issue have been offered. In Web chat systems users carry out conversations via text by sharing a Web Page log (message record). A system for conducting conversation by manipulating user alter egos known as “avatars” within a virtual world has also been offered. Still further, IRC in which chat servers signal-distribute conversation to a plurality of chat clients in conformity with IRC protocols have also been offered. These chat systems, conventionally, have been used as systems directed to the general user. Nevertheless, the actual situation recently is that use in business has been increasing, such as for in-house communications and brief meetings. [0007] A plurality of users—in general three persons or more—often join in on chat systems. When the number of participants increases, it can happen that a number of different topics will be going on at once within the same display area. In real-world conversations, the speaker's gaze can distinguish topics, as can approaching the person speaking. In conversations on the Internet, however, wherein the condition of the other party cannot be seen, conversations relating to a plurality of topics end up being intermingled and displayed within the same area. [0008] In chat systems on the WWW, modifying the colors of displayed messages facilitates distinguishing topics. Because changing colors of the messages for every topic is a bother for the user, however, at present this method is seldom used. [0009] Further, in IRC creating channels that differ according to topic is easy. In reality, however, multiple topics often break out within a single channel. SUMMARY OF THE INVENTION [0010] The object of the present invention is to display topics respectively segregated from other topics wherein a plurality of topics are under way simultaneously on a network, to promote accurate and efficient communication. [0011] In order to address the aforementioned problems, in one aspect the present invention is a display control method utilized in a chat system in which users on information terminals share identical networks mutually, enabling text conversation, the display control method: [0012] (A) correlating messages on the network based on user instructions and creating message groups and predetermined message group information relating to the message groups; [0013] (B) sharing the created message group information with users on the network; [0014] (C) sending messages to the message groups out to the network; and [0015] (D) in accordance with user instructions displaying the message groups independently of messages on the network. [0016] Taking an example wherein it is applied to IRC will illustrate the display control method of the present invention. Participants on a channel for example designate particular users, instructing the creation of a message group. Message group information concerned with the created message group is reported to other chat clients in the channel. Message group information may be, for example, nicknames of the users that form the message group, a message group ID, the message group author, and the message group name. Issuing messages to a message group sends that messages out on the channel. The way the message group is displayed conforms to user instructions. The message group can be displayed in the same display area the channel is displayed, or can be displayed independently of the channel display area. [0017] In a further aspect the invention is a display control device utilized in a chat device wherein, sharing an identical network mutually, transmission/reception of text messages is possible, and presents the display control device provided with creating means, reporting means, memory means and input/output control means. [0018] The creating means correlates messages on the network according to user instructions and creates message groups and predetermined message group information relating to the message groups. The reporting means transmits/receives the created message group information to and from other among display control devices on the network. The memory means stores the message group information. The input/output control means obtains the message groups from the chat device and in accordance with user instructions, enables display of the message groups independently of messages on the network. [0019] Likewise as described before, taking an example wherein it is applied to IRC will illustrate the display control device. A user, for example, designates the individual users constituting a message group. The creation means creates the message group out of the messages from the designated member users. The creation means also creates message group IDs, and predetermined message group information containing member users and the creating user, which is stored in the memory means. The created message group information is reported by the reporting means to other display control devices in the channel. The report may be either via a chat client, or directly transmitted/received among the display control devices. Other display control devices accept from the reporting means message group information that the other display control devices have created, which is stored in the memory means. [0020] With input/output control means, in accordance with user instructions, the message group can be displayed in a window separate from the messages within the channel. Of course, it is also possible to display both messages within a channel and message groups together in the same window. The message groups are obtainable, for example, from a message log that the chat client has created. [0021] The present invention in another aspect presents a display control device wherein the creating means in the second aspect of the invention accepts operations directed to the message groups and updates the message group information. [0022] For example, the creating means accepts message group link instructions and creates message group information in which linked message groups and the message group link source are correlated. [0023] In a further aspect the invention presents a display control device wherein the input/output control means in the second aspect of the invention accepts messages in which the message groups are designated and acquires from the network or sends to the network messages for the message groups. [0024] The input/output control means, for example in a window displaying the message groups, deems inputted messages to be messages to the message group, and sends them out to the channel. The input/output control means also obtains from the channel messages to message groups transmitted from other display control devices. According to user instructions, the obtained messages are displayed in a window for message groups or in an ordinary chat window. [0025] The present invention in yet another aspect presents a display control device wherein the creation means in the second aspect of the invention correlates messages within the network based on selection of the chat device from a user, and creates message groups out of messages from the selected chat devices and message group information containing information that designates the selected chat devices. [0026] When a user chooses individual users within a channel, the creation means creates a message group that will be constituted by messages from the chosen users. Information specifying the users comprising the message group, nicknames, for example, are contained in the message group information. Selecting user names, or selecting user messages can be given as methods of choosing users. [0027] In a still further aspect the invention presents a display control device wherein that of the second aspect of the invention is provided with a message list correlating messages within the network and message identifying information specifying the messages; wherein the creation means creates, based on selection of the messages from a user, message groups containing the selected messages and message group information containing message-identifying information for the selected messages. [0028] Selecting not the users, but specific messages creates the message groups. Message IDs that specify designated messages are contained in the message group information. [0029] The present invention in another aspect presents a display control device wherein the creation means in the second aspect of the invention creates message group information in which a disclosure level of the message groups that are created is contained. [0030] The disclosure level setting may be designated by the individual users, or automatically set in according to the type of message group. For example, wherein the message group is created by designating individual users, the creating means sets the disclosure level to “Private.” On the other hand, wherein the message group is created by designating messages, the creating means sets the disclosure level to “Public.” [0031] In a further aspect the invention presents a display control device wherein message-group identifying information specifying the message groups is contained in the message group information. [0032] Including a message group ID in the message group information enables sharing message groups mutually within the same channel. Consequently, the created message groups can be displayed in common among the users according to each user's respective preference. [0033] The invention in yet another aspect presents a display control device wherein the input/output control means in the second aspect of the invention judges based on the message group information whether to display the message groups, and displays the message groups based on the judgment. [0034] The input/output control means decides whether or not to display the message group according to, for example, the before-described disclosure level or to the type of message group. Specifically, if the disclosure level is “Public,” the decision is “displayable.” 0 Conversely, if the display level is “Closed to Public,” wherein chat clients constitute the message group, the decision is “not displayable.” [0035] In still a further aspect, the present invention presents a computer-readable recording medium on which is recorded a display control program utilized in a chat device wherein, sharing an identical network mutually, transmission/reception of messages through text is possible, the computer-readable recording medium on which is recorded the display control program for executing steps A-D below. [0036] (A) a step of correlating messages on the network based on instructions from a user and creating message groups and predetermined message group information relating to the message groups; [0037] (B) a step of transmitting/receiving the created message group information among other chat devices within the network; [0038] (C) a step of storing the message group information; and [0039] (D) a step of obtaining the message groups from the chat device and in accordance with instructions from users displaying the message groups independently of messages within the network. [0040] Examples of a computer-readable recording medium herein include computer-readable/writeable floppy disks, hard disks, semiconductor memory, CD-ROMs, DVDs (digital video disks), and MOs (magneto-optical disks). [0041] Utilizing the present invention enables the conversation of users chatting by sharing a network such as an electronic meeting room to be displayed to suit each person's liking. Moreover, users can also designate that one another's displays be made in common, enabling them to carry out efficient communication. [0042] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0043] [0043]FIG. 1 is a functional block diagram showing the configuration of a display control device pertaining to the present invention in a first embodiment; [0044] [0044]FIG. 2 is a conceptual illustration of a message list; [0045] [0045]FIG. 3 is a conceptual illustration of an administration table; [0046] [0046]FIG. 4 is a screen example showing a chat client pertaining to the present embodiment, in its state just after activation; [0047] [0047]FIG. 5 is a screen example following connection to a chat server; [0048] [0048]FIG. 6 is a diagram showing an example of a confirmation window; [0049] [0049]FIG. 7 is a diagram showing an example of a thread window; [0050] [0050]FIG. 8 is a screen example wherein selecting messages creates a thread; [0051] [0051]FIG. 9 is a diagram showing an example of a new thread window wherein users and messages are not selected; [0052] [0052]FIG. 10 is a diagram showing an example of a selection window wherein “Link” is selected; [0053] [0053]FIG. 11 is a conceptual illustration of a post-thread-linking administration table: [0054] (a) Linker's administration table, and [0055] (b) Administration table for a user apart from the linker; [0056] [0056]FIG. 12 is a diagram showing an example of a selection window wherein “Display” is selected; [0057] [0057]FIG. 13 is a flowchart depicting flow in an input control process that the display control device carries out; [0058] [0058]FIG. 14 is a flowchart depicting flow in an output control process that the display control device carries out; [0059] [0059]FIG. 15 is a flowchart depicting flow in main routine that the display control device carries out; [0060] [0060]FIG. 16 is a flowchart depicting flow in a creation process subroutine; [0061] [0061]FIG. 17 is a flowchart depicting flow in a linking process subroutine; [0062] [0062]FIG. 18 is a flowchart depicting flow in a cancellation process subroutine; and [0063] [0063]FIG. 19 is a flowchart depicting flow in a display process subroutine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0064] Next, a display control device of the present invention will be definitely explained with reference to the drawings. [0065] First Embodiment [0066] Configuration [0067] [0067]FIG. 1 is a function block diagram illustrating the configuration of a display control device in connection with the first embodiment of the present invention. For ease of description, the explanation takes an example in the present embodiment wherein the display control device is adapted to an IRC chat client. [0068] (1) Chat Client [0069] The chat client 3 in FIG. 1 can converse with other chat clients via the Internet 1 . The chat client 3 has a display control device 2 , a first input/output control module 31 , a control module 32 , a second input/output control module 33 , and a memory 4 . To begin with, a brief explanation will be made of the configuration of the chat client 3 apart from the display control device 2 . [0070] The first input/output control module 31 carries out data transmission/reception between it and the Internet 1 . [0071] The memory 4 stores predetermined information relating to the channels in which the chat client 3 participates. “Predetermined information” is, for example, channel name, nicknames of users in the channel, topics, and channel attributes. A log of messages in the channel is also stored in the memory 4 . [0072] The control module 32 ordinarily transmits/receives data between it and the Internet 1 via the first input/output control module 31 . In the present embodiment, however, the control module 32 carries out data transmission/reception via the display control device 2 . The predetermined information among the data received is stored in the memory 4 . Also, messages received from other chat clients are sent to the second input/output control module 33 and displayed. Further, the control module 32 accepts input messages from the second input/output control module 33 and sends them out on the channel via the display control device 2 . [0073] The second input/output control module 33 accepts received messages from the control module 32 and outputs them on an input/output section display. The second input/output control module 33 also sends inputted messages from the input/output section to the control module 32 . [0074] (2) Display Control Device [0075] The display control device 2 has a creation module 21 , a reporting module 22 , a third input/output control module 23 , and an administration module 24 as well as the memory 4 . The display control device 2 shares the memory 4 with the chat client 3 . [0076] The memory 4 holds a message list and an administration table, which it adds to predetermined information relating to the channels. A diagram conceptually illustrating a created message list in the memory 4 is shown in FIG. 2. Message lists are created for each channel. Thread IDs (in the figures, noted as “Th.ID”) that specify message groups (called “threads” hereinafter), message IDs that specify messages, and messages are correlated and stored in the message list. It is preferable that the message list be created by appending the message IDs and the thread IDs to the message log that the chat client control module 32 creates. [0077] The message IDs are identifying information attached in order to specify the messages, and are, for example, consecutive numbers. The thread IDs are identifying information for specifying threads. The FIG. 2 message list is a message list for the channel “CH1.” The messages in which the message IDs are “1,”“5” and “6” are included in the thread that is specified with thread ID “Th1.” The other messages are included in the thread that is specified with thread ID “Th2.” [0078] A diagram conceptually illustrating an administration table created in the memory 4 is shown in FIG. 3. For ease of description, the message list is as is in FIG. 2. Predetermined information (called “thread information” hereinafter) relating to each of the threads is described in the administration table. Thread information in the present instance consists of thread IDS, titles, authors, member users, message IDs, link sources, forwarding destination, disclosure level and status. [0079] “Titles” are preferably text information for displaying the threads to the users. Preferably, the users can set the titles arbitrarily. “Author” is the nickname of the user who created the thread. “Member users” are the users who construct the thread. This, as will be discussed later, is information that is described wherein the threads are created by selecting the users. In the present embodiment, the threads are created by the users or by selecting any message. [0080] “Link source” as will be discussed later is a linked thread ID wherein a plurality of threads is linked. It is information that is described in the administration table of the user linked to the thread. “Forwarding destination” is information for expressing link sources of threads linked by other users. [0081] “Disclosure Level,” if “Public,” indicates that messages within the thread are approved to be open to all of the users. If “Private,” it indicates that messages within the thread are approved to be open only to users in the thread. The thread author would best make the disclosure level setting. It is also possible that with the disclosure level of a thread formed by users being “Private,” the disclosure level of the other threads be set to “Private.” In the present embodiment, the disclosure level of threads created by selecting users is automatically made “Private.” “Status” indicates whether or not a window exclusively for threads (called “thread window” hereinafter) is currently being displayed. [0082] The creation module 21 receives from the administration module 23 instructions for a process on threads. Following the instructed process, the creation module 21 updates the administration table. As concrete examples of the process on threads, creation, segregation, linking and display can be given. For example, when thread creation is instructed, the creation module 21 creates thread information and records it in the administration table. The creation module 21 also reports updated thread information to the reporting module 22 . [0083] The reporting module 22 transmits/receives thread information via the administration module 23 . Specifically, the reporting module 22 receives thread information from other display control devices and updates the administration table and the message list. The reporting module 22 also sends thread information reported from the creation module 21 out to the other display control devices within the channel. Establishing predetermined thread commands is preferable for transmitting/receiving the thread information. For instance, an example of a thread command to create “Th1” is shown below. [0084] Th_create;ThID=Th1;Creator=Jun-Jun;User=Jun-Jun,ohtsuka,jormiya;Private [0085] Thread commands for reporting thread-linking, separating, and deleting are established likewise. [0086] The administration module 23 transmits/receives messages via the first input/output control module 31 and updates the message list and the administration table. The administration module 23 judges whether or not received messages are messages in the threads. This decision is executed, for example, according to whether a thread ID is present in the message. Wherein the administration module 23 has judged a message to be in the threads, it sends the message out to the control module 32 and the third input/output module 24 in accordance with user instructions. [0087] The administration module 23 also receives messages in the thread window from the third input/output module 24 . The administration module 23 sends the received messages and thread IDs out to the channel. [0088] Furthermore, the administration module 23 receives from the third input/output module 24 selection of processes on threads, and directs the processes to the creation module 21 . Wherein it has received selected users and messages from the third input/output module 24 , it also reports this information to the third input/output module 24 . For example, the administration module 22 executes a process in accordance with the selection by directing output of the toolbar 305 shown in FIG. 4 to the third input/output module 24 . [0089] In accordance with instructions from the administration module 23 and the creation module 21 , the third input/output module 24 displays the toolbar 305 and the various windows. The third input/output module 24 accepts process selections in the toolbar 305 and message input-through the thread window, which it reports to the administration module 23 . The third input/output module 24 accepts and reports to the creation module 21 users, message selections, and thread selections. The third input/output module 24 also receives messages themselves and thread IDs from the administration module 23 , and displays the messages in a designated thread window. [0090] Screen [0091] The following will illustrate examples of screens displayed by a display control device of the present invention. For ease of description, the message list is as is shown FIG. 2. [0092] [0092]FIG. 4 depicts a screen just after booting a chat client relating to the present embodiment. A main screen 301 , a user window 302 , and chat window 303 , and message input field 304 are displayed in the FIG. 4 screen. These windows are likewise as with general IRC clients; therefore explanation is omitted. [0093] In addition to the aforementioned general IRC screen, toolbar 305 is depicted in FIG. 4. The chat client is not connected to the network, and therefore only “Connect” is available on the toolbar 305 . When “Connect” is clicked, the chat client is connected via the Internet 1 to a chat server. It is otherwise connected directly to other chat devices or to a WEB server, however, wherein the display control device 2 is applied to other chat devices apart from IRC chat clients. [0094] [0094]FIG. 5 depicts a screen after connection to a chat server. In this state “connect” on the toolbar 305 is not available. On the other hand, “Create” and “Disconnect” are available. Selecting respective users in the user window 302 and clicking “Create” displays a confirmation window as shown in FIG. 6. In FIG. 6, users “jormiya” and user “ohtsuka” are selected. In this case, user “Jun-Jun” would be the author of the thread. [0095] The window shown in FIG. 6 is for confirming whether or not to display past messages in the freshly created thread window. Predetermined messages and a “Quote messages” checkbox are displayed in the confirmation window. When the “Quote messages” checkbox is checked and the “OK” button is pressed, a thread window is displayed. The messages displayed in the confirmation window will differ, however, depending on whether member users have been selected, whether messages have been selected, or whether neither has been selected. [0096] An example of a thread window 307 when a new thread has been created is depicted in FIG. 7. Thread window 307 includes message window 308 , input field 309 , and title field 310 . User messages composing the thread are displayed in the message window 308 . Messages for the thread can be input in the input field 310 . The default thread name “New Thread 1” is displayed in the title field 310 . Users can change the thread name-as they wish. [0097] In the FIG. 7 state, “Create,” “Cancel,” and “Disconnect” are available on the toolbar 305 . Wherein a selecting users creates the thread, thread-composing users are described in the thread information, as shown in the administration table in aforementioned FIG. 3. [0098] An example screen wherein a thread is created not by selecting users, but by selecting messages, is shown in FIG. 8. FIG. 8 depicts the situation in which a thread is created by selecting messages as a whole, or words included in messages. Wherein the thread is created by selecting messages, message IDs are described in the thread information, as shown in aforementioned FIG. 3 administration table. Herein, it is preferable that selecting messages means selecting users. [0099] It is possible, furthermore, to create threads without selecting users or messages. For example, wherein “Create” is pressed without making any selection, as shown in FIG. 9 a new thread window 307 is simply displayed with no message. Displaying a list of users in the channel by displaying a user list 311 , shown in FIG. 9 in the new thread window, is desirable. [0100] [0100]FIG. 10 illustrates a selection window displaying the situation wherein “Link” has been selected on the toolbar. A list of threads created in the channel is displayed in the selection window. When two or more threads are selected and the “OK” button is pressed, the selected threads (link source threads) are displayed in a linked-threads (forwarding destination threads) window. Wherein the “Quote Content” checkbox has been checked, past messages from the link source threads are displayed in thread window for forwarding destination threads. The message display order can be, for example, displaying in a time sequence, displaying in a user-and-time sequence, or otherwise designed to meet needs. [0101] [0101]FIG. 11 depicts an administration table wherein thread “Th3” has been created by user “Jun-Jun” linking thread “Th1” and “Th2.” FIG. 11( a ) illustrates an administration table for user “Jun-Jun.” FIG.( b ) illustrates an administration table for a user apart from user “Jun-Jun.” In FIG. 11( a ), thread IDs that have become link source threads are described as link sources in the thread information for linked thread “Th3.” In FIG. 11( b ), thread IDs that have become link source threads are described as forwarding destinations in the thread information for linked thread “Th3.” Accordingly, for user “Jun-Jun,” with whom there are linked users, a thread window is displayed in which messages in threads “Th1” and “Th2” are mixed. Nevertheless, this does not effect the displays for other users. If for example user “Jun-Jun” issues a remark in thread “Th3,” other display control devices receiving the message consult their administration tables and display the message in one forwarding destination thread or another. [0102] [0102]FIG. 12 illustrates an example of a selection window displaying the situation wherein “Display” has been clicked on the toolbar. A list of created thread titles is displayed in the selection window. When any of the threads is selected and the “OK” button is pressed, the selected thread window is displayed. Further, when the “Display Main Screen” checkbox has been checked the thread window is displayed on the main screen. In the FIG. 12 example, the title “Program” has been selected. [0103] Process Flow [0104] The following explains, by giving concrete examples, the flow of processes that the display control device 2 executes. The display control device 2 independently performs the input control routine, output control routine and main routine below. [0105] (1) Input Control Routine [0106] [0106]FIG. 13 is a flowchart illustrating flow of an input control routine that the display control device 2 executes. Activating the chat client starts the following processes. [0107] Initially, in step SI the third input/output control module 24 stands by for message input into the thread window. When a message is input into the thread window, step S 2 ensues. [0108] In step S 2 the third input/output control module 24 acquires the ID of the thread in the acquired message. Herein, the thread window being displayed and the thread ID are correlated and held in the third input/output control module 24 . [0109] In step S 3 , the third input/output control module 24 sends the input message content and the thread ID for the message to the administration module 23 . [0110] In step S 4 the administration module 23 updates the message list and the administration table. Specifically, the administration module 23 writes the message, the thread ID, and the message ID into the message list. The administration module 23 also consults the entries in the administration table and writes the message IDs into the administration table as needed. [0111] In step S 5 , the administration module 23 judges whether or not the chat client has terminated, and if it has not terminated, returns to step Si again and stands by for succeeding input. If it has terminated, the routine ends. [0112] (2) Output Control Routine [0113] [0113]FIG. 14 is a flowchart depicting flow of an output control routine that the display control device 2 executes. Like the aforementioned input control routine, activating the chat client starts the following routine. [0114] Initially* in step S 11 , the administration module 23 judges whether or not received data is a message from another chat client. If it is a message, step S 12 ensues. If it is other data, later-described step S 19 ensues. [0115] In step S 12 , the administration module 23 judges whether or not the message is in a thread. This decision judges based on whether or not, for example, a thread ID is included in a predetermined position in the message. If the message is in a thread, step S 13 ensues. If not, later-described step S 21 ensues. [0116] In step S 13 , the administration module 23 updates the message list and, if necessary, the administration table. Received messages, message IDs, and thread IDs are written in the message list. Wherein threads for message objects (object threads hereinafter) have not been composed from designated users, the administration module 23 writes the message ID into the administration table. [0117] In step S 14 , the administration module 23 consults the administration table and judges whether the disclosure level of the object thread is “Public” or not. If it is “Public,” step S 15 ensues. Otherwise, later-described step S 18 ensues. [0118] In step S 15 , the administration module 23 , consulting the administration table, judges whether or not the window for the object thread is being displayed. Wherein the thread window is being displayed, step S 16 ensues. Wherein the thread window is not being displayed, the administration module 23 sends the message to the control module 32 , and later-described step S 21 ensues. [0119] In step S 16 , the object thread is publicly open to all users, and therefore the administration module 23 outputs the received message to the thread window. [0120] In step S 17 , the administration module 23 judges whether or not the chat client is terminated or not, and if it is not terminated, returning to aforementioned step S 11 the foregoing routine is repeated. If it is terminated, the routine ends. [0121] In aforementioned step S 14 , when the object thread is judged to be “Private,” step S 18 ensues. In step S 18 , the administration module 23 judges whether or not the user is a member user in the object thread. If “Yes,” aforementioned step S 15 ensues; if “No,” aforementioned step S 17 ensues. That is, the received message is not displayed in either the thread window or in the chat window on the main screen. [0122] In aforementioned step S 11 , when the received data is judged not to be a message, step S 19 ensues. In step S 19 , the reporting module 22 judges whether or not the received data is a thread command. If the decision is “Yes,” step S 20 ensues. If the decision is “No,” the reporting module 22 sends the received data to the control module 32 , and later-described step S 21 ensues. That is, when the reporting module receives a thread command such as thread creation reports or link reports, step S 20 ensues. If, however, change in topic or mode reports from the server, change in participating user reports are received, for example, later-described step S 21 ensues. In step S 20 , the administration module 23 updates the administration table. There will be instances in which the update process will differ according to the received thread command. [0123] In the foregoing step S 12 , if the message is judged not to be a thread, step S 21 ensues. Herein, in step S 21 , the administration module 23 sends the message to the control module 32 . The message, likewise as in ordinary chat clients, is output to the main screen. [0124] Further, wherein in aforementioned step S 15 the decision is that the window for the object thread is not being displayed, step S 21 ensues. Herein, in step S 21 , the administration module 23 sends the thread message to the control module 32 . The thread message not being displayed in the thread window is therefore displayed in the main screen. [0125] Further, wherein in aforementioned step S 19 the decision is that the received data is neither a message nor a thread command, step 21 ensues. There are instances in which the joining/departing of channel participating users, change in topic, altering channel mode, or altering channel operator characteristics, for example, are received. Herein, the received data is sent from the reporting module 22 to the control module 32 . The control module 32 , likewise as in ordinary IRC routines, stores the received data into the memory 4 . [0126] Main Routine Flow [0127] The following explains the flow of the main routine executed by the display control device 2 . FIG. 15 is a flowchart illustrating flow of the main routine executed by the display control device 2 . Like the aforementioned input control routine and output control routine, activating the chat client starts the following processes. [0128] In step S 30 , the creation module 21 instructs the third input/output control module- 24 to-display the toolbar 305 . This instruction-displays the toolbar 305 in the input/output section. [0129] In step S 31 , the third input/output control module 24 stands by for any process to be selected, and reports a selected process to the administration module 23 . The administration module 23 judges whether or not “Connect” has been selected. If the decision is “Yes,” step S 32 ensues. Otherwise, later-described step S 34 ensues. [0130] In step S 32 , the administration module 23 performs a connection process. In the present example, the administration module 23 carries out the process of connecting to a chat server. However, wherein a display control device of the present invention is applied to Web chat, for example, the connection process is carried out with a Web server providing Web chat services. [0131] In step S 33 , the administration module 23 judges whether the chat client has terminated, and if it has not terminated, returns to step S 31 and repeats the foregoing processes. If it has terminated, the routine ends. [0132] In the decision in aforementioned step S 31 is “No,” step S 34 ensues. In step S 34 , the administration module 23 judges whether or not “Create” has been selected. If “Yes” is the case then step S 35 ensues. If “No” is the case then later-described step S 36 ensues. [0133] In step S 35 , the creation module 21 executes a later-described creation process subroutine. [0134] In step S 36 , the administration module 23 judges whether or not “Link” has been selected, and if “Yes,” step S 37 ensues. If “No,” later-described step S 38 ensues. [0135] In step S 37 , the creation module 21 executes a later-described linking process subroutine. [0136] In step S 38 , the administration module 23 judges whether or not “Separate” has been selected, and if “Yes,” step S 39 ensues. If “No,” later-described step S 40 ensues. [0137] In step S 39 , the creation module 21 executes the later-described creation process subroutine. [0138] In step S 40 , the administration module 23 judges whether or not “Cancel” has been selected. If “Yes,” step S 41 ensues. If “No,” later-described step S 42 ensues. [0139] In step S 41 , the creation module 21 executes a later-described cancellation process subroutine. [0140] In step S 42 , the administration module 23 judges whether or not “Display” has been selected. If “Yes,” step S 43 ensues. If “No,” later-described step S 44 ensues. [0141] In step S 43 , the administration module 23 executes a later-described displaying process subroutine. [0142] In step S 44 , the administration module 23 judges whether or not “Disconnect” has-been selected; if “Yes,” step S 45 ensues, and if “No,” returns to aforementioned step S 33 and repeats the foregoing processes. [0143] In step S 45 , the administration module 23 executes a process for disconnecting from the chat server. [0144] That is, in the main routine, the toolbar 305 is displayed and processes selected by the user are carried out. [0145] (3-1) Creation Process Subroutine [0146] [0146]FIG. 16 is a flowchart illustrating flow of a creation process that the creation module 21 carries out wherein “Create” has been selected in the toolbar 305 . When aforementioned step S 35 ensues in the main routine, the following process starts. [0147] In step S 351 , the creation module 21 judges whether or not either users composing a thread, or messages have been selected. If either selection is present, step S 352 ensues. If neither has been selected, later-described step S 354 ensues. [0148] In step S 352 , the creation module 21 directs display of the confirmation window in FIG. 6 to the third input/output control module 24 . [0149] In step S 353 , the third input/output control module 24 stands by for either the “OK” button or the “Cancel” button being pressed. The creation module 21 is notified when the “OK” button is pressed, and step S 354 ensues. Also included in the notification is the status of the “Quote Messages” checkbox. When the “Cancel” button is pressed, the creation process terminates and the flow returns to aforementioned step S 33 of the main routine. [0150] In step S 354 , wherein neither users composing a thread, nor messages have been selected, the creation module 21 creates and writes into the administration table thread information for a newly created thread. In particular, the thread ID is described in the thread information. Here the disclosure level may be set to “Public.” [0151] Conversely wherein either selection is present, the creation module 21 creates and writes into the administration table thread information in which selected member users or messages are described. In addition, if member users have been selected the disclosure level is set to “Private,” and if messages have been selected, to “Public” respectively. [0152] In step S 355 , the creation module 21 judges whether or not “Quote Messages” is checked. If “Yes,” step S 356 ensues; if “No,” later-described step S 357 ensues. [0153] In step S 356 , the creation module 21 acquires requisite messages from the message list. If member users have been selected, member users' messages are acquired using nicknames. If messages have been selected, messages are -acquired using message IDs. [0154] In step S 357 , the creation module 21 sends the acquired messages to the third input/output control module 24 . The third input/output control module 24 displays the thread window and outputs the messages within the window. [0155] In step S 358 , the creation module 21 reports the created thread information to the reporting module 22 . The reporting module 22 creates, and sends out to the channel via the administration module 23 , a thread command reporting creation of the thread. Thereafter, the flow returns to aforementioned step S 33 of the main routine. [0156] Moreover, the process carried out wherein “Separate” has been selected on the toolbar is like the thread-creation process, and explanation therefore will be omitted. [0157] (3-2) Link Process Subroutine [0158] [0158]FIG. 17 is a flowchart of a linking process that the creation module 21 carries out wherein “Link” has been selected in aforementioned toolbar 305 . When aforementioned step S 37 ensues in the main routine, the following process starts. [0159] In step S 371 , the creation module 21 directs display of the selection window shown in FIG. 10 to the third input/output control module 24 . The creation module 21 also retrieves from the administration table, and sends to the third input/output control module 24 , a title list for the created threads. The list of threads sent out is output to the selection window. [0160] In step S 372 , the third input/output control module 24 stands by for the “OK” button to be pressed, which selects a thread. The third input/output control module 24 notifies the creation module 21 when the “OK” button is pressed. The selected threads as well as the status of the “Quote Content” checkbox are included in this notification. Step S 373 then ensues. If the “Cancel” button is pressed, the linking process terminates. [0161] In step S 373 , the creation module 21 judges whether or not the “Quote Content” checkbox has been checked. If “Yes,” step S 374 ensues. If “No,” later-described step S 380 ensues. [0162] In step S 374 , the creation module 21 reports IDs for the selected threads to the administration module 23 . The administration module 23 acquires messages contained in the reported threads from the message list using the thread IDS. The administration module 23 also rearranges the acquired messages in accordance with predetermined criteria. They can be rearranged, for example, in a time sequence, or rearranged user-by-user. The administration module 23 sends the rearranged messages to the creation module 21 . [0163] In step S 375 , the creation module 21 directs to the third input/output control module 24 display of a new thread window for displaying the linked threads. [0164] In step S 376 , the creation module 21 sends the rearranged messages to the third input/output control module 24 . The third input/output control module 24 displays the received messages in the new thread window. [0165] In step S 377 , the creation module 21 consults the administration table to judge whether or not a window for link source threads is being displayed. If it is being displayed, instruction is to the third input/output control module 24 not to display the link-source window. Wherein this instruction is present, the third input/output control module 24 eliminates the link-source window. [0166] In step S 378 , the creation module 21 updates the administration table. That is, it writes into the new entries predetermined information relating to the linked threads (FIG. 11). In addition, wherein the link source threads are not to be displayed in aforementioned step S 377 , the creation module 21 changes the “Status” of the link source threads. [0167] In step S 379 , the creation module 21 reports to the reporting module 22 that threads have been linked. The reporting module 22 sends out thread commands that report link source thread IDs and forwarding destination thread IDs. Wherein, for example, user “Jun-Jun” links thread IDs “Th1” and “Th2,” a thread command example would be as follows. [0168] Th_merge Th1,Th2;Th3;Creator=Jun-Jun [0169] If “No” is judged in aforementioned step S 373 , step S 380 ensues. In step S 380 , a new thread window display instruction for displaying the linked threads is to the third input/output control module 24 . In response to the instruction, the third input/output control module 24 displays the new thread window. [0170] (3-3) Cancellation Process Subroutine [0171] [0171]FIG. 18 is a flowchart of processes in a cancellation process subroutine executed wherein “Cancel” has been selected in aforementioned toolbar 305 . When aforementioned step S 41 in the main routine ensues, the process here below begins. [0172] Initially, in step S 411 , the creation module 21 instructs to the third input/output control module 24 display of a selection window similar to FIG. 12. Preceding the instruction the creation module 21 acquires from the administration table the title list for the threads, which it sends along with the instruction to the third input/output control module 24 . In accordance with the instruction, the third input/output control module 24 displays a selection window. When the “Cancel” button is pressed, the cancellation process terminates. [0173] In step S 412 , when a thread selection is made and the “OK” button is pressed, the third input/output control module 24 reports to the creation module 21 the selected thread ID. [0174] In step S 413 , the creation module 21 deletes the entry for the reported thread ID from the administration table. [0175] In step S 414 , the creation module 21 deletes the aforementioned cancelled thread ID from the message list. [0176] In step S 415 , the creation module 21 reports cancellation of the thread to the reporting module 22 . The reporting module 22 sends out a thread command reporting the thread cancellation—a thread command as below, for example. [0177] Th_delete;ThID=Th1;Creator=Jun-Jun;User=Jun-Jun,ohtsuka,jormiya;private [0178] The process flow then returns to aforementioned step S 33 of the main routine. [0179] Herein, in case the cancelled thread is a linked thread, if when the link was made the link source threads were set to “Don't Display,” it is desirable to once again make the status of the link source threads “Display.” Therein, at first the creation module 21 consults the administration table and executes a decision as to whether the cancelled thread is a link thread or not. This decision is executed preceding aforementioned step S 413 . Wherein it is a link thread, the creation module 21 consults the link source thread status and if the status is “Don't Display,” changes it to “Display.” The creation module 21 also acquires messages in the link source threads from the message list. The creation module 21 then causes the link source threads to be displayed by sending an instruction for display of the link source threads, and the acquired messages, to the third input/output control module 24 . Presumably, when the threads are linked, the status of the link source threads is to be stored in memory, and if a linked thread is cancelled, the link source threads are returned to the stored state. [0180] (3-4) Displaying Process Subroutine [0181] [0181]FIG. 19 is a flowchart of a display process subroutine that the creation module 21 carries out wherein “Display” has been selected in aforementioned toolbar 305 . When aforementioned step S 43 ensues in the main routine, the process here below starts. [0182] In step S 431 , the creation module 21 directs display of the FIG. 12 selection window to the third input/output control module 24 . Preceding the instruction, the creation module 21 also retrieves a thread title list from the administration table, which it sends together with the aforementioned instruction to the third input/output control module 24 . The third input/output control module 24 displays a selection window in accordance with the instruction. [0183] In step S 432 , when any thread has been selected and the “OK” button is pressed, the third input/output control module 24 reports the selected thread to the creation module 21 . Step S 433 then ensues. When the “Cancel” button is pressed, the displaying process terminates. [0184] In step S 433 , the creation module 21 specifies IDs for the selected threads. The creation module 21 then acquires messages in the selected threads from the message list using the thread IDs. [0185] In step S 434 , the creation module 21 sends an instruction for thread window display, and the acquired messages, to the third input/output control module 24 . The third input/output control module 24 displays the thread window, and outputs the messages within the window. [0186] In step S 435 , the creation module 21 changes the “Status” of the aforementioned displayed thread in the administration table to “Display.” The flow then returns to aforementioned step S 33 of the main routine. [0187] Other Embodiments [0188] (a) In aforementioned FIG. 7, messages that have been displayed in thread window 307 are also displayed in chat window 303 . The setting, however, can be such that messages displayed in thread window are not displayed in the chat window. Preferably, the settings are such that the user can make them. [0189] (b) In the aforementioned first embodiment, the disclosure level is set automatically, but the user may set the disclosure level with every thread creation. In that case, presumably, a button for setting the disclosure level would be provided in the aforementioned confirmation window of FIG. 6. [0190] (c) In the aforementioned first embodiment, transmission/reception of thread information is carried out via a chat client, but may be carried out among display control devices directly. [0191] (d) For the situation in which a user that has linked threads issues messages to the thread window, a configuration is conceivable wherein other users' display control devices display the messages in all windows for those link source threads. Further, the text display method may be varied so as to distinguish the messages in the link threads. [0192] (e) Wherein threads are created, it is possible to make all members' display the same by sending to the selecting parties the selected message ID together with the thread creation command. [0193] Various details of the present invention may be changed without departing from its spirit nor its scope. Furthermore, the foregoing description of the embodiments according to the present invention is provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

The disclosure is directed to methods and devices for displaying conversations on a network for ease of viewing in accordance with user preferences. Based on thread (message-group) forming instructions from users, as well as on member users' instructions, threads are created from member users' remarks. Instead of designating users, remarks that include threads may be designated. Thread information relating to the created threads is at the same time created and stored. The thread information includes predetermined information such as thread IDs, member users and authors. The created thread information is reported to other users in the network, and is in common with thread information within the network. Remarks within a thread may be displayed in a thread window 307 only, or displayed in both it and a conversation window 303 , configurable to suit according to user instructions.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to footwear, and in particular to footwear having a "flasher module," i.e., an arrangement for illuminating the shoe in response to movement of the shoe. 2. Discussion of Related Art Shoes having flasher modules have been commercially available for several years. Generally, such shoes have utilized mercury switches and permanently mounted lithium batteries to provide the flashing effect, but there has been a recent trend to replace at least the mercury switches by safer, less expensive, and less environmentally harmful switching arrangements. Safety, cost, and environmental effects are all significant problems since the most common applications for flasher units of this type are in athletic and children's shoes, which wear out or are outgrown relatively rapidly, and which tend to be subject to greater abuse than other types of shoes. If the electrical units are not exposed during use, they will inevitably become exposed after being discarded, creating a great enough hazard that shoes containing mercury switches have been banned in a number of jurisdictions. There have been a number of attempts to design safer and less costly flasher units. U.S. Pat. No. 5,408,754, for example, discloses a "motion activated illuminating footwear and light module therefor" in which the sole "improvement" over the prior art involves the replacement of mercury or pressure sensitive switches by a less expensive conventional coil spring actuated switch. Although the light module described in this patent achieves cost savings by using a less expensive switch, the switch used is not as sensitive as a mercury switch, and the system described in the patent still requires a relatively expensive lithium battery, resulting in a light module having substantially decreased performance with minimal overall cost savings. One reason that the conventional motion sensitive switch, an example of which is illustrated in FIG. 3-1, is less sensitive to vibrations is that the soldering of the switch's inner spring contact to a printed circuit board results in a relatively small vibration angle for the spring contact. The addition of a plastic weight at the end of the spring to increase the inertia of the contact improves electrical engagement between the spring contact and the conductive casing of the switch, but does not increase the vibration angle. Furthermore, the manner in which the spring is soldered to the circuit board makes it likely that solder will be present on the upper portion of the spring, reducing the elasticity of the spring. Another disadvantage of this arrangement is that the LEDs in this arrangement have one lead soldered directly to the battery, requiring the legs of the LED to be bent during assembly. This has the disadvantage of making assembly without breaking the leads difficult, and also makes it impossible for the user to replace the battery. Because footwear illumination arrangements such as the one disclosed in U.S. Pat. No. 5,408,764 tend to use non-replaceable soldered-in battery arrangements, the footwear is discarded with the battery when the battery has reached the end of its useful life. Even if the footwear does not outlast the battery, the battery still must be discarded with the shoe. This is not only disadvantageous in terms of cost, but also dangerous to the environment, a problem which is compounded in the case of soldered battery terminals by the problem that most of the batteries are damaged during assembly as a result of the high solder temperatures required (>500° C.), most batteries having been designed to withstand a temperature of no greater than 50° C. While use of a battery bracket can alleviate the problem of heat damage, the problem of irremoveability remains in conventional designs. Other footwear illumination arrangements are disclosed in U.S. Pat. Nos. 4,848,009, 4,158,922, and 3,893,247, but these arrangements also have the disadvantage of a relatively high cost power source and less than optimal switching arrangements. SUMMARY OF THE INVENTION It is accordingly a first objective of the invention to provide a footwear illumination arrangement which utilizes a lower cost power supply by utilizing series-connected sets of low cost batteries in place of a single more expensive battery. It is a second objective of the invention to provide a footwear illumination arrangement which provides for increased battery life and at the same time lower costs by replacing the single battery of prior designs with multiple series connected battery sets connected in parallel. It is a third objective of the invention to provide a footwear illumination arrangement which provides for an increased useful life of the footwear by providing for replaceability of the power supply. It is a fourth objective of the invention to provide a footwear illumination arrangement having an improved motion sensitive switching design for greater sensitivity without significantly increased cost. It is a fifth objective of the invention to provide a footwear illumination arrangement having improved cushioning for heel installation. It is a sixth objective of the invention to provide a motion sensitive footwear illumination arrangement having improved sensitive in a low cost and easy-to-assemble package. These objectives of the invention are achieved, in a first preferred embodiment of the invention, by providing a power circuit for a footwear illumination arrangement which uses a plurality of ordinary button cell batteries, of the type widely used in the digital watch and toy business. The button cell batteries are connected in series in place of the expensive lithium power supplies required in prior designs. While a lithium battery has the advantage of high power (the battery sold by Maxwell Co. of Japan, Model #2032, for example, outputs 200 ma at 3 V), two conventional button style batteries connected in series at 120 ma and 1.5 V are just as effective at one-eighth the cost (a suitable battery is sold as Model LR 1154 by Golden Power Co. of Hong Kong). In fact, by connecting two series-connected battery sets in parallel, a cost savings of 75% can be achieved while greatly increasing the useful life of the device. In a particularly preferred embodiment of the invention, a footwear light module is provided which includes a housing having a removable press-fit cap from which upper battery contacts depend in such a manner that the batteries are sandwiched between lower battery contacts in the main housing and the upper battery contacts upon placement of the cap or cover on the main housing to complete an electrical power circuit. In this preferred embodiment of the invention, the upper battery contacts have opposite polarities so as to provide a series output. The batteries are connected to each other by means of a printed circuit board to form sets of parallel connected battery pairs in order to provide a desired current and voltage. For example, using the preferred module, a 3.0 V, 120 ma output can be obtained using two inexpensive 1.5 V, 120 ma batteries, and the current can be increased to 240 ma by using a parallel combination of the batteries. In addition, the preferred module includes an improved flasher module switching system made up of an at least partially cylindrical outer conductive member and an inner conductive spring contact arranged for movement within the outer conductive member. The inner spring contact is electrically connected to the positive power supply terminal and the surrounding conductive member is electrically connected to the positive terminal of the LED such that when the conductive spring contact engages the surrounding conductive member, a power circuit for the LED is completed and the LED is lit, the coil spring thereby acting as a bridge for the LED current rather than simply as a switch. In contrast to prior spring actuated motion sensitive switch arrangements, the coil spring contact has a 360° freedom of movement. Preferably, the coil spring of the invention has a narrower base for freedom of movement and an enlarged contact area to provide a larger current carrying capacity. A unique mounting arrangement for the coil spring of the invention prevents solder from adhering to the larger part of the coil and also offers the possibility of coil spring adjustment so that the coil spring will have the same distance to the cylinder wall in all directions. Additional advantageous features of the invention include the use of both upper and lower spring battery contacts to provide shock absorption features in heel applications, particularly for children's shoes, and the inclusion of a removable cap or cover which is press fit to the main housing by different diameter posts on the bottom and top permits easy assembly. In the preferred embodiment of the invention, the main housing is arranged to contain all component including the printed circuit board, LEDs, conductive terminals, and batteries, and in addition can also have an optical design or window in front of the LEDs to magnify the light therefrom or include diffraction effects. Preferably, circuitry is included to cause the LED to stay on or flash after activation for a predetermined number of cycles. In addition, the switching system may be replaced by a simple trigger plate. The invention thus involves an improved electrical circuit which permits greater flexibility in battery selection, an improved motion sensitive switch, and an improved housing and contact arrangement for the batteries, LED, and switch, resulting in a safer, easier to assemble, lower cost "flasher module" having improved flasher performance relative to prior "inexpensive" flasher module designs. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic circuit diagram showing an LED activation circuit including two series connected batteries constructed in accordance with a the principles of a first preferred embodiment of the invention. FIG. 1-A is a schematic circuit diagram showing a variation of the circuit of FIG. 1, in which two pairs of series-connected batteries are connected in parallel. FIG. 1-B is a schematic circuit diagram showing a further variation of the circuit of FIG. 1, in which two pairs of parallel connected batteries are connected in series. FIG. 2 is a perspective view of the main housing for a footwear light module constructed in accordance with the principles of the first preferred embodiment of the invention. FIG. 2-1 is a perspective view of the upper housing for the main housing shown in FIG. 2. FIG. 2-2 is a perspective view of a printed circuit board design for the module of FIGS. 2 and 2-1. FIG. 3 is a perspective semi-circular switching system design for use in the light module of the first preferred embodiment of the invention. FIG. 3-1 is a perspective view of a prior mounting arrangement for a coil spring in which the solder is allowed to flow up the spring. FIG. 3-2 is a perspective view of an improved coil spring mounting arrangement for use in the switching system of FIG. 3. FIG. 3-3 is a perspective view of a variation of the improved coil spring mounting arrangement shown in FIG. 3-2, in which the position of the coil spring is adjustable. FIG. 3-4 is a perspective view showing further details of the switching system illustrated in FIG. 3. FIG. 4 is a perspective view of an alternative switching system for use in the footwear light module of the first preferred embodiment of the invention. FIG. 4-1 is a top view of the switching arrangement of FIG. 4 showing the ideal location for the coil spring relative to the outer conductive member. FIG. 5 is a perspective view of a variation of the printed circuit board of FIG. 2-1. FIG. 6 is an exploded perspective view of a variation of the footwear light module shown in FIG. 2. FIG. 7 is an exploded perspective view of a further variation of the footwear light module shown in FIG. 2. FIG. 7-1 is a perspective view of a completed module made up of the parts shown in FIG. 7. FIG. 7-2 is a perspective view of a portion of the shown in FIG. 7, including batteries and a printed circuit board. FIG. 8 is an exploded perspective view of yet another variation of the footwear light module shown in FIG. 2. FIG. 9 is a perspective view of a shoe which includes a footwear light module constructed according to the principles of the first preferred embodiment of the invention. FIG. 10 is a bottom view of the shoe of FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates an improvement to the conventional lithium battery powered LED driver circuit in which, instead of a single lithium battery, the driver circuit 1 includes an LED 2 powered by two button type dry cell batteries 3 and 4 connected in series with each other and with a switch 5. While it is of course known to connect batteries in series, it is not conventional to connect button type batteries in series, particularly where the voltage and current requirements of the application can be met by a single lithium battery, and thus the present invention is both new and surprisingly advantageous because it turns out that the voltage and current requirements for driving the LEDs can actually be exceeded at less than half the cost of a single lithium battery. In FIG. 1 and each of the other Figures the collective output of the batteries is designated by terminals B+ and B-, and the respective positive and negative terminals of the LEDs are designated by terminals L+ and L-. By connecting two series connected battery sets in parallel, a cost savings of 75% over a lithium battery can be achieved while greatly increasing the useful life of the device. For example, using the preferred module, a 3.0 V, 120 ma output can be obtained using two inexpensive 1.5 V, 120 ma batteries, and the current can be increased to 240 ma by using a parallel combination of the batteries. The use of a parallel combination of series connected batteries is illustrated in FIG. 1-A, in which the voltage and current requirements for three parallel-connected LEDs 7-9 are met by providing two sets 10,11 of series connected batteries 12-15 connected in parallel with each other to double the current output without changing the voltage. While the circuits illustrated in FIGS. 1, 1-A, and 1-B provide an attractive lighting effect with just a motion sensitive switch, it will be appreciated by those skilled in the art that in the case of multiple LEDs, a more complex control circuit could be included, whether using conventional components or an integrated circuit, to vary the activation timing and duration for the various LEDs, some of which could be allowed to flash based on the motion sensitive switch and others based on a predetermined pattern. In a further variation of the circuit illustrated in FIG. 1, as shown in FIG. 1-B, the voltage and current requirements for the three parallel-connected LEDs 7-9 are met by providing two sets 17,18 of parallel connected batteries 19-22 connected in series with each other. The footwear light module in which the preferred circuit is used includes a main housing 24 having a base 25 and walls 26-29, cover post receiving openings 30-32, and battery isolation terminals 33 all integrally molded together. The upper housing or cover 38, shown upside-down in FIG. 2-1, in turn includes a plurality of press-fit mounting posts 39-41 having diameters slightly larger than those of openings 30-32 to provide a removable press-fit engagement between the cover and the main housing when posts 39-41 are inserted into openings 30-32, and a pair of upper conductive terminals 42 and 43 fastened to the cover by mounting posts 44-47. The preferred method of fastening the terminals is to stake them onto the mounting posts by inserting the mounting posts through holes in the terminals and melting the ends of the posts to form an expanded section which serves to retain the terminals on the posts, although those skilled in the art will appreciate that numerous other terminal mounting methods may be substituted. As illustrated, the terminals each have battery contact engagement portions 48-51 extending at an angle from the cover so as to bias the batteries in place in the main housing and establish a good electrical connection between both terminals of the batteries and the corresponding terminals or contacts in the housing. A preferred angle for the battery engagement portions is 45°. The main housing and cover are generally rectangular but asymmetric in that corners 52 and 53 of the rectangle are cut off so that the user does not unintentionally attempt to install the cover and circuit board in an incorrect orientation. In addition, the main housing includes a bay 54 and the base and upper cover include extensions 55 for accommodating the LED 56 of this embodiment. The shape of the housing may of course be varied by those skilled in the art, and a few of the possible variations are shown in connection with the remaining Figures of the present application. Advantageously, bay 54 which must be transparent to permit passage of light from the LED may be shaped to provide optical effects such as dispersion or diffraction of the light as desired. The circuit board 60 used in this embodiment of the invention is positioned between the front wall 29 of the main housing and the battery isolating posts 33, with the batteries being positioned between the battery isolating posts 33 and the rear and side walls 26-28 of the housing. Included on the circuit board 60 are the motion sensing switch 61, an LED 62, a common negative power terminal 63, and positive power terminals 64 and 65. Preferably, the common negative power terminal 63 is connected to a pair of individual negative contacts 66 and 67, while the positive power terminals are connected respectively connected to individual positive contacts 68 and 69. Contacts 66-68 extend rearwardly from the circuit board 60 when the circuit board is positioned in the main housing such that the contacts extend under the batteries 70-73 (which correspond to batteries 12-15 or 19-22 shown in FIGS. 2 and 3) which are positioned over the contacts by the posts 33, the batteries being biased against contacts 66-68 by respective contact portions 48-51 of the upper contacts, thus providing for easy installation and replacement of the batteries with good electrical contact in an especially compact structure. As illustrated, one lead 74 of LED 62 is connected to the common negative battery terminal 63 on circuit board 60, and the other lead 75 is connected to switch 61. Switch 61 is in turn connected by traces 76 and 77, as shown in FIG. 2-2, to the positive terminals 64 and 65 of the power supply. Details of the switch 61 and the manner in which the switch is assembled to the circuit board is shown in greater detail in FIG. 3, 3-2, 3-3, and 3-4, as well as FIG. 2-2. The switch is connected to the circuit board by means of two terminal pads 78 and 79. Lead 75 of LED 62 is soldered to terminal pad 78 and trace 76 is connected to terminal pad 79. Switch 61 is made up of a coil spring contact 80, a coil spring contact mounting member or bracket 81, and an outer contact member 82. In the embodiment of the invention illustrated in FIGS. 2, 2-2, 3, and 3-4, the outer contact member 82 is semi-cylindrical in shape although the contact could extend through any desired angle up to 360°. The outer contact member 81 is connected to terminal pad 78 by means of slots 83 in the terminal pad and tabs 84 on the contact, although those skilled in the art will appreciate that other suitable electrical connecting means may be used. The terminal pad itself forms, in this embodiment, a part of the outer contact assembly. The coil spring mounting member is similarly mounted, by way of example, on terminal pad 79 by means of slot 85 and tab or extension 86 on the mounting member 81. The manner in which the coil spring illustrated in FIGS. 3 and 3-2 to 3-4 is mounted provides particular advantages relative to prior art coil spring mounting arrangements involving, as illustrated in FIG. 3-1, directly attaching a coil spring 80' by means of solder 90' to a supporting terminal 60'. This presents the problem that solder is present on the portion of the spring which must bend in response to motion, limiting the motion of the spring. In addition, it is easy to get solder on the distal end of the spring, further stiffening the spring and making it less sensitive motion. In contrast, the present invention provides for attaching, by means of solder 90, an end 91 of the spring to the opposite side of the terminal or mounting member 81 from the moving or free end 92 of the spring. The free portion of the spring, from the terminal to the end is thus unencumbered by any solder, while at the same time it is easier to apply solder to the other side of the terminal 81 without the spread of soldering flux along the coil spring to the free end 92, since the terminal 81 protects the free side of the spring. As shown in FIGS. 3-3 and 3-4, by making the position of the spring adjustable relative to the mounting member, the spring can be centered within the outer conductive member. To provide the greatest possible range of motion. In addition, those skilled in the art will appreciate that the movement, and therefore the sensitivity, of the coil spring can be controlled by varying the diameter, material, and density of coils of the spring. In this embodiment, the coil spring is not just a switch, but a current bridge. By proper adjustment of coil position and by increasing the radius of the free end of the coil, the current handling capacity of the switch can be maximized, thereby maximizing the brightness of the LEDs powered by the switching circuit. Further, by varying the contact radii, the brightness of the LEDs will vary with the current handling capacity of the contact, creating a less uniform and therefore more interesting lighting effects. In a modification of the switch shown in FIGS. 3 and 3-2 to 3-4, the motion sensitive switching arrangement includes an outer conductive member in the form of a complete cylinder 100 which is vertically positioned on a circuit board 101, which may be similar to circuit board 60. In this arrangement, which is illustrated in FIG. 4, the positive lead 75 of one or more LEDs 62 may be directly connected to the cylinder 100 or to an annular trace 102 on which the cylinder is positioned, the annular trace 102 being connected by trace 102' to the positive terminal of the battery. The motion sensitive coil spring 103 in this embodiment extends all the way through the circuit board such that an end 104 of the spring 103 extending through to the opposite side of the circuit board can be soldered thereto without affecting its movement on the switching side, with the negative terminal of the battery being connected to the soldered end of the spring 103. The use of a complete cylinder, as indicated in FIG. 4-1, permits a uniform flashing effect as opposed to the more varied effect achieved by the semi-cylindrical design, with control of the flashes being obtained by varying the diameter of the free end 105 of the spring 103. FIGS. 5 and 6 illustrate an alternative version of the light module of FIG. 4. In this version, the circuit board is in the form of a L-shaped member 110, with one side having printed thereon a positive voltage trace 109 extending from a terminal 111 arranged to receive a first battery contact 112, contact 112 being arranged to contact the positive terminal of a battery and ending at the terminal pad 78 of a switch corresponding to that shown in FIG. 3, the opposite side of the switch being further connected by a positive trace 113 to the positive voltage lead 114 of an LED 115. In this version of the preferred embodiment, the negative lead 116 of the LED extends along the opposite side of the circuit board to a negative contact terminal 117 arranged to receive a negative battery contact 118. Both the positive and negative battery contacts 112 and 118 including battery engagement sections 119-121 extending at an angle of, for example, 45° from the main section of the contacts to provide a biasing force which ensures a good electrical connection between the contacts and the battery terminals. Connection to the circuit board member 110 is by means of tabs 122,123 on the contacts which extend into the slots which form terminals 111,117. The circuit board arrangement shown in FIG. 5 is used in connection with the module arrangement illustrated in FIG. 6. As with the embodiment of the invention illustrated in FIGS. 2 and 2-1, the module of this embodiment includes a main housing 200 in which the circuit board 110, LED 115, and batteries 201-204 are accommodated. To this end, the main housing 200 includes a main compartment having posts 207 extending thereinto for supporting the circuit board, and posts 208 for also supporting the circuit board, with the circuit board thereby dividing the compartment 206 into a two sections with batteries 201 and 202 on one side and batteries 203 and 204 on the other, the positions of the batteries being further established by curved portions 209 of the outer wall of the main housing. Optionally, posts 208 may also serve to receive press fit pins extending from the cover, as will be explained below. When the circuit board of FIGS. 5 and 6 is positioned in the compartment 206 by means of posts 207 and 208, LED 115 will extend into an opening 210 having a transparent wall 211 which can be shaped to provide optical effects if desired. The contacts 112 and 118, which have been pre-soldered to terminals 111 and 117 extend on opposite sides of the board with batteries 201-204 being place on top of the contacts such that the positive terminals of batteries 201 and 202 engage respective angled portions of contact 112, and the negative terminals of batteries 203 and 204 engage respective angled portions of contact 118. A rear compartment 212 of the main housing serves to accommodate leads for connecting addition LEDs to the switching circuit. As shown in FIG. 6, the main housing 200 can accommodate two different press-fit covers 215 and 215', the difference being that cover 215 is press-fit by means of pins 216 and 217 to respective openings 219 and 220 in the outer wall of the housing, and alternative cover 215' is press-fit by means of pins 221 and 222 and posts 208. Each of the alternative covers shares, however, upper battery contacts 223 and 224, which are preferably secured to the covers by mounting pins 225 staked to openings 226 in the contacts, with angled sections 227 and 228 of contacts 223 and 224 being respectively arranged in the illustrated example to engage the negative terminals of batteries 201 and 202, and angled sections 229 and 230 of contact 118 being respectively arranged to engage the positive terminals of batteries 203 and 204, thereby forming a circuit similar to that illustrated in FIG. 1-A. The variation of the preferred embodiment illustrated in FIGS. 7 to 7-2 uses a cover made up of a protective member 251 permanently secured to the main housing 252 and a removable press-fit cap 253 having openings 254 through which the user can insert the tip of a pen or the like in order to facilitate removal of the cap. In this embodiment, cap 253 includes a press fit pin 255, while the battery compartment includes various molded-in posts 256 for positioning a circuit board of the type illustrated in FIG. 5, positioning and isolating the batteries from each other and the circuit board, and cooperating with the press-fit pin 255. In addition, the main housing 252 of this embodiment also includes a compartment 257 for accommodating the LED, the compartment including a transparent wall 258, and a compartment 259 for accommodating external LED leads 260 of optionally multi-colored LEDs 261 and permitting their connection to the circuit board. The additional posts 256 extending from the base of the main housing in this embodiment are provided because the batteries 262-265 are supported by four separate lower contacts 266-269 extending from opposite sides of the circuit board 270 rather than the common contacts of the embodiment illustrated in FIG. 6. By positioning the batteries such that the lower contacts on each side of the board respectively engage one positive and one negative terminal, and the upper contacts 271 and 272 engage common negative and positive contacts of the batteries, a circuit such as the one in FIG. 1-B can be obtained. Additional modifications provided by this embodiment of the invention include the provision at one end of the circuit board of a plurality of terminals 273 for accommodating the leads 260, and the inclusion in the main housing of molded-in structures 274 for supporting LED 275. The arrangement shown in FIG. 8 is identical to that shown in FIGS. 7 to 7-2, except for the shapes of the housing and cover, and the location of the press-fit pins 277 and openings 278. Corresponding elements have therefore been designated by primed reference numerals and the details of the construction of this module are not discussed further herein. Finally, FIGS. 9 and 10 show an application of the flasher modules of any of the preferred embodiments of the invention to a shoe, and in particular to the heel 314 of a shoe 310. In this Figure, the flasher module is designated by the reference numeral 312, the circuit board by reference numeral 316, the batteries by reference numeral 318, the LED contained in the module by reference numeral 320, and additional multi-colored LEDs by reference numerals 322 and 324. Those skilled in the art that flasher module 312 of this embodiment could be represented by any of the flasher modules shown in 2-8, and that the flasher modules of the preferred embodiments of the invention could be used in a variety of footwear and other applications. Having thus described various preferred embodiments of the invention, those skilled in the art will appreciate that variations and modifications of the preferred embodiment may be made without departing from the scope of the invention. It is accordingly intended that the invention not be limited by the above description or accompanying drawings, but that it be defined solely in accordance with the appended claims.

A flasher module for footwear includes a main housing containing all necessary circuitry for supplying power to at least one LED and for causing the LED to flash in response to movement of the shoe, except that at least one upper contact is affixed to a press fit cover such that when the press fit cover is secured to the main housing, at least two batteries are sandwiched between the upper contact and a lower contact in the main housing to complete a power supply circuit. The at least two batteries are connected in series, and two additional batteries may also be included in various series and parallel combinations depending on the desired voltage and current. An improved motion sensitive switch includes a terminal member from which a coil spring extends on one side to engage an outer conductive member upon motion of the shoe, the coil spring being soldered to the terminal member on the opposite side from the free end of the spring. The outer conductive member can be semi-cylindrical in form to offer a lower profile and more interesting lighting patterns.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This patent application claims the benefit of U.S. Provisional Patent Application Nos. 61/544,108 filed Oct. 6, 2011, and 61/590,431, filed Jan. 25, 2012, the disclosure of which provisional applications are herein incorporated by reference. FIELD OF THE INVENTION [0002] The present invention encompasses crystalline forms of Afatininb di-maleate. BACKGROUND OF THE INVENTION [0003] The compound, (E)-4-Dimethylamino-but-2-enoic acid {4-(3-chloro-4-fluoro-phenylamino)-7-[(S)-(tetrahydro-furan-3-yl)oxy]-quinazolin-6-yl}-amide, known as Afatinib, having the following structure: [0000] [0000] is an investigational orally administered irreversible inhibitor of both the epidermal growth factor receptor (EGFR) and human epidermal receptor 2 (HER2) tyrosine kinases. [0004] Afatinib is under development for treatment of several solid tumors including non-small cell lung cancer (NSCLC), breast, head and neck cancer, and a variety of other cancers. [0005] WO2002/50043 and WO2005/037824 (WO′824) describe Afatinib, a salt thereof and a crystalline form of the di-maleate salt. [0006] The present invention relates to solid state forms of Afatinib di-maleate which possess different physical properties. The solid state form and the associated properties can be influenced by controlling the conditions under which Afatinib di-maleate is obtained in solid form. [0007] Polymorphism, the occurrence of different crystal forms, is a property of some molecules and molecular complexes. A single molecule may give rise to a variety of polymorphs having distinct crystal structures and physical properties like melting point, thermal behaviors (e.g. measured by thermogravimetric analysis—“TGA”, or differential scanning calorimetry—“DSC”), X-ray powder diffraction (XRPD or powder XRD) pattern, infrared absorption fingerprint, and solid state nuclear magnetic resonance (NMR) spectrum. One or more of these techniques may be used to distinguish different polymorphic forms of a compound. [0008] Discovering new polymorphic forms and solvates of a pharmaceutical product can provide materials having desirable processing properties, such as ease of handling, ease of processing, storage stability, ease of purification or as desirable intermediate crystal forms that facilitate conversion to other polymorphic forms. New polymorphic forms and solvates of a pharmaceutically useful compound or salts thereof can also provide an opportunity to improve the performance characteristics of a pharmaceutical product. It enlarges the repertoire of materials that a formulation scientist has available for formulation optimization, for example by providing a product with different properties, e.g., better processing or handling characteristics, improved dissolution profile, or improved shelf-life. For at least these reasons, there is a need for additional solid state forms of Afatinib di-maleate. SUMMARY OF THE INVENTION [0009] The present invention provides crystalline forms of Afatinib di-maleate, processes for preparing them, and pharmaceutical compositions containing them. [0010] The present invention also encompasses the use of any one of the crystalline forms of Afatinib di-maleate provided herein, for the preparation of Afatinib, other Afatinib salts, solid state forms thereof, and formulations thereof. [0011] The present invention also encompasses the use of any one of the crystalline forms of Afatinib di-maleate disclosed herein for the preparation of a medicament, preferably for the treatment of cancer, particularly for the treatment of cancers mediated by epidermal growth factor receptor (EGFR) and human epidermal receptor 2 (HER2) tyrosine kinases, e.g., solid tumors including NSCLC, breast, head and neck cancer, and a variety of other cancers mediated by EGFR or HER2 tyrosine kinases. [0012] The present invention further provides a pharmaceutical composition comprising any one of the Afatinib di-maleate crystalline forms of the present invention and at least one pharmaceutically acceptable excipient. [0013] The present invention also provides a method of treating cancer, comprising administering a therapeutically effective amount of at least one of the Afatinib di-maleate crystalline forms of the present invention, or at least one of the above pharmaceutical compositions to a person suffering from cancer, particularly a person suffering from a cancer mediated by epideimal growth factor receptor (EGFR) and human epidermal receptor 2 (HER2) tyrosine kinases, e.g., solid tumors including but not limited to NSCLC, breast, head and neck cancer, and a variety of other cancers mediated by EGFR or HERZ tyrosine kinases. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 shows an X-ray powder diffractogram of Afatinib di-maleate Form C. [0015] FIG. 2 shows a DSC thermogram of Afatinib di-maleate Form C. [0016] FIG. 3 shows a 1 H-NMR spectrum of Afatinib di-maleate Form C. [0017] FIG. 4 shows an X-ray powder diffractogram of Afatinib di-maleate Form D. [0018] FIG. 5 shows a DSC thermogram of Afatinib di-maleate Form D. [0019] FIG. 6 shows a 1H-NMR spectrum of Afatinib di-maleate Form D. [0020] FIG. 7 shows an X-ray powder diffractogram of Afatinib dimaleate Form E. [0021] FIG. 8 shows a Humidity-dependent weight increase of a sample of Afatinib di-maleate Form A. [0022] FIG. 9 shows an HPLC/UV chromatogram of analysis of Afatinib di-maleate Form A after storage for 4 weeks at 40° C./75% relative humidity. [0023] FIG. 10 shows a 1 H-NMR-spectrum of Afatinib di-maleate Form A after storage for 4 weeks at 40° C./75% relative humidity. [0024] FIG. 11 shows an X-ray powder diffractogram of Afatinib di-maleate, Form A. DETAILED DESCRIPTION OF THE INVENTION [0025] US 2005/0085495 (the US counterpart of WO′824) cites that “Afatinib di-maleate as suitable salt for pharmaceutical use as it exist in only one crystalline modification, which is moreover anhydrous and very stable. In addition, the described crystalline satisfies the physicochemical requirements”. Namely, this crystalline form has only limited hygroscopisity and is polymorphically stable. [0026] Unlike what is written in US 2005/0085495, additional crystalline forms of Afatinib di-maleate were prepared as described herein, which posses better physicochemical features. [0027] In some embodiments the crystalline forms of Afatinib di-maleate of the invention are substantially free of any other polymorphic forms, or substantially free of a specified polymorph of Afatinib di-maleate. In any embodiment of the present invention, by “substantially free” is meant that the forms of the present invention contain 20% (w/w) or less, 10% (w/w) or less, 5% (w/w) or less, 2% (w/w) or less, particularly 1% (w/w) or less, more particularly 0.5% (w/w) or less, and most particularly 0.2% (w/w) or less of any polymorphs or of a specified polymorph of Afatinib di-maleate. In other embodiments, the polymorphs of Afatinib di-maleate of the invention contain from 1% to 20% (w/w), from 5% to 20% (w/w), or from 5% to 10% (w/w) of any other polymorphs or of a specified polymorph of Afatinib di-maleate. [0028] The present invention provides new crystalline forms of Afatinib di-maleate that have advantageous properties over other solid state forms of Afatinib di-maleate, selected from at least one of: chemical purity, flowability, solubility, dissolution rate, morphology or crystal habit, stability, such as thermal and mechanical stability to polymorphic conversion, stability to dehydration and/or storage stability, low content of residual solvent, a lower degree of hygroscopicity, flowability, and advantageous processing and handling characteristics such as compressibility, and bulk density. [0029] A solid state form may be referred to herein as being characterized by data selected from two or more different data groupings, for example, by a powder XRD pattern having a group of specific peaks; or by a powder XRD pattern as shown in a figure depicting a diffractogram, or by “a combination thereof” (or “combinations thereof,” or “any combination thereof”), These expressions, e.g., “any combination thereof” contemplate that the skilled person may characterize a crystal form using any combination of the recited characteristic analytical data. For example, the skilled person may characterize a crystal form using a group of four or five characteristic powder XRD peaks, and supplement that characterization with one or more additional features observed in the powder X-ray diffractogram, e.g., an additional peak, a characteristic peak shape, a peak intensity, or even the absence of a peak at some position in the powder XRD pattern. Alternatively, the skilled person may in some instances characterize a crystal form using a group of four or five characteristic powder XRD peaks and supplement that characterization with one or more additional features observed using another analytical method, for example, using one or more characteristic peaks in a solid state NMR spectrum, or characteristics of the DSC thermogram of the crystal form that is being characterized. [0030] A solid state may be referred to herein as being characterized by graphical data “as depicted in” a Figure. Such data include, for example, powder X-ray diffractograms and solid state NMR spectra. The skilled person will understand that such graphical representations of data may be subject to small variations, e.g., in peak relative intensities and peak positions due to factors such as variations in instrument response and variations in sample concentration and purity, which are well known to the skilled person. Nonetheless, the skilled person would readily be capable of comparing the graphical data in the Figures herein with graphical data generated for an unknown crystal form and confirm whether the two sets of graphical data are characterizing the same crystal form or two different crystal forms. A crystal form of Afatinib di-maleate referred to herein as being characterized by graphical data “as depicted in” a Figure will thus be understood to include any crystal forms of Afatinib di-maleate characterized with the graphical data having such small variations, as are well known to the skilled person, in comparison with the Figure. [0031] The term “solvate,” as used herein and unless indicated otherwise, refers to a crystal form that incorporates a solvent in the crystal structure. When the solvent is water, the solvate is often referred to as a “hydrate.” The solvent in a solvate may be present in either a stoichiometric or in a non-stoichiometric amount. When the solvent is present in stoichiometric amount, the hydrate may be referred to as monohydrate, di-hydrate, tri-hydrate etc. The solvent content can be measured, for example, by GC, 1 H-NMR, Karl-Fischer (KF) titration or by monitoring the weight increase during dynamic vapour sorption (DVS) test. [0032] The term “anhydrous” as used herein, and unless stated otherwise, refers to crystalline Afatinib di-maleate which contains not more than 1% (w/w), preferably not more than 0.5% (w/w) of either water or organic solvents as measured by TGA. [0033] As used herein, the term “isolated” in reference to any of Afatinib di-maleate polymorphs thereof of the present invention corresponds to Afatinib di-maleate polymorph that is physically separated from the reaction mixture, where it is formed. [0034] The term “non-hygroscopic” as used herein, and unless stated otherwise, refers to crystalline Afatinib di-maleate uptaking/absorbing less than 0.2% (w/w) of atmospheric water to the crystalline Afatinib di-maleate in the below specified conditions, as measured by Karl-Fischer (KF) titration or by monitoring the weight increase during dynamic vapour sorption (DVS) test. [0035] As used herein, unless stated otherwise, the XRPD measurements are taken using copper Kα radiation wavelength A, =1.5406 Å. For the avoidance of doubt, the XRPD values described herein were measured using the diffractometer and conditions described below. [0036] A thing, e.g., a reaction mixture, may be characterized herein as being at, or allowed to come to “room temperature, often abbreviated as “RT.” This means that the temperature of the thing is close to, or the same as, that of the space, e.g., the room or fume hood, in which the thing is located. Typically, room temperature is from about 20° C. to about 30° C., or about 22° C. to about 27° C., or about 25° C. [0037] A process or step may be referred to herein as being carried out “overnight.” This refers to a time interval, e.g., for the process or step, that spans the time during the night, when that process or step may not be actively observed. This time interval is from about 8 to about 20 hours, or about 10-18 hours, typically about 16 hours. [0038] As used herein, the term “reduced pressure” refers to a pressure of about 10 mbar to about 50 mbar. [0039] As used herein, the term Afatinib di-maleate form A refers to the crystalline form provided in WO2005/037824, disclosed in the table provided below. [0000] 2-Θ [°] d-value [Å] intensity I/I o [%] 4.91 18.0 47 6.42 13.8 33 7.47 11.8 27 8.13 10.9 30 10.37 8.53 30 11.69 7.56 2 12.91 6.85 20 13.46 6.58 3 13.66 6.48 2 14.94 5.93 11 16.58 5.34 12 17.19 5.15 36 17.87 4.96 5 19.43 4.57 38 19.91 4.46 100 20.84 4.26 13 21.33 4.16 21 21.58 4.12 12 22.25 3.992 15 22.94 3.873 32 23.67 3.756 9 24.82 3.584 7 25.56 3.482 37 26.71 3.335 9 27.46 3.245 4 28.37 3.143 8 30.71 2.909 3 29.31 3.045 4 29.57 3.019 4 31.32 2.854 10 32.31 2.769 4 33.10 2.705 5 33.90 2.643 1 34.84 2.573 2 35.71 2.512 1 36.38 2.467 1 36.96 2.430 1 37.99 2.367 2 39.94 2.255 5 [0040] In particular, Afatinib di-maleate is characterized by an X-ray powder diffraction pattern substantially as depicted in FIG. 11 of the present application. [0041] The present invention encompasses a crystalline form of Afatinib di-maleate, designated as Form C. Form C can be characterized by data selected from: an X-ray powder diffraction pattern having peaks at 5.5, 9.3, 18.8, 19.1 and 21.5 degrees two theta±0.2 degrees two theta; an X-ray powder diffraction pattern substantially as depicted in FIG. 1 ; and combinations thereof. Crystalline Form C of Afatinib di-maleate may be further characterized by additional analytical data selected from: an X-ray powder diffraction pattern having any one, two, three, four, five, six, seven or eight additional peaks selected from peaks at 5.1, 5.9, 8.7, 12.5, 15.7, 24.1, 26.2 and 28.6 degrees two theta±0.2 degrees two theta; a DSC thermogram substantially as depicted in FIG. 2 ; and a 1 H-NMR spectrum substantially as depicted in FIG. 3 ; and combinations thereof. [0042] The above Afatinib di-maleate Form C may be anhydrous. [0043] Form C of the present invention seems to have advantageous properties such as: chemical purity, flowability, solubility, dissolution rate, morphology or crystal habit, stability, such as thermal and mechanical stability to polymorphic conversion, stability to dehydration and/or storage stability, low content of residual solvent, a lower degree of hygroscopicity, flowability, and advantageous processing and handling characteristics such as compressibility, and bulk density. [0044] According to some embodiments the crystalline Form C of Afatinib di-maleate of the invention are disclosed herein as being chemically stable under certain recited conditions, for example under conditions of 30° C./65% relative humidity for 4 weeks. By chemically stable is meant that the chemical purity of the Afatinib di-maleate when subjected to these conditions changes in an amount of less than about 1%; preferably less than about 0.8% w/w by HPLC, while the recited solid state form is maintained. [0045] The present invention encompasses a crystalline form of Afatinib di-maleate, designated as Form D. Form D can be characterized by data selected from: an X-ray powder diffraction pattern having peaks at 5.6, 9.5, 22.1, 26.3 and 29.5 degrees two theta±0.2 degrees two theta; an X-ray powder diffraction pattern substantially as depicted in FIG. 4 ; and combinations thereof. Crystalline Form D of Afatinib di-maleate may be further characterized by additional analytical data selected from: an X-ray powder diffraction pattern having any one, two, three, four, five, six, seven, eight, nine or ten additional peaks selected from peaks at 11.2, 14.4, 18.5, 19.7, 20.5, 20.7, 22.3, 23.5, 24.8 and 28.1 degrees two theta±0.2 degrees two theta; a DSC thermogram substantially as depicted in FIG. 5 ; and a 1 H-NMR spectrum substantially as depicted in FIG. 6 . [0046] The above Afatinib di-maleate Form D may be anhydrous. [0047] The present invention encompasses Afatinib di-maleate hydrate, for example, tri-hydrate. [0048] The present invention encompasses a crystalline form of Afatinib di-maleate, designated as Form E. Form E can be characterized by data selected from: an X-ray powder diffraction pattern having peaks at 5.5, 11.4, 17.7, 22.3 and 25.5 degrees two theta±0.2 degrees two theta; an X-ray powder diffraction pattern substantially as depicted in [0049] FIG. 7 ; and combinations thereof. Crystalline form of Afatinib di-maleate may be further characterized by additional analytical data selected from: an X-ray powder diffraction pattern having one, two, three, four or five additional peaks selected from peaks at 6.1, 13.1, 20.3, 28.0 and 29.1. [0050] The above form E can be a hydrate form; particularly it can be a tri-hydrate form. The tri-hydrate form E can have a water content from about 5.9% to about 8.1%, for example of about 7% (w/w), or from about 2.5 mole equivalents to about 3.5 mole equivalents, for example of about, 3 mole equivalents of water per one mole equivalent of Afatinib di-maleate, as measured by Karl-Fischer (KF) titration or by monitoring the weight increase during dynamic vapour sorption (DVS) test. [0051] Form E of the present invention seems to have advantageous properties such as: chemical purity, flowability, solubility, dissolution rate, morphology or crystal habit, stability, such as thermal and mechanical stability to polymorphic conversion, stability to dehydration and/or storage stability, low content of residual solvent, a lower degree of hygroscopicity, flowability, and advantageous processing and handling characteristics such as compressibility, and bulk density. [0052] According to some embodiments the crystalline Form E of Afatinib di-maleate of the invention are disclosed herein as being polymorphically stable under certain recited conditions, for example under conditions of 40° C./75% relative humidity. By polymorphically stable is meant that under these conditions, less than 1% of the stable form converts to any other solid state form of Afatinib di-maleate. Further, under these conditions, form E has found to be not hygroscopic. [0053] The above solid state forms of Afatinib di-maleate can be used to prepare 1) Afatinib free base and solid state forms thereof; 2) other Afatinib salts and solid state forms thereof; and 3) pharmaceutical formulations. [0054] The present invention provides a process for preparing Afatinib free base, for example, by preparing any one of the solid state forms of the present invention; and basifying the said salt to obtain Afatinib free base. The process can further comprise converting the obtained Afatinib free base to any other salt of Afatinib and solid state forms thereof. The conversion can comprise, for example, reacting the obtained Afatinib free base with an appropriate acid to obtain the corresponding acid addition salt. [0055] Alternatively, the conversion can be done by salt switching, i.e., reacting Afatinib di-maleate, with an acid having a pK a which is lower than the pK a of the acid of maleic acid. [0056] The present invention further encompasses 1) a pharmaceutical composition comprising any one of Afatinib di-maleate crystalline forms, as described above, and at least one pharmaceutically acceptable excipient; and 2) the use of any one or combination of the above-described crystalline forms of Afatinib di-maleate, in the manufacture of a pharmaceutical composition, and 3) a method of treating a solid tumor such as NSCLC, breast, head and neck cancer, and a variety of other cancers, comprising administration of an effective amount of a pharmaceutical composition comprising any one or more of the forms of Afatinib di-maleate described herein. [0057] The pharmaceutical composition can be useful for the treatment of solid tumors including NSCLC, breast, head and neck cancer, and a variety of other cancers. The present invention also provides crystalline forms of Afatinib di-maleate as described above for use as a medicament, preferably for the treatment of cancer, in particular, solid tumors including NSCLC, breast, head and neck cancer, and a variety of other cancers. [0058] Having thus described the invention with reference to particular preferred embodiments and illustrative examples, those in the art can appreciate modifications to the invention as described and illustrated that do not depart from the spirit and scope of the invention as disclosed in the specification. The Examples are set forth to aid in understanding the invention but are not intended to, and should not be construed to limit its scope in any way. X-Ray Powder Diffraction (“XRPD”) Method: [0059] Samples were analyzed on a D8 Advance X-ray powder diffractometer (Bruker-AXS, Karlsruhe, Germany). The sample holder was rotated in a plane parallel to its surface at 20 rpm during the measurement. Further conditions for the measurements are summarized below. The raw data were analyzed with the program EVA (Bruker-AXS, Germany). [0000] standard measurement radiation Cu K α (λ = {tilde over (1)}5{tilde over (4)}6 Å) Source 38 kV/40 mA detector Vantec detector slit variable divergence slit v6 antiscattering slit v6 2θ range/° 2 ≦ 2θ ≦ 55 step size/° 0.017 Differential Scanning Calorimetry: [0060] Mettler Toledo Model DSC 822; heating range for the samples 30 to 250 deg C; heating rate=10 deg C/min; purge gas=nitrogen 50 ml/min; 40 micron aluminum crucible. 1 H-NMR Spectroscopy: [0061] Instrument: Varian Mercury 400 plus NMR Spectrometer, Oxford AS, 400 MHz HPLC/UV Column: Phenomenex Kinetex 2.6μ C18 100A, 150*4.6 mm Oven: 40° C. λ: 260/4 nm Ref 550/100 nm Inj Vol.: 1 μl Eluent: [0062] A: acetonitrile [0063] B: 0.2% formic acid+0.1% HFBA pH 2. [0000] Gradient: Time [min] solvent B [%] flow [ml/min] 0 70 0.7 6 50 0.7 8 50 0.7 14 20 0.7 15 20 0.7 15.5 70 0.7 20.5 Stop Karl-Fischer Titration [0064] Karl-Fischer titration was carried out using Apura®-Testicit from Merck (HX908240). The instructions of the manual were followed and each sample was analyzed in triplicate. EXAMPLES Preparation of the Afatinib Base Starting Material [0065] Afatinib base was prepared according to WO2005/037824 example 2. [0066] 5.6 litres of 30% hydrochloric acid (53.17 mol) are added to 4.4 liters of water. Then 4.28 kg of 95% (dimethylamino)-acetaldehyde-diethyl-acetal (26.59 mol) are added dropwise within 20 minutes at 30.degree. C. The reaction solution is stirred for 8 hours at 35.degree. C. stirred, cooled to 5.degree. C. and stored under argon. This solution is referred to as solution B. [0067] 4.55 kg (68.06 mol) of potassium hydroxide are dissolved in 23.5 liters of water and cooled to -5.degree. C. This solution is referred to as solution C. [0068] 5.88 kg (10.63 mol) of diethyl ((4-(3-chloro-4-fluoro-phenylamino)--7-(tetrahydrofuran-3-yloxy)-quinazoline-6-ylcarbamoyl)-methyl)-phosphonate and 0.45 kg of lithium chloride (10.63 mol) are placed in 23.5 liters of tetrahydrofuran and cooled to -7.degree. C. The cold solution C is added within 10 minutes. Then solution B is added at −7.degree. C. within 1 hour. After stirring for a further hour at −5.degree. C. the reaction mixture is heated to 30.degree. C. and combined with 15 litres of water. After cooling to 3.degree. C. the suspension is suction filtered, the precipitate is washed with water and dried. Yield: 5.21 kg of crude product, 100%, water content: 6.7% [0069] The crystallisation of the crude product is carried out with butyl acetate/methylcyclohexane Yield: 78% purity HPLC 99.4FI %, water content 5.4%. Example 1 Preparation of Afatinib Di-Maleate Form C [0070] Afatinib free base (3 g) was dissolved in tetrahydrofuran (THF) (7.6 mL) and stirred at room temperature until a clear solution was obtained. While stirring the clear solution, a solution of maleic acid (1.48 g) in THF (7.6 mL) was added dropwise at room temperature. After completion of this addition, a suspension containing a sticky solid was obtained. THF (60 mL) was added to the suspension and this mixture was stirred at room temperature overnight. A solid precipitate Ruined and was collected by filtration and washed with THF (30 mL) to yield a yellowish solid. The product was dried at 40° C. and 20 mbar (yield: 4.28 g, 96.5%). XRPD peak data for the product is provided in the Table below. [0000] Angle (2Θ) D value (Å) Intensity % 5.165 17.09611 18.9 5.527 15.97735 36.2 5.926 14.903 12.9 8.735 10.11492 11.3 9.318 9.48368 17.2 10.12 8.73385 10.5 10.847 8.14996 12.9 11.075 7.98276 12.7 12.484 7.08486 12.8 13.488 6.55952 12.1 15.726 5.6305 17.9 16.285 5.43851 22.1 16.934 5.23157 29 17.29 5.12473 38.3 17.546 5.05056 31 18.819 4.71161 57.7 19.131 4.63556 64.5 19.425 4.56588 65.1 20.50 4.32888 38 21.483 4.13305 100 21.835 4.06722 79.3 22.113 4.01664 64.2 23.034 3.85807 40.5 23.291 3.81608 43.3 24.135 3.68456 51.1 24.802 3.58686 73.4 25.06 3.55058 75.3 26.156 3.40419 54 27.148 3.28209 54.1 27.831 3.20305 52.3 28.564 3.12244 61.8 29.082 3.06801 48.3 29.769 2.99873 40.9 33.878 2.64391 33.4 35.441 2.53074 33.7 36.839 2.43786 33.0 39.675 2.26988 37.0 41.327 2.1829 36.0 Example 2 Preparation of Afatinib Di-Maleate Form D [0071] A suspension of afatinib free base (1 g) in 96% EtOH (14.5 mL) was heated to 70° C. until a yellowish clear solution was obtained. While stirring this solution at 70° C., a solution of maleic acid (0.49 g) in EtOH (6 mL) was added dropwise. After completion of this addition, the reaction mixture was stirred for 15 minutes at 70° C. and then cooled slowly to ambient temperature. The cooled mixture was stirred at room temperature overnight, then cooled to 0° C. and stirred for another hour. A solid precipitate formed and was collected by filtration, washed with ethanol (6 mL) and dried at 40° C. and 20 mbar (yield: 1.26 g, 85.3%). XRPD peak data for the product is provided in the Table below. [0000] Angle (2Θ) d value (Å) Intensity % 5.598 15.77302 36.1 7.303 12.0942 3.3 9.492 9.31022 14.4 10.203 8.66292 5.4 10.829 8.1634 4.9 11.233 7.87046 11.9 11.909 7.42538 2.3 12.77 6.92667 11.7 14.429 6.13357 37.2 15.739 5.62609 3.6 16.311 5.43 3.2 16.822 5.26622 8.1 17.333 5.11218 3.6 17.86 4.96236 13.5 18.541 4.78162 47.7 18.842 4.70591 13.6 19.67 4.50976 67 20.012 4.43344 22.6 20.478 4.33349 70.1 20.683 4.29103 74 21.462 4.13697 60.9 21.817 4.07043 51.3 22.131 4.01335 100 22.325 3.9789 72.3 23.5 3.78261 40.6 24.169 3.67937 12.8 24.777 3.59054 81.1 25.288 3.51905 38.5 26.298 3.38616 39.9 26.985 3.30151 19.6 27.262 3.26862 10.5 28.087 3.17441 36.6 29.247 3.05115 14.1 29.524 3.02309 30.1 29.914 2.98455 12.1 30.902 2.89137 8.2 31.88 2.80483 14.1 32.397 2.76127 10 32.976 2.7141 13.1 33.642 2.6619 22.4 34.009 2.63402 16.7 36.887 2.43478 10.2 37.269 2.41075 4.8 37.948 2.36913 5.1 38.593 2.33102 7.3 39.965 2.25409 6.5 40.97 2.20108 4.6 41.477 2.17535 5.8 43.23 2.09112 9.4 45.047 2.01092 4.3 45.614 1.98722 4.9 Example 3 Preparation of Afatinib Di-Maleate Form E [0072] Afatinib di-maleate form A, prepared according to the procedure disclosed in Example 3 of WO2005/037824 (1 g) was tested for its Hygroscopicity by exposure of form A to different humidity conditions, as presented in the following table. Investigation of Hygroscopicity (Dynamic Vapour Sorption (DVS)) Instrument: SPSx-1μ, (Projekt Messtechnik) Temperature: 25° C. [0073] Humidity cycles: [0000] time [h] relative humidity [%] 0 50 1.02 45 1.85 40 2.85 35 3.68 30 4.68 25 5.52 20 6.51 15 7.35 10 8.36 5 9.18 0 10.68 5 11.68 10 12.69 15 13.68 20 14.51 25 15.35 30 16.18 35 17.18 40 18.01 45 18.85 50 19.85 55 21.18 60 25.02 65 40.18 70 46.85 75 62.35 80 73.85 85 81.35 90 86.18 95 89.01 90 90.18 85 91.19 80 92.51 75 93.52 70 94.68 65 95.85 60 97.35 55 100.36 50 Afatinib di-maleate after DVS of Form A weight (mg) 47.28 47.45 46.06 consumption (mL) 0.62 0.64 0.60 water content (% by 6.95 7.15 6.90 weight) average 7.00 [0074] The obtained product was analysed by 1 H-NMR Spectroscopy and also by HPLC to confirm there was no decomposition. Then the sample was analyzed by XRD diffraction. The solid state identity is provided in the Table below. [0000] Angle (2-Theta °) d value (Angstrom) Intensity % 5.515 16.01245 34.1 6.138 14.38804 12.6 11.384 7.76668 18.6 13.108 6.74852 14.1 15.05 5.88198 14.4 17.66 5.0182 22.7 20.323 4.36628 27.5 22.321 3.97968 35.2 25.551 3.4835 100 28.046 3.17897 41.3 29.107 3.06542 37.5

Crystalline forms of Afatinib di-maleate are described in the present application and processes for their preparation. The present invention also includes pharmaceutical compositions of such crystalline forms of Afatinib di-maleate, methods of their preparation and the use thereof hi the treatment of a patient in need thereof. The present invention also describes preparing Afatinib free base and salts of Afatinib, other than Afatibin di-maleate, and solid forms thereof.

This application is a continuation of Ser. No. 10/187,381, which is a continuation-in-part of Ser. No. 09/898,748 filed Jul. 3, 2001 and claims priority from GB Application No. 0115986.2 filed Jun. 29, 2001, which is here incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polymerisation process for forming light emitting polymers and networks thereof. The light emitting polymer may be used as a source of electroluminescence for use in displays for electronic products. 2. Prior Art Modern consumer electronics require cheap, high-contrast displays with good power efficiency and low drive voltages. Particular applications include displays for mobile phones and hand-held computers. Conventional displays comprise twisted nematic liquid crystal displays (TN-LCDs) with active matrix addressing and super-twisted nematic liquid crystal displays (STN-LCDs) with multiplex addressing. These however require intense back lighting which presents a heavy drain on power. The low intrinsic brightness of LCDs is believed to be due to high losses of light caused by the absorbing polarizers and filters which can result in external transmission efficiencies of as low as 4%. SUMMARY OF THE INVENTION The Applicants have now devised a new class of light emitting polymers. These can be employed in displays which offer the prospect of lower power consumption and/or higher brightness. The combination of these new light emitting polymers with existing LCD technology offers the possibility of low-cost, bright, portable displays with the benefits of simple manufacturing and enhanced power efficiency. The light emitting polymer is obtainable by a polymerization process. The process involves the polymerization of reactive mesogens (e.g. in liquid crystal form) via photopolymerization of suitable end-groups of the mesogens. According to one aspect of the present invention there is provided a process for forming a light emitting polymer comprising photopolymerization of a reactive mesogen having the formula: B-S-A-S-B  (general formula 1) wherein A is a chromophore; S is a spacer; and B is an endgroup which is susceptible to photopolymerization. The polymerisation typically results in a light emitting polymer comprising arrangements of chromophores (e.g. uniaxially aligned) spaced by a crosslinked polymer backbone. A typical process is shown schematically in FIG. 1 from which it may be seen that the polymerisation of reactive monomer 10 results in the formation of crosslinked polymer network 20 comprising crosslink 22 , polymer backbone 24 and spacer 26 elements. Suitable chromophore (A) groups include fluorene, vinylenephenylene, anthracene, perylene and any derivatives thereof. Useful chromophores are described in A. Kraft, A. C. Grimsdale and A. B. Holmes, Angew. Chem. Int. Ed. Eng. [1998], 37, 402. Suitable spacer (S) groups comprise organic chains, including e.g. flexible aliphatic, amine, ester or ether linkages. The chains may be saturated or unsaturated and be linear or branched. Aliphatic spacers are preferred. The presence of spacer groups aids the solubility and lowers the melting point of the light emitting polymer which assists the spin coating thereof. Suitable endgroups are susceptible to photopolymerization (e.g. by a radical process using UV radiation, generally unpolarized). Preferably, the polymerization involves cyclopolymerization (i.e. the radical polymerization step results in formation of a cyclic entity). A typical polymerization process involves exposure of a reactive mesogen of general formula 1 to UV radiation to form an initial radical having the general formula as shown below: B-S-A-S-B•  (general formula 2) wherein A, S and B are as defined previously and B• is a radicalised endgroup which is capable of reacting with another B endgroup (particularly to form a cyclic entity). The B• radicalised endgroup suitably comprises a bound radical such that the polymerisation process may be sterically controlled. Suitable endgroups include dienes such as 1,4, 1,5 and 1,6 dienes. The diene functionalities may be separated by aliphatic linkages, but other inert linkages including ether and amine linkages may also be employed. Methacrylate endgroups have been found to be less suitable than dienes because the high reactivity of the radicals formed after the photoinitiation step can result in a correspondingly high photodegradation rate. By contrast, it has been found that the photodegradation rate of light emitting polymers formed from dienes is much lower. The use of methacrylate endgroups also does not result in cyclopolymerization. Where the endgroups are dienes the reaction typically involves cyclopolymerization by a sequential intramolecular and intermolecular propagation: A ring structure is formed first by reaction of the free radical with the second double bond of the diene group. A double ring is obtained by the cyclopolymerization which provides a particularly rigid backbone. The reaction is in general, sterically controlled. Suitable reactive mesogens have the general formula: wherein R has the general formula: X—S2-Y-Z and wherein X=O, CH 2 or NH and preferably X=O; S2=linear or branched alkyl or alkenyl chain optionally including a heteroatom (e.g. O, S or NH) and preferably S2=a linear alkyl chain; Y=O, CO 2 or S and preferably Y=CO 2 ; and Z=a diene (end-group) and preferably Z=a 1,4, 1,5 or 1,6 diene. Exemplary reactive mesogens have the general formula: wherein R is: An exemplary reactive mesogen has the formula: (Compound 3) All of Compounds 3 to 6 exhibit a nematic phase with a clearing point (N-I) between 79 and 120° C. Other suitable exemplary reactive mesogens have the general formula: wherein n is from 2 to 10, preferably from 3 to 8 and as above, R has the general formula: X—S2-Y-Z and wherein X═O, CH 2 or NH and preferably X═O; S2=linear or branched alkyl or alkenyl chain optionally including a heteroatom (e.g. O, S or NH) and preferably S2=a linear alkyl chain; Y=O, CO 2 or S and preferably Y=CO 2 ; and Z=a diene (end-group) and preferably Z=a 1,4, 1,5 or 1,6 diene. Suitably, R is as for any of Compounds 3 to 6, as shown above. A particular class of exemplary reactive mesogens has the formula: wherein: n is from 2 to 10, preferably from 3 to 8; and m is from 4 to 12, preferably from 5 to 11. Still further suitable exemplary reactive mesogens have the general formula: wherein A=H or F and wherein, as above, R has the general formula: X—S2-Y-Z and wherein X=O, CH 2 or NH and preferably X=O; S2=linear or branched alkyl or alkenyl chain optionally including a heteroatom (e.g. O, S or NH) and preferably S2=a linear alkyl chain; Y=O, CO 2 or S and preferably Y=CO 2 ; and Z=a diene (end-group) and preferably Z=a 1,4, 1,5 or 1,6 diene. Suitably, R is as for any of Compounds 3 to 6, as shown above. Particular exemplary reactive mesogens of this type have the formula: In aspects, the photopolymerization process can be conducted at room temperature, thereby minimizing any possible thermal degradation of the reaction mesogen or polymer entities. Photopolymerization is also preferable to thermal polymerization because it allows subsequent sub-pixellation of the formed polymer by lithographic means. Further steps may be conducted subsequent to the polymerization process including doping e.g. with photoactive dyes. In preferred aspects, the polymerization process results in cross-linking e.g. to form a polymer network (e.g. an insoluble, cross-linked network). Suitably, the light emitting polymer is a liquid crystal which can be aligned to emit polarised light. A suitable class of polymers is based on fluorene. The reactive mesogen (monomer) typically has a molecular weight of from 400 to 2,000. Lower molecular weight monomers are preferred because their viscosity is also lower leading to enhanced spin coating characteristics and shorter annealing times which aids processing. The light emitting polymer typically has a molecular weight of above 4,000, typically 4,000 to 15,000. The light emitting polymer (network) typically comprises from 5 to 50, preferably from 10 to 30 monomeric units. According to another aspect of the present invention there is provided a process for applying a light emitting polymer to a surface comprising applying a reactive mesogen (as defined above) to said surface; and photopolymerizing said reactive mesogen in situ to form the light emitting polymer. The light emitter polymers herein can in one aspect be used in a light emitter for a display comprising a photoalignment layer; and aligned on said photoalignment layer, the light emitting polymer. The polymerization process herein can in one aspect be configured to form the light emitter by in situ polymerization of the reactive mesogens after their deposition on the photoalignment layer by any suitable deposition process including a spin-coating process The photoalignment layer typically comprises a chromophore attached to a sidechain polymer backbone by a flexible spacer entity. Suitable chromophores include cinnamates or coumarins, including derivatives of 6 or 7-hydroxycoumarins. Suitable flexible spacers comprise unsaturated organic chains, including e.g. aliphatic, amine or ether linkages. An exemplary photoalignment layer comprises the 7-hydroxycoumarin compound having the formula: Other suitable materials for use in photoalignment layers are described in M. O'Neill and S. M. Kelly, J. Phys. D. Appl. Phys. [2000], 33, R67. In aspects, the photoalignment layer is photocurable. This allows for flexibility in the angle in the azimuthal plane at which the light emitting polymer (e.g. as a liquid crystal) is alignable and thus flexibility in its polarization characteristics. The photalignment layer may also be doped with a hole transport compound, that is to say a compound which enables transport of holes within the photoalignment layer, such as a triarylamine. Examples of suitable triarylamines include those described in C. H. Chen, J. Shi, C. W. Tang, Macromol Symp. [ 1997] 125, 1. An exemplary hole transport compound is 4,4′,4″-tris[N-(1-napthyl)-N-phenylamino]triphenylamine which has the formula: In aspects, the hole transport compound has a tetrahedral (pyramidal) shape which acts such as to controllably disrupt the alignment characteristics of the layer. In one aspect, the photoalignment layer includes a copolymer incorporating both linear rod-like hole-transporting and photoactive side chains. The light emitting polymer is aligned on the photoalignment layer. Suitably, the photoaligned polymer comprises uniaxially aligned chromophores. Typically polarization ratios of 30 to 40 are required, but with the use of a clean up polarizer ratios of 10 or more can be adequate for display uses. In one aspect, the light emitter also comprises an organic light emitting diode (OLED) such as described in S. M. Kelly, Flat Panel Displays: Advanced Organic Materials, RSC Materials Monograph, ed. J. A. Connor, [2000]; C. H. Chen, J. Shi, C. W. Tang, Macromol Symp. [ 1997] 125, 1; R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Bredas, M. Logdlund, W. R. Salaneck, Nature [ 1999] 397, 121; M. Grell, D. D. C. Bradley, Adv. Mater. [ 1999] 11, 895; N. C. Greenman, R. H. Friend Solid State Phys. [ 1995] 49, 1. OLEDs may be configured to provide polarized electroluminescence. The light emitting polymer may be aligned by a range of methods including mechanical stretching, rubbing, and Langmuir-Blodgett deposition. Mechanical alignment methods can however lead to structural degradation. The use of rubbed polyimide is a suitable method for aligning the light emitting polymer especially in the liquid crystal state. However, standard polyimide alignment layers are insulators, giving rise to low charge injection for OLEDs. The susceptibility to damage of the alignment layer during the alignment process can be reduced by the use of a non-contact photoalignment method. In such methods, illumination with polarized light introduces a surface anisotropy to the alignment layer and hence a preferred in-plane orientation to the overlying light emitting polymer (e.g. in liquid crystal form). The aligned light emitting polymer is in one aspect in the form of an insoluble nematic polymer network. Cross-linking has been found to improve the photoluminescence properties. M. O'Neill, S. M. Kelly J. Appl. Phys. D [ 2000] 33, R67 provides a review of photalignment materials and methods. The light emitter herein may comprise additional layers such as carrier transport layers. The presence of an electron-transporting polymer layer (e.g. comprising an oxadiazole ring) has been found to increase electroluminescence. An exemplary electron transporting polymer has the formula: Pixellation of the light emitter may be achieved by selective photopatterning to produce red, green and blue pixels as desired. The pixels are typically rectangular in shape. The pixels typically have a size of from 1 to 50 μm, For microdisplays the pixel size is likely to be from 1 to 50 μm, preferably from 5 to 15 μm, such as from 8 to 10 μm. For other displays, larger pixel sizes e.g. 300 μm are more suitable. In one preferred aspect, the pixels are arranged for polarized emission. Suitably, the pixels are of the same color but have their polarization direction in different orientations. To the naked eye this would look like one color, but when viewed through a polarizer some pixels would be bright and others less bright thereby giving an impression of 3D viewing when viewed with glasses having a different polarization for each eye. The layers may also be doped with photoactive dyes. In aspects, the dye comprises a dichroic or pleachroic dye. Examples include anthraquinone dyes or tetralines, including those described in S. M. Kelly, Flat Panel Displays: Advanced Organic Materials, RSC Materials Monograph, ed. J. A. Connor, [2000]. Different dopant types can be used to obtain different pixel colors. Pixel color can also be influenced by the choice of chromophore with different chromophores having more suitability as red, green or blue pixels, for example using suitably modified anthraquinone dyes. Multicolor emitters are envisaged herein comprising arrangements or sequences of different pixel colors. One suitable multicolor emitter comprises stripes of red, green and blue pixels having the same polarization state. This may be used as a sequential color backlight for a display which allows the sequential flashing of red, green and blue lights. Such backlights can be used in transmissive and reflective FLC displays where the FLC acts as a shutter for the flashing colored lights. Another suitable multicolor emitter comprises a full color pixelated display in which the component pixels thereof have the same or different alignment. Suitable multicolor emitters may be formed by a sequential ‘coat, selective cure, wash off’ process in which a first color emitter is applied to the aligned layer by a suitable coating process (e.g. spin coating). The coated first color emitter is then selectively cured only where pixels of that color are required. The residue (of uncured first color emitter) is then washed off. A second color emitter is then applied to the aligned layer, cured only where pixels of that color are required and the residue washed off. If desired, a third color may be applied by repeating the process for the third color. The above process may be used to form a pixelated display such as for use in a color emissive display. This process is simpler than traditional printing (e.g. ink jet) methods of forming such displays. There is also provided a backlight for a display comprising a power input; and a light emitter as described hereinbefore. The backlight may be arranged for use with a liquid crystal display. In aspects, the backlight may be monochrome or multicolor. There is further provided a display comprising a screen; and a light emitter or backlight as described hereinbefore. The screen may have any suitable shape or configuration including flat or curved and may comprise any suitable material such as glass or a plastic polymer. The light source of the present invention has been found to be particularly suitable for use with screens comprising plastic polymers such as polyethylene or polyethylene terephthalate (PET). The display is suitable for use in consumer electronic goods such as mobile telephones, hand-held computers, watches and clocks and games machines. There is further provided a security viewer (e.g. in kit form) comprising a light emitter as described herein in which the pixels are arranged for polarized emission; and view glasses having a different polarization for each eye. There is further provided a method of forming a light emitter for a display comprising forming a photoalignment layer; and aligning a light emitting polymer on said photoalignment layer. There is further provided a method of forming a light emitter for a display comprising forming a photoalignment layer; aligning a light emitting reactive mesogen on said photoalignment layer; and forming a light emitting polymer (network) by photopolymerisation of said reactive mesogen. There is further provided a method of forming a multicolor emitter comprising applying a first color light emitter to the photoalignment layer; selectively curing said first color light emitter only where that color is required; washing off any residue of uncured first color emitter; and repeating the process for a second and any subsequent light color emitters. All references herein are incorporated by reference in their entirety. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of systems according to the invention will now be described with reference to the accompanying experimental detail and drawings in which: FIG. 1 is a schematic representation of a polymerization process herein; FIG. 2 is a representation of a display device in accord with the present invention; FIG. 3 is a representation of a backlight in accord with the present invention; and FIG. 4 is a representation of a polarised sequential light emitting backlight in accord with the present invention. FIGS. 5 to 12 show reaction schemes 1 to 8, respectively. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS General Experimental Details Fluorene, 2-(tributylstanyl)thiophene, 4-(methoxyphenyl)boronic acid and the dienes were purchased from Aldrich and used as received. Reagent grade solvents were dried and purified as follows. N,N-Dimethylformamide (DMF) was dried over anhydrous P 2 O 5 and purified by distillation. Butanone and methanol were distilled and stored over 5 Å molecular sieves. Triethylamine was distilled over potassium hydroxide pellets and then stored over 5 Å molecular sieves. Dichloromethane was dried by distillation over phosphorus pentoxide and then stored over 5 Å molecular sieves. Chloroform was alumina-filtered to remove any residual ethanol and then stored over 5 Å molecular sieves. 1 H nuclear magnetic resonance (NMR) spectra were obtained using a JOEL JMN-GX270 FT nuclear resonance spectrometer. Infra-red (IR) spectra were recorded using a Perkin Elmer 783 infra-red spectrophotometer. Mass spectral data were obtained using a Finnegan MAT 1020 automated GC/MS. The purity of the reaction intermediates was checked using a CHROMPACK CP 9001 capillary gas chromatograph fitted with a 10 m CP-SIL 5CB capillary column. The purity of the final products was determined by high-performance liquid chromatography [HPLC] (5 □m, 25 cm×0.46 cm, ODS Microsorb column, methanol, >99%) and by gel-permeation chromatography [GPC] (5 □m, 30 cm×0.75 cm, 2× mixed D PL columns, calibrated using polystyrene standards [molecular weights=1000-4305000], toluene; no monomer present). The polymers were found to exhibit moderate to high M w values (10,000-30,000) and acceptable M w /M n values (1.5-3). The liquid crystalline transition temperatures were determined using an Olympus BH-2 polarising light microscope together with a Mettler FP52 heating stage and a Mettler FP5 temperature control unit. The thermal analysis of the photopolymerisable monomers (Compounds 3 to 6) and the mainchain polymer (Compound 7) was carried out by a Perkin-Elmer Perkin-Elmer DSC 7 differential scanning calorimeter in conjunction with a TAC 7/3 instrument controller. Purification of intermediates and products was mainly accomplished by column chromatography using silica gel 60 (200-400 mesh) or aluminium oxide (Activated, Brockman 1, ˜150 mesh). Dry flash column chromatography was carried out using silica gel H (Fluka, 5-40 μm). Electroluminescent materials were further purified by passing through a column consisting of a layer of basic alumina, a thin layer of activated charcoal, a layer of neutral alumina and a layer of Hi-Flo filter aid using DCM as an eluent. This was followed by recrystallisation from an ethanol-DCM mixture. At this stage, all glass-wear was thoroughly cleaned by rinsing with chromic acid followed by distilled water and then drying in an oven at 100° C. for 45 minutes. Purity of final products was normally confirmed by elemental analysis using a Fisons EA 1108 CHN apparatus. Key intermediate 1: 2,7-bis[5-(4-hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene was synthesised as shown in Reaction Scheme 1. Full details each step are now given: 9-Propylfluorene: A solution of n-Butyllithium (18.0 cm 3 , 10M solution in hexanes, 0.18 mol) was added slowly to a solution of fluorene (30.0 g, 0.18 mol) in THF (350 cm 3 ) at −50° C. The solution was stirred for 1 h at −75° C. and 1-bromopropane (23.0 g, 0.19 mol) was added slowly. The solution was allowed to warm to RT and then stirred for a further 1 h. Dilute hydrochloric acid (100 cm 3 , 20%) and water (100 cm 3 ) were added and the product extracted into diethyl ether (3×150 cm 3 ). The ethereal extracts were dried (MgSO 4 ) and concentrated to a pale yellow oil (37.5 g, yield 100%). Purity 100% (GC). 1 H NMR (CD 2 Cl 2 ) δ: 7.75 (2H, dd), 7.52 (2H, m), 7.32 (4H, m), 3.98 (1H, t), 1.95 (2H, m), 1.19 (2H, m), 0.85 (3H, t). IR (KBr pellet cm −1 ): 3070 (m), 2962 (s), 1450 (s), 1296 (w), 1189 (w), 1030 (w), 938 (w), 739 (s). MS (m/z): 208 (M + ), 178, 165 (M100), 139. 9,9-Dipropylfluorene: A solution of n-Butyllithium (29.0 cm 3 , 2.5M solution in hexanes, 0.073 mol) was added slowly to a solution of 9-propylfluorene (15.0 g, 0.072 mol) in THF at −50° C. The solution was stirred for 1 h at −75° C., 1-bromopropane (10.0 g, 0.092 mol) was added slowly and the temperature raised to RT after completion of the addition. After 18 h, dilute hydrochloric acid (20%, 100 cm 3 ) and water (100 cm 3 ) were added and the product extracted into diethyl ether (2□100 cm 3 ). The ethereal extracts were dried (MgSO 4 ) and concentrated to a pale brown oil which crystallised overnight at RT. The product was purified by recrystallisation from methanol to yield a white crystalline solid (14.5 g, yield 80%) mp 47-49° C. (Lit. 49-50° C. 19 ). Purity 100% (GC). 1 H NMR (CDCl 3 ) δ: 7.68 (2H, m), 7.31 (6H, m), 1.95 (4H, t), 0.65 (10H, m). IR (KBr pellet cm −1 ): 3068 (m), 2961 (s), 1449 (s), 1293 (w), 1106 (w), 1027 (w), 775 (m), 736 (s), 637 (m). MS (m/z): 250 (M + ), 207 (M100), 191, 179, 165. 2,7-Dibromo-9,9-dipropylfluorene: Bromine (10.0 g, 0.063 mol) was added to a stirred solution of 9,9-dipropylfluorene (7.0 g, 0.028 mol) in chloroform (25 cm 3 ) and the solution purged with dry N 2 for 0.5 h. Chloroform (50 cm 3 ) was added and the solution washed with saturated sodium bisulphite solution (75 cm 3 ), water (75 cm 3 ), dried (MgSO 4 ) and concentrated to a pale yellow powder (11.3 g, yield 98%) mp 134-137° C. 1 H NMR (CDCl 3 ) δ: 7.51 (2H, d), 7.45 (4H, m), 1.90 (4H, t), 0.66 (10H, m). IR (KBr pellet cm −1 ): 2954 (s), 1574 (w), 1451 (s), 1416 (m), 1270 (w), 1238 (w), 1111 (w), 1057 (s), 1006 (w), 931 (w), 878 (m), 808 (s), 749 (m). MS (m/z): 409 (M + ), 365, 336, 323, 284, 269, 256, 248, 202, 189, 176 (M100), 163. 2,7-bis(Thien-2-yl)-9,9-dipropylfluorene: A mixture of 2,7-dibromo-9,9-dipropylfluorene (6.0 g, 0.015 mol), 2-(tributylstannyl)thiophene (13.0 g, 0.035 mol) and tetrakis(triphenylphosphine)-palladium (0) (0.3 g, 2.6×10 −4 mol) in DMF (30 cm 3 ) was heated at 90° C. for 24 h. DCM (200 cm 3 ) was added to the cooled reaction mixture and the solution washed with dilute hydrochloric acid (2□150 cm 3 , 20%), water (100 cm 3 ), dried (MgSO 4 ) and concentrated onto silica gel for purification by column chromatography [silica gel, DCM:hexane 1:1]. The compound was purified by recrystallisation from DCM: ethanol to yield light green crystals (4.3 g, yield 69%), mp 165-170° C. Purity 100% (GC). 1 H NMR (CDCl 3 ) δ: 7.67 (2H, d), 7.60 (2H, dd), 7.57 (2h, d), 7.39 (2H, dd), 7.29 (2H, dd), 7.11 (2H, dd), 2.01 (4H, m), 0.70 (10H, m). IR (KBr pellet cm −1 ): 2962 (m), 2934 (m), 2872 (m), 1467 (m), 1276 (w), 1210 (m), 1052 (w), 853 (m), 817 (s), 691 (s). MS (m/z): 414 (M + , M100), 371, 342, 329, 297, 207, 165. 2,7-bis(5-Bromothien-2-yl)-9,9-dipropylfluorene: N-Bromosuccinimide (2.1 g, 0.012 mol freshly purified by recrystallisation from water) was added slowly to a stirred solution of 2,7-bis(thien-2-yl)-9,9-dipropylfluorene (2.3 g, 5.55×10 −3 mol) in chloroform (25.0 cm 3 ) and glacial acetic acid (25.0 cm 3 ). The solution was heated under reflux for 1 h, DCM (100 cm 3 ) added to the cooled reaction mixture, washed with water (100 cm 3 ), HCl (150 cm 3 , 20%), saturated aqueous sodium bisulphite solution (50 cm 3 ), and dried (MgSO 4 ). The solvent was removed in vacuo and the product purified by recrystallisation from an ethanol-DCM mixture to yield yellow-green crystals (2.74 g, yield 86%). mp 160-165° C. 1 H NMR (CDCl 3 ) δ: 7.66 (2H, d), 7.49 (2H, dd), 7.46 (2H, d), 7.12 (2H, d), 7.05 (2H, d), 1.98 (4H, t), 0.69 (10H, m). IR (KBr pellet cm −1 ): 3481 (w), 2956 (s), 1468 (s), 1444 (m), 1206 (w), 1011 (w), 963 (w), 822 (m), 791 (s), 474 (w). MS (m/z): 572 (M + ), 529, 500, 487, 448, 433, 420, 407, 375, 250, 126. 2,7-bis[5-(4-Methoxyphenyl)thien-2-yl]-9,9-dipropylfluorene: A mixture of 2,7-bis(5-bromothien-2-yl)-9,9-dipropylfluorene (2.7 g, 4.7×10 −3 mol), 4-(methoxyphenyl)boronic acid (2.15 g, 0.014 mol), tetrakis(triphenylphosphine)palladium (0) (0.33 g, 2.9×10 −4 mol), sodium carbonate (3.0 g, 0.029 mol) and water (20 cm 3 ) in DME (100 cm 3 ) was heated under reflux for 24 h. More 4-(methoxyphenyl)boronic acid (1.0 g, 6.5×10 −3 mol) was added to the cooled reaction mixture, which was then heated under reflux for a further 24 h. DMF (20 cm 3 ) was added and the solution heated at 110° C. for 24 h, cooled and dilute hydrochloric acid (100 cm 3 , 20%) added. The cooled reaction mixture was extracted with diethyl ether (250 cm 3 ) and the combined ethereal extracts washed with water (100 cm 3 ), dried (MgSO 4 ), and concentrated onto silica gel to be purified by column chromatography [silica gel, DCM:hexane 1:1] and recrystallisation from an ethanol-DCM mixture to yield a green crystalline solid (1.86 g, yield 63%), Cr—N, 235° C.; N—I, 265° C. 1 H NMR (CD 2 Cl 2 ) δ: 7.71 (2H, dd), 7.61 (8H, m), 7.37 (2H, d), 7.24 (2H, d), 6.95 (4H, d), 3.84 (6H, s), 2.06 (4H, m), 0.71 (10H, m). IR (KBr pellet cm −1 ): 2961 (w), 1610 (m), 1561 (m), 1511 (s), 1474 (s), 1441 (m), 1281 (m), 1242 (s), 1170 (s), 1103 (m), 829 (m), 790 (s). MS (m/z): 584 (M + -C 3 H 7 ), 569, 555, 539, 525, 511, 468, 313, 277 (M100), 248, 234. Elemental analysis. Calculated: wt % C=78.56%; H, 6.11%; S, 10.23%. Found: C, 78.64%; H, 6.14%; S, 10.25%. 2,7-bis[5-(4-Hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene): A 1M solution of boron tribromide in chloroform (9 cm 3 , 9.0 mmol) was added dropwise to a stirred solution of 2,7-bis[5-(4-methoxyphenyl)thien-2-yl]-9,9-dipropylfluorene (1.3 g, 2.1×10 −3 mol) at 0° C. The temperature was allowed to rise to RT overnight and the solution added to ice-water (200 cm 3 ) with vigorous stirring. The product was extracted into diethyl ether (220 cm 3 ), washed with aqueous sodium carbonate (2M, 150 cm 3 ), dried (MgSO 4 ) and purified by column chromatography [silica gel DCM:diethyl ether:ethanol 40:4:1] to yield a green solid (1.2 g, yield 96%), Cr—I, 277° C.; N—I, 259° C. 1 H NMR (d-acetone) δ: 8.56 (2H, s), 7.83 (2H, dd), 7.79 (2H, d), 7.68 (2H, dd), 7.57 (4H, dd), 7.50 (2H, dd), 7.31 (2H, dd), 6.91 (4H, dd), 2.15 (4H, m), 0.69 (10H, m). IR (KBr pellet cm −1 ): 3443 (s, broad), 2961 (m), 1610 (m), 1512 (m), 1474 (m), 1243 (m), 1174 (m), 1110 (w), 831 (m), 799 (s). MS (m/z): 598 (M + ), 526, 419 (M100), 337. Compound 3: 2,7-bis(5-{4-[5-(1-Vinyl-allyloxycarbonyl)pentyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene: The 1,3-pentadiene monomer (Compound 3) was synthesised as depicted in Reaction Scheme 2. Full details of each step are now given: 1,4-Pentadien-3-yl 6-bromohexanoate: A solution of 6-bromohexanoyl chloride (3.2 g, 0.026 mol) in DCM (30 cm 3 ) was added dropwise to a solution of 1,4-pentadien-3-ol (2.0 g, 0.024 mol) and triethylamine (2.4 g, 0.024 mol) in DCM (30 cm 3 ). The mixture was stirred for 1 h and washed with dilute hydrochloric acid (20%, 50 cm 3 ), saturated potassium carbonate solution (50 cm 3 ), water (50 cm 3 ) then dried (MgSO 4 ) and concentrated to a brown oil. The product was purified by dry flash chromatography [silica gel, DCM] to yield a pale yellow oil (4.7 g, yield 75%). Purity>95% (GC). 1 H NMR (CDCl 3 ) δ: 5.82 (2H, m), 5.72 (1H, m), 5.30 (2H, d), 5.27 (2H, d), 3.42 (2H, t), 2.37 (2H, t), 1.93 (2H, m), 1.72 (2H, m), 1.54 (2H, m). IR (KBr pellet cm −1 ): 3095 (w), 1744 (s), 1418 (w), 1371 (w), 12521 (m), 1185 s), 983 (m), 934 (m). MS (m/z): 261 (M + ), 177, 67. 2,7-bis(5-{4-[5-(1-Vinyl-allyloxycarbonyl)pentyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene: A mixture of 2,7-bis[5-(4-hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene (0.6 g, 1.0×10 −3 mol), 1,4-pentadien-3-yl 5-bromohexanoate (0.7 g, 2.7×10 −3 mol) and potassium carbonate (0.5 g, 3.6×10 −3 mol) in acetonitrile (25 cm 3 ) was heated at 50° C. for 18 h. The mixture was then heated under reflux conditions for a further 20 h. Excess potassium carbonate was filtered off and precipitated product rinsed through with DCM (230 cm 3 ). The solution was concentrated onto silica gel for purification by column chromatography [silica gel, DCM:hexane 1:1 gradients to DCM] and recrystallisation from a DCM-ethanol mixture to yield a green-yellow solid (0.4 g, yield 40%), Cr—N, 92° C.; N—I, 108° C. 1 H NMR (CD 2 Cl 2 ) δ: 7.69 (2H, d), 7.58 (8H, m), 7.35 (2H, d), 7.22 (2H, d), 6.91 (4H, d), 5.83 (4H, m), 5.68 (2H, m), 5.29 (2H, t), 5.25 (2H, t), 5.21 (2H, t), 5.19 (2H, t), 3.99 (4H, t), 2.37 (4H, t), 2.04 (4H, m), 1.80 (4H, quint), 1.70 (4H, quint), 1.51 (4H, quint) 0.69 (10H, m). IR (KBr pellet cm −1 ): 2936 (m), 2873 (m), 1738 (s), 1608 (m), 1511 (m), 1473 (s), 1282 (m), 1249 (s), 1177 (s), 1110 (m), 982 (m), 928 (m), 829 (m), 798 (s). APCI-MS (m/z): 958 (M + ), 892 (M100). Elemental analysis. Calculated: wt % C=76.37, wt % H=6.93, wt % S=6.68. Found: wt % C=75.93, wt % H=6.95, wt % S=6.69. Compound 4: 2,7-bis(5-{(4-[5-(1-Allylbut-3-enyloxycarbonyl)pentyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene: The 1,3-heptadiene monomer (Compound 4) was synthesised as depicted in reaction Scheme 3. Full details of each step are now given: 1,6-Heptadien-5-yl 5-bromopentanoate: 5-Bromopentanoyl chloride (3.0 g, 0.015 mol) was added dropwise to 1,6-heptadien-4-ol (1.5 g, 0.013 mol) and triethylamine (1.4 g, 0.014 mol) in DCM (25 cm 3 ). The mixture was stirred for 2 h and washed with dilute hydrochloric acid (20%, 50 cm 3 ), saturated aqueous potassium carbonate solution (50 cm 3 ), water (50 cm 3 ) then dried (MgSO 4 ) and concentrated to a brown oil. The product was purified by dry flash chromatography [silica gel, DCM] to yield a pale yellow oil (1.7 g, yield 48%). Purity>92% (GC). 1 H NMR (CDCl 3 ) δ: 5.74 (2H, m), 5.08 (4H, m), 4.99 (1H, m), 3.41 (2H, t), 2.31 (6H, m), 1.88 (2H, m), 1.76 (2H, m). IR (Film cm −1 ): 2952 (m), 1882 (w), 1734 (s), 1654 (m) 1563 (w), 1438 (m), 1255 (m), 1196 (s), 996 (m), 920 (s). MS (m/z): 275 (M + ), 245, 219, 191, 183, 163 (M100), 135, 95, 79. 2,7-bis(5-{4-[5-(1-Allylbut-3-enyloxycarbonyl)pentyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene: A mixture of 2,7-bis[5-(4-hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene (0.3 g, 1.0×10 −3 mol), 1,6-heptadienyl 6-bromohexanoate (0.7 g, 2.7×10 −3 mol) and potassium carbonate (0.5 g, 3.6×10 −3 mol) in acetonitrile (25 cm 3 ) was heated under reflux for 20 h. Excess potassium carbonate was filtered off and precipitated product rinsed through with DCM (230 cm 3 ). The solution was concentrated onto silica gel for purification by column chromatography [silica gel, DCM: hexane 1:1 gradients to DCM] and recrystallisation from a DCM-ethanol mixture to yield a green-yellow solid (0.21 g, yield 21%), Cr—I, 97° C., N—I, 94° C. 1 H NMR (CDCl 3 ) δ: 7.68 (2H, d), 7.60 (2H, dd), 7.58 (2H, d), 7.57 (2H, d), 7.33 (2H, d), 7.20 (2H, d), 6.91 (2H, d), 5.75 (4H, m), 5.08 (8H, m), 5.00 (2H, quint), 4.00 (4H, t), 2.33 (12H, m), 2.02 (4H, t), 1.82 (4H, quint), 1.71 (4H, quint), 1.53 (4H, m), 0.72 (10H, m). IR (KBr pellet cm −1 ): 3443 (s), 2955 (s), 1734 (s), 1643 (w), 1609 (m), 1512 (m), 1473 (s), 1249 (s), 1178 (s), 996 (m), 918 (m), 829 (m), 799 (s). APCI-MS (m/z): 1015 (M+, M100), 921. Elemental analysis. Calculated: wt % C=76.89, wt % H=7.35, wt % S=6.32%. Found: wt % C=76.96, wt % H=7.42, wt % S=6.23. Compound 5: 2,7-bis(5-{4-[3-(1-Vinylallyloxycarbonyl)propyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene The 1,3-pentadiene homologue (Compound 5) was synthesised as depicted in reaction Scheme 4. Full details of each step are now given: 4-Bromobutanoyl chloride: Oxalyl chloride (15.2 g, 0.12 mol) was added dropwise to a stirred solution of 4-bromobutanoic acid (10.0 g, 0.060 mol) and DMF (few drops) in chloroform (30 cm 3 ). The solution was stirred overnight under anhydrous conditions and concentrated to a pale brown oil which was filtered to remove solid impurities (11.0 g, yield 99%). 1,4-Pentadien-3-yl 4-bromobutanoate: 4-Bromobutanoyl chloride (3.0 g, 0.016 mol) was added dropwise to a solution of 1,4-pentadien-3-ol (1.3 g, 0.015 mol) and triethylamine (1.5 g, 0.015 mol) in DCM (30 cm 3 ). The solution was stirred for 2 h and washed with dilute hydrochloric acid (20%, 50 cm 3 ), saturated potassium carbonate solution (50 cm 3 ), water (50 cm 3 ) then dried (MgSO 4 ) and concentrated to a pale brown oil. The product was purified by dry flash chromatography [silica gel, DCM] to yield a pale yellow oil (1.8 g, yield 51%). Purity>85% (GC; decomposition on column). 1 H NMR (CDCl 3 ) δ: 5.83 (2H, m), 5.72 (1H, m), 5.27 (4H, m), 3.47 (2H, t), 2.55 (2H, t), 2.19 (2H, quint). IR (KBr pellet cm −1 ): 3096 (w), 2973 (w), 1740 (s), 1647 (w), 1419 (m), 1376 (m), 1198 (s), 1131 (s), 987 (s), 932 (s), 557 (w). MS (m/z): 217, 166, 152, 149, 125, 110, 84, 67 (M100). 2,7-bis(5-{4-[3-(1-Vinylallyloxycarbonyl)propyloxy]phenyl}thien-2-yl)-9,9-dipropylfluorene: A mixture of 2,7-bis[5-(4-hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene (0.25 g, 4.2×10 −4 mol), 1,4-pentadien-3-yl 4-bromobutanoate (0.40 g, 1.7×10 −3 mol) and potassium carbonate (0.20 g, 1.4×10 −3 mol) in DMF (10 cm 3 ) was heated under reflux for 4 h. The cooled solution was filtered, rinsed through with DCM (3×20 cm 3 ) and concentrated to a pale green oil which was purified by column chromatography [silica gel, DCM:hexane 2:1] followed by recrystallisation from ethanol:DCM to yield a green-yellow powder (0.20 g, yield 53%), Cr—N, 92° C.; N—I, 116° C. 1 H NMR (CDCl 3 ) δ: 7.61 (10H, m), 7.33 (2H, d), 7.20 (2H, d), 6.92 (4H, d), 5.85 (4H, m), 5.74 (2H, m), 5.32 (4H, d, J=17 Hz), 5.24 (4H, d, J=10 Hz), 4.06 (4H, t), 2.56 (4H, t), 2.16 (4H, quint), 2.05 (4H, t), 0.72 (10H, m). IR (KBr pellet cm −1 ): 3449 (m), 2960 (m), 1738 (s), 1609 (m), 1512 (m), 1473 (s), 1380 (w), 1249 (s), 1174 (s), 1051 (m), 936 (m), 830 (m), 799 (s). APCI-MS (m/z): 903 (M + ), 837 (M100), 772. Elemental analysis. Calculated: wt % C=75.80, wt % H=6.47, wt % S=7.10. Found: wt % C=76.13, wt % H=6.48%, wt % S=6.91. Compound 6: 2,7-bis{5-[4-(8-Diallylaminooctyloxy)phenyl]-thien-2-yl}-9,9-dipropylfluorene The method of preparation of the N,N-diallylamine monomer (Compound 6) is shown in reaction Scheme 5. Full details of each step are now given: 8-Diallylaminooctan-1-ol. A mixture of 8-bromooctan-1-ol (10.0 g, 0.048 mol), diallylamine (4.85 g, 0.050 mol) and potassium carbonate (7.0 g, 0.051 mol) in butanone (100 cm 3 ) was heated under reflux for 18 h. Excess potassium carbonate was filtered off and the solution concentrated to a colourless oil. The product was purified by dry flash chromatography [silica gel, DCM:ethanol 4:1]. (10.0 g, yield 93%) 1 H NMR (CDCl 3 ) δ: 5.86 (2H, d), 5.14 (4H, m), 3.71 (4H, quart), 3.63 (4H, t), 3.09 (4H, d), 1.56 (4H, m), 1.45 (2H, quint), 1.30 (6H, m). IR (KBr pellet cm −1 ): 3344 (s), 2936 (s), 1453 (w), 1054 (m), 998 (m), 921 (m). MS (m/z): 225 (M + ), 198, 184, 166, 152, 138, 124, 110 (M100), 81. Toluene-4-sulphonic acid 8-diallylaminooctyl ester. 4-Toluene-sulphonyl chloride (12.5 g, 0.066 mol) was added slowly to a stirred solution of 8-diallylaminooctan-1-ol (10.0 g, 0.044 mol) and pyridine (7.0 g, 0.088 mol) in chloroform (100 cm 3 ) at 0° C. After 24 h, water (100 cm 3 ) was added and the solution washed with dilute hydrochloric acid (20%, 100 cm 3 ), sodium carbonate solution (100 cm 3 ), water (100 cm 3 ), dried (MgSO 4 ) and concentrated to a yellow oil which was purified by column chromatography [silica gel, 4% diethyl ether in hexane eluting to DCM:ethanol 10:1] to yield the desired product (6.7 g, yield 40%). 1 H NMR (CDCl 3 ) δ: 7.78 (2H, d), 7.34 (2H, d), 5.84 (2H, m), 5.13 (4H, m), 4.01 (2H, t), 3.41 (4H, d), 2.45 (3H, s), 2.39 (2H, t), 1.63 (2H, quint), 1.42 (2H, quint), 1.30 (2H, quint), 1.23 (6H, m). IR (KBr pellet cm −1 ): 3454 (w), 2957 (m), 1453 (s), 1402 (m), 1287 (m), 1159 (w), 1061 (m), 914 (w), 878 (m), 808 (s), 448 (m). MS (m/z): 380 (M + ), 364, 352, 338, 224, 110 (M100), 91, 79, 66. 2,7-bis{5-[4-(8-Diallylaminooctyloxy)phenyl]-thien-2-yl}-9,9-dipropylfluorene: A mixture of 2,7-bis[5-(4-hydroxyphenyl)thien-2-yl]-9,9-dipropylfluorene (0.5 g, 8.4×10 −4 mol), toluene-4-sulphonic acid-8-diallylaminooctyl ester (0.8 g, 2.1×10 −3 mol) and potassium carbonate (0.3 g, 2.2×10 3 mol) in butanone (30 cm 3 ) was heated under reflux for 24 h. Excess potassium carbonate was filtered off and rinsed with DCM (3×30 cm 3 ). The solution was concentrated onto silica gel for purification by column chromatography [silica gel, DCM:hexane 2:1 eluting to DCM:ethanol 4:1]. The product was obtained as a yellow-green glass (0.35 g, yield 41%), N—I, 95° C. 1 H NMR (CDCl 3 ) δ: 7.67 (2H, d), 7.58 (8H, m), 7.34 (2H, d), 7.20 (2H, d), 6.92 (4H, d), 5.94 (4H, m), 5.25 (8H, m), 3.99 (4H, t), 3.22 (8H, d), 2.02 (4H, t), 1.80 (4H, quint), 1.56 (4H, quint), 1.47 (4H, quint), 1.35 (12H, m), 0.71 (10H, m). IR (KBr pellet cm −1 ): 3437 (s), (2934 (s), 1609 (s), 1512 (s), 1472 (s), 1283 (m), 1249 (s), 1179 (s), 1031 (w), 918 (w), 829 (m), 798 (s). APCI-MS (m/z): 1014 (M + , M100), 973. Elemental analysis. Calculated: wt % C=79.40, wt % H=8.35, wt % N=2.76, wt % S=6.33. Found: wt % C=79.33, wt % H=8.29, wt % N=2.88, wt % S=6.17. Compound 7: poly(phenylene-1,3,4-oxadiazole-phenylenehexafluoropropylene) The electron-transporting polymer (Compound 7) was prepared according to a literature method described in Li, X.-C.; Kraft, A.; Cervini, R.; Spencer, G. C. W.; Cacialli, F.; Friend, R. H.; Gruener, J.; Holmes, A. B.; de Mello, J. C.; Moratti, S. C. Mat. Res. Symp. Proc. 1996, 413 13. In more detail the preparation details were as follows: A solution of 4,4′-(hexafluoroisopropylidine)bis(benzoic acid) (2.54 g, 6.48×10 −3 mol) and hydrazine sulphate (0.84 g, 6.48×10 −3 mol) in Eaton's reagent (25 cm 3 ) was heated under reflux for 18 h. The cooled solution was added to brine (300 cm 3 ) and the product extracted into chloroform (8×200 cm 3 ). The organic extracts were combined, dried (MgSO 4 ) and the solvent removed under reduced pressure to yield the crude product which was purified by dissolving in a minimum volume of chloroform and precipitating by dropwise addition to methanol (1000 cm 3 ). The precipitate was filtered off and washed with hot water before being dried in vacuo. The precipitation was repeated a further three times washing with methanol each time. The product was then dissolved in chloroform and passed through a microfilter (0.45 μm). The pure product was then precipitated in methanol (500 cm 3 ) and the methanol removed under reduced pressure to yield a white fibrous solid which was dried in vacuo. Yield 1.26 g (50%). 1 H NMR (CDCl 3 ) δ H : 8.19 (4H/repeat unit, d), 7.61 (4H/repeat unit, d). IR ν max /cm −1 : 3488 (m), 1621 (m), 1553 (m), 1502 (s), 1421 (m), 1329 (m), 1255 (s), 1211 (s), 1176 (s), 1140 (s), 1073 (m), 1020 (m), 969 (m), 929 (m), 840 (m), 751 (m), 723 (s). GPC: M w :M n =258211:101054. An alternative electron-transport copolymer is prepared according to the method described in Xiao-Chang Li et al J. Chem. Soc. Chem. Commun., 1995, 2211. In more detail the preparation details were as follows: Terephthaloyl chloride (0.50 g, 2.46×10 −3 mol) was added to hydrazine hydrate (50 cm 3 ) at room temperature and the mixture stirred for 2 h. The precipitate was filtered off, washed with water (100 cm 3 ) and dried in vacuo. The crude hydrazide (0.25 g, 1.3×10 −3 mol), 4,4′-(hexafluoroisopropylidine)bis(benzoic acid) (2.50 g, 6.4×10 −3 mol) and hydrazine sulphate (0.66 g, 5.2×10 −3 mol) were added to Eaton's reagent and the resultant mixture heated at 100° C. for 24 h. The reaction mixture was added to water (300 cm 3 ) and the product extracted into chloroform (3×300 cm 3 ). The organic extracts were combined, dried (MgSO 4 ) and the solvent removed in vacuo before re-dissolving the product in the minimum volume of chloroform. The solution was added dropwise to methanol (900 cm 3 ) to give a white precipitate which was filtered off and dried in vacuo. The precipitation was repeated twice before dissolving the product in chloroform and passing through a microfilter (0.45 μm) into methanol (500 cm 3 ). The methanol was removed under reduced pressure and the product dried in vacuo. Yield 1.1 g (41%) 1 H NMR (CDCl 3 ) δ H : 8.18 (dd, 4H/repeat unit), 7.60 (dd, 4H/repeat unit). IR ν max /cm −1 : 3411 (w), 2366 (w), 1501 (m), 1261 (s), 1211 (s), 1176 (s), 1140 (m), 1072 (m), 1021 (w), 968 (m), 931 (w), 840 (m), 722 (m). GPC: M w :M n =20572:8320. Key intermediate 2: 9,9-diethyl-2,7-bis(4-hydroxybiphenyl-4′-yl)fluorene was synthesised as shown in Reaction Scheme 7. Full details of each step are now given: 9-Ethylfluorene: A solution of n-butyllithium (79.52 cm 3 , 0.2168 mol, 2.5M in hexane) was added slowly to a solution of fluorene (30.00 g, 0.1807 mol) in THF (300 cm 3 ) at −70° C. The solution was stirred for 1 hour at −75° C. and 1-bromoethane (17.59 cm 3 , 0.2349 mol) was added slowly. The solution was allowed to warm to room temperature and then stirred overnight. Dilute hydrochloric acid (200 ml, 20%) was added to the reaction mixture and stirred for a further 10 minutes. Water (250 cm 3 ) was added and the product extracted into diethyl ether (3×300 cm 3 ). The combined organic extracts were dried (MgSO 4 ) and the solvent removed on a rotary evaporator. The resulting oil was purified by distillation to yield a pale yellow oil (25.00 g, 71%, b.pt.—150° C. @ 1 mbar Hg). 1 H NMR (DMSO) δ: 7.70 (2H, m), 7.50 (2H, m), 7.30 (4H, m), 4.00 (1H, t), 2.02 (2H, quart), 0.31 (3H, t). IR ν max /cm −1 : 3072 (m), 2971, 1618, 1453, 1380, 1187, 759, 734. MS m/z: 170 (M + ), 94, 82, 69. 9,9-Diethylfluorene: A solution of n-butyllithium (77.34 cm 3 , 0.1934 mol, 2.5M in hexane) was added slowly to a solution of 9-ethylfluorene (25.00 g, 0.1289 mol) in THF (250 cm 3 ) at −70° C. The solution was stirred for 1 hour at −75° C. and 1-bromoethane (17.59 cm 3 , 0.1934 mol) was added slowly. The solution was allowed to warm to room temperature and then stirred overnight. Dilute hydrochloric acid (200 cm 3 , 20%) was added to the reaction mixture and stirred for a further 10 minutes. Water (250 cm 3 ) was added and the product extracted into diethyl ether (3×300 cm 3 ). The combined organic extracts were dried (MgSO 4 ) and the solvent removed on a rotary evaporator. The resulting oil was cooled to room temperature and recrystallised with ethanol to yield white crystals (19.50 g, 68%, m.pt. 60-62° C.). 1 H NMR (DMSO) δ: 7.76 (2H, m), 7.51 (2H, m), 7.35 (4H, m), 1.51 (4H, quart), 0.30 (6H, t), IR ν max /cm −1 : 3069, 2972, 1612, 1448, 1310, 761, 736. MS m/z: 222 (M + ), 193, 152, 94, 82, 75. 2,7-Dibromo-9,9-diethylfluorene: Bromine (13.47 cm 3 , 0.2568 mol) was added to a stirred solution of 9,9-diethylfluorene (19.00 g, 0.0856 mol) in DCM (250 cm 3 ). The HBr gas evolved was passed through a scrubbing solution of NaOH (1.5M). The reaction mixture was stirred for 4 hours. The reaction mixture was washed with sodium metabisulphite solution and extracted into diethyl ether (3×300 cm 3 ). The combined organic extracts were dried and the solvent removed on a rotary evaporator. The crude product was recrystallised from ethanol to yield a white crystalline solid (20.00 g, 61%, m.pt. 152-154° C.). 1 H NMR (DMSO) δ: 7.52 (2H, m), 7.45 (4H, m), 1.99 (4H, quart), 0.31 (6H, t). IR ν max /cm −1 : 2966, 1599, 1453, 1418, 1058, 772, 734. MS m/z: 380 (M + ), 351, 272, 220, 189, 176, 165, 94, 87, 75. 4-Bromo-4′-octyloxybiphenyl: A mixture of 4-bromo-4′-hydroxybiphenyl (50.00 g, 0.2008 mol), 1-bromooctane (50.38 g, 0.2610 mol), potassium carbonate (47.11 g, 0.3414 mol) and butanone (500 cm 3 ) was heated under reflux overnight. The cooled mixture was filtered and the solvent removed on a rotary evaporator. The crude solid was recrystallised from ethanol to yield a white crystalline solid (47.30 g, 66%, m.pt. 120° C.). 1 H NMR (DMSO) δ: 7.46 (6H, m), 6.95 (2H, m), 3.99 (2H, t), 1.80 (2H, quint), 1.38 (10H, m), 0.88 (3H, t). IR ν max /cm −1 : 2927, 2860, 1608, 1481, 1290, 1259, 844. MS m/z: 362 (M + ), 250, 221, 195, 182, 152, 139, 115, 89, 76, 69. 4-Octyloxybiphenyl-4′-yl boronic acid: A solution of n-butylithium (50.97 cm 3 , 0.1274 mol, 2.5M in hexane) was added dropwise to a cooled (−78° C.) stirred solution of 4-bromo-4′-octyloxybiphenyl (40.00 g, 0.1108 mol) in THF (400 cm 3 ). After 1 h, trimethyl borate (23.05 g, 0.2216 mol) was added dropwise to the reaction mixture maintaining a temperature of −78° C. The reaction mixture was allowed to warm to room temperature overnight. 20% hydrochloric acid (350 cm 3 ) was added and the resultant mixture stirred for 1 h. The product was extracted into diethyl ether (3×300 cm 3 ). The combined organic layers were washed with water (300 cm 3 ), dried (MgSO 4 ), filtered and the filtrate evaporated down under partially reduced pressure. The crude product was stirred with hexane for 30 minutes and filtered off to yield a white powder (26.20 g, 73%, m.pt. 134-136° C.). 1 H NMR (DMSO) δ: 8.04 (2H, s), 7.84 (2H, m), 7.57 (4H, m), 7.00 (2H, m), 3.99 (2H, t), 1.74 (2H, quint), 1.35 (10H, m), 0.85 (3H, t). IR ν max /cm −1 : 2933, 2860, 1608, 1473, 1286, 1258, 818. MS m/z: 326 (M + ), 214, 196, 186, 170, 157, 128, 115, 77, 63 9,9-Diethyl-2,7-bis(4-octyloxybiphenyl-4′-yl)fluorene: Tetrakis(triphenylphosphine)palladium(0) (0.70 g, 0.0006 mol) was added to a stirred solution of 2,7-dibromo-9,9-diethylfluorene (4) (2.33 g, 0.0061 mol), 4-octyloxybiphenyl-4′-yl boronic acid (5.00 g, 0.0153 mol), 20% sodium carbonate solution (100 cm 3 ) and 1,2-dimethoxyethane (150 cm 3 ). The reaction mixture was heated under reflux overnight. Water (300 cm 3 ) was added to the cooled reaction mixture and the product extracted into DCM (3×300 cm 3 ). The combined organic extracts were washed with brine (2×150 cm 3 ), dried (MgSO 4 )), filtered and the filtrate evaporated down under partially reduced pressure. The residue was purified by column chromatography on silica gel using DCM and hexane (30:70) as eluent and recrystallisation from ethanol and DCM to yield a white crystalline solid (3.10 g, 65%, m.pt. 146° C.). 1 H NMR (DMSO) δ: 7.77 (6H, m), 7.63 (12H, m), 7.00 (4H, m), 4.01 (4H, t), 2.13 (4H, quart), 1.82 (4H, quint), 1.40 (20H, m), 0.89 (6H, t), 0.43 (6H, t). IR ν max /cm −1 : 3024, 2921, 2853, 1609, 1501, 1463, 1251, 808. MS m/z: 782 (M + ), 669, 514, 485, 279, 145, 121, 107, 83, 71. CHN analysis: % Expected C (87.42%), H (8.49%). % Found C (87.66%), H (8.56%). 9,9-Diethyl-2,7-bis(4-hydroxybiphenyl-4′-yl)fluorene: Boron tribromide (99.9%, 1.05 cm 3 , 0.0111 mol) in DCM (10 ml) was added dropwise to a cooled (0° C.) stirred solution of 9,9-diethyl-2,7-bis(4-octyloxybiphenyl-4′-yl)fluorene (2.90 g, 0.0037 mol) in DCM (100 cm 3 ). The reaction mixture was stirred at room temperature overnight, then poured onto an ice/water mixture (50 g) and stirred (30 minutes). The crude product was purified by column chromatography on silica gel with a mixture of ethyl acetate and hexane (30:70) as the eluent and recrystallisation from ethanol to yield a white powder (0.83 g, 40%, m.pt. >300° C.). 1 H NMR (DMSO) δ: 9.09 (2H, OH), 7.77 (6H, m), 7.64 (8H, m), 7.51 (4H, m), 6.94 (4H, m), 1.19 (4H, m), 0.42 (6H, t). IR ν max /cm −1 : 1608, 1500, 1463, 1244, 1173, 811. MS m/z: 558 (M + ), 529, 514, 313, 279, 257, 115, 77, 65. Compound 8: 9,9-Diethyl-2,7-bis{4-[5-(1-vinylallyloxycarbonyl)pentyloxy]biphenyl-4′-yl}fluorene: Compound 8 was synthesised as follows: A mixture of 9,9-diethyl-2,7-bis(4-hydroxybiphenyl-4′-yl)fluorene (0.83 g, 0.0015 mol), 1,4-pentadienyl-3-yl 6-bromohexanoate (0.97 g, 0.0037 mol), potassium carbonate (0.62 g, 0.0045 mol) and DMF (25 cm 3 ) was heated under reflux overnight. The cooled reaction mixture was added to water (500 cm 3 ) and then extracted with DCM (3×50 cm 3 ). The combined organic extracts were washed with water (250 cm 3 ), dried (MgSO 4 ) and the filtrate evaporated down under partially reduced pressure. The crude product was purified by column chromatography using silica gel using a mixture of DCM and hexane (80:20) as the eluent and recrystallisation from DCM and ethanol to yield a white crystalline solid (0.2 g, 22%). 1 H NMR (CDCl 3 ) δ: 7.78 (6H, m), 7.62 (12H, m), 7.00 (4H, m), 5.85 (4H, m), 5.74 (4H, m), 5.27 (4H, m), 4.03 (4H, t), 2.42 (4H, t), 2.14 (4H, quart), 1.85 (4H, m), 1.74 (4H, m), 1.25 (4H, q), 0.43 (3H, t). IR ν max /cm −1 : 3028, 2922, 2870, 1734, 1606, 1500, 1464, 1246, 1176, 812. CHN analysis: % Expected C (82.32%), H (7.24%). % Found C (81.59%), H (6.93%). Compounds 9-15: Compounds 9 to 15, comprising the 2,7-bis{ω-[5-(1-vinylallyloxycarbonyl)alkoxy]-4′-biphenyl}-9,9-dialkylfluorenes compounds of Table 1 were prepared analogously to Compound 8. n m Compound 9  3 5 Compound 10 4 5 Compound 11 5 5 Compound 12 6 5 Compound 13 8 5 Compound 14 8 7 Compound 15 8 11 All of Compounds 8 to 15 exhibit a nematic phase with a clearing point (N-I) between 58 and 143° C. Compound 16: 4,7-bis{4-[(S)-3,7-Dimethyl-oct-6-enyloxy]phenyl}-2,1,3-benzothiadozole Compound 16 was synthesised as depicted in Reaction Scheme 8. Full details of each step follows: 4,7-Dibromo-2,1,3-benzothiadozole: Bromine (52.8 g, 0.33 mol) was added to a solution of 2,1,3-benzothiadozole (8.1 g, 0.032 mol) in hydrobromic acid (47%, 100 cm 3 ) and the resultant solution was heated under reflux for 2.5 h. The cooled reaction mixture reaction mixture was filtered and the solid product washed with water (200 cm 3 ) and sucked dry. The raw product was purified by recrystallisation from ethanol to yield 21.0 g (65%) of the desired product. 1-Bromo-4-[(S)-3,7-dimethyloct-6-enyloxy]benzene: A mixture of 4-bromophenol (34.6 g, 0.20 mol), (S)-(+)-citronellyl bromide (50 g, 0.023 mol) and potassium carbonate (45 g, 0.33 mol) in butanone (500 cm 3 ) was heated under reflux overnight. The cooled reaction mixture was filtered and the filtrate concentrated under reduced pressure. The crude product was purified by fractional distillation to yield 42.3 g (68.2%) of the desired product. 4-[(S)-3,7-Dimethyloct-6-enyloxy]phenyl boronic acid: 2.5M n-Butylithium in hexanes (49.3 cm 3 , 0.12 mol) was added dropwise to a cooled (−78° C.) solution of 1-bromo-4-[(S)-3,7-dimethyloct-6-enyloxy]benzene (35 g, 0.11 mol) in tetrahydrofuran (350 cm 3 ). The resultant solution was stirred at this temperature for 1 h and then trimethyl borate (23.8 g, 0.23 mol) was added dropwise to the mixture while maintaining the temperature at −78° C. 20% hydrochloric acid (250 cm 3 ) was added and the resultant mixture was stirred for 1 h and then extracted into diethyl ether (2×200 cm 3 ). The combined organic layers were washed with water (2×100 cm 3 ) and dried (MgSO 4 ). After filtration the solvent was removed under reduce pressure to yield 20.35 g (65%) of the desired product. 4,7-bis{4-[(S)-3,7-Dimethyl-oct-6-enyloxy]phenyl}-2,1,3-benzothiadozole: A mixture of tetrakis(triphenylphosphine)palladium(0) (0.8 g, 0.70×10 −3 mol), 4,7-dibromo-2,1,3-benzothiadozole (2) (2 g, 6.75×10 −3 mol), 4-[(S)-3,7-dimethyloct-6-enyloxy]phenyl boronic acid (4.66 g, 1.70×10 −2 mol), 2M sodium carbonate solution (50 cm 3 ) and 1,2-dimethoxyethane (150 cm 3 ). The reaction mixture was heated under reflux overnight. The cooled reaction mixture was extracted with dichloromethane (2×150 cm 3 ) and the combined organic layers were washed with brine (2×100 cm 3 ) and dried (MgSO 4 ). After filtration the solvent was removed under reduced pressure and the residue was purified by column chromatography [silica gel, dichloromethane: hexane 1:4] followed by recrystallisation from ethanol to yield 3.2 g (79.5%) of the desired product. 4,7-bis(4-Hydroxyphenyl)-2,1,3-benzothiadozole: Boron tribromide (1.51 cm 3 , 1.61×10 −2 mol) was added dropwise to a cooled (0° C.) stirred solution of 2,5-bis{4-[(S)-3,7-dimethyl-oct-6-enyloxy]phenyl}-2,1,3-benzothiadozole (4.0 g, 7.40×10 −3 mol) in dichloromethane (100 cm 3 ). The reaction mixture was stirred at room temperature overnight, then poured onto an ice/water mixture (200 g) and stirred (30 min). The desired product was precipitated and it was filtered off and sucked dry to yield 1.23 g (71.5%) of the desired product. 4,7-bis(4-{5-[1-Vinyl-allyloxycarbonyl]pentyloxy}phenyl)-2,1,3-benzothiadozole: A mixture of 2,5-bis(4-hydroxyphenyl)-2,1,3-benzothiadozole (0.3 g, 0.93×10 −3 mol), 1,4-pentadien-3-yl 5-bromopentanoate (0.61 g, 2.34×10 31 ' mol) and potassium carbonate (0.38 g, 2.79×10 −3 mol) in N,N-dimethylformaldehyde (30 cm 3 ) was heated (80 C°) overnight. The cooled reaction mixture was filtered and the filtrate concentrated under reduce pressure. The crude product was purified by column chromatography [silica gel, ethyl acetate:hexane 1:5] followed by recrystallisation from ethanol to yield 0.39 g (61.8%) of the desired product. Compounds 17 and 18 are preparable by an analogous process. Thin Film Polymerisation and Evaluation Thin films of Compounds 3 to 6 and Compunds 9 to 15 were prepared by spin casting from a 0.5%-2% M solution in chloroform onto quartz substrates. All sample processing was carried out in a dry nitrogen filled glove box to avoid oxygen and water contamination. The samples were subsequently baked at 50° C. for 30 minutes, heated to 90° C. and then cooled at a rate of 0.2° C. to room temperature to form a nematic glass. Polarised microscopy showed that no change was observed in the films over several months at room temperature. The films were polymerized in a nitrogen filled chamber using light from an Argon Ion laser. Most of the polymerization studies were carried out at 300 nm with a constant intensity of 100 MWcm −2 and the total fluence varied according to the exposure time. No photoinitiator was used. Temperature dependent polymerization studies were carried out in a Linkham model LTS 350 hot-stage driven by a TP 93 controller under flowing nitrogen gas. A solubility test was used to find the optimum fluence: different regions of the film were exposed to UV irradiation with different fluences and the film was subsequently washed in chloroform for 30 s. The unpolymerized and partially polymerized regions of the film were washed away and PL from the remaining regions was observed on excitation with an expanded beam from the Argon Ion laser. Optical absorbance measurements were made using a Unicam 5625 UV-VIS spectrophotometer. PL and EL were measured in a chamber filled with dry nitrogen gas using a photodiode array (Ocean Optics S2000) with a spectral range from 200 nm to 850 nm and a resolution of 2 nm. Films were deposited onto CaF 2 substrates for Fourier Transform infra-red measurements, which were carried out on a Perkin Elmer Paragon 1000 Spectrometer. Indium tin oxide (ITO) coated glass substrates, (Merck 15 Ω/□) were used for EL devices. These were cleaned using an Argon plasma. 20 A PDOT (EL-grade, Bayer) layer of thickness 45 nm±10% was spin-cast onto the substrate and baked at 165° C. for 30 minutes. This formed a hole-transporting film. One or more organic films of thickness≈45 nm were subsequently deposited by spin-casting and crosslinked as discussed below. Film thicknesses were measured using a Dektak surface profiler. Aluminum was selectively evaporated onto the films at a pressure less than 1×10 −5 torr using a shadow mask to form the cathode. Photopolymerisation Details The optimum fluences required in order to polymerize the diene monomers (Compounds 3 to 6) efficiently with a minimum of photodegradation, were found to be 100 Jcm −2 , 20 Jcm −2 , 100 Jcm −2 and 300 Jcm −2 respectively, using the solubility test. As Scheme 6 shows, the 1,6-heptadiene monomer (e.g. Compound 4) forms a network with a repeat unit containing a single ring. Its polymerization rate is equal to that of the 1,4-pentadiene monomer (e.g. Compounds 3 and 5) but the increase of PL intensity after polymerization is less for Compound 4. This may be because of the increased flexibility of the C 7 ring in the backbone of the crosslinked material. The 1,4-pentadiene diene monomers (Compounds 3 and 5) are homologues and differ only in the length of the flexible alkoxy-spacer part of the end-groups. The PL spectrum of Compound 5 with the shorter spacer is significantly different to all other materials before exposure suggesting a different conformation. The higher fluence required to polymerize the 1,4-pentadiene monomer Compound 5 implies that the polymerization rate is dependent on the spacer length: the freedom of motion of the photopolymerizable end-group is reduced, because of the shorter aliphatic spacer in Compound 5. The diallylamine monomer Compound 6 has a significantly different structure to the dienes. It is much more photosensitive than the other diene monomers because of the activation by the electron rich nitrogen atom. Scheme 6 also shows (by way of comparison) that when a methacrylate monomer is employed the polymerization step does not involve the formation of a ring. Photopolymerization Characteristics The absorbance and PL spectra of 1,4-pentadiene monomer (Compound 3) were measured before and after exposure with the optimum UV fluence of 100 J cm −2 . The latter measurements were repeated after washing in chloroform for 30 s. The absorbance spectra of the unexposed and exposed films are almost identical and the total absorbance decreases by 15% after washing indicating that only a small amount of the material is removed. This confirms conclusively that a predominantly insoluble network is formed. The UV irradiation was carried out in the nematic glass phases at room temperature at 300 nm. The excitation of the fluorene chromophore is minimal at this wavelength and the absorbance is extremely low. The experiment was repeated using a wavelength of 350 nm near the absorbance peak. Although the number of absorbed photons is far greater at 350 nm, a similar fluence is required to form an insoluble network. Furthermore excitation at 350 nm results in some photodegradation. UV photopolymerization was also carried out at 300 nm at temperatures of 50° C., 65° C. and 80° C. all in the nematic phase. It was anticipated that the polymerization rate would increase, when the photoreactive mesogens were irradiated in the more mobile nematic phase. However, the fluence required to form the crosslinked network was independent of temperature, within the resolution of our solubility test. Furthermore, the integrated PL intensity from the crosslinked network decreases with temperature indicating a temperature dependent photodegradation. Bilayer Electroluminescent Devices Bilayer electroluminescent devices were prepared by spin-casting the 1,4-pentadiene monomer (Compound 3) onto a hole-transporting PEDT layer. The diene functioned as the light-emitting and electron-transporting material in the stable nematic glassy state. Equivalent devices using cross-linked networks formed from Compound 3 by photopolymerisation with UV were also fabricated on the same substrate under identical conditions and the EL properties of both types of devices evaluated and compared. The fabrication of such bilayer OLEDs is facilitated by the fact that the hole-transporting PEDT layer is insoluble in the organic solvent used to deposit the electroluminescent and electron-transporting reactive mesogen (Compound 3). Half of the layer of Compound 3 was photopolymerized using optimum conditions and the other half was left unexposed so that EL devices incorporating either the nematic glass or the cross-linked polymer network could be directly compared on the same substrate under identical conditions. Aluminum cathodes were deposited onto both the cross-linked and non cross-linked regions. Polarized electroluminescent devices were prepared by the polymerization of uniformly aligned Compound 3 achieved by depositing it onto a photoalignment layer doped with a hole transporting molecule. In these devices external quantum efficiencies of 1.4% were obtained for electroluminescence at 80 cd m −2 . Three layer devices were also prepared by spin-casting an electron transporting polymer (Compound 7), which shows a broad featureless blue emission, on top of the crosslinked nematic polymer network. In the case of both the three layer and bilayer devices the luminescence originates from the cross-linked polymer network of the 1,4-pentadiene monomer (Compound 3). The increased brightness of the three-layer device may result from an improved balance of electron and hole injection and/or from a shift of the recombination region away from the absorbing cathode. Multilayer Device A multilayer device configuration was implemented as illustrated in FIG. 2 . A glass substrate 30 (12 mm×12 mm×1 mm) coated with a layer of indium tin oxide 32 (ITO) was cleaned via oxygen plasma etching. Scanning electron microscopy revealed an improvement in the surface smoothness by using this process which also results in a beneficial lowering of the ITO work function. The ITO was coated with two strips (˜2 mm) of polyimide 34 along opposite edges of the substrate then covered with a polyethylene dioxthiophene/polystyrene sulfonate (PEDT/PSS) EL-grade layer 36 of thickness 45±5 nm deposited by spin-coating. The layer 36 was baked at 165° C. for 30 min in order to cure the PEDT/PSS and remove any volatile contaminants. The doped polymer blend of Compounds 1 and 2 was spun from a 0.5% solution in cyclopentanone forming an alignment layer 40 of thickness ˜20 nm. This formed the hole-injecting aligning interface after exposure to linearly polarized CV from an argon ion laser tuned to 300 nm. A liquid-crystalline luminescent layer 50 of Compound 3 was then spun cast from a chloroform solution forming a film of ˜10 nm thickness. A further bake at 50° C. for 30 min was employed to drive off any residual solvent. The sample was heated to 100° C. and slowly cooled at 02° C./min to room temperature to achieve macroscopic alignment of chromophores in the nematic glass phase. Irradiation with UV light at 300 nm from an argon ion laser was used to induce crosslinking of the photoactive end-groups of the Compound 3 to form an insoluble and intractable layer. No photoinitiator was used hence minimizing continued photoreaction during the device lifetime. Aluminium electrodes 50 were vapor-deposited under a vacuum of 10° mbar or better and silver paste dots 52 applied for electrical contact. A silver paste contact 54 was also applied for contact with the indium tin oxide base electrode. This entire fabrication process was carried out under dry nitrogen of purity greater than 99.99%. Film thickness was measured using a Dektak ST surface profiler. The samples were mounted for testing within a nitrogen-filled chamber with spring-loaded probes. The polymide strips form a protective layer preventing the spring-loaded test probes from pushing through the various layers. Optical absorbance measurements were taken using a Unicam UV-vis spectrometer with a polarizer (Ealing Polarcaot 105 UV-vis code 23-2363) in the beam. The spectrometer's polarization bias was taken into account and dichroic ratios were obtained by comparing maxima at around 370-380 nm. Luminescence/voltage measurements were taken using a photomultiplier tube (EMI 6097B with S11 type photocathode) and Keithley 196 multimeter with computer control. Polarized EL measurements were taken using a photodiode array (Ocean Optics S2000, 200-850 nm bandwidth 2 nm resolution) and polarizer as described above. The polarization bias of the spectrometer was eliminated by use of an input fiber (fused silica 100 μm diameter) ensuring complete depolarisation of light into the instrument. Monochrome Backlight FIG. 3 shows a schematic representation of a polarised light monochrome backlight used to illuminate a twisted nematic liquid crystal display. The arrows indicate the polarisation direction. An inert substrate 30 (e.g. glass coated with a layer of indium tin oxide (ITO) as in FIG. 2 ) is provided with a layer 50 of a polarised light emitting polymer (e.g. comprising Compound 3 as in FIG. 2 ). The assembly further includes a clean up polariser 60 comprising a high transmission low polarisation efficiency polariser; a twisted nematic liquid crystal display 70 ; and a front polariser 80 . It will be appreciated that the light emitting polymer layer 50 acts as a light source for the liquid crystal display 70 . Polarised Light Sequential Tricolor Backlight FIG. 3 schematic of a polarised light sequential red, green and blue light emitting backlight used to illuminate a fast liquid crystal display (ferroelectric display). The arrows indicate the polarisation direction. An inert substrate 30 (e.g. glass coated with a layer of indium tin oxide (ITO) as in FIG. 2 ) is respectively provided with red 52 , green 54 and blue 56 striped layers of a polarised light emitting polymer (e.g. comprising Compound 3 as in FIG. 2 and a suitable dye molecule as a dopant). The assembly further includes a clean up polariser 60 comprising a high transmission low polarisation efficiency polariser; a fast (ferroelectric) liquid crystal display 70 ; and a front polariser 80 . It will be appreciated that the striped light emitting polymer layer 52 , 54 , 56 acts as a light source for the fast liquid crystal display 70 . The sequential emission of the RGB stripes corresponds with the appropriate colour image on the fast liquid crystal display. Thus, a colour display is seen. Alignment Characteristics The PL polarization ratio (PL η /PL ⊥ ) of the aligned polymer formed from Compound 3 in its nematic glass phase can be taken as a measure of the alignment quality. Optimum alignment is obtained with the undoped alignment layer for an incident fluence of 50 mJ cm −2 . The alignment quality deteriorates when higher fluences are used. This is expected because there are competing LC-surface interactions giving parallel and perpendicular alignment respectively. When the dopant concentration is 40% or higher there is a detrimental effect on alignment. However with concentrations up to 30% the polarization ratio of emitted light is not severely effected although higher fluences are required to obtain optimum alignment. The EL intensity reaches its peak for the ˜50% mixture. A 30% mixture offers a good compromise in balancing the output luminescence intensity and polarization ratio. From these conditions and using the 30% doped layer we have observed strong optical dichroism in the absorbance (D˜6.5) and obtained PL polarization ratios of 8:1. Electroluminescence Characteristics Devices made with compound 3 in the nematic glassy state showed poor EL polarization ratios because the low glass transition temperature compromised the alignment stability. Much better performance was achieved when compound 3 was crosslinked. A brightness of 60 cd m −2 (measured without polarizer) was obtained at a drive voltage of 11V. The threshold voltage, EL polarization ratio and intensity all depend on the composition of the alignment layer. A luminance of 90 cd m −2 was obtained from a 50% doped device but with a reduction in the EL polarization ratio. Conversely a polarized EL ratio of 11:1 is found from a 20% doped device but with lower brightness. A threshold voltage of 2V is found for the device with a hole-transporting layer with 100% of the dopant comprising compound 2. Clearly a photo-alignment polymer optimised for both alignment and hole-transporting properties would improve device performance. This could be achieved using a co-polymer incorporating both linear rod-like hole-transporting and photoactive side chains.

There is provided a process for forming a light emitting polymer comprising photopolymerization of a reactive mesogen having an endgroup which is susceptible to photopolymerization e.g. by a radical polymerization process. Also provided are methods for using the light emitter in displays, backlights, electronic apparatus and security viewers.

[0001] This non-provisional application relies on the filing date of provisional U.S. Application Ser. No. 60/825,311 filed on Sep. 12, 2006, which is incorporated herein by reference, having been filed within twelve (12) months thereof, and priority thereto is claimed under 35 USC § 1.19(e). BACKGROUND [0002] Papermaking process generally involves passing a dilute aqueous slurry of cellulosic fibers obtained from a headbox onto a moving screen known as a fourdrinier wire to drain water from the slurry through the screen and allow a formation of substantially consolidated fiber mat, then pressing the fiber mat using a size press wherein the major volume of water remaining in the mat is removed by roll nip squeezing, and finally passing the resulting mat through a drying section of a paper machine to have the remaining water removed thermodynamically. [0003] Paper-based product such as paper and paperboard is typically coated to enhance its surface properties. Paper coating often requires complex and expensive equipment and is typically performed off-line from a papermaking process. As a result, the coating step adds a significant cost to production process of paper. Coating weights from about 2-6 lbs/1000 ft 2 are typically demanded to substantially enhance surface properties of the paper. Such high coat weight level is usually required because lower coating weights are typically not uniform enough to provide the desired improvement in surface properties. This relatively high coat weight not only substantially increases the production cost of paper, but also raises the basis weight of the paper and thus the shipping cost of paper. [0004] Paperboard typically has a thickness of greater than 0.3 mm, a caliper range of about 0.3 mm to about 1.2 mm, and a basis weight range of about 120 g/m 2 to about 500 g/m 2 . Paperboard is generally categorized into five grades: solid bleached sulfate, coated unbleached Kraft, clay coated news, folding boxboard, and uncoated recycled boxboard. [0005] When used for packaging applications, it is often desirable that the packaging board has good surface properties for high print quality. Therefore, the packaging board is commonly coated with pigment-based formulation. To impart opacity, the packaging board is typically coated with an opacifying pigment such as titanium dioxide and clay in a pigment binder. The surface gaps between wood fibers are in the range of 50-100 um, while the size of opaque pigment is less than 1 um. In order to fill fiber voids and create a smooth paperboard surface, high levels of opacifying pigment are required which adds significant cost to board production. Additionally, since opacifying pigments are denser than cellulose, they tend to increase the basis weight of the board resulting in higher shipping costs. Furthermore, this means of improving surface print quality is in many cases made at the expense of strength properties of packaging boards such as bending force and tensile stiffness. [0006] There has been a continuing effort to improve surface properties of paperboard e.g. smoothness, opacity, printability without diminishing physical performance and significantly increased production cost. U.S. Pat. No. 6,645,616 discloses laminated board having enhanced surface and strength properties suitable for use as beverage carrier or carrier board. The laminated board is produced by laminating lightweight coated unprinted white paper onto unbleached or bleached board substrate. In U.S. Patent Application No. 2003/0,091,762, white top paperboard is produced by laminating thin bleached fiber paper onto unbleached board substrate. These methods require additional steps to paperboard making process such as off-line coating and lamination, thus increasing production cost. U.S. Patent Application No. 2005/0,039,871 discloses the use of multilayer curtain for a one-step coating operation to reduce production cost. Another approach to reduce the production cost is by using low-cost fillers instead of titanium oxide pigment to enhance opacity and surface smoothness. U.S. Patent Application No. 2006/0,065,379 teaches the use of low cost mineral fillers, bleached fiber and binder for the production of white top paperboard. U.S. Patent Application No. 2004/086,626 uses mechanically ground fiber as a low-cost void filler in a coating formulation to produce a fine printing paper. In U.S. Pat. No. 4,888,092, pulp fines having a particle size which passes through a 100 mesh screen, containing less than 25% fiber and fiber fragments, and containing at least 50% by weight ray cells is applied as a layer on the surface of a primary paper sheet to enhance the surface smoothness of the paper. [0007] The use of ultrafine fibers to fill fiber voids and create smooth board surface has been explored. PCT Patent Application No. 2004/087,411 and U.S. Patent Application No. 2004/223,040 disclose the application of nanometer diameter electrospun fiber to the board surface. This method is, however, typically too costly for the commercial production of paperboard. Microcrystalline cellulose (MCC) has been used to fill surface voids and provide a smooth surface (U.S. Pat. No. 7,037,405; U.S. Patent Application No. 2005/2,39,744; PCT Patent Application No. 2006/034,837). U.S. Pat. No. 7,037,405 discloses that paperboard surface treated with texturized MCC suspension showed improved strength and surface printability. The disclosed texturized MCC is produced through acid hydrolysis of low-grade fiber pulps such as southern pines and other chemical softwoods, followed by mechanical defibrillation. However, MCC is quite expensive to produce since this type of texturized MCC is essentially isolated and purified from acid pre-extracted cellulosic fibers having high α-cellulose content. The MCC suspension must be formulated into suspension with starch or other viscosity modifier in order to control the rheology, so that the suspension could be applied to the paper and paperboard surface. [0008] Microfibrillated cellulose (MFC) has been investigated for surface treatment of paperboard to improve surface characteristics. PCT Patent Application NO. 2004/055,267 teaches the use of MFC obtained from enzymatic treatment of fibers for improving surface printability of packaging materials without deteriorating strength properties. However, the obtained enzymatic MFC suspension is unstable and must be dispersed and stabilized with carboxymethylcellulose. Furthermore, carboxymethylcellulose is required to improve the rheology property of MFC suspension so that the MFC suspension could be coated to the dried surface of packaging materials. U.S. Pat. Nos. 4,861,427 and 5,637,197 teach the use of bacterial cellulose MFC for surface treatment application. Similar to MCC, MFC is relatively costly. Currently, it is still a challenge to produce MFC in production scale. [0009] U.S. Pat. No. 4,474,949 discloses microfibrillar cellulose in the form of discrete platelets, also known as microplatelet cellulose particles (MPC). These MPC particles are produced by mechanically treating (beating) a dilute aqueous dispersion of cellulose fibers to a degree such that at least the outermost of the secondary walls of cellulose fibers are essentially completely disintegrated to microfibrillar form. The beaten dispersion is then freeze dried. The obtained MPC particles have high absorption capacity and fluid retention, rendering them suitable for use in absorbent products such as sanitary napkins, diapers, dressings or the like which are used for absorbing body fluids. [0010] Japanese Patent Application No. 2004/230,719 discloses MPC having a width of 1-50 μm, a length of 1-50 μm and a thickness of 0.1-10 μm. These easily oriented and uniformly dispersed MPC particles are obtained by grinding cellulose substance. A mixture of synthetic polymer, fatty acid, and water or an organic solvent can be mechanically ground with the cellulose substance. The synthetic polymers can be polyalcohol, polyether, polyolefin, and polyamide. Organic solvent suitable for the grinding process include alkane, alcohol, ketone, ether and aromatic hydrocarbon. Since the obtained MPC particles are tasteless and odorless, they can be used as food additive for enhanced thickening, improved water retention, and increased tactile feeling. Furthermore, they can be used as fillers in drugs and cosmetics. [0011] Since the amount of pigment used for coating is generally related to the smoothness of the substrate over which it is coated. Several means have been used to increase the smoothness of paperboard and, therefore, decrease the amount of opacity pigment needed. Either dry or wet calendering provides paperboard with enhanced surface smoothness. During calendering, the paperboard structure is compressed resulting in a reduced thickness (i.e., lower caliper). The relationship between caliper and bending stiffness is reported as an equation: [0000] S b =t 3 ×E/ 12 [0000] wherein [0012] S b is the bending stiffness; [0013] E is the elastic modulus; and [0014] t is the thickness or caliper. [0015] Bending stiffness property of paperboard is directly related to a cube of the board thickness. Improving the surface smoothness of paperboard through calendering leads to a reduction of caliper thickness, and thus a significant reduction of bending stiffness. Additionally, wet calendering frequently results in machine speed reductions due to the need to re-wet and re-dry the board. [0016] For packaging applications, it is desirable to have paperboard having several performances in addition to surface smoothness for high print quality and aesthetic appearance, such as high bending stiffness and excellent strength. [0017] High bending stiffness provides a rigid and strong packaging board. Furthermore, high bending stiffness is necessary for good runnability on packaging machinery, particularly for high speed printing and converting. It is also valued in paperboard beverage carriers, such as in milk or juice cartons, to prevent bulge. Several methods have been used to enhance the bending stiffness of paperboard, but these improvements are typically at an expense of other board properties. Bulking agents may be added to paperboard to improve bending stiffness. However, bulking agents also impart lower tensile strength to paperboard because of debonding effects of these materials. [0018] When used for packaging applications, it is desirable for the paperboard to have high strength. A typical approach to enhance strength property of packaging board results in an undesirable increase of board density. U.S. Pat. No. 6,322,667 teaches the use of superheated steam to improve dry tensile and strength of board without substantially increased board density. Board is dried in superheated steam rather than dried in air or as done conventionally, in air on a hot metal surface. Nevertheless, this method is rather sensitive towards types of pulps used for the board production. Board made of pure mechanical pulps shows significantly improved dry tensile and strength without increased board density. On the contrary, board made of pure chemical pulps such as kraft does not show any increase in strength after drying in superheated steam. [0019] Unfortunately, efforts to enhance one performance of packaging board are commonly achieved at an expense of other desired performance. For example, calendering improves surface smoothness of paperboard but deteriorates bending stiffness and strength. [0020] Therefore, there is still a need for packaging board having enhanced surface smoothness and other aesthetic properties without compromising bending stiffness and strength and vice versa. Additionally, it is beneficial for a method of imparting enhanced surface smoothness and other aesthetic properties, bending stiffness, or strength to packaging boards, while maintaining other desired performances. SUMMARY [0021] The present disclosure relates to paperboard containing microplatelet cellulose particles has improved surface smoothness, aesthetic properties, bending stiffness and strength performance. When microplatelet cellulose particles are used for surface treatment of the paperboard, the microplatelets fill voids between fibers on the board surface. As a result, treated board has enhanced strength and surface properties such as smoothness, opacity, coating hold-out, and printability without compromising bending stiffness. Furthermore, the present disclosure relates to a process for improving board strength, surface smoothness and/or bending stiffness without the needs for densification, while maintaining other desired performances. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 is a SEM image of the microplatelet cellulose particles (MPC) of the present disclosure. [0023] FIG. 2 is another SEM image of the microplatelet cellulose particles (MPC) of the present disclosure. [0024] FIG. 3 shows microscopy images at 6× magnifications of the DSF handsheets applied as a secondary layer at different levels of MPC particles: 0, 1.4, and 2.8 lb/1,000 ft 2 . [0025] FIG. 4 shows SEM surface negative images at 200× magnification of paperboard having softwood base layer, and secondary layer containing (A) no MPC particles, and (B) MPC particles at 1 lb/1,000 ft 2 in which MPC particles were added in the secondary head during the papermaking process. [0026] FIG. 5 shows SEM cross section negative images at 200× magnification of paperboard having softwood base layer, and secondary layer containing (A) no MPC particles, and (B) MPC particles at 1 lb/1,000 ft 2 in which MPC particles were added in the secondary head during the papermaking process. [0027] FIG. 6 is a graph showing a relationship between brightness and smoothness of paperboard containing MPC particles of the present disclosure. [0028] FIG. 7 . is a graph showing a relationship between Sheffield smoothness and Taber stiffness of the paperboards size press-applied with different sizing formulations and calendered at different pressure levels: 0, 50, and 100 pli. [0029] FIG. 8 . is a graph showing a relationship between Sheffield smoothness and Taber stiffness of the paperboards blade-coated with different coating formulations and calendered at different pressure levels: 0, 50, and 100 pli. DETAILED DESCRIPTION [0030] The following detailed description illustrates an embodiment of the present disclosure; however, it is not intended to limit the scope of the appended claims in any manner. [0031] The microplatelet cellulose MPC particles of the present disclosure may be obtained by passing a suspension of fiber pulps through a high-friction grinder or buhrstone mill under an atmospheric pressure at a temperature range of about 20° C. to about 95° C. The fiber pulps were repeatedly subjected to the grinding process for multiple times, and the volume average particle sizes of the resulting MPC in aqueous suspension were measured after each pass using Microtrac X-100 Tri-Laser-System, a laser light scattering particle size analyzer. FIGS. 1 and 2 are the SEM images of the disclosed dried form of MPC. [0032] The MPC of the present disclosure has a volume average particle size range of from about 20 microns to about 150 microns, a number average particle size range of from about 5 microns to about 20 microns, and a 95 th percentile volume average particle size of no more than about 300 microns. The 95 th percentile volume average particle size is defined as the volume average particle size of 95% of total MPC. The particle size of the disclosed MPC may be varied, depending on the targeted end use applications. The concentration of MPC particles was typically about 2% to about 3% solids, but a higher or lower % solid may be produced according to the selected applications. [0033] The water retention value of MPC was determined by placing 50 ml of 1.5% solids aqueous solution of MPC in a centrifuge tube at room temperature. The tubes used were 30 mm in diameter×100 mm in length with a scaled volume of 50 ml. The filled tubes were centrifuged for 15 min at 3000 rpm using a IEC CL2 centrifuge (1500 G). The tubes were carefully removed from the centrifuge, and the volume at the interface between the clear aqueous phase and opaque MPC layer was measured. The water phase was then decanted off and the MPC layer was dried in an oven at 105° C. for 48 hours to determine the weight of MPC. The water retention value was calculated using the following equation: [0000] Water retention value=ml (volume of precipitate in tube)/g (O.D. weight of MPC) [0034] The MPC of the present invention may have a water retention value in a range of from about 5 ml/g to about 80 ml/g. [0035] Cellulosic fibers from various natural origins may be used in the present disclosure. These include, but are not limited to, softwood fibers, hardwood fibers, cotton fibers, Esparto grass, bagasse, hemp, flax and vegetable-based fiber such as sugar beet and citrus pulp. Wood pulps may be made by chemical treatment such as Kraft, sulfite, and sulfate processes; mechanical pulps such as groundwood and thermomechanical pulp; and combination thereof. The fiber pulps may be modified before being subjected to a high friction grinding process. Several modifications may be applied including, but are not limited to, chemical modification, enzymatic treatment, mechanical treatment, and combinations thereof. Furthermore, synthetic fibers and/or fillers such as clay or titanium dioxide may be subjected to a high friction grinder in combination with fiber pulps. [0036] MPC particles of the present disclosure may be used for surface treatment of board and/or for secondary layer in the basecoat of board. The surface treatment may be carried out by various techniques known in the arts. These include, but are not limited to, size-press, roll coating, blade coating, rod coating, spraying, curtain coating, and surface layer forming by headbox on paperboard machine. [0037] In one embodiment of the present disclosure, the disclosed paperboard contains MPC in an amount range of from about 0.10 lbs to about 20 lbs per 1,000 ft 2 of the paperboard. [0038] In one embodiment of the present disclosure, the disclosed paperboard contains MPC in an amount range of from about 0.1% to about 50%, based on total weight of the paperboard. [0039] In one embodiment of the present disclosure, the disclosed paperboard containing MPC has a MD-CD geometric mean Taber stiffness value of about 25 g-cm to about 500 g-cm. [0040] MPC in a Secondary Layer of Paperboard Basecoat [0041] Handsheets consisting of a primary layer containing softwood pulp, and a secondary layer containing softwood pulp and a different amount of MPC particles were made using the dynamic sheet former (DSF). The DSF sheet containing solely softwood pulp in the secondary layer (0% MPC) was used as a control. MPC particles were added to the secondary layer at 2.5% and 5% weight of total secondary layer, which correlated to 1.4, and 2.8 lb/1,000 ft 2 , respectively. The obtained DSF handsheets containing different levels of MPC particles were evaluated for porosity, opacity, tensile strength, and smoothness. [0042] (i) Porosity Property [0043] The porosity of the DSF sheets was measured using Gurley porosity, according to the TAPPI method T 460 om-96. Gurley porosity (in sec) measures the time required for air to permeate through the DSF sheet. An increase in Gurley porosity value indicates the reduction of air permeability through the sheet due to the decrease in sheet porosity. (TABLE I) [0000] TABLE I COMPOSIITON OF THE SECONDARY LAYER PROPERTIES MPC in the Apparent B.W. Gurley % % 2 nd layer Density Cal. (lbs/ Porosity Softwood MPC (lb/1,000 ft 2 ) (g/cm 3 ) (mil) MSF) (sec)  100% 0% 0 0.62 16.1 60 140 97.5% 2.5%   1.4 0.68 14.6 58 210   95% 5% 2.8 0.70 14.1 57 790 [0044] The DSF sheet containing 5% MPC particles in the secondary layer (2.8 lb/1,000 ft 2 ) showed more than 5 times reduction in board porosity, indicated by the increase of Gurley porosity from 140 sec for the DSF sheet containing no MPC particle to 790 sec for the sheet containing MPC particles at 2.8 lb/1,000 ft 2 . (TABLE I) [0045] When applied in the secondary layer of the DSF sheet, MPC particles filled the fiber voids and formed a very smooth layer on the treated sheet surface. ( FIG. 3 ) As a result, the MPC surface-modified board had an improved surface smoothness, higher opacity and brightness at lower coat weights compared to non-MPC modified board. [0046] (ii) Opacity Property [0047] For opacity property, the DSF handsheets containing different levels of MPC particles in the secondary layer were calendered at a pressure of 20 bars and a temperature of 125° F., followed by topcoating with a pigment coating formulation containing about 80% clay based on total solid weight. The pigment coating was applied to the board surface using wire-wound rods No. 5 and No. 12. The brightness of DSF sheet was measured using a Brightimeter Micro S-5 manufactured by the Technidyne Corporation. The DSF sheet having only a basecoat was used as a control. (TABLE II) [0000] TABLE II Coating Base Coat MPC Application (lb/1,000 ft 2 ) (lb/1,000 ft 2 ) Brightness #5 wire-wound 9 0 56 rod 7 1.4 58 4 2.8 58 #12 wire-wound 9 0 58 rod 8 1.4 61 6 2.8 66 [0048] When MPC particles were added to the secondary layer of DSF sheet, the brightness of the coated sheet increased compared to that of the control, even at the reduced coating level. When MPC particles were used in the secondary layer, MPC filled the surface voids of the softwood base layer, thus improving the coating performance. [0049] (iii) Tensile Strength Property [0050] The tensile properties of the DSF handsheets containing different levels of MPC particles in the secondary layer were tested in the MD and CD directions. [0051] The MD:CD ratio ranged from 2.4 to 3.0 with no apparent effect from the type of secondary layer applied. The modulus increased significantly when MPC particles were applied as secondary layer. The addition of 7.5% MPC particles in the secondary layer of the sheet increased modulus from 617 to 806 Kpsi (a 30% increase), indicating that the strength of sheet may be increased by an addition of MPC particles to the secondary layer of the sheet. (TABLE III) [0000] TABLE III % MPC in Load MD:CD Modulus Secondary Caliper MD CD Ratio MD CD Layer (mil) (lbf) (lbf) (%) Kpsi Kpsi 0 17.0 183 62 3.0 617 291 2.5 15.1 179 68 2.6 678 339 5.0 14.2 189 63 3.0 713 331 7.5 13.3 161 66 2.4 806 405 0 14.6 165 62 2.7 720 321 5.0 13.2 163 54 3.0 751 372 [0052] MPC may be blended with fiber pulps and added to the paperboard at the secondary headbox during a papermaking process. [0053] (i) Surface Analysis [0054] The SEM surface negative images and cross section negative images were taken for the paperboard having softwood base layer and the secondary layer containing wood pulps and MPC particles, in which MPC particles were added in a secondary headbox during the papermaking process ( FIGS. 4 and 5 ). The SEM images confirm that MPC particles filled the fiber-to-fiber voids on the paperboard surface by forming a semi-continuous film on the surface. The thickness of MPC film formed on the paperboard surface was about 2 um. [0055] (ii) Tensile Strength and Porosity [0056] The MPC-modified paperboard containing MPC particles about 1 lb/1,000 ft 2 had a 47% increase in tensile strength and a 33% increase in an elastic modulus compared to the paperboard containing no MPC particle. The porosity measurement showed about 10 times decrease in air permeability; from a Gurley porosity of only 4 sec/100 cc of air for the paperboard containing no MPC particle to about 42 sec/100 cc for the MPC-modified paperboard. [0057] Application of MPC at Different Positions of Papermaking Process [0058] MPC particles of the present disclosure may be applied to the paperboard at different stages in the wet end of papermaking process using several means of applications. They may be added in a secondary headbox of the papermaking process as a blend with hardwood fibers for the secondary layer or added solely (without hardwood fibers) to the softwood base layer. Furthermore, the disclosed MPC may be applied to the paperboard on the wet end or dry end of the papermaking process using typical paper coating equipments such as slot coating, curtain coater, and spray coating. [0059] The smoothness of the TiO 2 topcoated-MPC basecoat paperboard was determined using a Parker Print Smoothness (PPS-10) according to the TAPPI method T 555 pm-94, wherein the lower PPS-10 numbers represent the higher smoothness of board. The brightness of paperboard was measured using a Brightimeter Micro S-5 manufactured by the Technidyne Corporation, wherein the brightness of board increases relative to the brightness value. (Table IV). [0000] TABLE IV Yellowness Means for Smoothness Index MPC Addition Addition of MPC PPS-10 Brightness (b value) Secondary Blend with hardwood pulp 5.71 77.88 0.61 Headbox for the secondary layer (MPC added to (20% MPC) hardwood fiber Blend with hardwood pulp 5.77 78.01 0.51 in secondary for the secondary layer layer) (10% MPC) Control 7.92 72.31 2.02 Hardwood pulp for the secondary layer (0% MPC) Secondary Apply solely as a secondary layer 4.69 80.19 −0.35 Headbox at 1 lb/1,000 ft 2 Control (0% MPC) 10.96 65.45 3.65 Spray Coating Apply on the wet end to the base layer 5.53 81.07 −0.05 at 0.5 lb/1,000 ft 2 Control (0% MPC) 6.97 73.75 1.83 Slot Coating Apply on the wet end to the base layer 4.15 82.19 −0.30 at 1 lb/1,000 ft 2 Control (0% MPC) 7.37 74.75 1.01 [0060] FIG. 6 showed the relationship between the brightness and smoothness of board. Additionally, the brightness and smoothness of the TiO 2 topcoat, MPC-modified paperboard of the present disclosure were compared to those of unbleached softwood base paperboard and those of coated board produced by coating the commercial base paperboard from the Mahrt Mill, MeadWestvaco Corp. with a top coat pigment. [0061] The brightness property of the TiO 2 topcoat, MPC-modified paperboard was directly proportional to the smoothness of the board. This confirmed that MPC was retained as a thin film that filled fiber-to-fiber voids on the unbleached fiber surface of board, as shown in the SEM images FIG. 4 even when it was added on the wet end with backside vacuum and in highly dilute feed conditions. The disclosed MPC exhibited a film-forming property on the cellulosic surface without any need for formulation with binder or rheology control agent. On the other hand, the microfibers of the known arts must be formulated with other ingredients such as binder and rheology control agent into stable colloidal before the addition to the paperboard. Under severe hydrodynamic conditions inherent in the papermaking process, the colloidal cellulosic microfibers of known arts tend to drain through the web without forming a flat film on the surface. The film-forming ability of the disclosed MPC on the fiber web surface allowed the addition of MPC using the existing equipment for the papermaking process, thus minimizing capital cost especially for an additional drying capacity. [0062] The TiO 2 topcoated paperboard containing MPC of the present disclosure had higher opacity for hiding the unbleached brown board layer compared to the TiO 2 topcoated paperboard containing no MPC, as indicated by both brightness and yellowness optical values. These enhanced optical properties of the TiO 2 topcoated, MPC-modified paperboard was due to the smoothness improvement of board surface, as MPC filled the fiber voids and formed a thin film on the surface of fiber web base layer. Consequently, the amount of TiO 2 pigment required on the topcoat of paperboard to hide the unbleached brown fibers in the base layer, could be minimized when the disclosed MPC was present in the secondary layer of paperboard prior to the application of TiO 2 topcoat. [0063] Application of MPC Through Size Press vs Surface Coating [0064] MPC was produced by wet grinding a suspension of bleached hardwood using a high-friction grinder. The produced MPC had a nominal volume average particle size of about 50-80 microns and a water retention value of 25-40 ml/g dry fiber as determined by centrifuging a 50 ml of a 1.5% solution of MPC at a rotation speed of 3000 rpm for 15 min, using IEC CL2 Centrifuge with 50 ml swing out buckets with a radius of 150 mm that gave a relative centrifugal force of about 1500 g. [0065] A suspension of the produced MPC at 2.7% solid was formulated with starch (Penford Gum 280 commercially available from Penford Products Co.) and clay (Kaobrite 90 commercially available from Thiele Kaolin Co.) at different compositions as in TABLE V. [0066] For size press application, the formulations were applied to both sides of a 10 mil-bleached SBS paperboard using flooded nip size press having a 12 inch web at a speed of 200 ft/minute and a minimal press load of 35 psi. [0067] For surface coating application, the formulations were applied on one side of a 10 mil-bleached SBS paperboard using bent blade applicator at a speed of 900 ft/min. [0068] Coat weights were calculated from the known ratios of MPC to starch to clay and measured ash content of the paperboards less the uncoated board. (TABLE V) [0000] TABLE V Coat Weights lbs/3000 ft 2 Coat Weights lbs/3000 ft 2 Press Applied Two Sides Blade Coated One Side Formulation Total Solids, % MPC Starch Clay MPC Starch Clay Water Only MPC 1% 1 0.085 0.050 Starch 8% 8 0.487 Starch 8%, clay 8% 16 1.119 1.119 0.397 0.397 Starch 8%, MPC 1% 9 0.049 0.439 0.040 0.357 MPC 1%, clay 8% 9 0.101 0.812 0.025 0.198 MPC 2.5%/clay 2.5% coprocessed** 5 0.158 0.158 0.129 0.129 Starch 8%, clay 8%, MPC 1% 17 0.181 1.445 1.445 0.082 0.653 0.653 Starch 4%, clay 4%, MPC 1% 9 0.131 0.525 0.525 0.025 0.099 0.099 **cellulose and clay wet milled together [0069] The coated paperboards were calendered at two different pressures: 50 and 100 pli pressure. [0070] (i) Taber Stiffness [0000] TABLE VI Bending Stiffness Results Bending Stiffness Results Press Applied Blade Coated Taber Two Sides Taber One Side Formulation Total Solids, % MD CD GM MD CD GM Water Only 31 11 18 MPC 1% 1 37 11 20 34 17 24 Starch 8% 8 40 14 24 Starch 8%, clay 8% 16 43 14 25 36 14 22 Starch 8%, MPC 1% 9 42 13 23 35 14 22 MPC 1%, clay 8% 9 44 14 25 38 15 24 MPC 2.5%/clay 2.5% coproccssed** 5 38 12 21 37 12 21 Starch 8%, clay 8%, MPC 1% 17 45 16 27 39 18 26 Starch 4%, clay 4%, MPC 1% 9 45 14 25 42 18 27 **cellulose and clay wet milled together [0071] The coated paperboards without calendering were tested for Taber Stiffness as shown in TABLE VI. The Taber stiffness was determined using the geometric mean (GM) of MD and CD stiffness according to a TAPPI test method T 489 om-04, revised version 2004. GM is a geometric mean of MD and CD Taber stiffness, wherein GM=(MD×CD) 1/2 . [0072] The Taber stiffness of coated paperboards calendering at two different levels was evaluated and compared to those of uncalendered, coated boards. (TABLE VII) [0000] TABLE VII Calendered Sheets Calendered Sheets Uncalendered Press Applied Two Sides Uncalendered Blade Coated One Side Bending Stiffness: MD − CD Bending Stiffness: MD − CD Geometric Mean Geometric Mean Formulation 0 pli 50 pli 100 pli 0 pli 50 pli 100 pli Water Only 18 16 14 MPC 1% 20 24 16 15 Starch 8% 24 20 18 Starch 8%, clay 8% 25 19 18 22 18 17 Starch 8%, MPC 1% 23 20 19 22 17 14 MPC 1%, clay 8% 25 20 16 24 18 16 MPC 2.5%/clay 2.5% coprocessed* 21 18 17 21 19 14 Starch 8%, clay 8%, MPC 1% 27 21 20 26 20 19 Starch 4%, clay 4%, MPC 1% 25 22 19 27 18 18 [0073] (ii) Surface Smoothness [0074] Using a TAPPI test method T 538 om-01 (revised version 2001), the Sheffield surface smoothness of the calendered, coated paperboards was determined and compared to those of uncalendered, uncoated paperboards. (TABLE VIII) [0000] TABLE VIII Calendered Sheets Calendered Sheets Uncalendered Press Applied Two Sides Uncalendered Blade Coated One Side Sheffield Smoothness Sheffield Smoothness Formulation 0 pli 50 pli 100 pli 0 pli 50 pli 100 pli Water Only 400 157 108 MPC 1% 410 400 135 122 Starch 8% 410 172 110 Starch 8%, clay 8% 410 217 157 410 162 98 Starch 8%, MPC 1% 400 178 128 400 138 98 MPC 1%, clay 8% 380 173 122 420 143 103 MPC 2.5%/clay 2.5% coprocessed* 400 178 138 400 148 110 Starch 8%, clay 8%, MPC 1% 410 205 150 395 150 100 Starch 4%, clay 4%, MPC 1% 400 197 148 400 150 108 [0075] FIG. 7 showed a relationship between Taber stiffness and Sheffield surface smoothness of the paperboards having different sizing formulations applied at size process, without calendering and with calendering at 50 and 100 pli pressures. [0076] When the coated paperboards were calendered, its surface smoothness improved while its bending stiffness deteriorated. The higher pressure level the board was calendered, the higher surface smoothness as indicated by a lower Sheffield Smoothness value, but the lower the bending stiffness property as indicated by a lower Taber Stiffness value. [0000] TABLE IX Taber Stiffness % Increase in for the Calendered Taber Stiffness Surface Sizing Board having a Sheffield Compared to Board Formulation Smoothness of 100 Sized With Water Only Water Only 13.10 — 8% Starch 17.14 31% 8% Starch, 8% Clay 16.91 29% 1% MPC, 8% 20.00 53% Starch, 8% Clay [0077] TABLE IX showed the Taber stiffness of paperboards having both surfaces sized with different formulations, after they were calendered to the same Sheffield Smoothness value of 100. The board surface sized with a formulation containing 1% MPC, 8% starch and 8% clay showed a Taber stiffness value of about 20, which was about a 53% increase from the Taber stiffness of paperboard without surface sizing (i.e., sized with water only) having a Taber stiffness of about 13.10. For paperboards surface sized with starch or a combination of starch with clay, their Taber stiffness improved compared to the paperboard without surface sizing) but the enhancement was only about 30%. [0078] FIG. 8 showed a relationship between Taber stiffness and Sheffield surface smoothness of the paperboards blade-coated with different coating formulations without calendering and with calendering at 50 and 100 pli pressure. [0000] TABLE X Taber Stiffness % Increase in Taber for the Calendered Stiffness Compared to Blade Coating Board having a Sheffield Board Coated Formulation Smoothness of 100 With Water Only Water Only 13.10 — 8% Starch, 8% Clay 17.46 34% 1% MPC, 8% Starch, 19.46 50% 8% Clay [0079] TABLE X showed the Taber stiffness of paperboards having one of the surfaces blade-coated with different formulations after being calendered to the same Sheffield Smoothness value of 100. The board blade-coated with a formulation containing 1% MPC, 8% starch and 8% clay showed a Taber stiff ness value of about 20, which was about a 50% increase from the Taber stiffness of paperboard blade-coated with only water having a Taber stiffness of about 13.10. For paperboards blade-coated with a formulation containing 8% starch and 8% clay, its Taber stiffness improved compared to the paperboard blade-coated with only water but the enhancement was only about 34%. [0080] When paperboard is applied with a formulation containing the disclosed MPC either as a surface sizing agent or a coating, calendering may be performed to enhance surface smoothness of the treated paperboard with a significant reduction of a negative impact on bending stiffness performance. [0081] It is to be understood that the foregoing description relates to embodiments that are exemplary and explanatory only and are not restrictive of the invention. Any changes and modifications may be made therein as will be apparent to those skilled in the art. Such variations are to be considered within the scope of the invention as defined in the following claims.

A paperboard containing microplatelet cellulose particles has improved surface smoothness, aesthetic properties, bending stiffness and strength performance. When microplatelet cellulose particles are used for surface treatment of the paperboard, the microplatelets fill voids between fibers on the board surface. As a result, treated board has enhanced strength and surface properties such as smoothness, opacity, coating hold-out, and printability without compromising bending stiffness. Furthermore, the present disclosure relates to a process for improving board strength, surface smoothness and/or bending stiffness without the needs for densification, while maintaining other desired performances.

BACKGROUND OF THE INVENTION The present invention relates to windows or doors having a fixed frame consisting of two frame-like parts which have a gap between them and are connected together by dowels, and having sealing and locking strips which are displaceably mounted in the gap in the fixed frame, which strips are guided by guide slots and guide dowels and are each insertable in a groove in the window-sash or door. In a known window of this kind, the fixed frame consists of two frame-like parts which are connected tightly together by screws near their outer edges and whose facing surfaces flex backwards in such a way that there is formed between them a gap which is open at one side. In this gap sealing and locking strips which are guided by special guide members are arranged to be displaceable. As a result, the construction of the known window is relatively complicated. In addition, the fact that the two frame-parts are secured at only one edge is a disadvantage, particularly because it means that it is precisely at the inside of the fixed frame, where it cooperates with the window-sash or door, that there is no hold. By contrast, it is an object of the invention to provide a window or door of the kind described in which while the frame-parts are of simple design and easy to connect, the sealing and locking strips are properly guided and are steady and secure. SUMMARY OF THE INVENTION To achieve this and other objects, the window or door is characterized in accordance with the invention in that the strips contain the guide slots and the dowels are arranged to act as guide dowels and hold the parts at a distance from one another. Advantageously, at least one of the frame-like parts is in the form of a hollow member of U-section which is open on the side remote from the strips, the member having a cover to close off the cavity in the U-section and the cavity having the actuating means for the strips arranged in it. In a refinement, elongated holes extending perpendicularly to the guide-slots are arranged in the strips, and pins, cams or the like arranged on actuators project through these holes. In a refinement, strips associated with adjoining sashes or doors are arranged in the gap between the two frame-like parts, these strips being displaceable in opposite directions. It is also possible to arrange distance pieces and/or seals, which project from the fixed frame on the side remote from the sash or door, in the gap between the two frame-like parts. In a further advantageous embodiment, abutments against which a spring connected to the strip bears, are arranged in the gap between the two frame-like parts at a distance from the side. BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the accompanying drawings which show some embodiments thereof by way of example as applied to windows and in which: FIG. 1 is a plan view of a first embodiment of window having a fixed frame and a sash with parts broken away, FIG. 2 is a section through the window of FIG. 1, FIG. 3 is a sectional view of a second embodiment of fixed frame and sash, FIG. 4 is a sectional view of a third embodiment of fixed frame and sash FIG. 5 is a sectional view of a fourth embodiment of fixed frame and sash, in the case of a pivoting-sash window, FIGS. 6 to 8, show various embodiments of displaceable strip and the grooves in the sash associated with them, FIG. 9 is a sectional view of a fifth embodiment of fixed frame and sash, FIG. 10 shows sealing and locking means for two sashes, arranged in a common corner piece, FIG. 11 shows another embodiment of sealing and locking means which act in two directions, FIG. 12 shows the arrangement of FIG. 11 rotated through 90°, FIG. 13 shows a further embodiment of means acting at an angle in two directions, FIG. 14 shows a spring-mounted sealing and locking arrangement, FIG. 15 shows the arrangement of FIG. 14 rotated through 90°, FIG. 16 shows a rail of a pivoting sash window provided with a tongue, FIG. 17 is a section on II--II of a sash of the pivoting sash window of FIG. 16, FIG. 18 is a plan view of another embodiment of sash for a pivoting sash window, FIG. 19 is a section on IV--IV of the sash of FIG. 18, FIG. 20 is a side-view of the sash of FIG. 18, FIG. 21 shows a rail of a pivoting sash window made up of U-channels inserted into one another, FIG. 22 is a longitudinal section through a window, FIG. 23 is a cross-section through a window having a roller blind and built-in air-blowers, FIG. 24 is a front-view of the window of FIG. 23, FIG. 25 shows a window-unit having arrangements for the entry and exit of ventilating air, FIG. 26 is a cross-section of another embodidiment of window, FIG. 27 is a front view of the window of FIG. 26, FIG. 28 shows an arrangement for ventilating an enclosure fitted with a window according to the invention, FIG. 29 is a front view of a curtained window, and FIG. 30 is a front view of another embodiment of window with a curtain. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings the window shown in FIGS. 1 and 2 has a fixed frame 1, and a sash 2 which is rotatably mounted in the fixed frame 1 to form a pivoting sash. The sash 2 supports the glazing 3, which is in the form of multiple panes. In accordance with the invention, the fixed frame 1 consists of two frame-like parts, an outer frame part 4 and an inner frame part 5, which are firmly connected together by dowels or sparers 6 in such a way that a gap or slot 7 is formed between the two parts. A strip 8 is displaceably mounted in the gap 7 formed in each rail of the frame and this strip 8 can be inserted in a groove 9 allotted to it in the sash in order to lock the sash and the fixed frame together and to seal them. The unlocked position is shown at the top of FIG. 2 and the locked position at the bottom. Each of the strips 8 contains guide-slots 10 extending in the direction of displacement which are open towards the outer edge of the strip and which engage with associated dowel 6. This arrangement means that when being moved forward into the sash the strips cannot go off course transversely to the direction of movement. Part 4 of the fixed frame is in the form of a hollow member and can be used to circulate air. Inner frame part 5 of the fixed frame is in the form of a hollow member of U-section and forms a channel opening at the side of such frame part remote from the outer frame part 4 and remote from the strip 8. The open side of the U-section can be closed off by a cover 11. The actuating means for the strips 8 are arranged in this part of the frame. The actuating means consist of a plurality of disc cranks 13 which are connected together by an actuating chain 12 and whose pins 14 engage in respective elongated holes 15 associated with them in the strip, the elongated holes 15 extending perpendicularly to the guide slots 10. At the edges where they make contact, the strips 8 are advantageously mitred so that when they have been moved forward into the sash they are supported against one another and form a closed frame. Also those edges of the strips which lie adjacent a pivot shaft 16 may be similarly bevelled, as shown on the right hand side of FIG. 1. In the embodiment of FIG. 3, the lower part of a fitted window is shown with a sealing and locking arrangement according to the invention. In this case the sash 2 carries sound insulating multiple glazing which is formed by three spaced panes of glass, with the outer pane 17 projecting from the sash 2 and resting against the fixed frame 1 when the window is closed. In this embodiment also the fixed frame has a part 5 in which the actuating means for the locking strip 8 are arranged. In the gap 7 which the dowels 6 form between the two parts of the frame, an additional distance and sealing piece 18 is arranged, which piece projects from the fixed frame on the side remote from the sash and can be cut to size when the fixed frame is being set in position in order to compensate for differences between the fixed frame and the opening in the wall. In the embodiment in FIG. 4, one 5 of the frame parts is once again in the form of a U-member while the other frame part 19 is in the form of an angle frame. In the embodiment shown in FIG. 5, which shows a pivoting-sash window, sealing fillets 20 and 21 are provided at both edges between the sash 2 and the frame 1. FIGS. 6 to 8 show various embodiments of the strip 8 and of the groove 9 associated with it in the sash. In FIG. 6, the outer edge 22 of the strip is of a pointed roof-like shape while in FIG. 7 it is outwardly cambered. It is advantageous for a seal 23 to be provided in the groove 9. In FIG. 8, there is in the groove 9 a resilient insert 24 which provides more resilient and easier guidance for the strip 8 as it enters the groove 9 in the sash 2. In the embodiment of FIG. 9, two locking strips 8 and 25 are arranged parallel to one another and engage in corresponding grooves 9 and 26 in a sash 2 carrying multiple glazing. In this case the fixed frame 1 consists of three parts 27, 28 and 29 and there are once again connected together by dowels 6 in such a way that gaps are left between the individual parts in which the strips 8 and 25 are displaceable and into which a compensating piece 30 and a resilient seal 31 project on the side remote from the sash 2. Part 29 of the fixed frame 1 is in the form of a hollow channel containing air outlet openings 32 and is used for ventilation. Part 27 of the fixed frame 1, which is U-shaped and is closed off by a cover 33, contains the actuating arrangements for the strips 8 and 25, these being operated by means of a common actuating shaft 34. In FIG. 10, one of the parts of the fixed frame 1 is formed as a corner member 4a and two parts 5a and 5b arranged at an angle are connected to it by means of dowels 6. In the gap 7 between parts 4a and 5a, and 5a and 5b, strips 8 which can be inserted in associated grooves 9 in the appropriate sash 2 are displaceably mounted. In the embodiment shown in FIGS. 11 and 12, two strips 8a and 8b which can be displaced in opposite directions are arranged in the gap 7 between parts 4 and 5 and these strips can be displaced outwards by a cam 14a connected to an actuator 13a and are connected together by a return spring 35. During their displacement, the strips are guided by elongated holes 10a which fit over the spacers 6. The embodiment in FIG. 13 differs from that in FIG. 10 in that the outer parts 4a and 4b are held together by an angled connector 36. In FIGS. 14 and 15, an abutment 37 is mounted in the gap 7 at a distance from the strip 8 and bearing against it are springs 38 whose other ends project into recesses 39 in the strip, thus spring loading the strip into the inserted position. To enable the strips to slide more easily in the groove 9 in the sash 2, slide pieces 40 are arranged on either side of groove 9. The sash shown in FIGS. 16 and 17 consists of rails 41 and 42 and of rails 43 and 44 extending perpendicularly thereto. The rails 41 and 42 carry tongues 45 which hold the pivot shafts of the sash. The rails 41 and 42 are reinforced on either side of the tongues 45 by strips of sheet-metal 46 and 47. By means of this reinforcement the loads acting on the tongues 45 are spread to the rails 41 and 42 of the frame. Also, reinforcing strips 49 are arranged in rails 41 and 42 parallel to and at a distance from the reinforcing strips 46 and 47 arranged on either side of the tongues 46. By this means it is possible for the rails 43 and 44 to be relatively weak. In the embodiment of FIGS. 16 and 17 the frame rails carry multiple glazing 48. In the embodiment shown in FIGS. 18 to 20, the rails 41 and 42 are once again reinforced by load-spreading strips 46a and 46b on one side and 47a and 47b on the other. In this embodiment the strips 46a and 47a are longer than the adjacent strips 46b and 47b which are connected to them and lie on top of them. In addition, reinforcing strips 50 lying transversely to the plane of the glazing are arranged in rails 41 and 42. In the embodiment of FIG. 21, the rails carrying the tongues 45 are formed from two U-channels 51 and 52 which are fitted into one another with their mutually parallel sides 53 acting as strengthening. In this embodiment also, the rails 43 and 44 extending perpendicularly to the rails 41 and 42 may be of very light construction since they perform no load-bearing function. The window in FIG. 22 has an outer frame part 101 and an inner frame part 102 at a distance therefrom. The two frame parts are held together by spacers 103 which form point connections between the frame parts 101 and 102 at a small number of places and which may consist of a plastics material or the like which is a poor conductor of heat. Each frame part 101 and 102 may have single or multiple glazing. The outer frame part 101 is formed as a hollow body, so that, as indicated by arrow 104, air from outside can flow upwards or vice versa inside the rails of part 101. At the upper end of the outer frame part 101 there are arranged, in accordance with the invention, one or more air circulation ducts 105 which project above the inner frame part 102 into the interior of a room or similar enclosure so that air can emerge from their ends, as indicated by arrow 106. In the embodiment of FIGS. 23 and 24, air is drawn in from the external atmosphere by a blower 107 and is pumped upwards through the cavity in the outer frame part 101. At the upper end of the outer frame part 101 are situated air circulation ducts 108, which extend past the sides of a casing 109 for a roller blind which is arranged above the window, and across the ceiling of the room into its interior. In the embodiment of FIG. 25, a plurality of windows 110, 111 and 112 is combined to form a window unit, with the outer frame parts once again being formed as hollow bodies. In this case too, air is pumped into the interior of the outer frame parts 101 by blowers 107 and it then flows upwards to emerge into the interior above the inner frame parts via air circulation ducts 105. In addition, a proportion of the stream of air flows through an air inlet duct 113 arranged underneath window 111 and from this duct air can reach the interior along the skirting through air outlet openings 114. Depending upon the setting of the blower, it is of course also possible to cause the flow of air to take place in the opposite direction so that air is pumped out of the room or the like into the surrounding atmosphere. In the case of the embodiment shown in FIGS. 26 and 27, there is once again provided an outer frame part 111 with an air circulation cavity and an air circulation duct 105, the outer frame part 111 being arranged at a distance from the inner frame part 102. Underneath the window is situated a blower 107 which draws in outside air and feeds it into the interior via the outer frame part 101 and the air circulation duct 105. Underneath the air circulation duct 105 is provided a support 115 for a curtain 106. Also arranged in the underside of the air circulation duct 105, between the inner frame part 102 and the curtain support 115, are air inlet openings 117 through which air rising from a radiator 118 for example can make its way into the air circulation duct 105. The flow of air which is being fed through the outer frame part 101 into the air circulation duct 105 carries this warm air with it and expells it at an accelerated rate. Underneath the blower 107 is provided a changeover device 119 which enables either external air or warm air coming directly from the radiator 118 to be fed to the blower 107, as selected. In this way it is possible to feed only warm air into the room for heating purposes or else to feed in a mixture of fresh air and warm air from inside. The embodiment shown in FIG. 28 can be used simultanenously to introduce air into an enclosure and extract it therefrom. In this case fresh air is introduced into the interior of an enclosure by a blower 107 through the outer frame part 101, of a door for example, and through air circulation ducts 105. For extraction, the used air flows over the top of the curtain 116 through the air circulation duct 105 and downwards through the air circulation cavity in the outer frame part 101 and from there into the surrounding atmosphere. FIGS. 29 and 30 show embodiments with curtains hung in front of them. In FIG., 29 air emerges into the interior of the room above the curtain through a wide outlet 120 which is closed off by a grille and there is a further air outlet underneath the curtain in a skirting panel 121. In the embodiment shown in FIG. 30, the openings of a plurality of air circulation ducts 105 can be seen spaced above the curtain support 115, while below the curtain a plurality of spaced air outlet openings 22 are provided above the floor.

This invention relates to closure systems of the kind comprising a closure member such as a window or door movable within a fixed frame consisting of two frame-like parts which have a gap between them and are connected together by connector members such as dowels or spacers, and comprising sealing and locking strips which are displaceably mounted in said gap in said fixed frame, said strips being guided by guide slots and guide connector members and each being insertable in a guide groove in the closure member. According to the invention, said strips contain said guide slots and said connector members are arranged to act as guide connector members to hold said parts at a distance from one another.

FIELD OF THE INVENTION [0001] The present invention generally relates to cooking ovens and, more particularly, to an improved cooking oven designed to operate at elevated pressures and temperatures. BACKGROUND [0002] The process of cooking of food generally involves raising the internal temperature of the food to a specified level. The higher the internal temperature is raised, the more “cooked” the food is. For example, raw meat at room (ambient) temperature starts off at approximately 70 degrees F. As the meat is heated the temperature of the meat rises. While temperatures vary depending on the type of meat, the consistency and the thickness, generally speaking, for rare meat, the internal temperature (temperature near the center) is approximately 120 to 130 degrees F. Meat in its medium state has an internal temperature of about 140 to 150 degrees F. Meat is deemed well done when the internal temperature is about 160° F. or more degrees F. [0003] There are a variety of conventional methods for cooking foods, such as on top of a flame (grilling, pan frying) and in an oven (e.g., baking, broiling). In all methods, the same concept of raising the temperature of the product is the ultimate goal. How that is accomplished affects the taste and time involved in the cooking process. [0004] There are three primary forms of heat transfer that occur in a cooking process. Conduction is direct heat flow through matter, such as the conduction of heat from the hot surface of a stove to a cooking pot, or from the surface of the food into the center of the food. More particularly, conduction is heat transfer by means of molecular agitation within a material (i.e., the vibration of the material's atoms) without any motion of the material as a whole. As such, the higher vibrating atoms transfer their increased energy to less energetic neighboring atoms. The result is no net motion of the solid as the energy propagates through the material. For example, if one end of a metal rod is heated to a higher temperature than the other end, energy will be transferred down the rod toward the colder end because the higher speed particles will collide with the slower ones with a net transfer of energy to the slower ones. For heat transfer between two surfaces, the rate of conduction heat transfer is: [0000] Q t = κ   A  ( T hot - T cold ) d Equation   1 Where: [0005] Q=heat transferred in time [0006] κ=thermal conductivity of the barrier [0007] A=area [0008] T=temperature [0009] d=thickness of barrier. [0010] Gases transfer heat by direct collisions between molecules and, as would be expected, the thermal conductivity of a gas is low compared to most solids. [0011] Convection is heat transfer by the motion of a heated fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it. The heat travels upward with the natural upward movement of air. Convection above a hot surface occurs because the surface heats the air adjacent to it. As the air heats up, it expands becoming less dense, and rising. [0012] Convection can also lead to circulation of a fluid. For example, as a pot of water is heated over a flame, the heated water expands and becomes more buoyant. Cooler, more dense water near the surface descends and patterns of circulation form. By controlling the circulation of the heated fluid it is possible to maximize heating or cooling of a particular location. In an oven, by controlling the flow of heated air, it is possible to maximize the heating of an item within the oven. [0013] Radiation is the third form of heat transfer and is the transmission of electromagnetic rays through space. These rays have no temperature, only energy. Every material or object with a temperature above absolute zero emits these rays. [0014] In a conventional oven the food is located spaced apart from the heat source. Air separates the food from the heat source. As such the heating process in a conventional oven involves radiation (from the heating source to the food), conduction (from the surface of the food toward the center of the food), and to a lesser degree convection (due to the naturally occurring heat flow in the oven.) [0015] A convection oven operates in a slightly different manner than a conventional oven. In a convection oven, a fan mounted within the oven produces circulation of the heated air within the oven. The fan circulates the air rapidly through the cooking chamber. This circulation of air has two principal effects. First, it causes the temperatures throughout the oven to be almost exactly equal. In a conventional oven, differences in temperature typically occur that can lead to uneven cooking and could require that the food be placed in specific areas within the oven to make sure that the food cooks properly. Convention ovens eliminate this problem. Second, a convection oven transfers heat more evenly to the food. The movement of the hot air past the food prevents regions of colder air from building up near the surfaces of cool foods. As such, the food in a convection oven heats and cooks faster. [0016] Also, since the heated air is forced past the food, a convection oven can operate at a lower temperature than a standard conventional oven and still cook food more quickly. Generally, with a convection oven there will be about a 25% reduction in cooking temperature and a 20% reduction in cooking time, compared to a conventional oven. [0017] There also tends to be less shrinkage with a convection oven, and, because the heat is forced to circulate in the oven, a convection oven can be filled as long as about an inch of space is left for the air to circulate between the food and the oven walls. [0018] In recent years, microwave ovens have become commonplace in the household. A microwave oven uses microwaves to heat food. Microwaves are radio waves. In the case of microwave ovens, the commonly used radio wave frequency is roughly 2,500 megahertz (2.5 gigahertz). Radio waves in this frequency range have an interesting property: they are absorbed by water, fats and sugars. When they are absorbed they are converted directly into atomic motion—heat. Microwaves in this frequency range have another interesting property: they are not absorbed by most plastics, glass or ceramics. [0019] In a conventional oven, the heat migrates (by conduction) from the outside of the food toward the middle. You also have dry, hot air on the outside of the food evaporating moisture on the surface of the food. As such, the surface dries out, becoming crispy and brown, while the inside stays moist. [0020] In microwave cooking, the radio waves penetrate the food and excite water and fat molecules pretty much more evenly throughout the food. No heat conduction toward the interior occurs. There is heat everywhere all at once because the molecules are all excited together. However, there are drawbacks to microwave cooking. The radio waves penetrate unevenly in thick pieces of food and, as such, they don't make it all the way to the middle, and “hot spots” can be caused by wave interference. [0021] Another method of cooking involves the use of a pressure cooker. These are pots for cooking food that are designed to maintain a pressure above atmospheric pressure. They consist of an enclosed pot that is placed on top of a stove file. Water in an open pot boils at 212 degrees F. at a standard atmosphere. No matter how long you continue to boil the water, it will stay at the same temperature. As the water evaporates and becomes steam it is also the same temperature, 212 degrees F. The only way to make the steam hotter (and/or to boil the water at a higher temperature) is to increase the pressure. This is what a pressure cooker does. The heat from the stovetop transfers through the metal pot to the contents (which generally include water and the items being cooked.) Since the pressure cooker is sealed, as the water inside the container expands to steam, the closed environment of the container causes the pressure inside the container to rise. The higher pressure, in turn, results in a higher temperature inside the vessel. [0022] The laws of physics hold that, as long as pressure is uniform on all surfaces of an object, the object will not distort. In a pressure cooker, the pressure is effective throughout the food, from the surface through to the center. Thus, the increased pressure will not crush the food in the cooker. [0023] At 15 psi, the temperature that water boils is about 250 degrees F., instead of 212 degrees F. The increased pressure inside the pot delays the water and/or other liquids inside the pot from boiling until the liquid reaches a much higher temperature. As a result, the cooking process is sped up considerably. [0024] Air is a poor conductor of heat; but water is a good conductor. Steam, due to its water content, has approximately six times the heat potential than dry air when it condenses on a cooler food product. This increased heat transfer potential makes steam a much more effective cooking medium. Steam is efficient in transferring cooking heat rapidly to foods upon contact without burning or damaging the final product, and for less energy. [0025] Generally, pressure cookers generate pressures from 5 to 15 psi. The main drawback to a pressure cooker is that the temperature inside the pressure cooker is limited to the boiling point of the water (i.e., 250 degrees F. at 15 psi). As such, the speed of cooking is also limited to this temperature. Table 1 lists the temperatures inside a pressure for various pressures. [0000] TABLE 1 Pressure Inside Cooking Temperature The Pressure Cooker 212° F. (100° C.)  0 psi 220° F. (104° C.)  5 psi 235° F. (113° C.) 10 psi 250° F. (121° C.) 15 psi [0026] As meat cooks, the muscle fibers shorten in both length and width. As a result, the juices in the meat are eventually squeezed out. Thus, the longer a food cooks the drier it becomes. [0027] For cooking purposes, meat consists of lean tissue, proteins, collagen and 75% water. Collagen exists in flesh, bone and connective tissue, and is very important to the cook because the amount of collagen in a piece of meat will determine the length of time it should be cooked. Therefore, the higher the level of connective tissue, the longer the meat will need to be cooked. Weight-bearing muscles and muscles that are constantly used contain higher amounts of collagen than muscles that aren't used for support or aren't used as frequently. [0028] A number of different things happen as a food cooks, especially meats and poultry. At about 104 degrees F., the proteins in meat start to denature. At about 122 degrees F., the collagen begins to contract. At about 131 degrees F., the collagen starts to soften. At about 160 degrees F., the meat no longer holds oxygen and turns gray. Finally, at about 212 degrees F., the water in the meat begins to evaporate into steam, drying out the meat. [0029] A turkey is considered cooked when the temperature inside the thickest part of the turkey is approximately 185 degrees F. Table 2 lists the approximate cooking times for a turkey at 325 degrees F. [0000] TABLE 2 Cooking times for a turkey at 325 degrees F. Weight Unstuffed Stuffed  8 to 10 pounds 2¾-3 hours 3-3½ hours 12 to 14 pounds 3-3¾ hours 3½-4 hours 14 to 18 pounds 3¾-4¼ hours 4-4¼ hours 18 to 20 pounds 4¼-4½ hours 4¼-4¾ hours 20 to 24 pounds 4½-5 hours 4¾- 5¼ hours [0030] As is evident from Table 2, the time to cook a turkey is significant. To date, no method has been introduced to speed the process along. Pressurized cooking has not been a viable option given the small size of the pot and the limited cooking temperature. [0031] A need exists for an improved oven for cooking food products. SUMMARY OF THE INVENTION [0032] The present invention relates to a pressurized oven system that includes an oven enclosure having front, back, top, bottom and side walls. A door is hingedly attached to one of the walls for sealing an opening in the walls. A heating system is connected to the enclosure for generating heat in the enclosure. The heating system may be a gas or electric heating system configured to heat the interior of the oven enclosure. [0033] A pressure source is connected to the enclosure for supplying a pressurized fluid into the enclosure in order to create an atmosphere inside the enclosure that is above atmospheric pressure. [0034] The oven system also includes a control system with at least one pressure sensor and at least one temperature sensor for monitoring and controlling the temperature and pressure within the enclosure. [0035] The pressure source may be an external gas supply for supplying pressurized air into the oven, preferably between about 0 and about 25 psi. [0036] The oven system may also include a liquid conduit for channeling a liquid into the enclosure to increase the moisture content within the enclosure during cooking. [0037] In one embodiment, the system includes an enclosure connected to the oven for generating a gaseous smoke for feeding into the oven enclosure. [0038] A process is also disclosed for cooking a food item in an oven. The process involves generating heat within the oven; creating pressure within the oven enclosure above atmospheric pressure during at least a portion of the cooking process; maintaining the pressure within the oven enclosure during at least a portion of the heating process; and controlling the heating and pressure during the cooking process. [0039] The process optionally involves creating a moist environment within the oven enclosure, such as by supplying a liquid into the enclosure. The process may also optionally include the step of creating an acidic environment within the oven enclosure, such as with the supply of a smoke and carbon dioxide. [0040] The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS [0041] For the purpose of illustrating the invention, the drawings show forms of the invention which are presently preferred; it being understood, however, that the invention is not limited to the precise arrangement and instrumentality shown. [0042] FIG. 1 is an isometric view taken from the rear of an oven assembly according to one embodiment of the invention. [0043] FIG. 2 is an isometric view taken from the front of the oven assembly of FIG. 1 . [0044] FIG. 3 is a rear view of the oven assembly of FIG. 1 . [0045] FIG. 4 is a side view of the oven assembly of FIG. 1 . [0046] FIG. 5 is a front view of the oven assembly of FIG. 1 . [0047] FIG. 6 is a top view of the oven assembly of FIG. 1 . [0048] FIG. 7 is an isometric view taken from the front of an oven according to a second embodiment of the invention. [0049] FIG. 8 is a front view of the oven of FIG. 7 . [0050] FIGS. 9A-9D illustrate another embodiment of a door for use in the present invention in various stages of closing. [0051] FIGS. 10A-10D illustrate side views of the door of FIGS. 9A-9D in the various stages of closing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0052] Referring to the figures wherein like reference numerals illustrate similar components, two embodiments of the invention are shown that are presently preferred. It would be readily apparent to those skilled in the art that a variety of modifications are possible within the scope of the present invention. The present invention is directed toward an improved cooking apparatus and associated method or process for cooking food stuffs. More particularly, the present invention, in one configuration, is directed to a pressurized oven 10 . [0053] FIG. 1 illustrates an isometric view of one embodiment of the oven 10 according to invention. The oven 10 generally includes a multisided, preferably five sided, walled oven enclosure 12 with an opening 14 . A door 16 is provided that is designed to close off the opening 14 . As will be discussed in more detail below, the door 16 is designed to seal the opening so as to prevent or inhibit heat and gases from passing out of the opening 14 when the door 16 is open. It should be readily apparent that the enclosure may be made so as to have any convenient shape and preferably includes an outer cabinet (not shown for simplicity of discussion.) [0054] The oven enclosure 12 is preferably made from conventional materials, such as steel, and configured to withstand pressures in excess of ambient. More preferably, the oven enclosure walls 12 are designed to withstand pressures greater than 5 psi and more preferably greater than 20 psi. The present invention contemplates that the oven will be subjected to internal pressures ranging between 0 psi and 20 psi during most cooking cycles, but the present invention is not limited to those pressures and, depending on the food it is designed to be used to cook, can be constructed so as to withstand pressures higher that 20 psi during use. The walls of the oven enclosure 12 are, thus, preferably designed to withstand the likely highest pressures that the particular oven is intended to be used for. Suitable walls may be constructed, for example, through the use of steel plates reinforced by an enclosure support frame. [0055] In one embodiment, the oven enclosure 12 is mounted to a frame 18 designed to support the oven enclosure 12 . In the illustrated embodiment of FIG. 1 , the frame 18 maintains the oven enclosure 12 at a suitable height off the floor so as to position the opening 14 at an appropriate height for use. As will be discussed in more detail below, various pieces of equipment may be located beneath the enclosure or, if desired, placed above or behind the enclosure 12 . Although the embodiment of FIGS. 1-6 position the oven off the floor, it is also contemplated that that oven enclosure 12 may be mountable to a pre-existing frame, such as in a wall of a home, or may be configured to sit on a countertop. [0056] A seal 20 is located between the door 16 and the edge of the enclosure 12 that surrounds the opening 14 . The seal 20 is preferably designed to be substantially air tight so as to prevent or minimize pressure loss from the oven when the door 16 is closed and the oven is operational. In addition, the seal 20 should tolerate the anticipated temperatures. The seal 20 may be mounted to the door 18 or the enclosure 12 . The seal may be pressurized to a higher pressure than the pressures anticipated inside the oven. [0057] The door 16 may include a window 19 , such as tempered glass, so as to permit the user to view the food item during the cooking process. A light (not shown) may also be mounted so as to provide illumination of the food item during cooking. [0058] A pressure source 22 is connected to the oven enclosure 12 . Preferably the pressure source 22 is mounted to the frame 18 , although it is also anticipated that the pressure source can be external from the oven 10 and connected through suitable conduits. In one exemplary embodiment, the pressure source 22 is a high pressure air or gas compressor capable of supplying pressurized air between 0 and 25 psi. One or more gas supply conduits 24 connect the pressure source 22 to the oven enclosure 12 . In the illustrated embodiment of FIGS. 2 and 3 , the gas supply conduit 24 connects to the side of the enclosure 12 at a location near the top. This location permits the pressurized air to flow into oven enclosure 12 and circulate around the enclosure. Other mounting locations are also envisioned. For example, the gas supply conduit 24 could be mounted to the bottom or top and a deflector or baffle could be positioned adjacent to the conduit end so as to deflect the incoming pressurized gas in a preferred or desirable direction. Generally, the design should refrain from channeling the gas directly toward the area where the food is placed. If more than one gas supply conduit is used, they may be located on opposite sides of the enclosure 12 . [0059] A pressure sensor 26 is mounted within the enclosure 12 and connected to a pressure gauge 28 mounted on the enclosure 12 or the frame 18 . The pressure sensor 26 monitors the pressure within the enclosure 12 and provides a reading on the pressure gauge 28 . The pressure gauge may be analog or digital. [0060] The oven includes a heating system 30 . Any conventional heating system, such a an electric or gas heater, may be used. In one embodiment, the heating system 30 is an electric heating system that includes one or more electric burners or heating coils or rods 32 mounted within the enclosure 12 . Preferably the electric coils are positioned along the bottom with a suitable deflector or mesh screen (not shown). In an electric heating system, the oven would preferably include an electric supply (not shown) for connecting to an electric power source. A control system would control the flow of the electric power to the coil. In one embodiment of the invention, the oven includes eight 1000 Watt heating rods and two 1500 Watt heating rods. To efficiently control the heat generation in the oven, the bottom may be insulated, such as with a ceramic sheets, thermal insulation or fiber board. [0061] In an alternative embodiment, the heating system can be a gas heating system that includes gas burners positioned along the bottom of the enclosure and a deflector for providing more efficient heat distribution, similar to conventional oven arrangements. A gas heating conduit would be used to supply natural gas from a natural gas source. An ignition system, such as a pilot light or electric igniter, would be incorporated for igniting the natural gas, as is common in the art. [0062] In addition to, or as an alternate for, the gas or electric heating systems, the present invention may include a radiant heating system. Radiant heaters are generally known, and can be incorporated into the heating system so as to provide a mechanism for crisping the external surface of the food product being cooked. [0063] A smoker assembly 34 may be incorporated into the system to provide optional flavor enhancement during cooking. In the illustrated embodiment, the smoker assembly 34 includes a smoke box 36 with an access door 38 . The access door is preferably hinged to the box 36 so that the operator can easily open the door 38 to feed suitable smoking products, like mesquite wood. The smoker box includes a burner assembly (not shown), such as a heating coil (electric) or natural gas burner, similar to the oven above, to heat the chips or wood. The smoker assembly 34 is preferably similar to conventional smoker assemblies attached to gas grills except that the smoker is pressurized. That is, an external pressure source, preferably the same pressure source as the oven, pressurizes the smoker box. A smoker conduit 40 connects the smoker box 36 to the interior of the oven enclosure 12 . A one way valve is preferably located on the conduit line and prevents backpressure into the smoker box from the oven. As long as the pressure within the smoker box is greater than the pressure in the oven, the smoke from the box will flow into the oven. [0064] Other methods can be used for channeling the smoke into the oven, such as a venturi line connected to the gas supply conduits 24 allowing the pressurized gas flowing into the oven to draw the smoke from the smoke box into the over enclosure. It is also contemplated that the smoker box may be sealed such that the heating of the air within the smoker box will naturally cause the pressure within the box to increase. Once the pressure is above a threshold amount, such as greater than the pressure in the oven, the smoke will channel into the oven enclosure from the smoker box. [0065] As shown in FIG. 5 , the heating system 30 also includes an oven temperature monitor 41 to detect the temperature of the inside of the oven. The oven temperature monitor preferably includes an oven temperature sensor 42 positioned within the enclosure 12 , and a display or gauge 44 preferably located outside the enclosure. The oven temperature monitor may be a conventional analog thermometer designed to operate within the anticipated temperature ranges and pressures. More preferably, the oven temperature monitor 41 is digital with a digital signal from the temperature sensor being displayed as a temperature value on the display 44 . Oven temperature sensors, displays and monitors are well know in the art and, therefore, no further discussion is necessary. [0066] The heating system 30 also preferably includes a food temperature monitor 45 to detect and monitor the temperature of the food. The food temperature monitor preferably includes a food temperature sensor 46 positioned within the enclosure 12 and which may be a conventional temperature probe designed to be inserted into the food product. A display or gauge 48 is preferably located outside the enclosure. The food temperature monitor may be a conventional analog thermometer designed to operate within the anticipated temperature ranges and pressures. More preferably, the food temperature monitor is preferably a digital device that receives a digital signal from the food temperature sensor and displays it as a temperature value on the display 48 . Food temperature sensors, displays and monitors are well know in the art and, therefore, no further discussion is necessary. [0067] An electronic controller 300 is used to control the supply of pressurized gas. The controller 300 is adapted to receive, for example, a variety of information, preferably including signals indicative of the pressure inside the enclosure from the pressure sensor 26 , the temperature inside the enclosure from the oven temperature sensor 42 , the temperature of the product being cooked from the food temperature sensor 46 . The electronic controller 300 is preferably configured to control one or more features and/or components of the oven. For example, the controller 300 is preferably connected to the pressure source 22 and/or the gas supply conduit 24 for controlling supply of the pressurized gas to the enclosure 12 . In such an embodiment, if the controller 300 senses that the pressure within the enclosure is below a desired value, the controller 300 controls a valve for supplying the pressurized gas along the gas supply conduit 24 until the pressure within the enclosure is above a desired level. Alternately, the controller could activate the pressure source 22 to begin to further pressurize the gas that is supplied. [0068] If the oven includes a smoker assembly as discussed above, the controller 300 can be used to separately control the smoker. [0069] The controller 300 could also activate an alarm if a prescribed time frame has completed (e.g., cooking cycle) or if a pressure exceeds a desired value. [0070] The controller 300 may also include a memory for storing various prescribed cooking procedures, and a selection device, such as a touch screen, buttons, keyboard or other mechanism for allowing an operator to program, store, and/or select a cooking procedure. Other uses and configurations for the controller will be explained below. A variety of controllers exist that can be configured to provide the necessary functionality described herein, including controllers using hardware, software or firmware components. The selection device may be physically attached to the controller or may be a separate component such as a remote control unit. It is also contemplated that the controller could be connected to a wireless or wired network (either directly or through the internet) so that remote programming and monitoring of the controller, and hence the oven, is possible using a standard general purpose computer or a dedicated computer device. As such, as series of ovens in a cooking facility can be monitored and controlled through a single computer system. [0071] A temperature limiter can be included to prevent over heating of the oven. The limiter can be fixed, such as a absolute maximum temperature, or could be adjustable, such as a maximum temperature for the particular food being cooked. [0072] Although the controller 300 has been described as being separate from the gauges and controls for the heating system, it is also contemplated that features of the heating controls, such as the gauges, can be part of the controller 300 , or that the heating controls, including the displays, and monitoring and control functionality can be provided through a software based system that operates through a display screen mounted to or separate from the oven. [0073] In order to permit the temperature to increase within the oven, one or more vents (not shown) are formed in the oven, preferably in the top on either side for the oven, and adapted to channel gas (air) out of the oven. The location of the vents provides for some controlled flow inside the oven. It should be readily apparent that the venting and/or pressurizing of the oven should be designed and/or controlled so that, during cooking, the volume of gas (air) being channeled into the oven is preferably equal to or greater than the volume of gas (air) being vented so that the gas (air) pressure within the oven increases. The controller 300 can control the pressure into and out of the oven so as to provide for the proper pressurization of the oven. [0074] Referring to FIG. 1 , the door 16 may be attached to the oven enclosure 12 in any convention manner. One preferred door hinge assembly 100 is illustrated in the drawings for attaching the door 16 to the frame 18 . In this embodiment, the door hinge assembly 100 is designed to pivot the door up and away from the opening of the enclosure. The door hinge assembly 100 includes two sets of upper and lower support arms 102 , 103 , each set being rigidly attached to the top and bottom of a side of the door 16 . The opposite end of each upper support arm 102 is pivotally attached to one leg of an upper dogleg link 104 . The upper dogleg link 104 is attached to an upper crossbar 105 at a point between its ends. The upper crossbar 105 preferably connects to both upper doglegs 104 and is support by a bracket on the frame 18 so as to permit the dogleg to pivot with respect to the frame 18 . [0075] The second end of each dogleg link 104 is attached to an upper end of a first piston assembly 106 . The piston assembly 106 may be a hydraulic or pneumatic piston. The lower end of each piston assembly 106 is attached to a first end of a lower dogleg link 108 . The lower dogleg link 108 is attached to lower crossbar 110 at a point between its ends. The lower crossbar 110 preferably connects to both of the lower doglegs 108 and is support by a bracket on the frame 18 so as to permit the lower doglegs 108 to pivot with respect to the frame 18 . [0076] A bracket 112 is fixedly attached to the end of the upper support arm 102 and pivotally attached to one end of a first control arm 114 . The opposite end of the first control arm 114 is pivotally connected to a second control arm 116 . The second control arm 116 is pivotally mounted to a bracket on the frame 18 between the ends of the second control arm 116 . The second end of the second control arm 116 is pinned to preferably two struts or dampers 118 , 120 which, in turn, are pinned to brackets on the bottom of the frame. These struts control the pivotal motion of the second control arm 116 about its pivotal mount to the frame 18 . [0077] The combination of the upper support arm 102 , the upper dogleg 104 , the piston assembly 106 and the lower dogleg 108 control the motion of the top of the door 16 toward and away from the enclosure. More particularly, in light of the increased pressure and temperature that is created in to over, the door attachment assembly is designed to move the top of the door 16 away from the enclosure about ½ to 1 inch in order to vent the heat and gas from the oven prior to the door opening completely. [0078] The combination of the upper support arm 102 , the first control arm 144 , the second control arm 116 and the struts 118 , 120 control the lifting and rotation of the door 16 . Thus, after the top of the door 16 has shifted away from the enclosure to vent the oven, this second combination of elements rotates the door away from the enclosure into the position shown in the figures. [0079] A control piston 122 is connected to the upper control arm 105 through a center dogleg link 124 and designed to rotate the upper control arm 105 . Rotation of the upper control arm controls the rotation of the upper doglegs 104 which, in turn, control the swiveling of the door between the open and closed positions. [0080] The piston 106 , 122 are connected to a switch which controls the operation of the pistons and, thus, the opening and closing of the door 16 . The switch is preferably part of the controller 300 . [0081] The lower support arms 103 preferably include a notch 126 designed to engage with a pin 128 extending out from the frame so as to secure the lower support arms to the frame when the door is closed. [0082] While one preferred embodiment of the door hinge assembly is shown in the drawings, it would be readily apparent to those skilled in the art to provide alternate door hinge assemblies, in light of the discussion above. For example, the door can be attached to the frame through a simple hinge and a lock provided that secures the door to the frame so as to prevent the internal pressure from forcing the door open. [0083] The increased pressure and higher temperature in the oven creates a denser atmosphere in the enclosure. The denser atmosphere allows for radiated energy from the heating source to reach the surface of the food quicker. The denser air acts like a solid material, resulting in a form of conduction through the gas. Preferably water is added to the gas or channeled into the oven so as to result in a steam being generated within the enclosure. This moist atmosphere produces a moisturizing of the food being cooked, thus preventing the food from drying out during cooking. A separate water supply may be attached to the oven and a conduit provided to supply the water into the oven in the form of a mist (such as with a diffuser) or injected into the gas stream flowing into the oven. Alternately, the natural water content of the food will assist in creating the steam environment. [0084] The applicant has determined that the skin of poultry is semi-permeable. Hence, the browning of the skin on poultry would tend to prevents permeation of moisture into the food. However, in the present oven, the increased pressure forces the moisture through the skin into the meat product, thus increasing the moisture content of poultry over conventional ovens. [0085] The addition of the smoke to the cooking process makes the air inside the oven more acidic. That is, the smoke changes the water molecules in the air to an acid which provides a unique and beneficial cooking environment. For example, the pressurized gas and liquid systems discussed above can be used to create a gaseous (gas-liquid) cooking marinade that is directed into the oven. In one embodiment, CO 2 can be added to water (or added to a moist environment within the oven enclosure) and combined with smoke from the smoker to create a carbonic acid within the enclosure. The carbonic acid will penetrate into the meat and tenderize the meat. The acid tends to breakdown tendons and other tough features of meat and poultry. The pressure assists in forcing the additional gas element into the water. [0086] The increased pressure of the gas within the oven allows for additional moisture to be added since the saturation level of the gas is generally higher at a higher temperature and pressure than at a lower pressure and temperature. As such, the oven permits more moisture than a conventional oven. Also, generally at higher temperature, air alone will have a lower density. So the addition of pressure into the oven raises the density of the air above where it would be in a conventional oven. For example, Table 3 shows the effect that temperature and pressure have on air. [0000] TABLE 3 Density of Air (lb/ft 3 ) at Different Temperatures Air Temp. Gauge Pressure (psi) (° F.) 0 5 10 20 30 30 0.081 0.109 0.136 0.192 0.247 40 0.080 0.107 0.134 0.188 0.242 50 0.078 0.105 0.131 0.185 0.238 60 0.076 0.102 0.128 0.180 0.232 70 0.075 0.101 0.126 0.177 0.228 80 0.074 0.099 0.124 0.174 0.224 90 0.072 0.097 0.121 0.171 0.220 100 0.071 0.095 0.119 0.168 0.216 120 0.069 0.092 0.115 0.162 0.208 140 0.066 0.089 0.111 0.156 0.201 150 0.065 0.087 0.109 0.154 0.198 200 0.060 0.081 0.101 0.142 0.183 250 0.056 0.075 0.094 0.132 0.170 300 0.052 0.070 0.088 0.123 0.159 400 0.046 0.062 0.078 0.109 0.141 500 0.041 0.056 0.070 0.098 0.126 600 0.038 0.050 0.063 0.089 0.114 [0087] One test was conducted using the oven described above. In the test, the oven was operated at 425 degrees and pressurized from 16-17.5 psi. The result was that a 16 pound turkey cooked completely in 50 minutes and remained very moist. This compares with a conventional oven which takes approximately 3½ A hours to cook the same size turkey. [0088] The oven illustrated in FIGS. 1-6 is configured as a large commercial oven. A smaller version has been designed for residential use. FIGS. 7 and 8 illustrate such as design. The components described above of the oven would preferably be mounted on the side and back of the oven enclosure within the cabinet. This design provides a more compact version of the oven. Most of the components described above with respect to the first embodiment of the invention would be included in the embodiment shown in FIGS. 7 and 8 , and are depicted with the same reference numerals. [0089] Referring to FIGS. 9A-9D illustrate an alternate embodiment of a door 400 for use in the pressurized oven system. Since the pressure in the oven tends to push the oven door outward, typical doors that pressure inward to seal are constantly fighting the pressure inside the oven. In an alternate concept, a unique door is disclosed that uses an inner door wall that, when the door is in its closed position, is located inside the door frame on the front wall such that pressure inside the oven forces the inner door wall against the door frame, providing a strong seal. [0090] As shown in FIG. 9A , in this embodiment, the door frame or opening 402 is not square or rectangular. Instead, it has a trapezoidal shape, with the top 402 T of the frame having a width that is less than the bottom 402 B of the frame and the sides 402 S tapering inward as shown. The door 400 includes an outer wall 404 and an inner wall 406 . The outer wall can have a conventional appearance, and is hinged to the oven near the bottom 402 B of the door frame. The inner wall 406 has a trapezoidal shape that is the same as the door frame only slightly larger. The inner wall 406 is mounted to the outer wall 404 through a linkage or articulation mechanism 408 that permits the inner wall to move parallel to the outer wall. The linkage 408 includes a handle 410 that passes through the outer wall to the inner wall. [0091] As FIGS. 9A-9D , and 10 A- 10 D illustrate, the inner door is mounted to the outer door such that when the outer door is placed against the oven, the inner door is positioned slightly downward from the door frame 402 . This permits the inner wall to pass through the door frame opening. Once the outer door 404 is against the front door frame 402 as shown in FIGS. 9C and 10C , the handle 410 is pivoted from an unlocked position (shown in FIGS. 9C and 10C as extending outward) to a locked position shown in FIGS. 9D and 10D . [0092] More particularly, the linkage mechanism includes, in one embodiment, two upper links 412 and two lower links 414 near the sides of the inner door 406 . Each link is attached at each end to the inner door and outer door through a pivot connection (such as a pinned connection). Thus, the linkages and the inner and outer doors form, in essence a four bar linkage system for controlling movement of the inner door relative to the outer door. As the outer door 406 is transitioned from the open position ( FIGS. 9A and 10A ) through the closed, but unlocked position ( FIGS. 9C and 10C ), the linkage mechanism 408 maintains the inner door in its unlocked position. As the handle 410 is engaged (pulled downward in FIGS. 9D and 10D ), the linkage causes the inner door to slide upward and slightly outward against the inside surface of the door frame, thus placing the door in its locked position. [0093] Those skilled in the art will recognize in light of the above discussion that there are other ways to form the door and locking mechanism and, thus, the present invention is not limited to the particular configuration disclosed. [0094] As discussed above, moisture created inside the oven can be used to enhance the cooking of the food. For example, spices and other flavor enhancers, can be placed on the item to be cooked in a dry state. During the heating process, the moisture in the oven enclosure can be controlled to cause the spices to form a marinate as the drain off into the cooking pan. The controller can be used to monitor the moisture content within the oven and in the food product using a humidistat or other conventional sensor. [0095] Variations, modifications and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and scope of the invention. Accordingly, the invention is in no way limited by the preceding illustrative description.

A pressurized cooking oven system is disclosed that includes an oven enclosure having front, back, top, bottom and side walls. A door is hingedly attached to one of the walls for sealing an opening in the walls. A heating system is connected to the enclosure for generating heat in the enclosure. The heating system may be a gas or electric heating system. A process is also disclosed for cooking a food item in an oven. The process involves generating heat within the oven; creating pressure within the oven enclosure above atmospheric pressure during at least a portion of the cooking process; maintaining the pressure within the oven enclosure during at least a portion of the heating process; and controlling the heating and pressure during the cooking process.

This application is a division of application Ser. No. 07/851,976 filed 16 Mar. 1992, now U.S. Pat. No. 5,426,043. TECHNICAL FIELD The present invention relates to the field of molecular biology. In particular, the invention relates to the cloning and expression of a DNA sequence encoding a fungal acetyl xylan esterase. The present invention provides a recombinant acetyl xylan esterase obtained by expression of the cloned DNA sequence encoding this protein. The protein thus obtained is used in xylan degradation in feed or pulp. BACKGROUND OF THE INVENTION The rigid structure of cell walls of plant tissues is due to xylans together with other hemicelluloses, pectins, cellulose and lignin. Xylans form the major hemicellulose, most xylans are heteropolysaccharides with a homopolymeric backbone chain of 1,4-linked β-D-xylopyranose units. The plant of origin determines the degree and the type of substitutions of the specific xylan. Xylans are found to contain many different side groups, among these L-arabinose, D-glucuronic acid or its 4-O-methyl ether, and acetic, p-coumaric, and ferulic acids are the most prominent. It has been suggested that both acetyl and arabinosyl substituents increase the solubility of hemicellulose by decreasing the possibility of intermolecular aggregation, however, these substituents are at the same time a severe hindrance to the enzymatic degradation of the plant tissues. For example, it has been reported that acetylation inhibits the digestibility of plant polysaccharides in ruminants. Poutanen and Puls (1989) (In Biogenesis and Biodegradation of Plant Cell Wall Polymers (Lewis, N. and Paice, M. eds) ACS Symp. Ser. 399:630-640), have shown that the major xylanase of Trichoderma reesei is unable to depolymerize acetylated soluble xylan. Grohmann et al. (1989) (Appl. Biochem. Biotechnol. 20/21:45-61) have shown that after chemical deacetylation xylan is 5-7 times more digestible by ruminants. Esterases (EC 3.1.1.6) are classified according to their substrate specificity. Since it is generally difficult to determine the natural substrate for these enzymes the classification is problematic and this problem is enlarged by the widespread appearence of esterases in nature. It is therefore not surprising that although the existence of enzymes that deacetylate xylan may have been anticipated in view of the long known occurrence of microbial esterases that were known to act on various synthetic substrates, it was not until recently that the existence of acetyl xylan esterases was demonstrated. Biely et al. (1985, FEBS Lett. 186:80-84) demonstrated the presence of acetyl xylan esterases in (fungal) cellulolytic and hemicellulolytic systems: Trichoderma reesei, Aspergillus nicer, Schizophyllum commune and Aureobasidium pullulans. As compared with plant and animal esterases, these fungal esterases exhibit high specific activities towards acetylated glucuronoxylan and were therefore named acetyl xylan esterases. Further investigations on the fungal acetyl esterases have been reported. Poutanen et al. (1988, Appl. Microbiol. Biotechnol. 28:419-425 and 1990, Appl. Microbiol. Biotechnol. 33:506-510) described the purification and characterization of acetyl xylan esterases from T. reesei. Enzymatic deacetylation of xylan using purified acetyl xylan esterase resulted in the precipitation of the remaining polymer structure. Due to this effect acetyl esterase is not used as a single first enzyme in the degradation of acetylated xylans. The highest xylose yield from acetylated xylan was obtained by the synergistic action of xylanase, β-xylosidase and acetyl xylan esterase. To achieve a practically useful degradation of xylans there is a need for large amounts of the enzymes involved in the enzymatic hydrolysis of these highly substituted molecules. The present invention provides a way for obtaining large amounts of fungal acetyl xylan esterases, optionally in a purified form. SUMMARY OF THE INVENTION It is an object of the present invention to provide a purified and isolated acetyl xylan esterase of fungal origin. This protein is the expression product of the gene encoding a fungal acetyl xylan esterase. The present invention further provides constructs for the microbial expression of the acetyl xylan esterase-encoding sequence using either its native regulatory sequences or, in an alternative embodiment, using the gene operatively coupled to regulatory regions such as promoter, secretion leader and terminator signals selected depending on the desired expression host. It is a further object of the present invention to provide expression hosts, transformed with the expression constructs of the present invention, which are capable of the overexpression and, if desired, the secretion of the acetyl xylan esterase of fungal origin. It is yet a further object of the present invention to provide methods for the production of large quantities of an acetyl xylan esterase. Furthermore the present invention provides a method for increasing feed digestibility characterized in that an effective amount of acetyl xylan esterase is added to the feed. The present invention also provides a method for decreasing the viscosity of xylan containing compositions characterized in that an effective amount of acetyl xylan esterase is added. The present invention also provides a method for the release of lignin from kraft pulp in the preparation of paper products. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the restriction map of a 3.4 kb Sst1 DNA fragment containing the Aspergillus niger axeA gene. FIG. 2 shows the release of acetic acid (HAc) and xylose oligomers (X 1 , X 2 , X 3 and X 4 ) from a 0.2% (w/v) steamed birchwood xylan solution by the combined action of acetyl esterase (1 μg/ml) and endo-(1,4)-β-xylanase I (0.1 μg/ml). DETAILED DESCRIPTION OF THE INVENTION Filamentous fungi are widely known for their capacity to secrete large amounts of a variety of hydrolytic enzymes such as α-amylases, proteases and glucoamylases, and various plant cell wall degrading enzymes such as cellulases, hemicellulases, and pectinases. The present invention describes a purified and isolated DNA molecule comprising the sequence of an acetyl xylan esterase gene of fungal origin and genetic variants thereof. Genetic variants are those DNA sequences encoding mutant acetyl xylan esterases. Also encompassed by the present invention are fungal DNA sequences that hybridize with the presented sequences under stringent conditions and that upon expression give rise to a protein which shows esterase activity. Specifically the A. niger acetyl xylan esteralse gene, isolated in one of the examples, was shown to hybridize with T. reesei chromosomal DNA. The present invention also pertains to homologous or heterologous hosts transformed by recombinant DNA molecules containing the DNA sequences described above. With "homologous host" is intended the species from which the gene is obtained. "Heterologous host" pertains to hosts other than the source from which the gene is obtained. Heterologous hosts may be selected from bacteria, yeasts or fungi. The terms homologous and heterologous are also used with respect to the regulating sequences. In this case "homologous" refers to the regulating sequences which are native to the cloned gene and "heterologous" to regulating sequences from other genes or from the same gene obtained from another species. Acetyl xylan esterases of particular interest are those which are obtained from fungi of the genera Asperqillus, Trichoderma, Schizophyllum. Preferred species are Trichoderma reesei, Aspergillus nicer and Schizophyllum commune. Fungi showing acetyl xylan esterase activity can be used to isolate the protein by methods well-known in the art. In the presented examples Aspergillus niger is used as the source of the acetyl xylan esterase. The acetyl xylan esterase is produced by culturing the Asperaillus strain. The protein is purified by known methods and the yield of the purification is followed by a suitable acivity assay. As a first step of the characterisation of the protein structure a part of the amino acid sequence of the isolated protein is determined. When N-terminal amino acid sequencing techniques are used this can be the N-terminal part of the mature protein, but this can also be the N-terminus of an internal peptide obtained after digestion of the purified protein with a specific proteinase such as trypsin, chymotrypsin etc or with a chemical reagent e.g. CNBr. When using C-terminal sequencing methods it is possible to determine C-terminal sequences of the protein or peptides. Once such a sequence is known it is possible to derive a nucleotide probe based on this sequence. Preferably this probe is devised against a part of the protein which contains amino acids which are encoded by codons that show little degeneracy. The probes that are obtained in such a way can be labeled and used to hybridize with the clones from a cDNA or genomic library. From the clones showing a positive hybridization signal the vector is isolated and the nucleotide sequence of the insert is determined. Hybridisation and sequencing can be repeated if no full length clone is found. Full-length clones can also be obtained by combining overlapping restriction fragments all encoding a part of the desired protein sequence. The obtained DNA sequence can be cloned in appropriate expression vectors. Where appropriate is related to the choice of the expression host organism. This cloning can also be performed without determination of the nucleotide sequence, however, this will probably give rise to a non-optimal construct. Preferred expression hosts can be bacteria, yeasts or fungi. Specifically Kluyveromyces, Bacillus, Aspergillus or E. coli are used. To regulate the expression, regulatory regions are cloned in such a way that the gene is operationally linked with them. Among these regulatory regions homologous and heterologous promoters, operators, enhancers, signal sequences and ribosomal binding sites can be used. Furthermore, the gene can be cloned on a self-replicating vector or it can be integrated into the genome of the host organism, preferably more copies of the gene are used. Finally, the obtained gene can in turn be used as a probe to hybridize with DNA libraries obtained from related species. Specifically the A. niger acetyl xylan eterase gene, isolated in one of the examples, was shown to hybridize with T. reesei chromosomal DNA. In the examples the cloning and expression of a 3.4 kb Sst1 DNA fragment obtained from Aspergillus niger is demonstrated. The expression is performed using the complete gene in A. niger. As described above acetyl xylan esterase can be used to deeacetylate xylan. Since it was observed that the activity of acetyl xylan esterase as a single enzyme may lead to precipitation of the obtained polymer it is preferable to use the enzyme in conjunction with other xylan degrading enzymes such as xylanases, arabinofuranosidases, xylosidases and glucuronidases preferably selected from the group consisting of xylzanase, α-arabinofuranosidase, β-xylosidase and α-glucuronidase. In Example 5 the combined action of acetyl xylan esterase and β-(1,4)-xylanase and β-(1,4)-xylosidase respectively, is demonstrated. Acetyl xylan esterases can preferably be used in processes wherein xylan has to be degraded. As a consequence of the deacylating reaction the xylan becomes better accessible for xylanases. Specific applications of acetyl xylan esterases or combinations of this enzyme with other xylan degrading enzymes include; the pretreatment of animal feed to increase the digestibility, addition of these enzymes to feed `treatment in situ`, treatment of fruit juices and beer in order to improve rheological characteristics and clarity, pulp and (waste-) paper processing in order to improve the process of bleaching and de-watering. In general this enzyme or combinations of this enzyme with other enzymes can be used to degrade biological cell-wall material to increase digestibility or flow characteristics in industrial applications relating to the preparation of fruit juices or beer. Another important aspect concerning the use of acetyl xylan esterase in feed is its effect on viscosity. Deacetylation of xylan decreases the solubility of the feed components and thereby the viscosity is diminished. This leads to an increased ease of handling, and a reduced anti-nutritional effect of the pentosanes. In accordance with this the present invention provides animal feed compositions containing acetyl xylan esterase. Furthermore, the accesibility of xylan for xylanases is increased. This is important in the release of lignin from pulp. Generally kraft pulp is treated with xylanases in order to remove lignin in the preparation of paper products. Due to the high degree of acetylation of xylan xylanase is not optimally used. The effectivity of xylanases is greatly increased when pulp is treated with acetyl xylan esterase either before or at the same time as the xylanase treatment. In accordance with the above the present invention provides a method for increasing feed digestibility characterized in that an effective amount of acetyl xylan esterase is added to the feed. The present invention also provides a method for decreasing the viscosity of xylan containing compositions characterized in that an effective amount of acetyl xylan esterase is added. The present invention also provides a method for the release of lignin from kraft pulp in the preparation of paper products. The following examples are offered by way of illustration and are not meant to limit the scope of the present invention in any way. EXPERIMENTAL Buffers and stock solutions Appropriate stock solutions were used in the experiments described in the examples. The following stock solutions were made according to Maniatis et al. (`Molecular Cloning` Cold Spring Harbor, 1982 and 1989, 2nd ed.); TE buffer, 20×SSC, Hybridization buffer, 100×Denhardt's solution, SM buffer, 50×TAE buffer, DNA loading buffer (xylene cyanol and bromophenol blue), NCZYM medium, LB medium. Ligation buffer was prepared as indicated by the supplier of the enzyme. Further solutions contained the following components; 5×RNB per 1000 ml 121.10 g Tris, 73.04 g NaCl, 95.10 g EGTA, pH 8.5 Visniac solution 10 g EDTA, 4.4 g ZnSO 4 .7H 2 O, 1.0 g MnCl 2 .4H 2 O 0.32 g CoCl 2 .6H 2 O, 0.32 g CuSO 4 5H 2 O 0.22 g (NH 4 ) 6 Mo 7 O 24 .4H 2 O, 1.47 g CaCl 2 .2H 2 O 1.0 g FeSO 4 .7H 2 O, pH 4.0 (Visniac and Santer, 1957, Bact. Rev. 21:195-213) Minimal medium per 1000 ml 6.0 g NaNO 3 , 1.5 g KH 2 PO 4 , 0.5 g MgSO 4 .7H 2 O 0.5 g KCl, 1 ml Visniac solution Carbon source as indicated, pH 6.0 Strains used in the Examples E. coli JM101 (Yanisch-Perron et al., 1985, Gene 33:103) E. coli LE 392 (Murray, 1977, Mol. Gen. Genet. 150:53-58) Asperqillus niger N402 (Goosen et al., 1987, Curr. Genet. 11:499-503) Aspergillus niger N593 (Goosen et al., 1987, supra) Vectors used in the Examples pUC9 (Vieirra and Messing, 1982, Gene 19:259-268 and Yanisch-Perron et al., 1985) M13mp18/M13mp19 (Messing, J., 1983, IOIC:10-78, Norrander et al., 1983, Gene 26:101-106) Acetyl esterase assay The assay was as described by Biely et al. (1985, supra). Enzyme solution (10-50 μl) was mixed with 1 ml of a freshly prepared saturated solution of 4-nitrophenyl acetate (SIGMA) in 0.2M phospate buffer, pH 6.5 and incubated at 22° C. Liberation of 4-nitrophenol was followed photometrically at 410 nm as a function of time. One unit of acetyl esterase activity hydrolyzes 1 μmole of the substrate in 1 min. Enzymes The endo-(1,4)-β-xylanase I, II, III (E.C. 3.2.1.8) and the β-(1,4)-xylosidase (E.C. 3.2.1.37) were purified as described by Kormelink et al. (1990, In: Proc. 5th European Congress on Biomass and Bioenergy, Lissabon 9-13 October 1989). from Aspegillus awamori CMI 142717. Combined action of acetyl esterase and xylan-degrading enzymes The release of acetic acid and xylose oligomers was determined by HPLC after degradation of steamed birchwood xylan by single or combined actions of acetyl esterase and endo-(1,4)-β-xylanase I, endo-(1,4)-β-xylanase II, endo-(1,4)-β-xylanase III and β-(1,4)-xylosidase. A 0.2% (w/v) steamed birchwood xylan solution was incubated with 1.0 μg/ml acetyl esterase and 0.1 μg/ml endo-(1,4)-β-xylanase I, endo(1,4)-β-xylanase II, endo-(1,4)-β-xylanase III or β-(1,4)xylosidase at 30° C. The degradation was followed over a time range from 0-8 hours. The reaction was terminated by placing the sample for 5 minutes in a boiling water bath. Steamed birchwood was prepared as described by Puls et al. (1985, Appl. Microbiol. Biotechnol. 22:416-423). HPLC--Neutral sugars Neutral sugars released by the single and combined action of endo-(1,4)-β-xylanase I, II, III, β-(1,4)-xylosidase and acetyl esterase on steamed birchwood xylan were determined by HPLC. Samples were pretreated with Pb(NO 3 ) 2 according to Voragenr et al. (1986, Food Hydrocolloids 1:65-70) and injected on a CH--Pb column (Merck, Darmstadt, FRG) eluted with millipore water (0.4 ml/min) at 85° C. Sugars were detected by a Shodex SE-61 RI detector. EXAMPLES Example 1 Purification and characterization of A. niger acetyl xylan esterase AXE I. Example 1.1 Purification of A. niger acetyl xylan esterase AXE I After growth of Aspergillus niger DS16813 the culture was centrifuged and the supernatant was concentrated through ultrafiltration. A sample of 73 ml was applied to a DEAE-trisacryl (IBF) column (a XK 50 Pharmacia column filled with 400 ml of DEAE-trisacryl and buffered with Tris-HCl 0.05M, pH 7.8) and eluted with a linear gradient 0.0-1.0M NaCl in Tris-HCl 0.05M, pH 7.8. Fractions were assayed for acetyl esterase activity, as described above. Fractions containing acetyl esterase activity were pooled and applied to a semi-preparative DEAE HPLC column (Waters; DEAE 5 PW 21.5 mm×15 cm) equilibrated with phosphate 0.05M pH 7.5. Elution was with a linear 0.0-1.0M NaCl gradient in the same buffer. The final purification was performed with an analytical DEAE HPLC column (same as above but in this case 7.5 mm×7.5 cm) or using SDS-PAA gelelectrophoresis. The fractions obtained were used for amino acid sequencing as such or the protein was first digested with an appropriate proteolytic enzyme. In the latter case the peptides obtained were separated through HPLC, before amino acid sequencing was performed. Example 1.2 Amino acid sequencing of N-terminal and internal peptides of acetyl xylan esterase Amino acid sequencing of the N-terminus of A. niger acetyl xylan esterase AXE I, using an Applied Biosystems gas phase sequencer, revealed the following sequence: (SEQ ID NO:1)(Formula 1) Amino acid sequence determination of CNBr peptides of acetyl xylan esterase AXE I, after separation using HPLC, revealed the following sequences: CNBr peptide 1 (SEQ ID NO:2)(Formula 2) CNBr peptide 2 (SEQ ID NO:3)(Formula 3) Example 2 Screening of the A. niger genomic library for the acetyl xylan esterase gene (axeA) and isolation of the gene. Example 2.1 32 P-labeling of synthetic oligonucleotides The amino acid sequence shown in Example 1.2 (Formula 1) was used to derive oligonucleotide mixes corresponding to the N-terminal amino acid sequence. The oligonucleotides were synthesized by the phosphoamidite method described by Crea et al. (1979, Tetrahedron Lett. 5:395-398) using an Applied Biosystems oligonucleotide synthesizer. The following oligonucleotide mixture was used; (SEQ ID NO:4) 29 (Formula 4) G G G G in a final concentration of 37 pmol oligonucleotides per μl. This oligonucleotide mixture was labeled in a reaction mixture of the following composition; 37 pmol oligonucleotide mixture, 66 mM Tris.HCl pH 7.6, 1 mM ATP, 1 mM spermidine, 10 mM MgCl 2 , 15 mM dithiothreitol, 200 μg/ml BSA, 34 pmol τ 32 -P ATP (NEN, 6000 Ci/mMol) and 30 U T 4 polynucleotide kinase (BRL) in a final volume of 50 μl. The reaction was terminated by the addition of 4 μl 0.5M EDTA pH 8.0. The labeled oligonucleotide mixture was used without further purification in screening of the genomic library (Example 2.3) and in Southern blottings (Example 2.5 and 2.6). Example 2.2 Construction of a genomic library of Aspergillus niger strain DS16813 (CBS 323.90) DNA from Aspergillus niger DS16813 (deposited at the Centraal Bureau voor Schimmelcultures, Baarn, The Netherlands on Jul. 20, 1990 (CBS 323.90)) was isolated using the procedure described by de Graaff et al. (1988, Curr. Genet. 13:315-321). Briefly, mycelium, grown overnight was harvested and stored at -80° C. Nucleic acids were isolated by disrupting 0.5 g frozen mycelium using an microdismembrator (Braun). The mycelial powder was extracted with extraction buffer containing: 1 ml tri-isopropylnaphtalene sulfonic acid (TNS) (20 mg/ml), 1 ml p-aminosalicylic acid (PAS) (120 mg/ml) and 0.5 ml 5×RNB buffer and which was equilibrated with 1.5 ml phenol. The extraction buffer was added to the mycelium powder and a phenol/chloroform, chloroform extraction was performed. The DNA was subsequently isolated by ethanol precipitation. RNA was removed from the solution by treating with RNase A. DNA, isolated from Aspergillus niger DS16813, as described above, was partially digested by Sau 3A. The resulting fragments were size fractionated by electrophoresis on 0.4% agarose in TAE. Fragments of 14 kb to 22 kb in size, were recovered from the gel by cutting the appropriate region from the gel and subsequent electroelution. The fragments were ligated with bacteriophage lambda EMBL 3 Bam HI arms, obtained from Promega, using a standard procedure. The ligated DNA was packaged in vitro using Gigapack II Gold packaging extract (Stratagene) and plated on E. coli LE392 using NZYCM medium according to the manufacturer's instructions. The primary library thus obtained was titrated and amplified. A phage stock was made containing approximately 10 10 pfu/ml. Example 2.3 Screening of the A. niger genomic library for the axeA gene. A genomic library of A. niger was constructed as described above. For obtaining the axeA gene, 3×10 3 pfu per plate are plated in NZYCM topagarose containing 0.7% agarose on four 85-mm-diameter NZYCM (1.2% agar) plates as described (Maniatis et al., 1982, supra, pp. 64), using E. coli LE392 as plating bacteria. After overnight incubation of the plates at 37° C. two replicas of each plate were made on HybondN + filters (Amersham) as described in Maniatis et al. (1982, supra, pp. 320-321). After wetting the filters in 3×SSC, the filters were washed for 60 min. at room temperature in 3×SSC. The filters were prehybridized at 65° C. for two buffer in prehybridization buffer containing; 6×SSC, 0.5% SDS, 10×Denhardt's solution and 100 μg/ml heat denatured herring sperm DNA (Boehringer Mannheim). After two hours of prehybridization the buffer was replaced by hybridization buffer which is identical to the prehybridization buffer, except that this buffer does not contain herring sperm DNA, but contains 32 -P labeled oligonucleotide mix Formula 1, prepared as described in Example 2.1. The filters were hybridized for 18 hrs at a final temperature of 47° C., slowly reached from the initial temperature of 65° C. After hybridization the filters were first washed in 2×SSC, after which the filters were washed in prewarmed hybridization buffer at 47° C. Finally the filters were washed twice for 30 min. at 56° C. in 6×SSC, 0.05% sodium pyrophosphate. The air dried filters were taped on a sheet of Whatman 3MM paper, keying marks were made with radioactive ink and the Whatman paper and filters covered with Saran Wrap. Hybridizing plaques were identified by exposure of Kodak XAR X-ray film for 72 hrs at -70° C. using an intensifying screen. Seven hybridizing plaques, were identified and named lambda axe1 to lambda axe7 . Each positive plaque was picked from the plate using a Pasteur pipette and the phages were eluted from the agar plug in 1 ml of SM buffer containing 20 μl chloroform, as described in Maniatis et al. (1982, supra, pp. 64). The phages obtained were purified by repeating the procedure described above using filter replicas from plates containing 50-100 plaques of the isolated phages. After purification the phages were propagated by plating 5×10 3 phages on NZYCM medium. After overnight incubation at 37° C. confluent plates were obtained, from which the phages were eluted by adding 5 ml SM buffer and storing the plate for 2 hrs at 4° C. with intermittent shaking. After collection of the supernatant using a pipette, the bacteria were removed from the solution by centrifugation at 4,000×g for 10 min. at 4° C. To the supernatant 0.3% chloroform was added and the number of pfu determined. These phage stocks contain approximately 10 10 pfu/ml. Example 2.4 Isolation of DNA from bacteriophage lambda Each of the isolated phages were propagated by combining 5*10 9 E. coli LE392 bacteria in 300 μl SM buffer with 2*10 6 pfu for 15 min. After incubation the infected bacteria were used to inoculate 100 ml prewarmed (37° C.) NZYCM medium and subsequently incubated for 9-12 hrs at 37° C. in a New Brunswick rotation shaker at 250 rpm, after which period the bacteria were lysed. The bacterial debris was removed by centrifugation for 10 min. at 10 krpm. at 4° C., in a Sorvall High Speed centrifuge. The phages were precipitated from the supernatant obtained (100 ml) by the addition of 10 g polyethyleneglycol-6000 and 11.7 g NaCl and storing the solution overnight at 4° C. The precipitated phages were collected by centrifugation at 14,000×g at 4° C. for 20 min. The supernatant was removed by aspiration, while the rest of the liquid was removed using a paper towel. The phages were carefully resuspended in 4 ml SM buffer and extracted once with an equal volume of chloroform. Before the DNA was extracted from the phage particles, DNA and RNA originating from the lysed bacteria was removed by incubation of the phage suspension with DNase I and RNase A (both 100 μg/ml) for 30 min. at 37° C. The phage DNA was subsequently released from the phages by the addition of EDTA to a final concentration of 20 mM while the protein was removed from the solution by extracting twice with an equal volume phenol/chloroform/isoamyl alcohol (25:24:1). After separation of the phases by centrifugation using a Sorvall centrifuge (14,000×g, 10 min.), the aqueous phase was extracted once with an equal volume chloroform/isoamylalcohol (24:1). The phases were separated by centrifugation after which the DNA was precipitated from the aqueous phase by the addition 0.1 vol. 5M sodiumperchlorate and 0.1 vol. isopropanol and incubation on ice for 30 min. The DNA was recovered by centrifugation for 10 min. at 4° C. (14,000×g). The supernatant was removed by aspiration after which the DNA was resuspended in 400 μl TE buffer. The DNA was precipitated once again from this solution by the addition of 0.1 vol. 3M sodium acetate and 2 vol. ethanol. The DNA was collected by centrifugation for 10 min. at 4° C. (14,000×g). Tie supernatant was removed by aspiration, the remaining pellet was briefly dried under vacuum, after which the DNA was resuspended in 125 μl TE buffer containing 0.1 μg/ml RNase A. This purification procedure results in the isolation of approximately 50-100 μg DNA from each phage. Example 2.5 Restriction analysis of axeA containing phages The isolated DNA of phages lambda axe1 to lambda axe7 was analyzed by Southern analysis using the following restriction enzymes; EcoRI; HinDIII; SI and HinCII. The DNA was digested for 3 hrs at 37° C. in a reaction mixture composed of the following solutions; 5 μl (≈1 μg) DNA solution; 2 μl of the appropriate 10×Reaction buffer (BRL); 10 U Restriction enzyme (BRL) and sterile distilled water to give a final volume of 20 μl. After digestion the DNA was precipitated by the addition of 0.1 vol. 3M NaAc and 2 vol. ethanol. The DNA was collected by centrifugation for 10 min. at room temperature (14,000×g). The supernatant was removed by aspiration, the remaining pellet was briefly dried under vacuum and resuspended in sterile distilled water. After addition of 4 μl DNA loading buffer the samples were incubated for 10 min. at 65° C. and rapidly cooled on ice, before loading the samples on a 0.6% agarose gel in TAE buffer. The DNA fragments were separated by electrophoresis at 25 V for 15-18 hrs. After electrophoresis the DNA was transferred and denatured by alkaline vacuum blotting (VacuGene XL, Pharmacia LKB) to nylon membrane (Gene Bind 45, Pharmacia LKB) as described in the instruction manual (pp. 25-26) and subsequently prehybridized and hybridized using the labeled oligonucleotide mixture Formula 1 as described in Example 2.1 and hybridization conditions as described in Example 2.2. The hybridization pattern was obtained by exposure of Kodak XAR-5 X-ray film for 18 hrs at -70° C. using an intensifying screen. From the results obtained it is concluded that the DNA of five out of the seven isolated clones hybridize with the oligonucleotide mixture derived from the N-terminal amino acid sequence. In all five clones fragments originating from the same genomic region were found. In a more extensive Southern analysis, using the enzymes BglII, EcoRV, NcoI, PstI, SstI and XbaI, a partial restriction map of this genomic region was constructed. From this experiment it is concluded that a 3.4 kb SstI fragment contains the A. niger axeA gene. Example 2.6 Subcloning of the A. niger axeA gene From phage lambda axe3 the 3.4 kb SstI fragment was isolated by digesting the phage DNA with SstI and separation of the fragments as described in Example 2.4. The fragment was cut from the agarose gel, after which it was recovered from the piece of agarose by electroelution using ISCO cups. Both on the large and the small container of this cup a dialysis membrane was mounted, the cup was filled with 0.005×TAE and the piece of agarose is placed in the large container of the cup. Subsequently the cup was placed in the electro-elution apparatus, with the large container in the cathode chamber containing TAE and the small container at the anode chamber containing TAE/3M Nacl. The fragments were electro-eluted at 100 V during 2 hrs. After this period the cup was taken from the electro-elution apparatus and the buffer was removed from the large container, while from the small container the buffer was only removed from the upper part. The remaining buffer (200 μl) containing the DNA fragments was dialyzed in the cup against distilled water during 30 min. Finally the DNA was precipitated by the addition of 0.1 vol. 3M NaAc, pH 5,6 and 2 vol. cold (-20° C.) ethanol. The DNA was collected by centrifugation (Eppendorf centrifuge) for 30 min. at 14,000×g. at 4° C. After removal of the supernatant the DNA pellet was dried using a Savant Speedvac vacuumcentrifuge. The DNA was dissolved in 10 μl TE buffer and the concentration determined by agarose electrophoresis, using Lambda DNA with a known concentration as a reference and ethidiumbromide staining to detect the DNA. The fragment obtained was ligated in the vector pEMBL18 digested with SstI and dephosphorylated with alkaline phosphatase prepared as follows; 1 μl (1 μg/μl) pEMBL18 was mixed with 2 μl 10×React 10 (BRL), 1 μl (1 U/μl) SstI and 16 μl sterile distilled water. The DNA was digested for 1 hr at 37° C., after which 0.5 μl alkaline phosphatase (1 U/μl (Pharmacia LKB) was added followed by further incubation at 37° C. for another 30 min. The linearized vector was isolated from a 0.6% agarose gel as described above. The 3.4 kb SstI fragment was ligated in the vector resulting in the plasmid pIM150, by the following procedure. 100 ng pEMBL18 fragment was mixed with 100 ng 3.4 kb SstI fragment and 4 μl 5*ligation buffer (composition; 500 mM Tris-HCl, pH 7.6; 100 mM MgCl 2 ; 10 mM ATP; 10 mM dithiotreitol; 25% PEG-6000) and 1 μl (1.2 U/μl) DNA ligase (BRL) was added to this mixture in a final volume of 20 μl. After incubation for 16 hrs at 14° C. the mixture was diluted to 100 μl with sterile water. 10 μl of the diluted mixture was used to transform E. coli JM101 competent cells, prepared by the CM1, CM2 method as described in the Pharmacia Manual for the M13 cloning/sequencing system. A selection of six of the resulting colonies were grown overnight in LB medium containing 100 μg/ml ampicillin. From the cultures plasmid DNA was isolated by the alkaline lysis method as described by Maniatis (et al. (1982, pp. 368-369), which was used in restriction analysis, as described in Example 2.4 to select a clone harboring the desired plasmid. Plasmid DNA was isolated on a large scale from 500 ml cultures E. coli JM101 containing the plasmid pIM150 grown in LB medium containing 100 μg/ml ampicillin (Maniatis et al., 1982, p 86). The plasmid was purified by CsCl centrifugation, phenolized, ethanol precipitated and dissolved in 400 μl TE. The yield was approximately 500 μg. The plasmid pIM150 was further analyzed by restriction enzymes resulting in the restriction map shown in FIG. 1. This plasmid was deposited with the Centraal Bureau voor Schimmelcultures (CBS) in Baarn, the Netherlands. In E. coli DH5α on Mar. 11 1991, under number CBS 157.91. Example 3 Sequence determination of the A. niger axeA gene The sequence of the A. niger axeA gene, its promoter-regulation region, the structural part of the gene and the termination region, was determined by subcloning fragments from pIM150 in M13mp18/mp19, in combination with the use of specific oligonucleotides as primers in the sequencing reactions. For nucleotide sequence analysis restriction fragments were isolated as described in Example 2.5 and cloned in bacteriophage M13 mp18/19 RF DNA vectors (Messing, 1983, supra; Norrander et al., supra, 1983), digested with the appropriate restriction enzymes, as described in Example 2.5. The nucleotide sequences were determined by the dideoxynucleotide chain termination procedure (Sanger et al., 1977, Proc. Natl. Acad. Sci. USA 74:5463-5467) using the Pharmacia T 7 DNA polymerase sequencing kit. Computer analysis was done using the PC/GENE program. The sequence determined is given as SEQ ID NO:7 (in the Sequence Listing). The position of the introns was derived based on the consensus sequences for 5' and 3' splice sites. Example 4 Expression of the cloned axeA gene in A. niger N593 Example 4.1 Introduction of the axea gene in A. niger N593 by cotransformation The plasmid pIM150, obtained in Example 2.5 was introduced in A. niger by cotransformation of A. niger N593 (a pyr mutant of A. niger N402) using the A. niger pyrA as a selective marker on the plasmid pGW635 (Goosen et al., 1989, Mol. Gen. Genet. 219:282-288) and the plasmid pIM150 as the cotransforming plasmid. Protoplasts were prepared from mycelium by growing A. niger N593 on minimal medium supplemented with 0.5% yeast extract, 0.2% casamino acids, 50 mM glucose and 10 mM uridine for 20 hrs at 30° C. The preparation of protoplasts of A. niger N593 and the transformation procedure was performed as described by Goosen et al., 1987 (supra). The resulting PYR + transformants were analyzed for the expression of the axeA gene by Western blot analysis. Example 4.2 Screening of transformants for the expression of the axeA gene The transformants obtained in Example 4.1 were analyzed for the formation of the axeA gene product, the AXE I protein. Twenty transformants were selected and grown for 72 hrs on medium containing per 1; 30 g birch wood xylan (Roth); 6 g NaNO3, 0,5 g KCl, 0,5 g MgSO4.7H 2 O, 0.5 g CaCl 2 , 1,5 g KH2PO., and 0,1 g yeast extract and 1 ml/l Visniac solution (pH 6.0). After growth the mycelium was removed by filtration and the culture filtrate was analyzed by SDS-polyacrylamide gel electrophoresis, using a gel containing 12% acrylamide. The AXE I protein was detected on nitrocellulose after electroblotting and incubation with polyclonal antibodies raised against the AXE I protein purified as described in Example 1.1. The antibody bound, was detected after incubation with goat-anti-rabbit antibody conjugated to alkaline phosphatase, according to the Biorad instruction manual. Four of the twenty transformants analyzed overproduced the AXE I protein as detected by this procedure. The protein was secreted into the medium. Of the transformants analyzed one was selected for giving the highest yields of the AXE I protein, transformant TrA10. Example 5 Combined action of acetyl xylan esterase and endo-(1,4)-β-xylanase and β-(1,4)-xylosidase respectively A 0.2% (w/v) steamed birchwood xylan solution was incubated with acetyl esterase and combinations of acetyl esterase and endo-(1,4)-β-xylanase I, endo-(1,4)-β-xylanase II, endo-(1,4)-β-xylanase III or β-(1,4)-xylosidase in time. Time curves (as shown for endo-(1,4)-β-xylanase in FIG. 2) show that endo-(1,4)-β-xylanase I, II and III start releasing significant amounts of xylose and xylose oligomers (X2, X3 and X4) only after most of the acetyl groups have been released. The acetyl esterase does not release more acetic acid than when used in combination with xylan-degrading enzymes. The release of xylose by β-(1,4)-xylosidase from steamed birchwood xylan is slowly but steady. Without acetyl xylan esterase, the endo-(1,4)-β-xylanases and the β-(1,4)-xylosidase do not degrade the steamed birchwood xylan i.e. they do not release significant amounts of X1, X2, X3 and X4. The acetyl groups may therefore block the enzyme activity of the endo-(1,4)-β-xylanases or β-(1,4)-xylosidase activity. To emphasize the degradation of the steamed birchwood xylan, comparative studies were carried out by incubation of a steamed birchwood xylan for 24 hrs with only acetyl esterase, endo-(1,4)-β-xylanase I, endo-(1,4)-β-xylanase II, endo-(1,4)-β-xylanase III or β-(1,4)-xylosidase, and with combinations of acetyl esterase and these xylan-degrading enzymes. Also pre-incubations with acetyl esterase for 1 hr followed by 1 and 24 hrs incubations with the xylan-degrading enzymes were carried out. Table 1 shows the results of the release of acetic acid, xylose, and xylose oligomers after 24 hours of incubation. The acetyl xylan esterase releases 2.60-2.80 and 4.30 μmol/ml of acetyl groups after 1 and 24 hrs respectively (4.30 μmol/ml equals 80-90% release of all the acetyl groups). There is no increase in the initial rate for the release of acetic acid by using the combination of xylan-degrading enzymes and acetyl xylan esterase. Without acetyl xylan esterase, the endo-(1,4)-β-xylanases and β-(1,4)-xylosidase from A. awamori release no or only traces of xylose oligomers from steamed birchwood xylan (i.e. X 1 or X 1 , X 2 , and X 3 , by β-(1,4)-xylosidase and endo-(1,4)-β-xylanase I respectively). In combination with acetyl xylan esterase, these xylan-degrading enzymes release reasonable amounts of xylose oligomers after 24 hrs of incubation. However, by pretreating the steamed birchwood xylan with acetyl esterase for only 1 hr, the amount of xylose oligomers is somewhat lower. The combination of acetyl xylan esterase and xylan-degrading enzymes thus releases the highest amount of X 1 , X 2 , X 3 , and X 4 . This discrepancy may be explained by a linearization of the xylose oligomers by deacylation of the steamed birchwood xylan. If not degraded into smaller oligomers by the xylan-degrading enzymes, the higher xylose oligomers may aggregate as a result of this linearization and cause a precipitate. This precipitate is less accessible for degradation (Poutanen et al, 1989 and 1990). From the results presented here, it is clear that by the initial release of acetyl groups by the acetyl esterase, new sites have been created on the polysaccharide backbone suitable for the binding of endo-(1,4)-β-xylanase. The fact that the purified xylan-degrading enzymes from A. awamori did not degrade the steamed birchwood xylan significantly, coincides with the findings of Poutanen et al. (supra) that a crude preparation of A. awamori did not degrade steamed birchwood xylan significantly. TABLE 1______________________________________Release of acetic acid, xylose and xylose oligomersfrom a 0.2% (w/v) steamed birchwood xylan solutionby the single and combined action of 1.0 μg/mlacetyl esterase and 0.1 μg/ml endo-β-(1,4)-D-xylanase I, endo-β-(1,4)-D-xylanase II, endo-β-(1,4)-D-xylanase III or β-(1,4)-xylosidase. Product formation AceticType of incubation acid.sup.1 X.sup.2 X2.sup.2 X3.sup.2 X4.sup.2______________________________________Blanc 0.0 0.008 0.002 0.003 0.000AE 4.30Endo I 0.06 0.022 0.027 0.079 0.000Endo II 0.12 0.010 0.011 0.011 0.000Endo III 0.02 0.010 0.010 0.011 0.000β-xylosidase 0.16 0.065 0.000 0.000 0.000AE + Endo I 4.30 0.043 0.210 0.265 0.048AE + Endo II 4.30 0.010 0.104 0.252 0.105AE + Endo III 4.30 0.020 0.209 0.222 0.054xylosidase. 4.30 0.237 0.006 0.007 0.006AE.sup.3 + Endo.sup.4 I 2.64 0.036 0.149 0.253 0.063AE.sup.3 + Endo.sup.4 II 2.76 0.010 0.038 0.080 0.045AE.sup.3 + Endo.sup.4 III 2.55 0.012 0.067 0.077 0.042xylosidase.sup.4. 2.99 0.113 0.005 0.005 0.000______________________________________ .sup.1 μmol/ml .sup.2 mg/ml .sup.3 Preincubation 1 hr .sup.4 Preincubation 24 hrs Example 6 In vitro test of acetyl xylan esterase activity under conditions simulating the digestive tract of poultry 1.1 grams of feed or feed components (with or without acetyl xylan esterase) was incubated for 1 hour in 50 mM sodium acetate buffer pH 5.5 at 39° C., simulating chicken's crop. After lowering the pH to 3.0 with HCl and addition of 5 ml of a pepsin solution (Merck: 5.28 g/l) the mixture was incubated for 1.5 hours at 39° C. as in the stomach. The small intestine of birds was simulated by raising the pH to 6.5 by the addition of sodium phosphate (2.5 ml 1M) and 2.5 ml pancrealine/bile acids. After another 1.5 hours incubation at 39° C. the mixture was centrifuged. The pellet was dried and its weight determined. The difference between the weights of the pellets of treated and untreated material was a measure for enzymatic activity under the standard conditions. As examples of feed constituents wheat bran and maize meal were incubated with acetyl xylan esterase, according to the description given above. The dry matter digestibility was improved by several percents. This indicates that acetyl xylan esterase can be used in the degradation of other than wood-borne hemicellulose material. __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 8(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 21 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(v) FRAGMENT TYPE: N-terminal(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:SerGlySerLeuGlnGlnValThrAspPheGlyAspAsnProThrAsn151015ValGlyMetTyrIle20(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(v) FRAGMENT TYPE: N-terminal(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:TyrIleTyrValProAsnAsnLeuAlaSerAsnProGlyIleValVal151015AlaIleHisTyr20(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 amino acids(B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: peptide(v) FRAGMENT TYPE: N-terminal(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: 1(D) OTHER INFORMATION: /note= "This position is ?."(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: 11(D) OTHER INFORMATION: /note= "This position is(His/Thr)."(ix) FEATURE:(A) NAME/KEY: Modified-site(B) LOCATION: 15(D) OTHER INFORMATION: /note= "X represents eitherHistidine(His) or Threonine(Thr)"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:XaaSerGlyTyrSerGlySerPheProThrXaaGlnIleTyrXaaSer151015GlySerSerAsp20(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 29 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: group(9, 18, 21)(D) OTHER INFORMATION: /note= "N represents the nucleotideInosine(I)"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:GGRTTRTCNCCRAARTCNGTNACCTGCTG29(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(ix) FEATURE:(A) NAME/KEY: misc.sub.-- difference(B) LOCATION: group(9, 12)(D) OTHER INFORMATION: /note= "N represents the nucleotideInosine(I)"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:CCRAARTCNGTNACYTGYTG20(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: group(6, 9)(D) OTHER INFORMATION: /note= "N represents the nucleotideInosine(I)"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:TTRTTNGGNACRTAKATRTA20(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1943 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(vi) ORIGINAL SOURCE:(A) ORGANISM: Aspergillus niger(H) CELL LINE: E. coli. JM101::pGW150(ix) FEATURE:(A) NAME/KEY: TATA.sub.-- signal(B) LOCATION: 606..612(ix) FEATURE:(A) NAME/KEY: CAAT.sub.-- signal(B) LOCATION: 534..538(D) OTHER INFORMATION: /note= "CCAAT box."(ix) FEATURE:(A) NAME/KEY: CDS(B) LOCATION: join(713..917, 971..1227, 1306..1755)(ix) FEATURE:(A) NAME/KEY: misc.sub.-- feature(B) LOCATION: 713..787(D) OTHER INFORMATION: /note= "From 713 to 800prepropeptide."(ix) FEATURE:(A) NAME/KEY: mat.sub.-- peptide(B) LOCATION: join(788..917, 971..1227, 1306..1756)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:AAATATGTCTTTTATTACCTTGTTCTGTTGACTGGTGCATTACTTAAAACTAGAACAGTT60GTTCAAACACAAGTTGGACCTATACCTGTCATAACTCGCCTCGTCGCGTTATTCATCATG120CAAAAACTATCCGTTATCAGCGCCGGGAGTATACTCCCAAGAAGCTCACTCACATGCAAA180GAAATGTGCCGATTGCTTAAGCTTTACCCCAGATTATTCCGTAACCATATATCCATTCTG240GCTGAATACCGGCTATTTGATGCTGCATACTCTCACATTCCGCACAGCCGCCAGTGTGAA300GAATCACCAGTGGTCCAGCCCTGCAGTGGCTCTAACGGGATCTGTTACGGAGTTCGGCCC360GCAACGTCGATCTCTAACCATTTCGATCTGGAGTTCCCACTCCGTGCCGTCTATCCCAGA420CTCCTCATGTCGGAGCTGTCACGGCTGTCACATTAGCCCTGCTTAATTTCCGTGATGAAA480TCAGCCTACACTGTCATTTCTATGTCTAGACCACTGCCAAATACCCACTGAACCCAATAC540TTCCCACAACTATAGAAACATACTATTACTCCATAATGTTTCAATTTACCCGCTCTCTGC600AGCGCTATAAATCGTCTTCAAATCCTCTGGCGTCTTTCCTACTGCCCAAGCTGCATCTCT660TTTCACCTAGCAGGATTCAAGCGTAGTGCCTAGCACGGCAGAAGAAACCACCATG715MetCTACTATCAACCCACCTCCTCTTCGTCATCACCACCTTCTTAACCTCC763LeuLeuSerThrHisLeuLeuPheValIleThrThrPheLeuThrSer51015CTCCTCCACCCCATCGCCGCCCATGCTGTCAAGCGCAGTGGCAGTCTT811LeuLeuHisProIleAlaAlaHisAlaValLysArgSerGlySerLeu202530CAACAGGTCACCGATTTCGGTGACAACCCTACAAATGTAGGCATGTAC859GlnGlnValThrAspPheGlyAspAsnProThrAsnValGlyMetTyr354045ATCTACGTGCCTAACAACTTGGCCTCAAATCCAGGTATCGTGGTTGCA907IleTyrValProAsnAsnLeuAlaSerAsnProGlyIleValValAla50556065ATCCACTACTGTACGTTCCCCCACATTTCTACAATATAAACCACAATACT957IleHisTyrAAGCATGGCATAGGCACCGGTACCGGCCCCGGCTACTACAGCGCCTCC1005CysThrGlyThrGlyProGlyTyrTyrSerAlaSer707580CCCTACGCCACCCTCTCCGAGCAATACGGCTTTATCGTGATCTACCCG1053ProTyrAlaThrLeuSerGluGlnTyrGlyPheIleValIleTyrPro859095TCCAGCCCATACTCCGGTGGCTGTTGGGACGTGAGTTCACAGGCAACG1101SerSerProTyrSerGlyGlyCysTrpAspValSerSerGlnAlaThr100105110TTAACACACAACGGGGGCGGAAACAGTAACTCCATTGCCAACATGGTC1149LeuThrHisAsnGlyGlyGlyAsnSerAsnSerIleAlaAsnMetVal115120125ACCTGGACGATTAGCGAGTACGGGGCCGATAGTAGCAAGGTGTTCGTG1197ThrTrpThrIleSerGluTyrGlyAlaAspSerSerLysValPheVal130135140ACGGGATCGAGTTCGGGGGCTATGTTGACGGTATTTCCTCTTCCCTTCCA1247ThrGlySerSerSerGlyAlaMetLeuThr145150ACCGTTCCCCCTCTCTACAAATTAAAATAGTAAAAGTTGTGCATGCTAATAAAATTAG1305AACGTAATGGCAGCAACCTACCCCGAACTCTTCGCCGCCGCCACCGTC1353AsnValMetAlaAlaThrTyrProGluLeuPheAlaAlaAlaThrVal155160165170TACTCCGGAGTCTCAGCCGGGTGCTTCTACTCGAACACCAACCAAGTA1401TyrSerGlyValSerAlaGlyCysPheTyrSerAsnThrAsnGlnVal175180185GATGGATGGAATTCCACTTGCGCCCAGGGTGATGTAATCACCACCCCC1449AspGlyTrpAsnSerThrCysAlaGlnGlyAspValIleThrThrPro190195200GAGCACTGGGCCAGTATTGCAGAGGCAATGTACTCGGGATACTCAGGA1497GluHisTrpAlaSerIleAlaGluAlaMetTyrSerGlyTyrSerGly205210215AGTCGTCCAAGGATGCAGATCTACCACGGTACTCTCCATACGACGCTG1545SerArgProArgMetGlnIleTyrHisGlyThrLeuHisThrThrLeu220225230TATCCTCAGAACTACTATGAGACGTGCAAGCAGTGGTCTGGAGTGTTT1593TyrProGlnAsnTyrTyrGluThrCysLysGlnTrpSerGlyValPhe235240245250GGATATGATTATAGCGCACCGGAGAAGACGGAGGCGAATACCCCACAG1641GlyTyrAspTyrSerAlaProGluLysThrGluAlaAsnThrProGln255260265ACGAATTACGAGACGACGATTTGGGGAGATAGTCTGCAGGGAATCTTC1689ThrAsnTyrGluThrThrIleTrpGlyAspSerLeuGlnGlyIlePhe270275280GCGACAGGCGTGGGTCATACGGTGCCGATTCATGGGGATAAGGATATG1737AlaThrGlyValGlyHisThrValProIleHisGlyAspLysAspMet285290295GAGTGGTTTGGGTTTGCTTGATTGGATGATCGAATGGTTTAGCCTGGG1785GluTrpPheGlyPheAla300GGTATCTCGGAACCGGGAATGATGAAACTTCTGAAGTATGATATGTTAACGATATCGCGT1845CAACGAGCGTTTGTTGAAGCTTTAGTGTGTAATGTGGAGTATGAGCAAAATGTGCGCTGC1905CCGTGTCTGATGCCAAAACCAATGCAGCACAAGAGCTC1943(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 304 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:MetLeuLeuSerThrHisLeuLeuPheValIleThrThrPheLeuThr151015SerLeuLeuHisProIleAlaAlaHisAlaValLysArgSerGlySer202530LeuGlnGlnValThrAspPheGlyAspAsnProThrAsnValGlyMet354045TyrIleTyrValProAsnAsnLeuAlaSerAsnProGlyIleValVal505560AlaIleHisTyrCysThrGlyThrGlyProGlyTyrTyrSerAlaSer65707580ProTyrAlaThrLeuSerGluGlnTyrGlyPheIleValIleTyrPro859095SerSerProTyrSerGlyGlyCysTrpAspValSerSerGlnAlaThr100105110LeuThrHisAsnGlyGlyGlyAsnSerAsnSerIleAlaAsnMetVal115120125ThrTrpThrIleSerGluTyrGlyAlaAspSerSerLysValPheVal130135140ThrGlySerSerSerGlyAlaMetLeuThrAsnValMetAlaAlaThr145150155160TyrProGluLeuPheAlaAlaAlaThrValTyrSerGlyValSerAla165170175GlyCysPheTyrSerAsnThrAsnGlnValAspGlyTrpAsnSerThr180185190CysAlaGlnGlyAspValIleThrThrProGluHisTrpAlaSerIle195200205AlaGluAlaMetTyrSerGlyTyrSerGlySerArgProArgMetGln210215220IleTyrHisGlyThrLeuHisThrThrLeuTyrProGlnAsnTyrTyr225230235240GluThrCysLysGlnTrpSerGlyValPheGlyTyrAspTyrSerAla245250255ProGluLysThrGluAlaAsnThrProGlnThrAsnTyrGluThrThr260265270IleTrpGlyAspSerLeuGlnGlyIlePheAlaThrGlyValGlyHis275280285ThrValProIleHisGlyAspLysAspMetGluTrpPheGlyPheAla290295300__________________________________________________________________________

Methods and DNA constructs are provided for the expression of a fungal acetyl xylan esterase gene in microbial hosts. A purified fungal acetyl xylan esterase is obtained which is suited for the use as an accessory enzyme in the degradation of acetylated xylans.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the inclusion of break slots in broadcast video signals. 2. Description of the Prior Art The editing of additional material (for example a commercial break or an expert commentary or summary) into recorded video material presents no problem as regards preserving continuity in the original material. That is to say, it is easy to ensure that the editing operation does not involve the loss of wanted parts of the original material. However, the situation is altogether different in the case of at least some live broadcasts. In the case, for example, of live television transmissions of sporting events, natural breaks of sufficient length usually do not occur with sufficient regularity and/or predictability. To take a more specific example, consider a soccer game. The only predictable break long enough for the transmission to include commercials is at half-time. To include a break during play would involve the risk of an exciting and/or crucial part of the game being missed by the viewers. An object of the invention is to enable a break slot to be inserted into a broadcast signal in such a manner as to minimize the risk of desired program material thereby not being transmitted. SUMMARY OF THE INVENTION The invention provides a method of including a break slot in a broadcast video signal, in which the signal is fed through a RAM recorder having a variable delay, reading of the signal from the variable delay RAM recorder is controlled in such a manner that the delay produced by the RAM recorder is reduced from an accumulated value, and, after the delay produced by the variable delay RAM recorder has been reduced by a desired amount, reading out of the signal from the RAM recorder is inhibited until the delay produced by the RAM recorder has increased again to no more than said accumulated value, thereby to produce a break slot having a duration no more than said reduction of the delay produced by the RAM recorder. By employing the above method, no desired part of the material to be broadcast need be lost. A transmission can, for example, start by setting the delay of the variable delay RAM recorder to zero and writing the video signal into it until the delay has reached an initial accumulated value. While this is taking place (that is, during an initial break slot), other material, such as commercials, can be transmitted. The material written into the RAM recorder is then read out and transmitted with a total delay equal to the sum of the initial accumulated delay and any other delay (for instance that of a fixed delay RAM recorder mentioned below) that may be produced in the signal processing path. The initial accumulated delay of the variable delay RAM recorder may, for example, be equal to up to about three minutes, whereby the transmission is almost live, being delayed only by a small amount with respect to real time. As transmission carries on, the total delay is reduced as the delay produced by the variable delay RAM recorder is reduced from the initial accumulated value by controlling the reading of the signal from the RAM recorder. After the delay has been reduced by a sufficient amount, for example by up to about three minutes over a period of time equal to about twenty minutes, a further break slot (up to about three minutes in the above example) is available for the transmission of other material, such as commercials, after which transmission of the main material to be broadcast can be resumed at the same point at which it was stopped at the start of the further break slot. This process of creating a further break slot (for example, every 20 minutes or so) may be repeated indefinitely. In one embodiment of the invention, the signal is fed through a RAM recorder having a fixed delay before it is fed through the variable delay RAM recorder, the signal is viewed prior to its being fed through the fixed delay RAM recorder in order to identify portions of the signal to be edited out, and the step of controlling reading of the signal from the variable delay RAM recorder comprises causing the variable delay RAM recorder to skip reading said identified portions, whereby the delay produced by the variable delay RAM recorder is reduced from said accumulated value by the sum of the durations of said identified portions. The time for the break slot is thus, in this case, accumulated effectively by editing out portions (usually of different lengths) of the material that the operator considers need not be transmitted. The transmission can take place at normal speed. In another embodiment, the step of controlling reading of the signal from the variable delay RAM recorder comprises causing the signal to be read from the variable delay RAM recorder at a rate greater than the rate at which the signal is written to the variable delay RAM recorder, whereby the delay produced by the variable delay RAM recorder is reduced as time elapses in proportion to the difference between the reading and writing rates. In this case, no material need be edited out. Instead, the time for the break slot is accumulated by transmitting the material at a speed that is greater than its real speed. For instance, pursuing the example given above, the signal can be transmitted at a speed equal to 20/17 times the real speed so as to accumulate time for a break slot of three minutes (by reducing the delay produced by the variable delay RAM recorder from an accumulated value of three minutes to a final value of zero) over a period of twenty minutes. Provided that the ratio of the transmission speed to the real speed is reasonably close to unity, the fact that the transmission is speeded up will hardly be apparent to (or at least not irritating to) the viewer, at least for some types of program material. For the avoidance of doubt, the expression "broadcast" as used herein covers diffusion of a video signal by any medium, for example by radio broadcasting and/or cable diffusion. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will be apparent from the following detailed description of illustrative embodiments, which is to be read in conjunction with the accompanying drawings, in which like references designate like items throughout, and in which: FIG. 1 is a schematic block diagram of a first apparatus for including break slots in a broadcast video signal; FIG. 2 is a schematic representation of the manner of operation of RAM recorders forming part of the apparatus of FIG. 1; FIG. 3 is a schematic block diagram of a second apparatus for including break slots in a broadcast video signal. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the apparatus shown in FIG. 1, digital video and audio program signals outputted by a switcher (not shown), for example a switcher provided in an outside broadcast control unit covering a sporting event, are applied via busses 10 and 12 to a fixed delay video RAM (random access memory) recorder 14 and a fixed delay audio RAM recorder 16, respectively. Each of the recorders 14 and 16 has the same fixed delay. If the video RAM recorder 14 is (or is similar to), for example, a Type DEM1000 video RAM recorder as marketed by Sony Corporation, which can produce a delay of up to three minutes in accordance with the amount of RAM therein, the fixed delay of each of the recorders 14 and 16 is selected to be of a value, of no more than the maximum of three minutes available, sufficient to enable editing out (as described below) of the maximum sequence length for which it is anticipated that editing out will be required. Thus, for some applications, the fixed delay of each of the recorders 14 and 16 may be as little as (say) 20 seconds, whereas for others it may be larger. In view of the high cost of RAM at the present time, it is desirable that the fixed delay (and therefore the amount of RAM in the recorders 14 and 16) be as short as possible. A pre-preview monitor 18 is connected to the bus 10 to enable an operator of the apparatus to view the real time video signal outputted, for transmission, by the switcher. After having been subjected to the fixed delay in the recorders 14 and 16, the video and audio signals are passed via busses 20 and 22 to a variable delay video RAM recorder 24 and a variable delay audio RAM recorder 26, respectively. The recorders 24 and 26 subject the video and audio signals, respectively, to the same variable delay. If the video RAM recorder 24 is, for example, a Type DEM1000 recorder, the delay of each of the recorders 24 and 26 is advantageously variable between three minutes and zero. A preview monitor 28 is connected to the bus 20 to enable the operator of the apparatus to view the delay video signal outputted by the RAM recorder 14 before it is further delay by the RAM recorder 24. After having been subjected to a total delay equal to the sum of the fixed delay in the recorders 14 and 16 and the variable delay in the recorders 24 and 26, the video and audio signals are passed via busses 30 and 32 to be outputted to air, that is for broadcasting or transmission by radio (though cable diffusion could additionally or alternatively be employed.) A program monitor 34 is connected to the bus 30 to enable the operator of the apparatus to view the video signal outputted to air by the RAM recorder 24. The apparatus includes a controller 36 connected by a bus 38 to the recorders 24 and 26 to control their operation. The controller 36 can be of a design based upon that conventionally employed to control a Sony DEM1000 video RAM recorder in conventional applications thereof, except that (as described below) it must be able to store information, defining the timing of switching operations, included in an RS422 status report signal, and be able to translate that information into cue in and cue out commands. The controller 36 incorporates (or, as shown, is connected to) a delay display 40 that displays to the operator of the apparatus the value of the variable delay to which the signals are currently being subjected by the variable delay RAM recorders 24 and 26. A bus 42 is connected to the controller 36 to supply thereto the above-mentioned RS422 status report signal, which is outputted in conventional manner by the above-mentioned switcher. The controller 36 is fitted with a control panel 44 for use by the operator of the apparatus. The control panel 44 has mounted thereon three controls which may, for example, be in the form of pushbuttons, namely a mark cue in button 46, a mark cue out button 48 and a cancel segment button 50. The operation of the apparatus will be described below. Firstly, however, the construction and operation of the video RAM recorders 14 and 24 will be described. Each of the recorders 14 and 24 is capable of delaying a digital video signal by up to a predetermined amount of time by virtue of the fact that it contains an amount of RAM sufficient to store a commensurate number of fields. Consider for example the case of the Sony DEM1000 type RAM recorder which, when fitted with its maximum amount of RAM, can delay a signal for up to three minutes. A video RAM recorder able to produce a delay of three minutes will have sufficient RAM to store, for example, up to 10800 fields of the signal for a 60 field per second video system, or up to 9000 fields of the signal for a 50 field per second video system. To simplify comprehension of operation, the RAM can be considered to be arranged in a circle C of the appropriate number (for example 10800 or 9000 ) of addressable field spaces, as shown in FIG. 2 of the drawing. (It will of course be appreciated that, in reality, the physical arrangement of the RAM will not be circular.) At any one time, a write field space address pointer W (shown schematically by an arrow in FIG. 2) determines the field space into which a field of the input signal is being written (recorded) and a read field space address pointer R (shown schematically by an arrow in FIG. 2) determines the field space from which a stored field is being read (played back). For a fixed delay, the write and read field space address pointers (hereinafter referred to, for brevity, as the write and read pointers) W and R are stepped between the field spaces at the same speed, namely, for a 60 (50) field per second system, at a rate of (60) (50) steps per second. That is to say, pursuing the conceptual illustration shown in FIG. 2, the pointers W and R can be considered to be caused to rotate at the same speed around the circle C of field spaces in a counterclockwise direction, namely in the direction represented by an arrow a. The delay produced by the video RAM recorder is determined by the spacing between the current locations of the write and read pointers W and R and the angular speed of the read pointer R. In the case of FIG. 2, this delay is represented by the angle traversed, in the direction of the arrow a, in moving from the position of the read pointer R to the position of the write pointer W and the angular speed of the read pointer. For the particular positions of the pointers W and R illustrated in FIG. 2, in which the pointers are pointing to two adjacent field spaces, the delay is at a maximum (three minutes) in that each field space is not read (played back) until a full "revolution" (that is, up to 9000 fields) after video data was written into it. In the fixed delay video RAM recorder 14, the pointers W and R always remain, relative to one another, in the positions shown in FIG. 2, so that a fixed delay, more specifically the above-mentioned selected delay of up to three minutes (up to 10800 or 9000 fields), is always obtained. However, as described below, in the variable delay video RAM recorder 24 the read pointer R (but not the write pointer W) is caused to skip (jump) field spaces, that is to say it is caused to step in increments of more than one field space (in the direction of the arrow a), whereby some of the field spaces are not read (played back) and the delay produced by the recorder (the spacing between the pointers) is reduced. The audio RAM recorders 16 and 26 may be constructed and may operate in the same way as the video RAM recorders 14 and 24, except that each of the addressable spaces thereof (the selected value of up to 10800 or 9000 in the case of the recorder 16 and the value of 10800 or 9000 in the case of the recorder 26) will store the audio information corresponding to one video field rather than the video information constituting one video field. The operation of the apparatus will now be described. The object is to provide, once every (say) 20 minutes or so, a break slot of up to three minutes in a live program received by the apparatus from the switcher to enable transmission of, for example, commercials or an expert commentary/summary. The object is achieved, as set forth in more detail below, by first filling up the recorders 24 and 26 so as thereby to define an initial break slot while they are being filled up, and then creating at least one further break slot by using the apparatus effectively to edit out portions (hereinafter also referred to as redundant portions) of the program which it is not desired to transmit, the respective durations of which portions sum to a value equal to or greater than the duration of the break slot. Initially, the operator commands the controller 36 to cause the write and read pointers W and R for the variable delay RAM recorders 24 and 26 to be relatively positioned (as described above) to produce a zero delay, which value is displayed in the delay display 40, and to cause the write pointers W to advance and the read pointers R to remain stationary ("frozen"). Thus, the program material outputted by the fixed delay RAM recorders 14 and 16 is written into (recorded by) the variable delay RAM recorders 24 and 26, and the material is not read (reproduced) from the recorders 24 and 26. That is, the recorders 24 and 26 start to be filled up with program material. While this is taking place, that is during the initial break slot, commercials or the like can be transmitted. During the initial break slot, the delays produced by the recorders 24 and 26 increase from their initial (zero) values. When the delays reach an accumulated value of not greater than the maximum capacities (three minutes in the present example) of the RAM recorders 24 and 26, by which time the transmission of commercials or the like has ended, the operator commands the controller 36 to unfreeze the read pointers R for the variable delay RAM recorders 24 and 26. The read pointers R thus advance in step with the write pointers W, the spacings between them corresponding to the accumulated delay value of up to three minutes. This value (which remains constant for the time being) is displayed in the delay display 40. The operator then watches the pre-preview monitor 18 with the aim of identifying redundant portions of the program received from the switcher; and makes a physical and/or mental note thereof. Having decided on a portion that can be omitted from the broadcast program, the operator waits for that portion to come up (after the fixed delay produced by the RAM recorders 14 and 16) on the preview monitor 28. At the start of the display of the portion on the preview monitor 28, the operator presses the mark cue in button 46 on the control panel 44, which applies a mark cue in command to the controller 36. The mark cue in command has no effect on the write pointers W. That is, the signals continue to be written in an uninterrupted manner, field by field, into the recorders 24 and 26. However, the controller 36 notes the timing of the mark cue in command (that is, the position in memory of the field at which the button 46 was pressed) and starts to count elapsed fields from the moment that the button 46 was pressed. At the end of the display of the redundant portion on the preview monitor 28, the operator presses the mark cue out button 48, which applies a mark cue out command to the controller 36. The mark cue out command also has no effect on writing of the signals into the recorders 24 and 26. However, on issuance of the mark cue out command, the controller 36 notes the duration (number of fields) of the redundant portion, subtracts this from the current delay of the recorders 24 and 26 and displays the new (reduced) delay on the display 40. Also, knowing the current delay, the controller 36 determines when the read pointer R for each of the recorders 24 and 26 will point to that one of the field spaces located immediately before the first field space in which the redundant portion is recorded (cue in). When, for each of the recorders 24 and 26, the read pointer R points to said one field space, the controller 36 causes the read pointer to skip the redundant portion, that is to jump ahead to the next field space following the redundant portion (cue out). This action has two consequences. First, the redundant portion, though written into the recorders 24 and 26, is not read therefrom and is therefore not transmitted. Second, the delay produced by the recorders 24 and 26 is reduced from its previous value by the duration of the redundant portion. The foregoing editing operation is repeated, the duration of each redundant portion being subtracted from the previous value of the delay produced by the variable delay RAM recorders 24 and 26. That is, the delay (which can be viewed by the operator on the display 40) produced by the recorders 24 and 26 is reduced by the sum of the durations of successively operator-selected redundant portions. Repetition of the editing operation is stopped when the delay is reduced to near zero, if a three minute break slot is desired, or until it is reduced to some value greater than near zero if a break slot of less than three minutes is desired. When (e.g. twenty minutes after the start of the program or after the previous break slot) it is desired that a bread slot should commence, the controller 36 is responsive to an indication thereof by the operator to "freeze" the read pointers R of the recorders 24 and 26. Thus, the recorders 24 and 26 stop reading out the signals stored therein, but continue to have signals written into them. Thus, the write pointers W start to catch up the read pointers R. That is, the delay produced by the recorders 24 and 26 starts to increase towards the maximum value, at which, for each recorder, the write and read pointers are adjacent to one another, as shown in FIG. 2. The break slot is stopped at or before this point since, if it went on after this point then, in the absence of any preventive measure, the write pointer W would overtake the read pointer R and reduce the delay to zero. At least one further break slot may then be established by repeating the pre-viewing and editing steps as described above. It was explained above how redundant (unwanted) program portions could be marked by using the mark cue in and mark cue out buttons 46 and 48 to mark the beginnings and ends of the portions. As will now be described, the apparatus enables redundant portions to be marked in an alternative way. As the program is being created, the switcher mentioned above is used to switch between different cameras. That is, the program outputted by the switcher comprises successive program segments, of different lengths, each originating from a different camera than the preceding segment and each having its start and end defined by a camera switching operation. As is well known to those skilled in the art, the above-mentioned RS422 status report signal produced by the switcher (applied via the bus 42 to the controller 36) contains information defining the timing of the switching operations and therefore defining the beginning and end of each program segment. Now it may be the case that, when looking at the preview monitor 18, the operator will decide that an entire program segment is unwanted. Should this be the case, the operator can define that segment as being a redundant portion without any need to mark its beginning and end. Instead, all he has to do is to wait for the segment in question to come up on the preview monitor 28 and, when it does, to press the cancel segment button 50 on the control panel 44 to issue a segment cancel command to the controller 36. The controller 36 is (as mentioned above) operative to store the timings of the switching operations contained in the status report signal on the bus 42. When the controller 36 receives a segment cancel command, it treats the previous (stored) switching operation as a mark cue in command and the following switching operation as a mark cue out command whereby the entire segment is treated as a redundant portion just as if it had been marked, as described above, by use of the mark cue in and mark cue out buttons 46 and 48. FIG. 3 shows a modification of the apparatus described above with reference to FIG. 1. In the apparatus of FIG. 3, break slots are created without editing out portions of the program outputted by the switcher. Therefore, in the modification, the monitors 18 and 28, the fixed delay RAM recorders 14 and 16 and the buttons 46, 48 and 50 are not needed. Instead, the controller 36 is operative to cause the variable delay RAM recorders 24 and 26 to read out (play back) the signals stored therein at a speed which is greater than that at which the signals are written into (recorded in) the recorders 24 and 26. This has the effects that: (i) the transmitted signal is transmitted at a speed that is higher than its original (real) speed; and (ii) starting from its accumulated value of up to three minutes, the delay produced by the recorders 24 and 26 is reduced as time elapses in proportion to the difference between the reading and writing speeds. For example, if the ratio of the reading speed to the writing speed is 20:17, the delay produced by the recorders 24 and 26 will be reduced from three minutes to zero, producing a break slot of three minutes, over a period of twenty minutes. Provided that the ratio of the transmission (reading) speed to the real (writing) speed is reasonably close to unity, the fact that the transmission is speeded up will hardly be apparent to (or at least not irritating to) the viewer, at least for some types of program material. The invention can, of course, be carried into effect in other manners than those described above by way of example. For instance, whereas in the illustrated arrangements the video and audio output signals from the switcher are processed through respective pairs (14/24 and 16/26) of fixed and variable delay RAM recorders in the case of FIG. 1 or a respective pair (24/26) of variable delay RAM recorders in the case of FIG. 3, if the audio signal were (in a manner known per se) digitally inserted into the video signal, the fixed delay and variable delay audio RAM recorders 16 and 26 would not be needed and could be dispensed with. Although the above-described embodiments preferably employ Sony Type DEM1000 or similar video RAM recorders, in which the RAM is of semiconductor form, it is to be noted that the expression "RAM" is not to be interpreted as being restricted to random access memory which is wholly in semiconductor or other electronic form. While the recorders must be of a random access form, whereby the use of serial access devices such as tape recorders is precluded, it is believed that RAM recorders having an access arrangement at least partially of a mechanical nature could be employed. For example, it is contemplated that storage of video information could be effected on an erasable video disc. While random access to such a disc is, unlike random access to a semiconductor memory, not substantially instantaneous, it is believed that a RAM recorder with the majority of information recorded on disc, and with a semiconductor type buffer memory interacting with the disc storage to make access substantially instantaneous, might well operate satisfactorily. Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope and spirit of the invention as defined by the appended claims.

In order to include a break slot in a broadcast video signal, the signal is first fed through a RAM recorder having a variable delay. Reading of the signal from the RAM recorder is controlled in such a manner that the delay produced by the RAM recorder is reduced from an accumulated value. After the delay has been reduced by a desired amount, reading out of the signal from the RAM recorder is inhibited until the delay has increased again to no more than the accumulated value, thereby to produce a break slot having a duration no more than the reduction of the delay produced by the RAM recorder. The reduction of the delay produced by the RAM recorder may be brought about by: skipping the reading of unwanted portions of the signal stored in the RAM recorder, by feeding the signal through a fixed delay RAM recorder before feeding it through the variable delay RAM recorder and viewing the signal before it is fed through the fixed delay RAM recorder to identify portions of the signal to be edited out; or by reading from the variable delay RAM recorder at a speed greater than the speed at which the signal is written to the variable delay RAM recorder.

BACKGROUND OF THE INVENTION The antibiotic lincomycin, formerly known as lincolnensin, can be produced by the microorganism S. lincolnensis var. lincolnensis, NRRL 2936, as disclosed in U.S. Pat. No. 3,086,912. The incubation temperature range disclosed in said patent for the production of lincomycin is 18° to 40° C., and preferably 26° to 30° C. Also produced during the lincomycin fermentation is the compound known as lincomycin B. Though lincomycin and lincomycin B have activity against essentially the same spectrum of microorganisms, it is known that lincomycin B is significantly less active against said microorganisms than is lincomycin. Accordingly, lincomycin is the preferred antibiotic of the two. In conducting the above fermentation, it is necessary to use a large amount of cooling water in most fermentation equipment to maintain the desired fermentation temperature. Further, the maintenance of a temperature within the range of 18° C. to 40° C., though essential for antibiotic production as disclosed above, is conducive to the development and proliferation of contaminating microorganisms in the fermentation vessel. BRIEF SUMMARY OF THE INVENTION The subject invention concerns the fermentation preparation of lincomycin by the novel microorganism Streptomyces vellosus var. vellosus, NRRL 8037, at a temperature range of 18° to 45° C. It has been found, unexpectedly, that the titer of lincomycin produced at 45° C. is comparable to that which is produced at 28° C. The production of lincomycin at 28° C. and 45° C. for the microorganism of the subject invention is shown in the following table. The zone sizes of inhibition are given in millimeters. The test is a standard microbiological disc plate assay using 13 mm. paper discs. ______________________________________Organism 28° C. 45° C.______________________________________Bacillus subtilis 21 18Staphylococcus aureus 22 24Sarcina lutea 31 29Klebsiella pneumoniae 0 0Escherichia coli 0 0Salmonella schottmuelleri 0 0Mycobacterium avium 22 25Penicillium oxalicum 0 0______________________________________ The results shown in the above table are unexpected since our tests have shown that S. lincolnensis var. lincolnensis, NRRL 2936, does not produce lincomycin when incubated at a temperature of about 45° C. A distinct advantage in using this microorganism to prepare lincomycin is the need for less fermentor cooling capacity. The need for less cooling capacity is especially significant in high temperature climates and in areas having limited water supplies since water is the generally used means for cooling and maintaining fermentation temperatures. A further distinct advantage in the process of the subject invention is that lincomycin is produced without the concomitant production of lincomycin B. DETAILED DESCRIPTION OF THE INVENTION THE MICROORGANISM The novel actinomycete used according to this invention for the production of lincomycin is Streptomyces vellosus. One of its strain characteristics is the production of lincomycin without the concomitant production of lincomycin B. Another of its strain characteristics is the production of comparable titers of lincomycin at a temperature of 28° C. and 45° C. A subculture of this living organism can be obtained upon request from the permanent collection of the Northern Regional Research Laboratories, Agricultural Research Services, U.S. Department of Agriculture, Peoria, Illinois, U.S.A. Its accession number in this repository is NRRL 8037. The microorganism of this invention was studied and characterized by Alma Dietz of the Upjohn Research Laboratory. A thermoduric Streptomyces species isolated from Arizona soil produces the antibiotic lincomycin. The culture is readily differentiated from other lincomycin-producers as may be noted in Table 4. The thermoduric property, the microscopic characteristics of long, straight spore chains coiled at the tip, spores with long spines and hairs, and the distinctive antibiotic-producing capability of Streptomyces vellosus are not reported for any of the Streptomyces species with blue-gray spore color mass cited in the significant Streptomyces taxonomy publications of Hutter [Hutter, R. 1967. Systematik der Streptomyceten unter besondere Berucksichtigung der von ihnen gebildeten Antibiotica. S. Karger, Basel], Krassilnikov [Krassilnikov, N. A. et al. 1966. Biology of Antibiotic-Producing Actinomycetes. Akademiya Nauk SSSR. Edited by Ya. I. Rautenstein. Published for the U.S. Department of Agriculture and the National Science Foundation, Washington, D.C. by the Israel Program for Scientific Translations], Kutzner [Kutzner, H. J. 1956. Beitrag zur Systematik und Okologie der Gattung Streptomyces Waksm. et Henrici. Diss. Landw. Hochst. Hohenhein], Pridham, et al [Pridham, T. G., C. W. Hesseltine, and R. G. Benedict. 1958. A guide for the classification of streptomycetes according to selected groups. Placement of strains in morphological section. Applied Microbiol. 6:52-79], Shirling and Gottlieb [Shirling, E. B., and D. Gottlieb. 1968. Cooperative description of type cultures of Streptomyces. II. Species descriptions from first study. Int. J. Of Syst. Bacteriol. 18:69-189; Shirling, E. B. and D. Gottlieb. 1968. Cooperative description of type cultures of Streptomyces. III. Additional species descriptions from first and second studies. Int. J. of Syst. Bacteriol. 18:279-392; Shirling, E. B. and D. Gottlieb. 1969. Cooperative description of type cultures of Streptomyces. IV. Species descriptions from the second, third and fourth studies. Int. J. Of Syst. Bacteriol. 19:391-513; and Shirling, E. B. and D. Gottlieb. 1972. Cooperative description of type strains of Streptomyces V. Additional descriptions. Int. J. of Syst. Bacteriol. 22:265-394], Trejo [Trejo, W. H. and R. E. Bennett. 1963. Streptomyces species comprising the blue-spore series. J. Bacteriol. 85:676-690], or Waksman [Waksman, S. A. 1961. The actinomycetes, vol. 2, Classification, identification, and descriptions of genera and species. The Williams & Wilkins Co., Baltimore]. Therefore, it is proposed that this isolate be designated Streptomyces vellosus Dietz, sp.n. and that this type species be designated the type variety Streptomyces vellosus var. vellosus. The species and variety designations are made in accordance with the Rules set forth in the International Code of Nomenclature of Bacteria [International Code of Nomenclature of Bacteria. 1966. Edited by the Editorial Board of the Judicial Commission of the International Committee on Nomenclature of Bacteria. Int. J. Syst. Bacteriol. 16:459-490]. Streptomyces vellosus Dietz, sp. n. Color characteristics. Aerial growth blue-gray to gray. Melanin-positive. Color on Ektachrome [Dietz, A. 1954. Ektachrome transparencies as aids in actinomycete classification. Ann. N.Y. Acad. Sci. 60:152-154] is given in Table 1. Reference color characteristics are given in Table 2. Streptomyces vellosus may be placed in the Blue (B) and White (W) color series of Tresner and Backus [Tresner, H. D., and E. J. Backus. 1962. System of color wheels for Streptomycete taxonomy. Applied Microbiol. 11:335-338]. Microscopic characteristics. Spore chains long, straight with a tight to open coil at the tip. Spore chains spiral (S) as defined by Pridham et al. [Pridham, T. G., C. W. Hesseltine, and R. G. Benedict. 1958. A guide for the classification of streptomycetes according to selected groups. Placement of strains in morphological sections. Applied Microbiol. 6:52-79]. Spores large, mostly oval. Spore surface adorned with long spines and hairs. Spore surface hairy as defined by Dietz and Mathews [Dietz, A. and J. Mathews. 1971. Classification of streptomyces spore surfaces into five groups. Appl. Microbiol. 21:527-533]. Cultural and biochemical characteristics. See Table 3. Carbon utilization. The growth of S. vellosus on carbon compounds was determined using the snythetic media of Pridham and Gottlieb [Pridham, T. G., and D. Gottlieb, 1948. The utilization of carbon compounds by some Actinomycetales as an aid for species determination. J. Bacteriol. 56:107-114] and of Shirling and Gottlieb [Shirling, E. B., and D. Gottlieb. 1966. Methods for characterization of Streptomyces species. Int. J. of Syst. Bacteriol, 16:313-340]. In the former, the culture showed trace growth on the control (basal medium without a carbon compound), dulcitol, D-sorbitol, sodium oxalate, and sodium tartrate, moderate growth on sodium acetate, sodium citrate, and sodium succinate; good growth on D-xylose, L-arabinose, rhamnose, D-fructose, D-galactose, D-glucose, D-mannose, maltose, sucrose, lactose, cellobiose, raffinose, dextrin, inulin, soluble starch, glycerol, D-mannitol, and inositol. The culture did not grow on salicin, phenol, cresol, sodium fomate or sodium salicylate. In the medium of Shirling and Gottlieb the culture grew slightly on the negative control (basal medium without a carbon compound) as well on the positive control (basal medium with D-glucose). Growth was equal to or better than on the basal medium plus glucose on D-xylose, inositol, D-mannitol, rhamnose and raffinose. Growth was significantly better than on the negative control but less than on the D-glucose control on L-arabinose, sucrose, and D-fructose. Growth on cellulose was doubtful. Temperature. S. vellusus is a thermoduric actinomycete. It grows well at temperatures of 18-55 C. Optimum growth occurs at 28-37 C. in 10-14 days; at 45° C. in 48 hours. Antibiotic-producing properties. S. vellosus produces the antibiotic lincomycin. Source. Soil from Arizona. Type culture. Streptomyces vellosus Dietz. sp.n. NRRL 8037. Type variety. Streptomyces vellosus var. vellosus NRRL 8037. TABLE 1______________________________________Appearance of Streptomyces vellosus on Ektachrome*Agar Media Surface Reverse______________________________________Bennett's Gray Tan-brownCzapek's sucrose Trace gray Yellow-tanMaltose tryptone -- BrownPeptone-iron -- Brown0.1% Tyrosine Trace blue-gray BrownCasein-starch Blue-gray Tan-brown______________________________________ *Dietz, A. 1954. Ektachrome transparencies as aids in actinomycete classification. Ann. N.Y. Acad. Sci. 60:152-154. TABLE 2__________________________________________________________________________Reference Color Characteristics of Streptomyces vellosus Color Harmony Manual NBS Circular 553,Agar medium Determination 3rd ed., 1948* 1955**__________________________________________________________________________Bennett's S 15ba (g) to 5ba blue tint 184m very pale blue to shell pink 189gm bluish white 9m pinkish white R 3gc light tan 76gm light yellowish brown P 3ie camel, maple sugar, 76m light yellowish brown Tan 77g moderate yellowish brownCzapek' s sucrose S 3cb sand -- R 3ec bisque, light beige 79gm light grayish yellowish brown 90 grayish yellow P -- --Maltose-tryptone S 5ba shell pink 9 pinkish white R 31g adobe brown, cinnamon 77gm moderate yellowish brown brown, light brown P 3ie camel, maple sugar, tan 76m light yellowish brown 77g moderate yellowish brownHickey-Tresner S 15ba to 3cb blue tint to 184m very pale blue sand 189gm bluish white R 31g adobe brown, cinnamon 77m moderate yellowish brown brown, light brown P 31e cinnamon, yellow maple 74g strong yellowish brown 76m light yellowish brownYeast extract- S 15ba to 2ba blue tint to 184m very pale bluemalt extract pearl, shell tint 189gm bluish white(ISP-2) 92gm yellowish white R 3b 74g strong yellowish brown 76m light yellowish brown P 31e 74g strong yellowish brown 76m light yellowish brownOatmeal S 15cb cloud blue 184m very pale blue(ISP-3) 190g light bluish gray R 2gc bamboo, chamois 90 gm grayish yellow P -- --Inorganic- S 19dc aqua gray 149g pale greensalts starch 190m light bluish gray(ISP-4) R 2fb bamboo, buff, 87g moderate yellow straw, wheat 89m pale yellow P -- --Glycerol- S 15ba blue tint 184m very pale blueasparagine 189gm bluish white(ISP-5) R 2fb bamboo, buff, 87g moderate yellow straw, wheat 89m pale yellow P -- --__________________________________________________________________________ S = Surface (g) = all from glossy surface of color chip R = Reverse g = glossy surface of color chip P = pigment m = matte surface of color chip gm = glossy or matte surface of color chip *Jacobson, E., W. C. Granville, and C. E. Foss. 1948. Color harmony manual, 3rd ed. container Corporation of America, Chicago, Illinois. **Kelly, K. L., and D. B. Judd. 1955. The ISCCNBS method of designating colors and a dictionary of color names. U.S. Dept. Comm. Circ. 553. TABLE 3__________________________________________________________________________Cultural and Biochemical Characteristics of Streptomyces vellosusMedium Surface (aerial growth) Reverse Other Characteristics__________________________________________________________________________Agar mediaPeptone-iron None at 28 C. Brown Brown pigment Gray at 45 C. Melanin-positiveCalcium-malate Trace white Colorless No pigment Malate not solubilizedGlucose- Pale pink-white Cream at 28 C. Yellow pigment at 28 C.asparagine Olive at 45 C. No pigment at 45 C.Skim milk Trace gray at 28 C. Tan brown Tan brown pigment None at 45 C. Casein not solubilizedTyrosine Trace gray at 28 C. Brown at 28 C. Brown pigment at 28 C. Fair gray at 45 C. Tan at 45 C. Tan pigment at 45 C. Tyrosine not solubilized at 28 C. Tyrosine solubilized under growth at 45 C.Xanthine None at 28 C. Yellow Yellow pigment Pink white at 45 C. Xanthine not solubilizedNutrient starch None at 28 C. Yellow tan at 28 C. Yellow tan pigment at 28 C. Pink-white at 45 C. Yellow at 45 C. Yellow pigment at 45 C. Starch not hydrolyzedYeast extract- Pink white (best at 45 C.) Red tan at 28 C. Red tan pigment at 28 C.malt extract Tan at 45 C. Tan pigment at 45 C.Bennett's Pale cottony blue-white Tan Tan pigmentCzapek's Pale cream pink Yellow Yellow pigmentsucroseMaltose- Pale cottony blue-white Brown Brown pigmenttryptoneHickey-Tresner Pale cottony blue-white Orange-tan Pale tan pigmentPeptone-yeast None Brown Brown pigmentextract-iron Melanin-positive(ISP-6)Tyrosine Pink-white Brown Brown Pigment(ISP-7) Melanin-positiveGelatin MediaPlain -- -- Brown pigment at surface Olive pigment top half No liquefactionNutrient -- -- Brown pigment at surface Tan pigment throughout No liquefaction - 2 tubes Trace liquefaction - 2 tubesBroth mediaSynthetic nitrate -- -- Colorless vegetative growth throughout broth and at base No pigment Nitrate not reduced to nitriteNutrient nitrate -- -- Colorless compact bottom growth Yellow pigment Nitrate not reduced to nitriteLitmus milk White-gray aerial -- Brown pigment growth on surface Litmus reduced ring pH 6.8__________________________________________________________________________ TABLE 4__________________________________________________________________________Comparison of Streptomyces vellosus with other lincomycin-producers S. vellosus S. lincolnensis S. espinosus NRRL 8037 NRRL 2936 NRRL 3890__________________________________________________________________________Aerial mycelium Blue gray to gray Cream to pink to gray Gray greenMelanin Positive Positive NegativeSpore chains Spiral (S)-very long Long flexuous (RF) Short, straight to and coiled at tip flexuous to open spiral (RF,RA)-shortSpores Spherical Rectangular SphericalSpore surface Long spines and hairs Smooth with surface detail Thorny to spiny- transition to hairy on some spinesCalcium malate agar Malate not solubilized Malate not solubilized Malate not solubilizedSkim milk agar Casein not solubilized Casein not solubilized Casein solubilizedTyrosine Not solubilized Solubilized SolubilizedXanthine Not solubilized Solubilized around Not solubilized growthNutrient starch Starch not hydrolyzed Starch hydrolyzed Starch hydrolyzed__________________________________________________________________________ S. pseudogriseolus S. variabilis chemovar linmyceticus chemovar liniabilis NRRL 3985 NRRL 5618__________________________________________________________________________Aerial mycelium Gray to white to red Gray to whiteMelanin Negative NegativeSpore chains Short to moderately long straight (RF) Short to moderately to open spiral (RA) to spiral (S) long flexuous (RF) to open spiral (RA)Spores Oval to oblong Oval to oblongSpores surface Sparsely spiny to smooth Smooth to poorly warty to spinyCalcium malate agar Malate not solubilized Malate solubilizedSkim milk agar Casein solubilized under growth Casein solubilizedTyrosine Solubilized SolubilizedXanthine Solubilized SolubilizedNutrient starch Starch hydrolyzed Starch hydrolyzed around growth__________________________________________________________________________ Lincomycin is produced by the novel microorganism of the subject invention when said microorganism is grown in an aqueous nutrient medium under submerged aerobic conditions. It is to be understood also that for the preparation of limited amounts surface cultures and bottles can be employed. The organism is grown in a nutrient medium containing a carbon source, for example, an assimilable carbohydrate, and a nitrogen source, for example, an assimilable nitrogen compound or proteinaceous material. Preferred carbon sources include glucose, brown sugar, sucrose, glycerol, starch, cornstarch, lactose, dextrin, molasses, and the like. Preferred nitrogen sources include corn steep liquor, yeast, autolyzed brewer's yeast with milk solids, soybeam meal, cottonseed meal, cornmeal, milk solids, pancreatic digest of casein, distillers' solids, animal peptone liquors, fishmeal, meat and bone scraps, and the like. Combinations of these carbon and nitrogen sources can be used advantageously. Trace metals, for example, zinc, magnesium, manganese, cobalt, iron, and the like, usually need not be added to the fermentation media since tap water and unpurified ingredients are used as media components. Production of lincomycin by the process of the subject invention can be effected at a temperature of about 18° to about 45° C., and preferably at a temperature of about 20° C. to about 45° C. Ordinarily, optimum production of lincomycin is obtained in about two to ten days. The final pH is dependent, in part, on the buffers present, if any, and in part on the initial pH of the culture medium. When growth is carried out in large vessels and tanks, it is preferable to use the vegetative form, rather than the spore form, of the microorganism for inoculation to avoid a pronounced lag in the production of lincomycin and the attendant inefficient utilization of the equipment. Accordingly, it is desirable to produce a vegetative inoculum in a nutrient broth culture by inoculating this broth culture with an aliquot from a soil or a slant culture. When a young, active vegetative inoculum has thus been secured, it is transferred aseptically to large vessels or tanks. The medium in which the vegetative inoculum is produced can be the same as, or different from, that utilized for the production of lincomycin, as long as it is such that a good growth of the microorganism is obtained. The lincomycin produced by the subject process can be recovered by the procedure disclosed in U.S. Pat. No. 3,086,912. In preferred recovery process. lincomycin is recovered from its culture medium by separation of the mycelia and undissolved solids by conventional means, such as by filtration and centrifugation. Lincomycin is then recovered from the filtered or centrifuged broth by passing said broth over a resin which comprises a non-ionic macro porous copolymer of styrene crosslinked with divinylbenzene. Resins of this type are disclosed in U.S. Pat. No. 3,515,717. Exemplary of this type of resin in Amberlite XAD-2. Lincomycin is eluted from the resin with a solvent system consisting of methanol water (95:5 v/v). Bioactive eluate fractions are determined by a standard microbiological disc plate assay using the microorganism Sarcina lutea. Biologically active fractions are combined, concentrated to an equeous solution which is then freeze dried. The freeze dried material is then triturated with methylene chloride. The methylene chloride extract is concentrated to dryness and the residue triturated with acetone. The filtrate is mixed with ether to give a precipitate which is separated. The remaining filtrate is mixed with methanolic hydrogen chloride (1 N) to precipitate colorless lincomycin hydrochloride. This precipitate is isolated by filtration and crystallation from water-acetone to give crystalline lincomycin hydrochloride. The process of the subject invention is not limited to the particular microorganism fully described by the cultural characteristics disclosed herein. It is intended that this invention also include other lincomycin-producing strains or mutants of the said microorganism which can be produced by procedures well known in the art, for example, by subjecting the novel microoganism to x-ray or ultraviolet radiation, nitrogen mustard, phage exposure, and the like. Hereinafter is described a non-limiting example of the process of the present invention. All percentages are by weight and all solvent portion mixtures are by volume unless otherwise noted. EXAMPLE 1 Part A. FERMENTATION AT 28° C. A soil slant of Streptomyces vellosus, NRRL 8037, is used to inoculate a series of 500-ml. Erlenmeyer flasks containing 100-ml. of sterile seed medium consisting of the following ingredients: Glucose monohydrate: 25 g./liter Pharmamedia*: 25 g./liter Tap water q.s.: Balance Presterilization pH=7.2 The flasks are grown for 3 days at 28° C., on a rotary shaker. Seed inoculum, described above, is used to inoculate a series of 500-ml. Erlenmeyer fermentation flasks containing 100-ml. of sterile medium consisting of the following ingredients: Glucose monohydrate: 15 g./liter Wilson's Peptone Liquor No. 159*: 15 g./liter Difco Yeast Extract**: 2.5 g./liter Tap water q.s.: Balance Presterillization pH=6.0 The flasks are inoculated with 5 ml. of seed inoculum per 100 ml. of fermentation medium. The flasks are then incubated at 28° C. on a rotary shaker operating at 250 rpm with a 6 cm. stroke. The flasks are harvested after 96 hours of fermentation. Part B. FERMENTATION AT 45° C. Seed inoculum, as described above in Part A, is used to inoculate a series of 500-ml. Erlenmeyer fermentation flasks containing 100 ml. of sterile medium consisting of the following ingredients: Glycerol: 30 g./liter NZ-amine B*: 20 g./liter Difco Yeast Extract: 2 g./liter Sodium chloride: 3 g./liter Tap water q.s.: Balance Presterilization pH=7.2 The flasks are inoculated with 5 ml. of seed inoculum per 100 ml. of fermentation medium. The flasks are then incubated at 45° C. on a rotary shaker operating at 250 rpm with a 6 cm. stroke. The flasks are harvested after 96 hours of fermentation. Part C. RECOVERY The lincomycin produced in the fermentations as disclosed in Parts A and B is recovered in pure form by first filtering the fermentation beers using diatomaceous earth as filter aid. The filter cake is washed with water and the wash is combined with the clear filtrate. The clear filtratewash is then passed over a column containing Amberlite XAD-2 resin packed in water. The lincomycin is eluted from the resin with methanol-water (95:5 v/v). Fractions are collected and analyzed by thin layer chromatography on silica gel G using the solvent system consisting of methyl ethyl ketone-acetone-water (186:52:20 v/v). Active fractions are combined and concentrated to an aqueous and freeze dried. The dry material is then triturated with methylene chloride. The methylene chloride extract is concentrated to dryness. The resulting residue is triturated with acetone. Insoluble material is removed by filtration and the remaining filtrate is mixed with ether. Again, precipitated material is removed by filtration and the remaining filtrate is mixed with methanolic hydrogen chloride (1 N). The resulting precipitated colorless lincomycin hydrochloride is isolated by filtration. This material is converted to the crystalline form by crystallzation from water-acetone. The amount of lincomycin B in a normal fermentation of Streptomyces lincolnensis var. lincolnensis will vary with the media composition, incubation time and temperature, aeration, etc. Under normal operating conditions amounts of lincomycin B in such a fermentation will range from 5 to 10% of the total lincomycin present. The lincomycin B is removed by repeated recrystallization of the lincomycin product in suitable solvents, for example, water-acetone mixtures, or water-lower alcohol mixtures. Since the process of the subject invention does not produce lincomycin B, these crystallizations are unnecessary.

Microbiological process for preparing the antibiotic lincomycin at temperatures ranging from 18° C. to 45° C. using the newly discovered microorganism Streptomyces vellosus. The subject process advantageously results in the preparation of lincomycin without the concomitant production of lincomycin B (4'-depropyl-4'-ethyllincomycin). The absence of lincomycin B production results in increased lincomycin recovery efficiency.

BACKGROUND [0001] The present invention relates to a glass substrate, which is applied to the flat panel display (citing FPD hereinafter) such as the liquid crystal device panel and to a manufacturing method thereof. The present invention is particularly useful for a glass substrate using for a large size FPD for example televisions, computer displays and the like. [0002] In a few years, FPD represented by a liquid crystal type and a plasma type, spreads rapidly. An emission type display was also released recently, and a development is further activated. [0003] For manufacturing these types of FPD, it is necessary to precisely form minute patterns on a tabular glass plate. For example, the explanation will be provided below in accordance with a TFT type liquid crystal device. The TFT type liquid crystal device is made by forming and arranging plurality of thin film transistors on a glass substrate in precisely to match each TFT on each pixel. For arranging TFT precisely a photolithography technology is used. [0004] Namely, a metal layer is formed on a first glass substrate, and then photoresist is coated on the metal layer. Next, after TFT patterns for plurality of panels are exposed and developed, etching is performed. As the result, the metal layer is remained in a shape of TFT patterns on the first glass substrate. In this specification, it is described that thing in this state as TFT substrate. [0005] On a second glass substrate, a shading material layer is formed and further photoresist is coated on the shading material layer. Next, plurality of color filter (citing CF hereinafter) patterns, which will correspond to TFT patterns, are exposed and then etched. As the result, the shading material layer is remained in a shape of CF patterns on the second glass substrate. Next, by using photolithography technology, which is the same as that used for forming the TFT patterns, CF is formed in accordance with the patterns of the shading material layer. A red filter, a green filter, and a blue filter are formed by repeating CF forming process three times. In this specification, it is described that thing in this state as CF substrate. [0006] After an alignment layer is coated on each of the TFT substrate and CF substrate, both substrates are adhered together through glass beads as spacers in a state that the alignment layer of each substrate becomes inner side, and further, out of pattern areas are adhered by sealant. [0007] Next, after cutting out each panel, material of liquid crystal is injected to a space between the TFT substrate and the CF substrate through a hole previously provided for supplying the material of liquid crystal, and the hole is sealed. Finally, a polarizer is adhered on a screen, and then TFT type liquid crystal panel is completed. [0008] Each pixel of TFT pattern should be aligned with each area of correspondent CF pattern. It is because; if both patterns misaligned in each other, a precise image cannot be processed. Therefore both of the TFT pattern and the CF pattern should be formed in high dimensional precision. [0009] As an index for estimating whether the TFT pattern or the CF pattern is formed in predetermined dimensional precision, plurality of measurement patters are provided out of the TFT pattern or the CF pattern. After exposing the TFT pattern or the CF pattern and then developing, distances between these measurement patterns are measured and difference from design values are obtained, and then preciseness is estimated. [0010] In the meantime, majority of glass substrates using for FPD are manufactured by a process what is called fusion process. The fusion process is the method for manufacturing a plate like glass in which; flowing fused glass into a container called fusion pipe, overflowing the fused glass from the fusion pipe, and solidifying the fused glass during flowing downward. The fusion process can manufacture glass substrates in a low cost because a polishing process is not needed. [0011] A method for manufacturing a glass substrate by fusion process will be explained below. FIG. 8 shows a fusion pipe which is used for manufacturing a glass substrate by fusion process. As it is shown in To enlarge FPD and to increase efficiency of manufacturing FPD, a size of a glass substrate for FPD is expanding year by year. As far as a substrate for liquid crystal is concerned, a size of the substrate called as seventh generation, which is already practically used, is very large as 1870 mm×2200 mm, and still larger size substrate is proposed. [0012] FIG. 8 ( a ), a fusion pipe 4 has a structure that its upper part is a trough like portion 41 which is open to upper direction, and that both sides of the trough like portion 41 are bank like portions 42 whose levels are higher than the that of the trough like portion 41 . A lower part of the fusion pipe 4 has a wedge like shape, and its bottom is a blade like portion 43 . Heaters (not showing) are built in the fusion pipe 4 and surfaces of the fusion pipe 4 can hold a temperature at which maintaining a glass-fusing state. A cross sectional view of the fusion pipe 4 in A—A direction is shown in FIG. 8 ( b ). [0013] FIG. 9 shows a process for manufacturing a glass substrate by fusion process. A fused glass G is flown successively into the trough like portion 41 of the fusion pipe 4 , which is maintained in high temperature. The fused glass G overflows from bank like portions 42 to both sides of the fusion pipe, further flowing down along side surfaces of the fusion pipe 4 , and reaches to the blade like portion 43 , which is bottom of the fusion pipe 4 . At the blade like portion 43 , flows of fused glass joins together and it turns a plate like glass GP, and the plate like glass GP is gradually cooled as it falls down. In this process, the plate like glass GP is gradually solidified, and further it is pulled down by a rotation of rollers 45 . Afterwards, by cutting in desired dimension a glass substrate is completed. [0014] Additionally, in accordance with manufacturing processes by fusion process are described in following documents. [0015] (Patent document 1) Specification of the U.S. Pat. No. 3,338,696 [0016] (Patent document 2) Specification of the U.S. Pat. No. 3,682,609 [0017] To enlarge FPD and to increase efficiency of manufacturing FPD, a size of a glass substrate for FPD is expanding year by year. As far as a substrate for liquid crystal is concerned, a size of the substrate called as seventh generation, which is already practically used, is very large as 1870 mm×2200 mm, and still larger size substrate is proposed. [0018] However, in case forming patterns on a large size glass substrate, there is a problem that the dimension of actually formed pattern occasionally has an error beyond allowable range in comparison with design value. [0019] As far as this problem is concerned, as optical systems of an exposure apparatus, which is used for exposing patterns, is adjusted in high precision level, it is confirmed that patterns to be exposed have substantially no distortion. Namely, it does not due to a precision level of optical systems. Moreover, a stage of the exposure apparatus is finished as a very high precision flat surface, and it is confirmed that the surface of the vacuum contacted glass substrate on the stage is in the focus depth of the exposure optical system installed in the exposure apparatus. Therefore, it also does not due to a problem of flatness level of the stage. Accordingly, it can be considered that distances between measurement patterns exposed on the glass substrate are in allowable ranges at least in the state that the substrate is vacuum contacted on the stage of the exposure apparatus. [0020] However, in spite of above confirmations, still there is a problem that the distances between measurement patterns which measured after exposing and developing are occasionally not in the allowable ranges. [0021] Moreover, as another problem; there is a phenomenon that a static electricity is generated when the glass substrate being coated photoresist and being exposed the TFT patterns or CF patterns is unloaded from the stage; and by discharging the static electricity to a surface of photoresist, a defect of the TFT pattern or the CF pattern occurs. [0022] The inventors of the present invention found out that there is an effect for these problems by decreasing contact area between a vacuum contact portion of the stage and the glass substrate. For decreasing the contact area between a vacuum contact portion of the stage and the glass substrate, the present inventors considered to form appropriate asperity on at least one of surfaces of the vacuum contact portion of the stage and the glass substrate. The present inventors formed minute asperity on the surface of the vacuum contact portion of the stage by a grinding process. Then it appears that in spite of an effect for preventing the static electricity is achieved in a short period after the grinding process, the effect decrease as time passes, and it also appears that the effect increases again by applying the grinding process again on the surface of the vacuum contact portion of the stage. This is the reason why the asperity on the surface of the vacuum contact portion shrinks during successively holding the glass substrates by attrition with the glass substrate, and as the result the effect for preventing the static electricity decreases. [0023] Although it can be considered to form an asperity by applying a machining the glass substrate which is once manufactured, such process increase a cost for manufacturing the glass substrate. Therefore, for decreasing the cost, it is expected to establish a method for manufacturing the glass substrate in which an appropriate asperity is formed in process of making the substrate. [0024] The present invention was made under these circumstances explained above, and objects of the present invention are to provide a glass substrate which enables to manufacture a FPD in keeping cost low and in efficient, and to provide an efficient manufacturing method of a glass substrate. SUMMARY [0025] To solve the above described subject matter, the present invention adopts a below described structures shown in embodiments which correspond to figures. However, each reference sign with parentheses, which indicates each element, is only an exemplification and it does not limit each element. [0026] A first aspect of the present invention provides a glass substrate whose surface has an asperity of a height in the range from 10 nm to 20 nm and of a period in the range from 0.1 mm to 1 mm. [0027] According to the glass substrate of the first aspect, it is possible to satisfy stabilization of contact and preventing generation of the static electricity simultaneously. [0028] A second aspect of the present invention provides a glass substrate whose surface has an asperity of a height in the range from 15 nm to 20 nm and of a period in the range from 0.1 mm to 0.6 mm. [0029] According to the glass substrate of the second aspect, it is possible to satisfy stabilization of contact and preventing generation of the static electricity simultaneously. [0030] A third aspect of the present invention provides a method for manufacturing a glass substrate by fusion process, the method comprising the steps of; flowing fused glass (G) into a fusion pipe ( 1 ), and gradually cooling and solidifying the fused glass (G) by flowing downward from the fusion pipe ( 1 ), wherein forming an asperity on a surface of the glass substrate by depositing particles (GB) on a surface of the fused glass (G). [0031] According to the method for manufacturing the glass substrate of the third aspect, it is possible to manufacture the glass substrate, which satisfies stabilization of contact and preventing generation of the static electricity simultaneously. [0032] A fourth aspect of the present invention provides a method for manufacturing a glass substrate by fusion process, the method comprising the steps of; flowing fused glass (G) into a fusion pipe ( 1 ), and gradually cooling and solidifying the fused glass (G) by flowing downward from the fusion pipe ( 1 ), wherein forming an asperity on a surface of the glass substrate by colliding particles against the glass flowing down from the fusion pipe ( 1 ) from a side direction. [0033] According to the method for manufacturing the glass substrate of the fourth aspect, it is possible to manufacture the glass substrate, which satisfies stabilization of contact and preventing generation of the static electricity simultaneously. [0034] A fifth aspect of the present invention provides a method for manufacturing a glass substrate by fusion process having the following steps; flowing fused glass (G) into a fusion pipe ( 1 ), and gradually cooling and solidifying the fused glass (G) by flowing downward from the fusion pipe ( 1 ), wherein forming asperity on a surface of the glass substrate by fastening and pressing the glass (GP) toward a direction of thickness of the glass with a pair of transfer rollers ( 16 A and 16 B) during the glass is flowing down from the fusion pipe. [0035] According to the method for manufacturing the glass substrate of the fifth aspect, it is possible to manufacture the glass structure, which satisfies stabilization of contact and preventing generation of the static electricity simultaneously. [0036] A sixth aspect of the present invention provides a method for manufacturing a glass substrate by fusion process, the method comprising the steps of, flowing fused glass (G) into a fusion pipe ( 3 ), overflowing the fused glass (G) toward two directions of the fusion pipe ( 3 ) and flowing the fused glass (G) along two side surfaces ( 36 and 37 ) of the fusion pipe ( 3 ), joining the fused glass at a blade portion ( 33 ) which is a bottom end of the fusion pipe ( 3 ), and gradually cooling and solidifying the fused glass (G) by flowing downward from the blade portion ( 33 ), wherein forming an asperity on a surface of the glass substrate by periodically changing a temperature difference between the two side surfaces ( 36 and 37 ) of the fusion pipe ( 3 ). [0037] According to the method for manufacturing the glass substrate of the sixth aspect, it is possible to manufacture the glass structure, which satisfies stabilization of contact and preventing generation of the static electricity simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS [0038] FIG. 1 is a conceptual figure showing a glass substrate manufacturing by fusion process according to the first embodiment of the present invention. [0039] FIG. 2 is a conceptual figure showing a glass substrate manufacturing by fusion process according to the first embodiment of the present invention. [0040] FIG. 3 is a conceptual figure showing a glass substrate manufacturing by fusion process according to the second embodiment of the present invention. [0041] FIG. 4 is a conceptual figure showing a glass substrate manufacturing by fusion process according to the third embodiment of the present invention. [0042] FIG. 5 is a conceptual figure showing transfer rollers, which is used for a glass substrate manufacturing, by fusion process according to the third embodiment of the present invention. [0043] FIG. 6 is a conceptual figure showing a glass substrate manufacturing by fusion process according to the fourth embodiment of the present invention. [0044] FIG. 7 is a conceptual figure showing a fusion pipe, which is used for a glass substrate manufacturing, by fusion process according to the fourth embodiment of the present invention. [0045] FIG. 8 is a conceptual figure showing a fusion pipe, which is used for a glass substrate manufacturing, by fusion process according to a prior art. [0046] FIG. 9 is a conceptual figure showing a glass substrate manufacturing by fusion process according to a prior art. DETAILED DESCRIPTION OF EMBODIMENTS [0047] Now, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited by the embodiments. Embodiment 1 [0048] FIG. 1 is a conceptual figure showing a manufacturing method according to the first embodiment. In FIG. 1, 1 shows a fusion pipe. Upper part of the fusion pipe 1 is made as a trough like portion 11 , which is open to the air, and a bank like portions 12 are arranged on both sides of the trough like portion 11 . Moreover, bottom part of the fusion pipe 1 is made as a blade like portion 13 . Moreover, heaters (not shown) are installed inside the fusion pipe 1 , and surfaces of the fusion pipe 1 can be kept in temperature for maintaining a glass fusing state by heating fusion pipe 1 with the heaters. [0049] Fused non-alkaline glass G is flown into the trough like portion 11 of the fusion pipe 1 . Wherein, non-alkaline glass means a glass, which does not content alkaline metal as Sodium (Na), Potassium (K), and so forth. Fused non-alkaline glass G fills the trough like portion 11 . [0050] Nozzle 14 is arranged above the fusion pipe 1 , and glass particles GB comprise the same glass material as the fused glass G are discharged from the tip of the nozzle. The glass particles GB fall down on a surface of the fused glass G and adhere to the surface of the fused glass G. With maintaining this state, the fused glass G overflows the bank like portion 12 and flow down along side surface of the fusion pipe 1 . [0051] The fused glass G reached to the blade like portion 13 , which is at a bottom of the fusion pipe 1 , descents with solidifying as being plate like glass GP, and further the plate like glass GP is pulled down by revolution of rollers 15 . Afterwards, the plate like glass GP is cut in desired size and a glass substrate is completed. [0052] As the glass particles GB are adhered on the surface of the glass substrate manufactured in above described method, each glass particle is in the state that it protrudes from the surface of the glass substrate. Namely, an asperity according to the protrusion is formed on the surface of the glass substrate. [0053] When forming TFT patterns or CF patterns on such glass substrate, a process control is conducted so as to vacuum contact a side on which asperity is formed. By this procedure, a condition for stabilization of contact and preventing generation of the static electricity are satisfied simultaneously, and defect prevention is stably accomplished. Moreover, as light is scattered in moderate by the asperity on the surface of the glass substrate, there is also an effect for anti reflection. [0054] In the present embodiment, it is desirable that diameters of the glass particles are in the range from 15 nm to 40 nm. Moreover, it is only necessary to appropriately determine quantity of the glass particle discharged from the nozzle in accordance with quantity of flowing fused glass G and size of the glass particles. [0055] In addition, FIG. 1 shows that the fused glass G flows down on both side surfaces of the fusion pipe 1 and joins at the blade like portion 13 . However, it is also available that the fused glass G flows down on either side of the fusion pipe 1 and descents from the blade like portion 13 . [0056] Moreover, nozzle 14 does not have to be arranged above the fusion pipe 1 . It can be arranged above a flow passage which leads the fused glass to the fusion pipe 1 , and alternatively, it can be arranged side direction of the fusion pipe 1 . The configuration in which the nozzle is arranged side direction of the fusion pipe 1 is shown in FIG. 2 . [0057] Moreover, in the present embodiment, the asperity is formed on the glass substrate by adhesion the glass particles on the fused glass G. However, it is available that the asperity can be formed by removing the glass particles, which once adhered on the fused glass G, from the glass substrate by method for example ultrasonic cleaning. In this case, glass particles comprise glass other than non-alkaline glass can be used, and further, particles comprise material other than glass can also be used. In these cases, it is convenient that melting point of such particles is higher than that of non-alkaline glass. Embodiment 2 [0058] FIG. 3 is a conceptual figure showing a manufacturing method according to the Embodiment 2. In FIG. 3 , the fusion pipe 1 has the same structure as that of one which is used in the Embodiment 1, and reference sign is used in common with the Embodiment 1. [0059] In the present embodiment, a nozzle 14 is arranged obliquely downward of a fusion pipe 1 . Glass particles having diameters of about 0.1 μm are discharged from the nozzle 14 . [0060] Fused non-alkaline glass G flown into the trough like portion 11 of the fusion pipe 1 fills the trough like portion 11 , and after that, overflows and flows down along side surface of the fusion pipe 1 . [0061] The fused glass G reached to the blade like portion 13 , which is at a bottom of the fusion pipe 1 , descents with solidifying as being plate like glass GP, and further the plate like glass GP is pulled down by revolution of rollers 15 . [0062] During descending the plate like glass GP, the glass particles are discharged from the nozzle 14 and collided against the surface of the plate like glass GP before the plate like glass GP solidifies completely. Through this process, the asperity is formed on the surface of the plate like glass GP by being generated a plastic deformation. Afterwards, the plate like glass GP is cut in desired size and a glass substrate is completed. [0063] When forming TFT patterns or CF patterns on such glass substrate, a process control is conducted so as to vacuum contact a side on which asperity is formed. By this procedure, a condition for stabilization of contact and preventing generation of the static electricity are satisfied simultaneously, and defect prevention is stably accomplished. Moreover, as light is scattered in moderate by the asperity on the surface of the glass substrate, there is also an effect for anti reflection. [0064] In the present embodiment, diameters of the glass particles are not limited to about 0.1 μm, and it is only necessary to appropriately determine them in accordance with conditions of a placement of the nozzle, discharging speed of the glass particles, and so forth. [0065] Moreover, glass particles are used in the present embodiment, however, material of particles is not limited to glass, and it is available to use ceramics or metal particles. [0066] Moreover, a structure in the present embodiment is that the fused glass flown into the fusion pipe overflows and flows down along a side surface or (side surfaces) of the fusion pipe. However, it is only necessary that the fused glass flows down from a slit opened at the bottom of the fusion pipe without overflowing. Enbodiment 3 [0067] FIG. 4 is a conceptual figure showing a manufacturing method according to the Embodiment 3. In FIG. 4 , the fusion pipe 11 has the same structure as that of one which is used in the Embodiment 1, and reference sign is used in common with the Embodiment 1. [0068] In the present embodiment, a pair of transfer rollers 16 A and 16 B is placed below the fusion pipe 11 . An asperity is formed in advance on a surface of either one of the transfer rollers ( 16 A or 16 B). The pair of transfer rollers is placed to pinch and apply a pressure on both surfaces of a plate like glass GP in a direction of thickness of it in a phase in which solidification of the plate like glass GP is not completed. [0069] Fused non-alkaline glass G flown into the trough like portion 11 of the fusion pipe 1 fills the trough like portion 11 , and after that, overflows and flows down along side surface of the fusion pipe 1 . [0070] The fused glass G reached to the blade like portion 13 which is at a bottom of the fusion pipe 1 descents with solidifying as being plate like glass GP. The plate like glass GP is applied a pressure on both surfaces of it to a direction of thickness of the plate like glass by the pair of transfer rollers 16 A and 16 B firstly, and then is pulled down by revolution of rollers 15 . [0071] At that point, surfaces of the plate like glass are plastic deformed by a pressure applied by the pair of transfer rollers 16 A and 16 B, and an asperity is formed on the surface of the plate like portion. A configuration magnified A—A portion of FIG. 4 is shown in FIG. 5 Afterwards, the plate like glass GP is cut in desired size and a glass substrate is completed. [0072] When forming TFT patterns or CF patterns on such glass substrate, a process control is conducted so as to vacuum contact a side on which asperity is formed. By this procedure, a condition for stabilization of contact and preventing generation of the static electricity are satisfied simultaneously, and defect prevention is stably accomplished. Moreover, as light is scattered in moderate by the asperity on the surface of the glass substrate, there is also an effect for anti reflection. [0073] In the present embodiment, as the asperity formed on the surface of the transfer roller 16 A or 16 B is concerned, it is desired that a height is in the range from 10 nm to 40 nm and a period is in the range from 0.1 mm to 1.2 mm, however, it is only necessary to determine these values appropriately according to the pressure applying by the transfer rollers 16 A and 16 B and the degree of solidification of the glass. Moreover, the asperity can be formed on the surfaces of both of the transfer rollers 16 A and 16 B. In this case, as the asperity is formed on both sides of the glass, it makes not necessary to process control so as to vacuum contact a side on which asperity is formed. [0074] In addition, a structure in the present embodiment is that the fused glass flown into the fusion pipe overflows and flows down along a side surface or (side surfaces) of the fusion pipe. However, it is available that the fused glass can be flown down from a slit opened at the bottom of the fusion pipe without overflowing. Embodiment 4 [0075] FIG. 6 is a conceptual figure showing a manufacturing method according to the Embodiment 4. In FIG. 6 , although a fusion pipe is similar to that used in the Embodiment 1, an applied temperature control is different from that used in the Embodiment 1. It will be provided an explanation according to this fusion pipe below by using FIG. 7 . [0076] Upper part of the fusion pipe 3 is made as a trough like portion 31 , which is open to the air, and a bank like portions 32 are arranged on both sides of the trough like portion 31 . Moreover, bottom part of the fusion pipe 3 is made as a blade like portion 33 . Moreover, heaters 34 and 35 are installed inside the fusion pipe 3 . These heaters maintain a temperature on the surfaces of the fusion pipe 3 in a glass fusing state, and in the same time, the heaters are controlled so as to generate periodic temperature difference between side surfaces 36 and 37 in accordance with time passage. [0077] Fused non-alkaline glass G is flown into the trough like portion 31 of the fusion pipe 3 . Fused non-alkaline glass G fills the trough like portion 31 . The fused glass G filled the trough like portion 31 overrides the bank like portions 32 and overflows to both direction of the fusion pipe 3 and falls down along side surfaces 36 and 37 . [0078] The fused glass G reached to the blade like portion 33 , which is at a bottom of the fusion pipe 3 , descents with solidifying as being plate like glass GP. [0079] At this point, as explained above, the heaters are controlled so as to generate periodic temperature difference between side surfaces 36 and 37 in accordance with time passage. In this embodiment, as the heater 35 is controlled to output virtually constant while the heater 34 is controlled to generate periodic output, the temperature of the side surface 37 is being constant while that of the side surface 36 is being up-and-down. [0080] As the result, a flow rate of the fused glass flowing along the side surface 37 is being constant while a flow rate of the fused glass flowing along the side surface 36 is being up-and-down in accordance with time passage. Therefore, an asperity is formed on the surface of the plate like glass GP as which falling down after joining at the blade like portion 33 . [0081] The plate like glass descents with solidifying and is pulled down by revolution of rollers 15 . Afterwards, the plate like glass GP is cut in desired size and a glass substrate is completed. [0082] When forming TFT patterns or CF patterns on such glass substrate, a process control is conducted so as to vacuum contact a side on which asperity is formed. By this procedure, a condition for stabilization of contact and preventing generation of the static electricity are satisfied simultaneously, and defect prevention is stably accomplished. Moreover, as light is scattered in moderate by the asperity on the surface of the glass substrate, there is also an effect for anti reflection. [0083] In the present embodiment, the heater 35 is controlled to output virtually constant while the heater 34 is controlled to generate periodic output. However, in the present invention, it is only necessary that periodic temperature difference be generated with time passage between side surfaces 36 and 37 of the fusion pipe. Therefore, it is applicable that the heater 34 is controlled to output virtually constant while the heater 35 is controlled to generate periodic output. Alternatively, it is also applicable that both of heaters 34 and 35 are controlled to generate periodic output. In the latter case, obtained glass substrate have asperities on both surfaces, and it makes unnecessary to apply a process control so as to vacuum contact a side on which asperity is formed. [0084] In the present embodiment, it is possible to form asperities, which have various height and period, by controlling power supply to heaters 34 and 35 . Industrial Applicability [0085] The present invention can provide a large size glass substrate; which is used for FPD especially for display device like a TFT type liquid crystal device on which minute pattern is to be formed in good yield; and also provide a manufacturing method thereto.

A method for manufacturing a glass substrate by fusion process comprising the following steps; flowing fused glass into a fusion pipe, and gradually cooling and solidifying the fused glass by flowing downward from the fusion pipe, wherein forming an asperity on a surface of the glass substrate by fastening and pressing the glass toward a direction of thickness of the glass with a pair of transfer rollers during the glass is flowing down from the fusion pipe.

This is a continuation of U.S. Pat. application Ser. No. 368,992, filed June 16, 1989, now abandoned, which is a continuation of Ser. No. 253,411, filed Oct. 4, 1988, now abandoned, which is a continuation of Ser. No. 009,275, filed Jan. 30, 1987, now abandoned. BACKGROUND OF THE INVENTION The present invention relates generally to signal transmission lines built on silicon wafers for the purpose of wafer-scale integration, and more particularly to micro-strip signal transmission lines for programmable interconnection wafers which are constructed to optimize signal transmission speeds. In the past, integrated circuit (IC) chips were electrically connected together through the use of "pin" packages and printed circuit boards. Each IC chip would first be mounted in the cavity of a separate pin package which had to be large enough to provide a number of sturdy pin connections. Then, these IC chips containing packages would be mounted to a printed circuit board which was designed to provide a specific pattern of electrically conductive paths necessary to interconnect the pins of these packages together in the desired way. While this technique of interconnecting IC chips together has been used for many years, it has several drawbacks. In the first place, it takes up far too much room. Since the IC chips themselves occupy only a very small amount of a typical pin package, and the pin packages must be separated on the circuit board, a great deal of wasted space is built in to each multi-chip circuit design. While the amount of this wasted space can be reduced by integrating more transistors into each IC chip, eventually the designer will be faced with the need to interconnect various IC chips together in order to achieve a unique circuit design. Accordingly, achieving higher densities within each chip only addresses one aspect of the wasted space problem. The interconnection between discrete IC chips must still be addressed in order to provide a truly dense circuit design. It will also be appreciated that substantial costs are associated with this type of low density interconnection technique. Each circuit board has to be individually designed to provide a printed pattern of conductive paths which is appropriate to the size, type and number of IC chips contained on the circuit board card. Additionally, a separate pin package must be provided for each IC chip manufactured, and these pin packages may also have to be designed specifically for its intended IC chip. Perhaps the most important consideration involved in interconnecting IC chips together in one of time. Since the conductive paths through the pin packages and the circuit board are relatively long, the operation of the IC chips is constrained by the time it takes for signals to be transmitted between the IC chips. Accordingly, if the length of these conductive paths can be reduced, then the transmission delays can also be reduced as well. This consideration is particularly important in the field of super computers where processing speed and heat dissipation are paramount considerations. In order to decrease the distance between IC chips, "thick film" ceramic circuit boards have been proposed. While such circuit boards permit the mounting of IC chips directly to the ceramic substrate of these boards, the layout of conductive paths for these circuit boards still need to be individually designed for each application. Additionally, the density of the number of IC chips per circuit board area is limited by the nature of the pattern of conductive paths which is typically formed on a single layer of the ceramic substrate. A further advance toward the goal of providing dense interconnections between IC chips has recently been realized through the use of a universally programmable silicon circuit board (SCB). An SCB is a standardized, electrically programmable interconnect system which is formed on a silicon wafer or substrate. An SCB can be characterized as "thin film" circuit board technology, due to the fact that the conductive paths have dimensions in the micron region. The SCB permits a product designer to mount diverse IC chips and hybrid components directly to a very compact silicon substrate which acts as a circuit board. No pin packages are required, and the SCB can be programmed electronically so that a single SCB design can serve a wide variety of multi-chip circuit designs. Each SCB includes a matrix of orthogonal metal lines which are disposed on distinct planes. These planes are separated at crossovers by an amorphous silicon material which normally has a high resistance. However, this layer of amorphous silicon is designed to operate as an "anti-fuse" in that selected electrical connections can be made between the metal lines on different planes. Specifically, when a threshold voltage is applied to the amorphous silicon, the material will switch from a high resistance value to a low resistance value at a desired interconnection point. This "anti-fuse" capability of the amorphous silicon allows many thousands of possible interconnections to be made between various metal lines of the SCB matrix, and hence a host of different IC chip interconnections can be readily made using automated programming techniques. In addition to the above, other advantageous features of the SCB include the ability to mount the IC chips to the substrate through conventional wire bonding techniques, and temperature matching of silicon IC chips with the silicon substrate to reduce stress and fatigue. The integrity of the interconnection network can also be automatically tested, and faults can be readily corrected by programming alternate routes through the network. The electrical programming of the network by firing the appropriate "anti-fuses" can be accomplished within hours, so that a design engineer does not have to wait long periods of time for masks to be developed and the line. A further general discussion of SCBs may be found in the following references: U.S. Pat. No. 4,467,400, issued on Aug. 21, 1984 to Herbert Stopper, entitled "Wafer Scale Integrated Circuit"; U.S. Pat. No. 4,479,088, issued on Oct. 23, 1984 to Herbert Stopper, entitled "Wafer Including Test Lead Connected To Ground For Testing Networks Thereon"; U.S. Pat. No. 4,458,297, issued on July 3, 1984 to Herbert Stopper et. al., entitled "Universal Interconnection Substrate"; and an article entitled "A Wafer With Electrically Programmable Interconnections", 1985 IEEE International Solid-State Circuits Conference, Digest of Technical Papers, pp. 268-269. These references and hereby incorporated by reference. As will be discussed further below, the metal lines of the SCB may approach the "lossy line" transmission characteristics of a Thomson Cable. This lossy line characteristic has the advantage of eliminating the need for terminating resistors. However, this characteristic can also result in undesirable transmission delays through the interconnection network. Specifically, for homogeneous metal lines in an SCB network, this delay has been found to be proportional to the square of the length. Accordingly, it should be appreciated that the length of the SCB signal transmission lines can become an important design consideration when extremely high processing speeds are desired. Thus, on one hand, long signal transmission lines can facilitate the interconnection of many IC chips on a single SCB. However, on the other hand, it is possible that such long signal transmission lines may not be consistent with achieving the goal of maximizing the overall processing speed for multi-chip circuits and other micro-electronic circuits. Accordingly, it is a principal objective of the present invention to provide an interconnection method and apparatus for increasing signal transmission speeds through micro-electronic circuits. It is a more specific objective of the present invention to provide an improved SCB transmission line network geometry which approaches an almost linear relationship between the length of the transmission line and the signal delay through the transmission line. It is another objective of the present invention to provide an interconnection method and apparatus which maximizes the signal transmission speed over a given distance, such that over this distance the transmission line is capable of modeling the signal transmission characteristics of a coaxial "lossless" transmission line. It is a further objective of the present invention to provide a method and apparatus for increasing signal transmission times which achieves an optimum relationship between total resistance of the transmission line and its characteristic impedance. It is an additional objective of the present invention to provide a plurality of micro-strip transmission line structures which can be readily fabricated and interconnected together in combination to achieve a high speed signal transmission path. It is yet another objective of the present invention to provide a high speed transmission path for use in a variety of micro-electronic circuit applications, including applications with signal frequencies above 1GH z . It is still another objective of the present invention to create a high speed transmission path which provides an optimized termination resistor effect that is distributed along the transmission path. SUMMARY OF THE INVENTION To achieve the foregoing objectives of the present invention, a method of optimizing the signal transmission between a signal source and a signal receiver is disclosed which includes the steps of providing a signal transmission path or transmission line structure which is "semi-lossy", nonhomogeneous and governed by a predetermined relationship between its length and its various electrical parameters. A transmission line in this context is primarily an R-L-C line composed of two conductors having a loop resistance R, a loop inductance L, and a conductor to conductor capacitance C. For the convenience of further discussion, a loss factor can be defined as ##EQU1## Strictly speaking, a lossy line is one with α>0, and a lossless line is one with α=0. Practically and customarily, however, a line for micro-electronic assemblies is considered to be lossless for α<<1 and lossy for α>>1. Lossless lines are known to impose a delay on a signal traveling from the signal source to the signal receiver which can be calculated as t o =√LC. This delay varies linearly with the length of the line and is equal to the delay which would be incurred by a light wave travelling through the same medium. Hence, this delay is the smallest delay which can be attained by any means. Lossy lines, on the other hand, are known to impose a delay which can be approximately calculated as t.sub.α =√LC·α. This delay varies approximately with the square of the line length and can be significantly larger than the minimum delay t o . Lossless lines are known to require terminators, i.e., resistors whose value is equal or close to the characteristic impedance ##EQU2## of the line. Terminators can be placed at either or both ends of a line. Without terminators, multiple signal reflections at both line ends would lead to intolerable signal distortions otherwise known as over-shorting, under-shooting, ringing, or bouncing. Lossy lines, on the other hand, are known to be free of such problems even when used without any terminators. A transmission line according to the present invention is optimized for a fixed length in such a way that it shares with the loss-less line the property of minimal, linear delay and with the lossy line the property of zero bouncing without terminators. Thus, under the appropriate circumstances, a signal can travel through a micro-electronic assembly on a signal path designed according to the methods of the present invention at essentially the speed of light and without bouncing. The possibility of using thin film lossy lines for propagating high speed pulses near the speed of light without terminating resistors has been discussed in the following references: U.S. Pat. No. 4,210,885, issued on July 1, 1980 to Chung W. Ho, entitled "Thin Film Lossy Line For Preventing Reflections In Microcircuit chip Package Interconnections"; and an article entitled "The Thin-Film Module As A High-Performance Semiconductor Package," by C. W. Ho, et. al., IBM J. Res. Develop., Vol 26, No. 3, May 1982, pgs. 286-296. However, as will be appreciated from the description below, the present invention provides several advantages not found in these references. For example, the present invention provides a way of increasing the transmission line length while still permitting propagation speeds approaching the speed of light. Additionally, a critical transmission line distance has been found in which the signal being received will precisely reproduce the waveform of the signal transmitted at the other end of the transmission line. A transmission line optimized according to the methods of the present invention has a loss factor in the vicinity of 1 and could therefore be called "semi-lossy." It is important to understand that in most micro-electronic assemblies and particularly in SCB's the physical constraints are such that lossy lines can be made easily but lossless lines cannot be made at all. The lossy lines, however, can be upgraded to be semi-lossy lines by appropriate design. It is therefore a particular accomplishment of the present invention to provide a transmission line which can be produced even under the physical constraints of an SCB and which is still superior to either of the previously known lines, namely, the lossless and the lossy line. The previous discussion implied that the lines considered, be they lossy, lossless, or semi-lossy according to the present invention, are homogeneous, i.e., that the electrical parameters R,L,C if normalized per unit of length do not change over the length of the line. Nonhomogeneous lines, on the other hand, are lines in which these parameters do change, either abruptly at certain points or continuously along the line. The methods of the present invention make use of nonhomogeneity in order to either increase the fixed length for which optimization can be performed or to ease the physical construction of micro-electronic transmission lines at lesser distances. Particularly in SCB's, nonhomogeneous lines are applied in such a way, that they simultaneously serve the purposes of implementing programmable routing and enhancing signal transmission characteristics. For example, in a transmission line network where optimization cannot be achieved, the use of nonhomogeneous lines according to the present invention can still provide improvements in transmission speeds. In one form of the present invention, a nonhomogeneous signal transmission path is constructed from a plurality of different micro-strip conductors which are connected together for transmitting a signal in a particular direction. Preferably, three sets of micro-strip conductors of varying width are formed in two separate planes of a substrate structure which will enable interconnections to be made between these conductors. The two planes have distinctly different altitudes over a common ground plane which is used as a common current return path for all conductors in the structure. Specifically, the widest conductor is placed into the upper plane and connected to the signal source, the narrowest conductor is also placed into the upper plane but connected to the signal receiver, and the conductor of intermediate width is placed into the lower plane and used to interconnect the other two conductors together. It should be appreciated that the principals of the present invention are susceptible for use in a variety of micro-electronic circuits and other applications involving transmission lines whose characteristics can be optimized in accordance with the present invention. Thus, for example, the present invention can be used in a wide range of interconnection technologies, even within the IC chips themselves. Additional advantages and features of the present invention will become apparent from reading the detailed description of the preferred embodiments which make reference to the following set of drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a SCB structure whose general layout is applicable to the method and apparatus according to the present invention. FIG. 2 is an artist's conception, in perspective, of a general SCB layout for purposes of illustration. FIG. 3A-3C are schematic circuit diagrams of electrically long, single phase, transversal electromagnetic transmission lines which are lossless (A), piecewise approximated lossy (B), or semi-lossy (C). FIGS. 4A-4B are diagrammatic representations of nonhomogeneous transmission line structures according to the present invention. FIG. 5 is a graph illustrating relative time delays for homogeneous and non-homogeneous lossy lines versus a homogeneous lossless line. FIG. 6 is a diagrammatic representation of a nonhomogeneous micro-strip conductor structure formed in two planes according to one embodiment of the present invention. FIG. 7 is a drawing of a micro-strip line example of transmission line according to a method of the present invention for controlling the relationship between the total resistance of the line and its characteristic impedance. FIG. 8 is an enlarged top elevation view of a portion of the SCB shown in FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a plan view of an SCB 10 is shown. While the general layout of the SCB 10 is applicable to the method and apparatus according to the present invention, it should be appreciated that the principles of the present invention are not limited to this particular SCB structure or any SCB structure. As will be appreciated from the description below, the present invention is applicable to a wide variety of micro-electronic circuit interconnection technologies. Accordingly, while the present invention is particularly applicable for use in SCB structures, the SCB structures described below are set forth for exemplary purposes only. The SCB 10 is fabricated using a thin silicon wafer as a substrate or base for the composite SCB structure. The SCB 10 provides a pair of generally square sections or segments 12 and 14 for mounting a plurality of IC chips to the SCB substrate. For example, FIG. 1 shows IC chips 16 and 18 which are wire bonded to the segment 12 of the SCB 10. Similarly, FIG. 1 also shows a set of five IC chips 20-28 which are wire bonded to the section 14 of the SCB 10. As will be discussed below in connection with FIG. 2, the SCB 10 provides a matrix of micro-strip conductors whose interconnections are programmed to provide a network of signal transmission paths between the appropriate IC chips mounted to the SCB substrate. The combination of the SCB 10 with the IC chips (such as chips 16-18 and 20-28) provide a hybrid circuit and wafer assembly which can be used in virtually any electronic circuit application. The silicon wafers of the segments 12 and 14 are mounted to a header assembly 30. The header assembly 30 provides several input and output lines 32 which extend to the periphery of the SCB 10. Accordingly, the periphery of the SCB 10 provides a connector junction for interfacing the SCB to other circuits and devices. Referring to FIG. 2, an artist's conception of an SCB section or cell 34 is shown in a way which illustrates the matrix of micro-strip conductors used in the SCB structure. It should be understood that this Figure is not intended to depict an actual SCB structural design. Rather, FIG. 2 is being used to illustrate the basic elements used in an SCB structure. As shown in FIG. 2, the SCB section 34 includes a fist set of micro-strip conductors 36 which are aligned in parallel along one horizontal plane of the SCB. The microstrip conductors 36 are generally referred to as "pad" lines, as each of these lines is provided with at least one bonding pad 38. The bonding pads 38 are used to connect IC chips, such as the IC chip 40, to the network of micro-strip conductors provided in the SCB. In this regard, conventional wire bonding techniques can be used to connect an appropriate lead of the IC chip with the pad of an appropriate microstrip line conductor 36. The SCB section 34 also includes a second set of micro-strip conductors 42 which are aligned in parallel along a horizontal plane which is beneath the plane used for the pad lines 36. The micro-strip conductors 42 are generally referred to as "net" lines, as they provide the necessary links to create a signal transmission path network through the SCB. Since the net lines 42 may be used to transmit a signal to a plurality of receivers, these lines may generally be wider than the pad lines 36. This difference in width between pad lines and net lines is illustrated in FIG. 7 of U.S. Pat. No. 4,458,297, which has previously been incorporated by reference. It should also be noted that more than one plane of pad lines 36 and/or net lines 42 may be provided in an appropriate SCB structure. The pad lines 36 are separated from the net lines 42 at their cross-over points by a continuous layer of an amorphous silicon material (SiO 2 ), which is more fully described in the Ronald G. Neale U.S. Pat. No. 3,675,090, issued on July 4, 1982, entitled "Film Deposited Semiconductor Devices," which is hereby incorporated by reference. One unique characteristic of this amorphous silicon material is that it has the ability to act as an electronic switch or "anti-fuse." More specifically, the amorphous silicon material is capable of switching from a normal insulating state (e.g.,>200 MΩ) to an electrically conductive state (e.g.,<5 Ω). This switching is achieved by electrically "firing" individual cross-over points or bridges between selected pad and net lines. Specifically, a threshold voltage (e.g., approximately 20 volts) is applied across the amorphous silicon bridge which will cause the amorphous silicon to switch to a stable conductive state. Accordingly, it should be appreciated that this switching ability enables selected pad lines 36 to be interconnected to selected net lines 42 through an electrical programming process to create a desired network of signal transmission paths through the SCB. In this regard, the amorphous silicon material has been referred to as an "anti-fuse," because it is normally an insulator, whereas a fuse is normally a conductor. However, it should be understood that other suitable semiconductor materials may be used in the place of the amorphous silicon material, as long as they have the ability to switch between conductive and nonconductive states. Thus, for example, certain amorphous chalcogenide materials have been suggested for the purpose. FIG. 2 also illustrates that the SCB section 34 includes a pair of conductor planes 44 and 46. These conductor planes are used to provide electrical power connections for the SCB structure. The conductor plane 44 is preferably used as the ground plane, while the conductor plane 46 is preferably used as the voltage plane. However, it should be appreciated that the role of these two conductor planes could be reversed in the appropriate application. Each of the conductor planes 44 and 46 are preferably made out of aluminum, as are the micro-strip conductors 36 and 38. However, other suitable electrically conductive materials may be used in the appropriate application. Each of the conductor planes 44 and 46 are provided with a plurality of pads for enabling the appropriate power connections to be made with each of the IC chips wire bonded to the SCB structure. For example, FIG. 2 illustrates a pad 48 which is connected to the conductor plane 44 through a pedestal 50. Similarly, FIG. 2 illustrates a pad 52 which is connected to the conductor plane 46 through a pedestral 54. The conductor plane 46 is preferably formed on a thin silicon wafer which extends across the entire matrix of micro-strip conductors used in the SCB. In general, it is a goal of the present invention to increase the signal transmission speed in otherwise lossy transmission paths, such as a Thomson Cable transmission line, while avoiding the requirement of a termination resistor. Such an increase in the signal transmission speed is particularly advantageous in an SCB interconnection network, since the delay has been found to be proportional to the square of the length of the micro-strip conductors. Thus, for example, if it is assumed that a particular lossy transmission line has a delay T for one-third of the total length of the line, then the transmission delay over the entire length of the line would be nine times T. However, in accordance with the present invention, the design parameters of the signal transmission paths in an SCB interconnection network can be optimized so as to substantially reduce the transmission delay times. Additionally, the signal transmission paths according to the present invention can be used to carry signals of extremely high frequencies (e.g., greater than 1GH z ). It will, of course, be appreciated that in most SCB applications, interconnections will not always be made at the extreme ends of the lines, and that a line may also have two or more orthogonally directed lines connected across its length. Accordingly, these line loading effects will make it difficult to accurately determine the propagation delays through an interconnected network without actual testing or speed simulations. Nevertheless, the present invention provides two complementary techniques for substantially reducing the transmission delays which achieve surprising results. For example, it will be shown that there is a critical line length which will enable the waveform of the transmitted signal to be precisely reproduced at the receiver on the first transition. FIGS. 3A-3C show schematic diagrams of three transmission line circuits 56-60. FIG. 3A is drawn around a length of coaxial cable 62 which is a classical example of a single-phase, transverse electromagnetic (TEM) transmission line. The coax cable 62 serves only as an example and the transmission characteristics explained below are equally applicable to any other conductor pair which can sustain TEM waves, particularly a micro-strip over a ground plane. The coax cable 62 is presumed to have an inductance L and a capacitance C, but no resistance. A signal put on the line by the signal generator or source 64 arrives at the signal receiver 66 after a time delay t o =√LC. The signal may see an amplitude modification A at the receiver end which is governed by the value of the terminating resistor R T as follows: ##EQU3## Ideally, R T is equal to Z o which leads to A=1. For larger or smaller values of R T , the line shows ringing. In the extreme cases of R t =0 or R T =∞, the signal bounces back and forth between the end points of the line forever. FIG. 3B shows a piece-wise approximation of a line with not only distributed inductance and capacitance but also with distributed resistance. At the end of each cable section 68, a partial signal reflection will take place and the resulting amplitude (the sum of the arriving and the returning signal) will be modified by a factor which follows the same rule which is valid for the end of the line in FIG. 3A, except that R T has to be replaced by the load represented by the following line section. This load, including the series resistor R/n, is equal to R/n +Z o , except for the last section where the load "resistor" is infinite. At the same time, there will be a voltage reduction at each input of a line section 68 because the series resistor R/n and the line input resistance Z o comprise a voltage divider. Thus, the original signal supplied by the signal generator is increased or decreased at each junction as it travels down the line and has experienced a total amplitude modification when it arrives at the signal receiver which can be expressed by the factor ##EQU4## With the introduction of a loss factor ##EQU5## this equation can be rewritten as ##EQU6## The initial waveform travelling down the line creates reflections at the each of each line section 68 which in turn create more secondary reflections. However if "n" is a large number, the numerous but individually small reflections add up in such a way that their sum is slowly moving smooth curve which provides the transition from the initial response delineated by the above factor A to the final response. It is important to note that the time required by the initial waveform to reach the signal receiver is equal to that found in the lossless line of FIG. 3A because the sum of the lengths of the "n" sections is equal to the length of the whole line, hence again ##EQU7## FIG. 3C shows an R.L.C. line 70 with a truly distributed resistance. Its amplitude transfer function can be derived from the previous case by growing "n" to infinity: ##EQU8## Again, a replica of the original signal from the signal generator 64 with a scaling factor A is presented to the signal receiver 66 after the minimum delay time of t o =√LC. After the arrival of the replica, additional slow responses follow which become negligible as A approaches 1. In other words, when A=1, the waveform of the transmitted signal will be reproduced at the receiving end of the line without any adverse reflections being generated. For example, with a step signal being transmitted down the line, this step function will be reproduced at the receiving end with a sharp rise and little or no tail. An optimized line can thus be defined as a line which is characterized by A=1 which, in the case of the most simple implementation with only one homogeneous line, is synonymous with α=1n 2 or R=2 (1n2) Z o =1.39Z o . This means that the optimized, semi-lossy, unterminated line 70 duplicates the behavior of the terminated, lossless line. This optimization is related to a fixed distance in as much as R is a function of distance or line length while R T is not. It should be appreciated that a fixed line length in the context of an SCB is not a restriction but a design parameters. Another way of describing the optimized line is to say that the discrete terminator R T =Z o has been replaced by a distributed terminator R=1.39Z o . The concept of the optimized line can be illuminated further by the following design example. FIG. 7 shows a micro-strip line 72 with a width w, a thickness s, a height h over the ground plane 74, and a length d. The resistance of line 72 can be calculated as ##EQU9## and the characteristic impedance Z o can be calculated as ##EQU10## δ is the resistivity of the conductor material. ε r is the permittivity of the dielectric between the conductors. K is the fringe field correction factor which can be approximated as ##EQU11## and which usually ranges between 0.5 and 0.9. If δ=3×10 -8 μm (aluminum), ε r =4 (silicon dioxide), and K is assumed to be 0.7 for simplicity, then the dimensions of the micro-strip may be optimized as follows: ##EQU12## If the desirable length d of the lines on an SCB is 40 mm, the design requirements are reduced to h·x=6.54 (μm) 2 . An example of a design which would satisfy this equation would be S=2 μm, h=3.27 μm. It should be noted that this optimization is not overly sensitive to variations from the ideal condition of R=1.39 Z o . Depending on pulse rise times, this ideal condition can be missed by a factor on the order of 1.5 without substantial performance degradation. However, variations from the ideal condition will cause the amplitude modification factor A to change from A=1, such that a precise replica of the signal waveform will not be achieved. FIG. 4A and 4B show two examples of non-homogeneous transmission line circuits 76-78. The transmission line of FIG. 4A is comprised of two series connected or cascaded sub-lines 80-82 which are homogeneous in themselves. Similarly, the transmission line of FIG. 4B is comprised of three sub-lines 84-88 which are homogeneous in themselves. While these two transmission line structures are preferred embodiments of the present invention, it should be understood that the principals of using nonhomogeneous lines is not restricted to any particular number of sub-lines or even any identifiable sub-lines which are homogeneous in themselves. The sub-lines 80-82 in FIG. 4A by themselves behave like a homogeneous transmission line except that the reflection-related voltage increase at the end of the first line is ##EQU13## instead of 2. Therefore, the total amplitude transfer factor is ##EQU14## It can now be seen, that optimization (A=1) can be reached for attenuation values which are larger than in the case of the homogeneous line, provided that Z o2 >z o1 . In one preferred embodiment of an SCB according to the present invention, the impedance relation is Z o2 =2Z o1 , the loss factor relation is α 1 =α 2 = Z α and, hence, ##EQU15## From this optimization equation follows α=0.98. Thus, α has been improved over the homogeneous case by a factor of 0.98/0.69=1.42. An improved (increased) α means that the length of the line can be increased for the same cross section or that the cross section can be made easier to manufacture for the same line length. Since optimization according to the present invention is based on the manipulation of the first pulse or signal transition arriving at the end of the line, it is necessary that the two sub-lines are equally long. If they are not, the optimized loss factor will be somewhere between 0.98 and 0.69, and the improvement will be accordingly smaller. The line of FIG. 4B, is analyzed similarly, yields ##EQU16## Again, improvements can be gained if Z o3 >Z o2 >Z o1 In One embodiment of an SCB, parameters are chosen such that Z o3 =2Z o2 =3Z o1 , α 1 =α 2 =α 3 = 3 .sup.α, and hence Optimization (A=1), in this case, leads to α=1.16. While FIGS. 4A and 4B illustrate non-homogeneous transmission lines having two and three sub-lines or sections respectively, the following equations may be used to generally characterize the amplitude transfer factor for a non-homogeneous transmission line. If it is assumed that Z o of the first subsection is called Z a and that both R/n and Z o of the following subsections are increased from subsection to subsection by a factor F (which implies that the attenuation factor per subsection remains constant), then: ##EQU17## Accordingly, the equation for A n now becomes: ##EQU18## The relations become clearer if one substitutes ##EQU19## and obtains ##EQU20## The difference between the non-homogeneous and the homogeneous line is then that the attenuation factor α is reduced by an amount β. If Z o of the last subsection is called Z B , the equation for 1/F can be transformed into ##EQU21## This means that the characteristic impedance grows exponentially over the length of the line from Z A to Z B with a growth factor ##EQU22## The critical distance can now be redetermined such that A=1, and a "stretch factor" s c can be obtained by dividing the new critical distance over the old one: ##EQU23## With Z B /Z A =4, for instance, s c =2. This means that ideal transmission conditions are now bound for lines with the length 2d c rather than d c . In practice, it may be desirable to grow Z o not exponentially but rather in one or two discrete steps, which will reduce the stretch factor slightly. Thus, for example, with two steps and Z B /Z A =4, then S c =1.83. Since β subtracts from but does not divided into α, the stretch factor decreases with increasing line length but not as drastically and as far as suggested by the equation for "A" set forth above, because of the not yet considered secondary component. In this regard, the summated effect of all the reflections and re-reflections on the line output signal is referred to as the secondary component. In contrast, what reaches the end of the line first may be called the primary component of the output signal. FIG. 5 shows stretch factors obtained by simulation and their effect on t e as a function of d o . In this regard, t e is the end of line delay, d o is the total distance, and d c is the critical distance. The overall result is that lossy lines can be made quite effective up to at least 3d c by suitable impedance control. In order to provide proper distributed termination for very short lines, the above process can be reversed: inverse impedance ratios shrink d c . It should be understood that a nonhomogeneous line according to the present invention will permit an increase in the optimized length as long as Z o increases in he direction from the signal generator to the signal receiver. Accordingly, the particular relationships between the characteristic impedances of the sub-lines shown above are intended to be used only for illustrative purposes. It is further important to understand that the nonhomogeneous line affords smaller delay times even if it exceeds slightly or substantially differs from the optimization value. Thus, even when it is not possible to achieve an optimized transmission line structure (A=1) in a particular application, a non-homogeneous construction may be employed to substantially reduce the transmission delay for signal transmissions in a particular direction. For example, while homogeneous "lossy" transmission lines in an SCB have a delay which is proportional to the square of the line length, an almost linear relationship between the transmission delay and the line length can be achieved with a directionally specific nonhomogeneous or cascaded transmission line within the distance constrains discussed above. Specifically, a plurality of signal conductor lines or line sections may be interconnected together in a way which will cause Z o to increase in the direction from the signal generator to the signal receiver. One way in which the variation in Z o may be achieved is to provide signal conductor lines of varying width, with the widest line being connected to the signal generator and the thinnest line being connected to the signal receiver. Of course, it will be appreciated that other suitable construction techniques may be employed in the appropriate application to achieve the desired variation in Z o . However, in one form of an SCB according to the present invention, conductor lines of varying width are deposited or formed on two different planes of the structure to facilitate connections with one or more IC chips. In this regard, FIG. 6 shows an interconnected conductor network 100 in which the widest conductor 102 is disposed on the same plane that the thinnest conductor 104 is disposed on. The conductors 102 and 104 are interconnected by the conductor 106 of intermediate width which is disposed on a plane below these two conductors. Any suitable means may be used to interconnect these conductors, such as amorphous silicon bridges 108 and 110. With this construction, it will be appreciated that both the conductors 102 and 104 are readily accessible to one or more IC chips which may be disposed in the vicinity above them. Thus, for example, a signal generator and a signal receiver may be disposed on the same IC chip or on different IC chips. FIG. 6 also shows that the conductor 102 is orthogonal to the conductor 106, and that the conductor 106 is orthogonal to the conductor 104. This orthogonality permits logic nets to be created for interconnecting various IC chips disposed on the SCB substrate. However, it should be appreciated that other suitable angular relationships between the various conductors in the SCB matrix may be employed in the appropriate application. It should also be noted that the conductor 102 is shorter than the conductors 104 and 106. The use of such a short and fat conductor 102 is advantageous from the standpoint of the topology of an SCB strip-line conductor matrix. Since the strip-line conductors in an SCB matrix typically run across the entire length of the wafer, the use of a long and wide conductor would consume a substantial amount of space on the top interconnection plane of the SCB. However, by making the widest conductors very short (e.g., 1/3 of the normal length), it will be much easier for an SCB designer to permit a sharing of the space between the widest and thinnest conductors on a single plane. While it would be more desirable to have the widest conductor 102 on a plane which is between that of the conductor 106 and the ground path from the standpoint of capacitive coupling, this difference can be made up by an appropriate adjustment to the width and/or height of the conductor 102. It should be noted that the conductor network 100 will decrease signal transmission delays, even though the RC coupling of the individual conductors 102-106 with the ground plane is the same. Thus, for example, the width and height of the conductors 102-106 can be constructed such that each of these conductors will provide the same RC time constant. However, as shown above the increase in speed is due to the change in impedance through the conductor network 100. Specifically, as a signal is transmitted from conductor 102 to conductor 104, the impedance level increases and correspondingly the load decreases. Referring to FIG. 8, an enlarged top view of a portion of the CB 10 of FIG. 1 is shown. FIG. 8 illustrates one possible form of an SCB structure which generally utilizes the type of conductor network shown in FIG. 6. Specifically, a plurality of relatively short and wide micro-strip conductors 112 and plurality of relatively long and thin micro-strip conductors 114 run parallel to each other and are disposed on the same plane of the SCB 10. Additionally, SCB 10 includes a plurality of micro-strip conductors 116 which are orthogonal to conductors 112-114, and which are disposed on a plane below that of the conductors 112-114. Amorphous silicon dioxide vias or bridges are used to provide programmable interconnections between these conductors at cross-over points shown as dots in FIG. 8. Each of the conductors 112-114 are connected to at least one of the plurality of pads 118 which are used to facilitate connections between the IC chips and the appropriate conductors of the SCB. Accordingly, it should be appreciated that one or more of the conductors 112 may be connected to a signal generator and one or more of the conductors 114 may be connected to a signal receiver. Then, the appropriate amphorous silicon dioxide bridges may be programmed to interconnect the conductors 112 and 114 together. In this regard, any suitable means may be employed to program these interconnections (e.g., through electrical, optical or thermal processes). FIG. 8 also illustrates that the SCB 10 includes a plurality of signal input and output pads 120-122, as well as test pads 124. Additionally, the SCB 10 includes a plurality of voltage and ground pads 126-128 which are disposed at various places along the top surface of the SCB to enable power connections to be made with the IC chips. It should be appreciated that FIG. 8 illustrates only one possible topology, and that other suitable SCB topologies may be employed in the appropriate application. The various embodiments which have been set forth above were for the purpose of illustration and were not intended to limit the invention. It will be appreciated by those skilled in the art that various changes and modifications may be made to these embodiments described in this specification without departing from the spirit and scope of the invention as defined by the appended claims.

A method and apparatus for optimizing the signal transmission speed between a signal source and a signal receiver of a microelectronic circuit is disclosed. The method includes the step of providing a signal transmission path whose length provides a predetermined ratio between its resistance and characteristic impedance which will reproduce the transmitted signal at the receiving end upon the first signal transition. The length of this transmission path may be increased by using a nonhomogeneous line structure in which the characteristic impedance increases in the direction of the signal transmission. In one form of the invention, the signal transmission path is formed by interconnecting a plurality of micro-strip conductors disposed on different planes of a universally programmable silicon circuit board. Under the appropriate circumstances, a signal can travel through such a "semi-lossy" transmission path at approximately the speed of light.

INTRODUCTION The invention relates to DNA sequences from the genome of mammals, in particular from the human genome, coding for proteins having the biologicl activity of HUSI-type I inhibitors and to cloning and expression vectors containing such DNA sequences, using recombinant DNA technology. The invention further relates to host organisms transformed with said vectors and to methods for the preparation of proteins having the biological activity of HUSI-type I inhibitors using said transformed host organisms. The invention finally relates to proteins having the biological activity of HUSI-type I inhibitors and to pharmaceutical compositions containing such proteins. BACKGROUND OF THE INVENTION In living cells and organisms the activity of enzymes is first regulated by the novo synthesis and chemical modification of enzymes. When fast adaptation of a cell or an organism to an altered environmental situation and simultaneously a higher activity of a specific enzyme is required, it does not mean that always a higher amount of this enzyme is synthesized de novo. Often, an already existing pool of enzymes is activated. For instance digestive enzymes (proteinases) are transferred from their storage form, the so-called zymogenes, to active proteinase. When necessary, blood coagulation factors are likewise transferred from the inactive storage form to the biologically active form. Known activating mechanisms of storage enzymes are cleavage by specific peptidases, phosphorylation by proteinkinases, release from vesicles and the changing of the protein conformation by allosteric ligands. An excess of activating reactions mentioned and the long-term effect of the activated enzymes is prevented by the controlled degradation or the specific inhibition of these enzymes. For example, the biological activity of activated proteinases is often blocked by specific proteinase inhibitors. In the past few years the clinical and pathogenetic relevance of different proteinase inhibitors was recognized (1,2). It was found that lysosomal proteinase inhibitors are suitable for the therapy of sepsis, of chronic diseases of the rheumatic type as well as of diseases of the upper pulmonary system. At the moment, however, there are not proteinase inhibitors known that could be used in the treatment of these diseases. For the time being only the proteinase inhibitor aprotinin is used in therapy. Aprotinin is used for the treatment of postoperative haemorrhages caused by hyperfibrinolysis and the early treatment of shocks. For the therapy of the above-mentioned diseases HUSI (Human-Seminalplasma Inhibitor)-type I inhibitors might be suitable. They are proteins. Examples for the group of HUSI-type I inhibitors are the proteinase inhibitors HUSI-I, CUSI-I (Cervix-Uterus-Secretion Inhibitor) and BSI (Bronchial-Secretion Inhibitor). HUSI-I is an acid-resistant proteinase inhibitor from human seminal plasma and inhibitors proteinases from the lysosomal granula of the granulozytes, such as elastase. HUSI-I only exhibits a reduced inhibitory activity against other intracellular or extracellular proteinases. Its molecular weight is about 11,000. A partial amino acid sequence of HUSI-I was published by Fritz (48). In addition to HUSI-I there exists a further acid-resistant proteinase inhibitor in the human seminal plasma, namely HUSI-II (3). Its molecular weight is about 6,500. HUSI-I and HUSI-II have completely different inhibitory spectra. While the inhibitory activity of HUSI-II is limited to trypsin and akrosin, the most remarkable property of HUSI-I is the specific inactivation of proteases from the lysosomal granula of the granulozytes, e.g. of elastase. Because of its different biological activity, HUSI-II is thus no HUSI-I inhibitor. The acid-resistant inhibitor CUSI-I was isolated from the cervix-uterus secretion (4). The molecular weight of CUSI-I is almost identical with that of HUSI-I. Moreover, HUSI-I and CUSI-I have the same inhibition spectrum. In the Ouchterlony immuno-diffusion test HUSI-I and CUSI-I show immunological cross-reaction with anti-HUSI-I antibodies (5, 6). Finally, the amino acid analyses of HUSI-I and CUSI-I, so far only fragmentarily known, are almost identical (47). The bronchial-secretion inhibitor (BSI) was isolated from the bronchial secretion (41, 44, 45, 46). The sequence of the first 25 amino acids of BSI was incompletely published in (41). BSI has a molecular weight of about 10,000. In immunological tests BSI shows a cross-reaction with rabbit anti-HUSI-I antibodies (47). BSI is acid-resistant and inhibits the proteinases leukozyte elastase, cathepsin G, trypsin and chymotrypsin. Although the biological activity of HUSI-type I inhibitors was essentially known, so far these inhibitors could not be used for therapeutical purposes since they were not available in sufficient amounts in essentially pure form. SUMMARY OF THE INVENTION Thus the problem underlying the present invention is to provide DNA sequences coding for proteins with the biological activity of HUSI-type I inhibitors and to prepare by biotechnological methods proteins with the biological activity of HUSI-type I inhibitors using such DNA sequences. This problem is solved by providing DNA sequences derived from a mammalian genome, particularly from the human genome, which hybridize, preferably under stringent conditions, to a DNA sequence according to FIG. 4 and/or 5 and which code for proteins having the biological activity of HUSI-type I inhibitors. In the present invention, the expression "proteins having the biological activity of HUSI-type I inhibitors" relates to fusion proteins and non-fusion proteins having the biological activity of the inhibitors HUSI-I, CUSI-I or BSI, i.e. for example the immunological properties of the natural proteins and/or the specific inhibitory properties of natural proteins. The inhibitory activity of the proteins of the invention having the biological activity of HUSI-type I inhibitors is in the following determined by measuring the inhibition of the enzyme chymotrypsin. As regards the expression "hybridizing under stringent conditions" and "conventional hybridization conditions" see (28), pages 387-389, and Bonner et al. (28). In general Tm -15 to Tm -30, preferably Tm -20 to Tm -27 is used. Fusion proteins and also non-fusion proteins, which embrace only part of the amino acid sequences of HUSI-I, CUSI-I and BSI are called in the invention proteins having the biological activity of HUSI-type I inhibitors. Partial regions of the amino acid sequence of proteins are also called "domains". In a preferred embodiment of the present invention, the DNA sequences code for proteins having the biological activity of the CUSI-I protein. In a further preferred embodiment of the present invention, the DNA sequence codes for a protein having the amino acid sequence shown in FIG. 5. Particularly preferred embodiments of the present invention are the DNA sequences shown in FIGS. 4 and 5 which are contained in plasmids pRH31 and pRH34 in the form of PstI fragments. Plasmids pRH31 and pRH34 have been deposited with the Deutsche Sammlung fur Mikroorganismen (DSM) under deposition Nos. DSM 3634 and DSM 3635, respectively. Plasmids pRH31 and pRH34 or fragments and synthetic oligonucleotides derived thereof are suitable as probes for the identification and isolation of further DNA sequences which code for proteins having the biological activity of the HUSI-type I inhibitors, i.e. for example for HUSI-I and BSI. This conclusion is possible for the expert since the primary structure data of inhibitors HUSI-I and BSI, although incomplete, which are available so far, show great similarity. From this a high sequence homology on DNA level can be expected. Because of this high sequence homology, it cannot be excluded that only a single gene codes for all three inhibitors and that the individual inhibitors are tissue-specific expression products. Suitable for the purposes of the present invention are also DNA sequences hybridizing, preferably under stringent conditions, to one of the above DNA sequences. Said DNA sequences are either of natural, semisynthetic or synthetic origin, they are related to one of the above-mentioned DNA sequences by mutations, nucleotide substitutions, nucleotide deletions, nucleotide insertions or inversion of nucleotide regions and they code for proteins with the biological activity of HUSI-type I inhibitors. Subject matter of the invention are furthermore vectors for the cloning and expression of the above-mentioned DNA sequences. In the invention, the term "vectors" relates e.g. to plasmids, such as pBR322, pU18, pUR290, pWH701 and pSP6 or to virus genomes and their fragments or derivatives, e.g. to the genome of the lambda phage or of the phage M13. In expression vectors of the present invention, the inventive DNA sequence is operatively linked to an expression control sequence. In a preferred embodiment, the expression vector at the 5' end of the gene contains a DNA fragment having the following sequence: ##STR1## As expression control sequences (promoter systems) according to the invention there may be used the E. coli lac promoter, the E. coli trp promoter, the E. coli lipoprotein promoter, the alkaline phosphatase promoter, the lambda-P L promoter, the lambda P R promoter, a yeast expression control sequence or other eukaryotic expression control sequences. Particularly preferred plasmids of the present invention are plasmids pRH31 (DSM 3634) and pRH34 (DSM 3635). Further particularly preferred plasmids are plasmids pRH24, pRH21 and pBA17 which may be constructed with plasmids pRH31, pRH34 and pRH1810 (DSM 3905). A further subject matter of the invention are host organisms which have been transformed with the above-mentioned vectors. Preferred host organisms are strains of the species E. coli, Bacillus subtilis or other bacteria, Saccharomyces cerevisiae, other microscopically small fungi, animal or human cells. Subject matter of the present invention are furthermore proteins having the biological activity of HUSI-type I inhibitors. The proteins of the invention preferably exhibit the biological activity of the CUSI-I protein. In a particularly preferred embodiment, the protein having the biological activity of the CUSI-I protein exhibits the amino acid sequence shown in FIG. 5. In a further particularly preferred embodiment, the protein having the biological activity of the CUSI-I protein has the following amino acid sequence Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. In a further particularly preferred embodiment, the protein having the biological activity of the CUSI-I protein has the following amino acid sequence Asp-Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. The proteins of the invention are preferably essentially pure proteins. The invention further relates to a process for the preparation of the above-mentioned proteins comprising culturing one of the above-mentioned transformed host organisms in a conventional nutrient medium, optionally including the expression of the gene product, isolating the expression product from the culture, i.e. fro the cultivated cells and/or from the nutrient medium and optionally further treating the expression product under controlled acidic hydrolytic conditons to effect a partial hydrolysis and separating the desired biologically active protein fragment from the hydrolysate by gel chromatography. Depending on their use, the proteins thus obtained can be further purified, preferably by chromatography, e.g. affinity chromatography or high performance liquid chromatography (HPLC) or a combination of these methods. The proteins and protein fragments prepared according to the invention are particularly suitable for the treatment of chronic bronchitis, of chronic cervix inflammations, as well as for the treatment of other chronic inflammatory processes associated with excessive mucous secretion and acute emergency situations resulting therefrom. They are further suitable for the early treatment of shocks and e.g. for the treatment of postoperative haemorrhages due to hyperfibrinolysis. Correspondingly, pharmaceutical compositions comprising an effective amount of a protein having the biological activity of the HUSI-type I inhibitors and conventional carriers and/or diluents and/or adjuvants are also a subject matter of the present invention. For treatment, the protein having the biological activity of HUSI-type I inhibitors may be administered in the form of sterile isotonic solutions by intramuscular, intravenous or subcutan injections into the inflammed area or optionally by infusion. In the invention, pharmaceutical compositions in the form of sprays or inhalation preparations are preferred. They are particularly suitable for the treatment of diseases of the respiratory tract by direct application of the active ingredients to the affected parts of the bronchial tubes and te lungs. In a first aspect of the present invention there is provided a composition comprising an acid-resistant proteinase inhibitor HUSI-type I protein in a form essentially free from impurities which interfere with activity of said protein as an antiinflammatory agent; and any additional ingredients being biologically inert to said activity. In a preferred embodiment of this aspect provides an acid resistant proteinase inhibitor HUSI-type I protein having an amino acid sequence including at least that portion capable of imparting said HUSI-type I activity from the amino acid sequence of the formula: Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. In another preferred embodiment of this aspect provides an acid resistant proteinase inhibitor HUSI-type I protein having an amino acid sequence including at least that portion capable of imparting said HUSI-type I activity from the amino acid sequence of the formula: Asp-Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. The terminology "a form essentially free from impurities which interfere with activity of said protein" refers to the exclusion from the scope of the present invention of any impurities stemming from the isolation process of the protein which interfere with the antiinflammatory activity of the protein. Also, the "additional ingredients" encompass conventional additives and excipients which also do not interfere with the antiinflammatory activity of the protein. A second aspect of the present invention provides an acid-resistant proteinase inhibitor HUSI-type I protein having an amino acid sequence transcribed from DNA having a sequence capable of imparting said HUSI-type I activity, said amino acid sequence including at least that portion of FIG. 5 capable of imparting said HUSI-type I activity. A third aspect of the present invention provides a method of treating a patient suffering from a chronic inflammatory disease or postoperative hemorrhages which comprises administration to said patient of an effective amount of an acid-resistant proteinase inhibitor HUSI-type I protein having an amino acid sequence transcribed from DNA having a sequence capable of imparting said HUSI-type I activity, said sequence including at least that portion of FIG. 5 capable of imparting said HUSI-type I activity. A preferred embodiment of this aspect involves the administration of the acid-resistant proteinase inhibitor HUSI-type I protein through inhalation. A further aspect of the present invention provides a composition comprising an acid-resistant proteinase inhibitor CUSI-type I protein in a form essentially free from impurities which interfere with activity of said protein as an antiinflammatory agent; and any additional ingredients being biologically inert to said activity. In a preferred embodiment of this aspect provides an acid resistant proteinase inhibitor CUSI-type I protein having an amino acid sequence including at least that portion capable of imparting said CUSI-type I activity from the amino acid sequence of the formula: Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. In another preferred embodiment of this aspect provides an acid resistant proteinase inhibitor CUSI-type I protein having an amino acid sequence including at least that portion capable of imparting said CUSI-type I activity from the amino acid sequence of the formula: Asp-Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. In another aspect of the present invention there is provided an acid-resistant proteinase inhibitor CUSI-type I protein having an amino acid sequence transcribed from DNA having a sequence capable of imparting said CUSI-type I activity, said amino acid sequence including at least that portion of FIG. 5 capable of imparting said CUSI-type I activity. In a final aspect of the present invention there is provided a method of treating a patient suffering from a chronic inflammatory disease or postoperative hemorrhages which comprises administration to said patient of an effective amount of an acid-resistant proteinase inhibitor CUSI-type I protein having an amino acid sequence transcribed from DNA having a sequence capable of imparting said CUSI-type I activity, said sequence including at least that portion of FIG. 5 capable of imparting said CUSI-type I activity. A preferred embodiment of this aspect involves the administration of the acid-resistant proteinase inhibitor CUSI-type I protein through inhalation. DESCRIPTION OF THE INVENTION In order to construct a host organism which is able to synthesize a foreign protein it is necessary to carry out a number of experimental steps. First the gene carrying the information for the biosynthesis of the desired protein is identified and isolated. There are different methods known for the identification and isolation of genes. For example, for isolating a DNA sequence coding for a protein with the biological activity of the CUSI-I protein, there are first prepared two mixtures of synthetic oligonucleotides on the basis of partial protein sequence data of the HUSI-I protein. These oligonucleotides are complementary to a DNA sequence encoding 6 amino acids and can be used as gene probes (cf. FIG. 1, RHI and RH2). On the basis of the incomplete data on the primary structure of CUSI-I, HUSI-I (48) and BSI (41), it was not possible to synthesize suitable oligonucleotide mixtures. For the known data of the amino acid sequences were obtained on the basis of chemically non-uniform mixtures of tryptic fragments, of bromocyano fragments or of NH 2 -termini (48). The partial sequences thus obtained moreover deviate by more than 30% from the amino acid sequence of the CUSI-I protein determined according to the invention. It is well-established that already one single incorrectly determined amino acid in a sequence of amino acids can lead to the inoperability of the oligonucleotide probe derived from this amino acid sequence. In (48) for example the amino acid sequence in the region of RH2 is stated to be Cys-Ser-Met-Gly-Met-Cys, the amino acid sequence determined according to the invention in this region is, however, Cys-Cys-Met-Gly-Met-Cys (see FIG. 4). According to the invention, cDNA libraries are screened using the above-mentioned mixtures of synthetic oligonucleotides. These cDNA libraries were prepared with mRNA from human cervix tissue as starting material. As starting material for the preparation of a cDNA library according to the present invention there may also be used mRNA from the tissue of the upper respiratory tract of the human lung (autopsy material, taken 10 hours post mortem) (7). The mRNA isolated from the donor tissue is used in a conventional manner for the synthesis of complementary DNA (cDNA) molecules, which are finally inserted into the PstI site of plasmid pBR322. With the thus prepared cDNA molecules host organisms, e.g. E. coli K12 DH1, are transformed and in a conventional manner plated on agar plates containing tetracycline. Colonies of transformed host bacteria containing a plasmid with a cDNA sequence coding for a protein with the biological activity of the CUSI-I protein are identified in a hybridization experiment, the so-called colony hybridization. For this experiment a replica nitrocellulose filter is prepared from bacteria colonies growing on agar plate, cf. Thayer (8). The replica nitrocellulose filters are then hybridized with the two above-mentioned oligonucleotide mixtures according to Wallace (9). From the positive colonies, the recombinant cDNA-containing plasmid is isolated. The size of the cDNA insert in the plasmid is determined and a plasmid with an insert of appropriate size is characterized in more detail by an analysis of the DNA sequence of the cDNA insert. Thus the recombinant plasmid pRH31 is isolated. It is deposited with the Deutsche Sammlung fur Mikroorganismen under deposition no. DSM 3634. By further screening a cDNA library prepared from nRNA of cervix tissue samples with an oligonucleotide derived from the DNA sequence of plasmid pRH31 and acting as probe in the hybridization the recombinant plasmid pRH34 is isolated (see FIG. 4, RH5). When determining the DNA sequence of the insert of recombinant plasmid pRH34 it can be seen that this plasmid comprises the whole region coding for the CUSI-I protein. Recombinant plasmid pRH34 has been deposited with the Deutsche Sammlung fur Mikroorganismen under deposition no. DSM 3635. With the assistance of the cDNA sequences contained in plasmids pRH31 and pRH34 expression vectors are then constructed. First recombinant plasmid pRH24 is prepared from recombinant plamid pRH1810 acting as intermediate. Recombinant expression plasmid pRH24 contains the region of plasmid pRH34 coding for a protein with the biological activity of the CUSI-I protein as well as a synthetized DNA fragment comprising both the Shine-Dalgarno sequence and the translation origin. The expression product derived from recombinant expression vector pRH24 comprises all amino acids shown in FIG. 5. Furthermore recombinant expression plasmid pRH21 is prepared. For this a SauIIIA fragment is cut out from plasmid pRH31 and inserted into the BamHI restriction site of plasmid pUR290. The expression product derived from the thus constructed recombinant expression plasmid pRH21 is a fusion protein whose N-terminus consists of the amino acid sequence of the β-galactosidase and whose 59 C-terminal amino acids correspond to the last 59 amino acids of the CUSI-I protein (see FIG. 5). A polypeptide having a length of 58 amino acids is separated in a conventional manner from this expression product by acidic hydrolysis of the aspartic acid-proline linkage (e.g. by treating for 20 to 40 hours with 10 to 70% acetic acid or formic acid, preferably with about 30% acetic acid or 70% formic acid, at temperatures in the range from about 10° to 30° C., preferably at room temperature). It is subsequently purified by gel chromatography. This polypeptide having a length of 58 amino acids corresponds to the C-terminal domain of the protein described in FIG. 5 having the biological activity of the CUSI-I protein. Plasmid pBA17 is constructed as a further recombinant expression plasmid. For this a BamHI/HinfI fragment is cut out from plasmid pRH1810 and ligated into expression plasmid pSP6 after the ends have been filled up. The expression plasmid is prepared for ligation by HindIII cleavage and subsequent treatment with Mungbean nuclease and alkaline phosphatase. The expression product obtained from the resulting recombinant expression plasmid pBA17 consists of 59 amino acids. Its sequence corresponds to the one of the 59 C-terminal amino acids in FIG. 5. The expression product exhibits the biological activity of the CUSI-I protein. The expression of the above-mentioned proteins by the corresponding transformed host organisms is demonstrated by an immunoprecipitation (10) or by a Western blot analysis (11, 12). The biological activity of the expression products is determined by the inhibition of the proteinase chymotrypsin. The Figures show: FIG. 1: Amino acid sequence of fragments of the natural HUSI-I protein which were purified by HPLC and obtained by enzymatic cleavage of the protein with trypsin. The sequence regions from which the two mixtures of synthetic oligonucleotides were derived are called RH1 and RH2. They are underlined. FIG. 2: Restriction map of plasmid pRH31. Recombinant plasmid pRH31 is shown with restriction sites of P=PstI, E=EcoRI, B=BamHI, H=HindIII. The black bar shows the cDNA insert, the arrows in the circle show the tetracycline-resistance gene (tet r ) and the interrupted ampicillin-resistance gene (amp s ). FIG. 3: Scheme of the sequencing strategy of the cDNA insert of plasmid pRH31. The black bar shows the 500 bp-Pst I fragment of plasmid pRH31, the black arrows correspond in each case to a sequencing reaction. The white, unfilled arrow designates the region on the cDNA insert coding for CUSI-I. FIG. 4: Nucleotide sequence of the CUSI-I-cDNA fragment of plasmid pRH31. The double-stranded DNA sequence is shown. The open reading frame of the CUSI-I sequence starts immediately after the 5'-(G:C). homopolymer tail of the cDNA insert. The reading frame encodes 90 amino acids which are indicated in the three letter code. Further shown are 178 base pairs following the stop codon TGA. FIG. 5: Nucleotide sequence of the CUSI-I-cDNA fragment of plasmid pRH34. The double-stranded DNA sequence is shown. The amino acids derived from the DNA sequence are given in the three letter code. The nucleotides from position 59 to 133 encode the signal peptide of the CUSI-I protein. FIG. 6: Sequencing strategy of the PstI insert of pRH1807 (containing the CUSI-I cDNA fragment of the plasmid pRH34). Each arrow represents a sequencing experiment. H=HindIII, P=PstI, B=BamHI. FIG. 7: Construction scheme of expression vector pRH24 which carries the CUSI-I gene at the 3'-end of the regulatable promoter lambda-P L . ______________________________________amp.sup.r : ampicillin-resistance geneN-CUSI-I: DNA fragment coding for the CUSI-I-N terminusC-CUSI-I: DNA fragment coding for the CUSI-I-C terminusO.sub.L P.sub.L : Left operator and promoter region of the bacteriophage lambdaSD: Shine-Dalgarno sequence or ribosome-binding site______________________________________ Abbreviations of the restriction endonucleases: B=BamHI, E=EcoRI, H=HindIII, Hae=HaeIII, P=PstI, Sph=SphI FIG. 8: Restriction map of plasmid pRH34 Recombinant plasmid pRH34 is shown with restriction sites for P=PstI, E=EcoRI, B=BamHI, H=HindIII, Hae=HaeIII. The black bar indicates the position of the cDNA insert, the arrows in the circle indicate the position of the tetracycline-resistance gene (tet r ) and of the destroyed ampicillin-resistance gene (amp s ). FIG. 9: An analysis of the amino acid sequence raises an interesting aspect: When neglecting two shifts of the sequence, all cystein residues existing in the molecule can be superimposed when the protein is divided into two halves and they are written over one anothr (amino acids 1-54 and 55-107). It is further noted that adjacent amino acids are often conserved relative to the cystein residues. There are two different explanations for this observation: 1. CUSI could comprise two almost identically folded inhibitor-active segments, namely one for trypsin and one for leukozyte elastase or chymotrypsin. 2. The protein was possibly formed on the level of the genetic code from an existing domain, both domains then having developed independently from each other. FIG. 10: Cloning strategy for the expression of partial CUSI-I sequences as β-galactosidase fusion protein. The black bar represents partial CUSI-I sequences, the unfilled bar the β-galactosidase gene (lacZ), and the arrows in the circle show the position of the tetracycline-resistance gene (tet r ) or the ampicillin-resistance gene (amp r ). P=PstI, S=Sau3A, E=EcoRI, H=HindIII, B=BamHI, p=lac promoter, o=lac operator. FIG. 11: Construction Scheme of Expression Vector pBA17 for the expression of the C-terminal CUSI-I domain (=CUSI-I 2nd domain). Amp r `ampicillin resistance gene P tac =tac promoter Tet s =inactive tetracycline resistance residual gene rrnBT 1 T 2 =transcription terminator signal of ribosomal RNA genes. The abbreviations used below have the following meanings: ______________________________________A.sub.578 absorption at 578 nmDTT dithiothreitolBis N,N,N',N'--methylenebisacrylamidebp base pairsD DaltonsDE(DEAE) diethylaminoethylds cDNA double-stranded cDNAdNTP deoxynucleoside-5'-triphosphateEDTA ethylenediaminetetraacetic acidIgG immunoglobulinIPTG isopropyl-β-D-thiogalactopyranoside.sup.32 P isotope of phosphorus of the relative mass 32RPM revolutions per minute35.sub.S sulfur isotope of relative mass 35SDS sodiumdodecylsulfatess cDNA single-stranded cDNATPEG p-aminophenyl-I--thio-β-D-galactopyranosideTris trishydroxymethylaminomethaneU unit of enzyme activitysarcosyl N-laurylsarcosineα-(.sup.32 P)-dCTP deoxycytidyl-5'-triphosphate with isotope .sup.32 P in the alpha phosphate residueLB medium 10 g/l casein enzymatically digested (Sigma), 5 g/l yeast extract (Sigma), 8 g/l NaCl, adjusted to pH 7.5______________________________________ In the examples the methods described below and the mentioned materials are used. Materials and methods are further described in T. Maniatis et al. (28). 1. Enzymes Restriction endonucleases (Bethesda Research Laboratory (BRL)) and T4-DNA ligase (Boehring Mannheim) as well as calf intestinal alkaline phosphatase (Boehringer Mannheim), T4-polynucleotidekinase (Boehringer Mannheim) and Mungbean nuclease (Pharmacia) are commercially available and used according to the manufacturer's directions. Terminal deoxynucleotidyl transferase (BRL) is used as described in section 7. E. coli DNA polymerase (BRL), ribonuclease H (BRL) as well as AMV reverse transcriptase (Life Science) are used according to (13). E. coli DNA polymerase I (Klenow fragment) (Boehringer Mannheim) is used as described in (14). 2. Microorganisms Both gram-negative and gram-positive strains, for example strains of E. coli or Bacillus subtilis, may be used as microorganisms for the expression of a protein having the biological activity of CUSI-I. With suitable vectors containing the structural gene for a protein having the biological activity of CUSI-I, the usual expression systems for eukaryotes, e.g. Saccharomyces cerivisiae or mammalian cells, may be used as well. According to the invention E. coli strain K 12 MC 1061 λ 15 (deposited with DSM under deposition number DSM 3631) is used for the direct expression of the complete natural CUSI-I protein. Its genotype may be defined as follows: araD139, Δ(ara, leu) 7697, Δ lacX74, galU - , galk - , hsr - ,hsm + , strA. According to the present invention E. coli strain K12 JM 101 (deposited with American Type Culture Collection (ATCC) under deposition number ATCC 33876) is used for the expression of the fusion protein between the β-galactosidase and the C-terminal domain of the CUSI-I protein. Its genotype can be defined as follows: Δ(lac pro), thi, strA, supE, endA, sbcB, hsdR - , F'tra D36, pro AB, lacIq, ZΔM15. For isolating recombinant plasmids which were obtained after the insertion of synthetic cDNA (cf. also example 1c), E. coli K12 DH 1 (deposited with ATCC under deposition no. ATCC 33849) is used (17). Its genotype can be defined as follows: F - , recA1, endA1, gyrA96, thi-1, hsdR17 (r k - , m k + ), supE44, relA1. In order to isolate plasmids and newly constructed recombinant plasmids, containing promoter p L of the lambda-phage, E. coli K12 wild-type W6 bacteria are transformed first. In these host bacteria, the lambda-p L promoter is constantly blocked by a temperature-resistant lambda repressor, E. coli K12 wild-type W6 has been deposited with DSM under deposition number DSM 3632. 3. Vectors For transforming E. coli bacteria, the following known plasmids are used. Some of them are commercially available. pBR322 (ATCC 31344, (23), Pharmacia, Freiburg), pUC18 (deposited with Deutsche Sammlung fur Mikroorganismen under deposition no. DSM 3424, (24), Pharmacia, Freiburg), pUR 290 (DSM 3417, (25)), pWH 701 (DSM 3633, (26)), pRK 248 cIts in E. coli K12 JMB9 (ATCC 33766, (27), (49)), pSP6 (DSM 3904) and pRH1810 (DSM 3905). The man skilled in the art is familiar with further suitable vectors which may be used according to the invention in connection with host organisms that are known to him as well. 4. Gel Electrophoresis Depending on the length of the DNA, agarose or polyacrylamide gels are used for the separation of DNA fragments. DNA fragments>800 bp are separated on 1-1.2% agarose gels in TAE buffer (40 mM Tris-acetate, pH 8.3, 2 mM EDTA), DNA fragments<800 bp on 5% polyacrylamide gels (acrylamide/bis-acrylamide (19:1) in TBE buffer (60 mM Trs-base, 60 mM boric acid, 1 mM EDTA, pH 8.3). Denaturating agarose gel electrophoresis for the separation of cDNA is for example carried out in 1.2% alkaline agarose gels according to McDonell et al. (19). The electrophoretic separation of mRNA is carried out with 1.4% agarose gels and 15 mM methylmercurihydroxide. Samples can be subjected to electrophoresis and denaturated according to the method of Bailey et al. (20). For the separation of proteins in SDS-polyacrylamide gels, the method of Laemmli (21) is used. 5. Gel Elution Methods The preparative separation of DNA fragments<1,000 bp is carried out in 5% polyacrylamide gels. The elution of fragments is done according to Maxam and Gilbert (22). The thus isolated fragments were used for subcloning and sequence analysis, respectively. 6. Isolation of RNA Total RNA from human tissue is isolated according to the method of Maniatis et al. (28). The extraction of the total RNA is followed by CsCl-gradient centrifugation, in which the DNA is separated (29). For this 3 ml 5.7M CsCl, 100 mM EDTA are placed into a 16 ml Beckman-SW27 centrifuge tube, overlaid with 4 ml RNA solution (3-4 mg nucleic acid in 1% N-laurylsarcosine, 5 mM Tris-HCl, pH 7.5, 1 mM EDTA, 4 g/4 ml CsCl) and subjected to centrifugation for 17 hours at 15° C. at 17,000 rpm in a Beckman SW-27 rotor. The RNA sediment is resuspended in TE buffer (10 mM Tris-HCl, pH 8.0, 1 mM EDTA), precipitated with ethanol and finally subjected to chromatography for enrichment of poly(A + )-mRNA with oligo(dT) cellulose (Type 9, Pharamcia, Freiburg) according to Aviv and Leder (30). The mRNA is precipitated from the eluate with ethanol and kept in 70 % ethanol at -70° C. The viability of the mRNA isolate can be checked by in vitro translation in rabbit reticulocyte lysate (see section 16) or by denaturating gel electrophoresis. The thus isolated mRNA is then used for cDNA synthesis and Northern blot analysis. 7. cDNA-Syhthesis Complementary single-stranded or double-stranded DNA is synthesized according to Gubler et al. (13). The synthesis yield is screened by inserting α-[ 32 P]-dCTP, while the length of the resulting cDNA-molecules is determined by 1.2% alkaline agarose gel and radioactively labelled standard DNA-molecules. Tailing of the 3'-ends of the cDNA with oligo-(dC) homopolymers is performed in a total volume of 40 μl under the following conditions: 100 mM K-cacodylate, pH 7.2, 10 mM CoCl 2 , 1 mM DTT, 500 μM dCTP, 1-2 mg/ml cDNA, 600 U/ml terminal deoxynucleotidyl transferase. The reaction mixture is incubated for 50 minutes at 20° C. and the reaction is stopped by adding EDTA (final concentration 20 mM). After precipitation with ethanol from an 0.3 M sodium acetate solution, the precipitated cDNA is suspended in TE buffer (10 mM Tris-HCl, pH 8.0, 1 mM EDTA) and hybridized with PstI-cleaved, 3'-oligo(dG)-tailed plasmid pBR322 (100 mM NaCL, 10 mM Tris-HCl, pH 7.8, 0.1 mM EDTA, 0.1-0.3 ng/μl cDNA, 1.2 ng/μl plasmid-DNA). For hybridization this mixture is subsequently incubated for 5 minutes at 65° C., for 45 minutes at 56° C., for 45 minutes at 43° C. and for 15 minutes at room temperature. It is then directly used for transformation (see section 9). 8. Northern Blot Analysis RNA is subjected to denaturating gel electrophoresis and transferred to nitrocellulose filters according to Thomas (31). Prehybridization and hybridization with 5'-labelled oligonucleotides can be carried out in the manner described in (9) (cf. section 11). Non-specifically bound oligonucleotides can be removed after hybridization by washing the nitrocellulose filter, e.g. by washing the filters 15 minutes at room temperature and 3 minutes at 2° C. below the melting point in SSC buffer (900 mM NaCl, 90 mM sodium citrate, pH 7.0). The melting temperature is calculated according to Suggs et al. (32). 9. Transformation of E. coli and Isolation of Plasmids For transformation with recombinant plasmids containing cDNA synthesized de novo (see example 1 c)), competent cells of E. coli K12 DH1 are prepared according to Hanahan (17). Cells of E. coli K12 strains JM101, W6 and Mc1061 are transformed according to Mandel and Higa (33). Plasmid DNA is prepared from a one liter culture according to the method described in (34). Rapid analyses of plasmids are carried out according to Holmes et al. (35). 10. Oligonucleotide Synthesis Oligonucleotides are synthesized according to the phosphoamidite method (36). Oligonucleotides are purified e.g. by reversed-phase chromatography on Shandon-Hypersil ODS® (particle size 5 μm, column size 4.6×250 mm). After removal of the trityl group with 80% acetic acid, the products are again subjected to chromatography on the mentioned column material and analysed in 20% polyacrylamide gels after labelling at the 5'-end (see section 11). According to this method two oligonucleotide mixtures, namely RH1 and RH2 are synthesized. These oligonucleotide mixtures are both used as probes. The sequences of the oligonucleotide molecules in the two mixtures are derived from appropriate amino acid sequences of tryptic fragments of the HUSI-I protein (see FIG. 1). The amino acid sequences of these fragments were determined according to W. Machleidt (50). Only by correcting known HUSI-I sequences by the analysis of several tryptic fragments and several bromocyano fragments it became possible to arrive at the oligonucleotide mixtures of the invention. The oligonucleotide mixtures are so-called "mixed probes", i.e. mixtures of oligonucleotides differing in defined positions due to the degeneration of the genetic code (9). The disadvantages of usual "mixed probes" could be offset by high purification of the oligonucleotides with HPLC as well as by their quantitative 32 P phosphorylation. The oligonucleotide mixture RH1 corresponds to an amino acid sequence of the tryptic fragment T2 of the CUSI-I protein (see FIG. 1). Thus the oligonucleotide mixture comprises 16 different oligonucleotides, each having a length of 17 bases. The sequences are as follows: ##STR2## the oligonucleotide mixture RH2 corresponds to an amino acid sequence of the tryptic fragment T3 of the HUSI-I protein (see FIG. 1). There are thus synthesized 32 different oligonucleotides with a length of 17 bases each. They have the following sequences: ##STR3## 11. Radioactive Labelling of DNA The phosphorylation of chemically synthesized oligonucleotides and double-stranded dephosphorylated DNA fragments is carried out with the enzyme T4-polynucleotide-kinase in 20 to 50 μl reaction volume (50 mM Tris-HCl, pH 9.5, 20 mM MgCl 2 , 1 mM EDTA, 10-20 pmol 5'-OH-ends substrate, 8 μl γ-[ 32 P]-ATP (˜8000 Ci/mmol), 0.2 U/μl T4-polynucleotide-kinase), the subsequent separation of unconverted γ-[ 32 P]-ATP by preparative gel electrophoresis, subsequent gel elution and ion exchange chromatography on DE-52 (diaminodiethyl cellulose) (Whatman). 5'-protruding ends of DNA restriction fragments can be filled up with the Klenow fragment of the E. coli DNA polymerase I in the presence of the complementary α-[ 32 P]-deoxyribonucleosidetriphosphates according to Volkert et al. (14). α-[ 32 P]-dNTPs which are not incorporated are separated by gel permeation chromatography on Sephadex G-50 and eluted fractions are concentrated under reduced pressure. 12. DNA Sequence Analyses The sequences of DNA molecules are determined according to Maxam and Gilbert (22). 13. Purification of the β-Galactosidase Fusion Protein The CUSI-I-β-galactosidase fusion protein is purified by affinity chromatography according to Ullmann (37). 14. Transfer of Proteins to Nitrocellulose Filters Proteins separated in SDS-polyacrylamide gels are transferred to nitrocellulose filters according to Towbin et al. (12). 15. CUSI-I Inhibition Tests The activity of proteins having the biological activity of CUSI-I is shown by measuring the inhibition of trypsin (38) and chymotrysin (39). 16. Cellfree Translation of mRNA The cellfree translation of mRNA in the reticulocyte lysate is carried out according to Pelham et al. (40) using 35 S-methionin having a specific activity of 1200 Ci/mmol as radioactively labelled amino acid. The examples illustrate the invention. EXAMPLE 1 Cloning and Identificaton of a partial CUSI-I Protein-Specific cDNA Clone (a) Isolation and Characterization of nRNA Total RNA or mRNA is isolated from human cervix tissue (biopsy material) as described above in section 6. Approximately 1.6 to 2.2 mg total RNA are obtained from 14 to 17 g cervix tissue. After enrichment of poly(A + )-mRNA by affinity chromatography with oligo(dT)-cellulose (Type 9, Pharmacia) 20 to 25 μg mRNA/mg total RNA are obtained. This corresponds to a yield of about 2.0 to 2.5% mRNA. An gel electrophoretic analysis in a denaturating agarose gel shows that the RNA is not degraded during isolation. Corresponding results are also obtained from an in vitro translation of the total and poly (A + )-mRNA in rabbit reticulocyte lysate. (b) Northern blot analysis of the isolated mRNA with a synthetic oligonucleotide for detection of CUSI-I protein-specific sequences The Northern blot analysis is carried out for identifying specific mRNA sequences in the cervix-mRNA isolate. The oligonucleotide mixture RH1 which is complementary to an mRNA coding for the amino acids Phe-Cys-Glu-Met-Asp-Gly (see FIG. 1) serves as hybridizing probe. By exposure of an X-ray film ("Kodak X-o-matAR") with a nitrocellulose filter obtained during hybridization a specific signal is detected. With the oligonucleotide mixture RH2 no positive signal was found although one of the oligonucleotide sequences of the mixture later (after sequencing) proved to be the right sequence. When comparing the side of the molecules of the hybridizing mRNA species with DNA standard molecules in a denaturating gel it is found that the length of the hybridizing mRNA is about 650 to 800 bases. (c) Preparation of a cDNA library with the plasmid pBR322 4 to 6 μg poly(A + )-mRNA are used as starting material for the synthesis of cDNA. The yield of single-stranded cDNA is about 280 ng (about 7%). The synthesized single-stranded c-DNA molecules have a size from about 400 to 2,500 nucleotides. From 280 ng ss cDNA about 270 ng double-stranded cDNA are obtained when synthesizing the second strand. Thus the yield of the double-strand synthesis is about 50%. The 3'-ends of the cDNA molecules are tailed with homopolymeric (dC)-regions. The thus obtained cDNA molecules are added in a hybridizing reaction to molecules of plasmid pBR322 which are PstI-cleaved and have been tailed at the 3'-ends with homopolymeric (dG)-regions. The addition products are used for the transformation of E. coli K12 DH1. Then the transformants are selected for tetracycline resistance and ampicillin sensitivity. Per ng cDNA employed, 120 transformants (12,000 transformants/100 ng ds cDNA) are obtained. The proportion of tetracycline-resistant and ampicillin-sensitive transformants or colonies is about 80 %. These transformants are plated in microtiter plates (98 wells/plate) as storage cultures (medium: LB-medium, 10 g/l casein enzymatically digested (Sigma), 8 g/l NaCl, pH 7.5, 5 g/l yeast extract (Sigma), 20 μg/ml tetracycline, 20% glycerol) and kept at -20° C. (d) Identification of a recombinant plasmid with a CUSI-I-protein-specific cDNA For the analysis of 6,000 transformants obtained as described above, colony hybridization is carried out with the oligonucleotide mixture RH1. The activity of the oligonucleotide mixture is about 1×10 6 cpm in the hybridization volume at a specific activity of 0.8 μCi/pmol. X-ray films are exposed with the filters obtained during hybridization for 12 hours each at -70° C. in the presence of two intensifying screens. A positive signal is detected. Starting from the storage culture of the corresponding transformant, the recombinant plasmid called pRH31 is prepred from a 0.5 liter culture (LB-medium, 10 g/l casein enzymatically digested (Sigma), 10 g/l NaCl, 5 g/l yeast extract (sigma), pH 7.5, 20 μg/ml tetracycline). By using restriction endonucleases PstI, EcoRI, BamHI as well as HindIII a restriction map of recombinant plasmid pRH31 is prepared (see FIG. 2). The cDNA insert has a length of 500 bp (see FIG. 2). Plasmid pHR31 has been deposited with DSM under deposition number DSM 3634. (e) Sequence analysis of the cDNA insert of pRH31 For sequencing accoding to Maxam and Gilbert (22), the PstI fragment (500 bp) from plasmid pRH31 is recloned into plasmid pUC18. For this purpose 10 μg DNA or pRH31 are cleaved with 30 U or restriction endonuclease PstI, preparatively separated on an agarose gel and the obtained 500 bp fragment is eluted from the gel. In addition 10 μg DNA of plasmid pUC18 are cleaved with restriction endonuclease PstI, dephosphorylated, extracted with phenol and diethylether and finally precipitated with ethanol from an 0.3 molar sodium acetate solution. For the following T4-DNA ligase reaction 0.2 pmol plasmid DNA and 0.4 pmol of the PstI fragment are used. The thus obtained recombinant DNA molecules are used for the transformation of E. coli K12 JM101. A selection is carried out on LB plates containing ampicillin (10 g/l casein, 8 g/l NaCl, 5 g yeast extract, 100 μg/ml ampicillin). Recombinant plasmids contained in ampicillin-resistant transformants are characterized by plasmid rapid analyses. There are obtained recombinant plasmids pRH181 and pRH182 containing the PstI fragment of pRH31 in opposite orientation. The sequencing strategy shown in FIG. 3 results from the construction of these plasmids which only serve as auxiliary constructions for easier DNA sequencing. The nucleotide sequence of the 500 bp PstI fragment of plasmid pRH31 determined by sequencing (22) is shown in FIG. 4. The sequence starts at the 5'-end with 20 (dG)-residues. It is followed by an open reading frame extending over 273 bp (see FIG. 4, positions 25 to 297). This open reading frame codes for 90 amino acids and ends with a stop codon TGA (see FIG. 4). From the nucleotide sequence it can be seen that the oligonucleotides of the oligonucleotide mixture RH1 are complementary to positions 208 to 224 of the nucleotide sequence and that the oligonucleotides of the oligonucleotide mixture RH2 are complementary to positions 247 to 263 of the nucleotide sequence. The stop codon TGA is followed by further 178 bp. An analysis of the nucleotide sequence demonstrates that the region coding for the N-terminal segment of the CUSI-I protein is not contained in the nucleotide sequence. EXAMPLE 2 Isolation of a recombinant plasmid with a cDNA fragment coding for the entire CUSI-I protein (a) Synthesis of the oligonucleotide RH5 For isolating a cDNA fragment comprising the entire region coding for the CUSI-I protein, the oligonucleotide RH5 is synthesized according to the phosphamidite method (36). The oligonucleotide RH5 has a length of 20 bases. It is complementary to positions 31 to 50 of the coding DNA strand shown in FIG. 4 and has the following sequence: ##STR4## The oligonucleotide RH5 is radioactively labelled and used as probe in order to identify in a new cDNA library transformants which contain recombinant plasmids, whose cDNA fragments contain at least the 5'-terminal region of plasmid pRH31 at their 5' ends. (b) Preparation of a new cDNA gene library comprising a recombinant plasmid with the entire coding region of the CUSI-I protein. For the preparation of a new cDNA library in E. coli using plasmid pBR322 the mRNA coding for the CUSI-I protein is isolated. For this 250 μg total RNA from human cervix tissue are electrophoretically separated according to their size in a denaturating, 1.4% "Low Melting Point" (LMP) agarose gel containing 15 nM methylmercurihydroxide (see section 4). Approximately 10 μg mRNA with a length of about 700 to 850 bases are isolated by extraction from this gel. 4 μg of this mRNA are used for cDNA synthesis (see section 7) and introduced into E. coli K12 DH1 (see section 9). There are obtained 4,300 transformants with 53 ng double-stranded cDNA. The transformants are analysed by colony hybridization with 5'-labelled oligonucleotide RH5 (see example 2a). The activity of the oligonucleotide in the hybridization solution is 2×10 5 cpm/ml with a specific activity of 0.72 μCi/pmol. There are isolated 12 transformants, the recombinant plasmid of which hybridizes with the oligonucleotide RH5. With an aliquod of the storage cultures of the transformants, the recombinant plasmids are prepared and mapped by restriction cleavages with PstI, BamHI and HindIII. It is found that 11 of these plasmids have a restriction pattern almost identical with that of plasmid pRH31, i.e. each of them contains one BamHI/PstI fragment of 380 bp and one of about 125 bp as well as one HindIII/PstI fragment of about 290 bp and one of about 200 bp. The length of the PstI fragments is in each case about 500 bp. Only one plasmid shows a different restriction map, i.e. it comprises one BamHI/PstI fragment of 285 bp and one of 275 bp as well as a HindIII/PstI fragment of about 450 bp and one of about 105 bp. The length of the insert of the deviating recombinant plasmid is about 550 bp. This recombinant plasmid is called pRH34. Its restriction map is shown in FIG. 8. Plasmid pRH34 has been deposited with DSM under deposition number DSM 3635. (c) Nucleotide sequence of the insert of recombinant plasmid pRH34 The PstI-cDNA fragment from pRH34 and both BamHI/PstI fragments from pRH34 are subcloned in DNA of plasmid pUC18 after the DNA has been cleaved with PstI or PstI and BamHI and treated with alkaline phosphatase. The recombinant plasmids thus constructed which are auxiliary constructs for DNA sequence analysis are designated pRH1807 (PstI fragment), pRH1808 (N-terminal BamHI/PstI fragment) and pRH1809 (C-terminal BamHI/PstI fragment). The sequence of the subcloned DNA fragments is analyzed according to Maxam and Gilbert (22). The sequencing strategy of the recombinant plasmids can be seen from FIG. 6. The nucleotide sequence of the cDNA fragment from pRH34 is shown in FIG. 5. It is identical with the sequence of the cDNA insert of pRH31 from position 25 to 308 (see FIG. 4). However, the cDNA insert of pRH34 is 184 bp longer at the 5'-end. Of these, 143 bp correspond to the sequence complementary to the mRNA and 41 bp stem from the homopolymer tailing of the cDNA with dCTP including the PstI restriction site. The amino acids ##STR5## were identified as N-terminus of the HUSI-I inhibitor. When the amino acid codons are deduced from the 5'-terminal nucleotides of the isolated DNA sequence, no stop codon is found in this part of the reading frame. Thus the ATG which appears in the reading frame is responsible for the initiation and codes for the start of the CUSI-I protein. Moreover, signal peptide structures of secretory proteins are rarely longer than 25 amino acids. The restriction sites between signal peptides and the corresponding natural proteins are most often found behind the amino acids alanin, serin and glycin; thus the sequence Gly-Ser is quite common. The primary structure of the human CUSI-I protein from cervix secretion is therefore composed of 107 amino acids. The amino acid sequence encoded by the determined nucleotide sequence is essentially identical with the N-terminal amino acid sequence of the bronchial antileukoprotease which previous to the invention was only incompletely known (41). EXAMPLE 3 Expression of the CUSI-I Protein in E. coli (a) Construction of an expression plasmid comprising the entire CUSI-I cDNA downstream of the regulatable lambda-p L promoter. To begin with, two synthetic oligonucleotides are synthesized which are designated RH6 and RH7. They are complementary to each other and carry the sequences for an optimal ribosome binding site (42), a SalI and EcoRI restriction site and the nucleotide sequence of the coding region of CUSI-I from position 1 to position 14. Both oligonucleotides are phosphorylated 5'-terminally with the enzyme T4-polynucleotide-kinase, preparatively electrophoretically separated in a 12% polyacrylamide gel, eluted from the gel and subjected to chromatography with DE 52. After subsequent gel permeation chromatography on Sephadex G-50 10 pmol of each oligonucleotide are mixed, denaturated at 90° C. and hybridized with each other by slow cooling to room temperature. In this way, the following double-stranded DNA fragment is obtained: ##STR6## The second isolated component is the 210 bp (HaeIII/BamHI) fragment of plasmid pRH34 which codes for the further N-terminal region. For this, 10 μg of plasmid pRH34 are cleaved with restriction endonucleases HaeIII and BamHI and electrophoretically separated in a 5% polyamide gel. The 210 bp fragment is then eluted from the polyacrylamide gel. Plasmid pRH1807 (FIG. 6) serves as third component and thus as vector (FIG. 7). For this, 10 μg of this plasmid are cleaved with the restriction enzymes EcoRI and BamHI. The vector fragment is treated with alkaline phosphatase, then extracted with phenol and precipitated with ethanol. For the three-component ligation (FIG. 7), 1 pmol of the synthetic oligonucleotides hybridized with each other, 0.2 pmol of the N-terminal HaeIII-BamHI fragment and 0.03 pmol of the vector DNA are mixed and ligated with each other in a reaction volume of 30 μl with 5 U T4-DNA ligase. The E. coli K12 strain JM101 is used for transformation. The plasmids of the transformants thus obtained are screened by hybridization with radioactively labelled oligonucleotide RH6. In addition the restriction sites for SalI, EcoRI and BamHI are checked and the length of the corresponding fragments is determined. The correct newly constructed plasmid is designated pRH1810 (DSM 3905) (FIG. 7). For constructing an expression plasmid, 10 μg of the vector pWH701 (26) are cleaved with EcoRI and SphI, dephosphorylated, extracted with phenol and precipitated with ethanol. For preparing the EcoRI-SphI fragment from plasmid pRH1810, 10 μg DNA are cleaved with EcoRI and SphI. The resulting 525 bp fragment is separated from the vector by gel electrophoresis with a 5% polyacrylamide gel and eluted from the gel. Then 0.3 pmol vector pWH701 and 1 pmol of the EcoRI-SphI fragment are ligated with each other and introduced into E. coli K12 wild-type W6. The plasmids of the resulting transformants are characterized by plasmid rapid analyses and subsequent agarose gel electrophoresis. The recombinant expression plasmids are by 280 bp longer than the expression plasmids without insert. The newly identified recombinant expression plasmid is designated pRH24 and used in the subsequent expression experiments. FIG. 7 shows the construction scheme of the recombinant expression plasmid pRH24. (b) Expression of the CUSI-I cDNA with the expression plasmid pRH24 in E. coli K12 MC1061/pRK248 cIts (15, 27). The host bacteria strain alone is not lambda-lysogenic, i.e. it does not contain a lambda-cI repressor. The genetic information for the temperature-sensitive repressor lambda-cI 857 is localized on plasmid pRK248 cIts, which confers to the host bacterium also tetracycline-resistance (27). At 30° C., the lambda-p L promoter controlled transcription is completely suppressed. At 42° C., the temperature-sensitive cI 857-repressor exists in its inactivated form and the genes lying downstream of the p L promoter are transcribed. This E. coli K12 MC1061/pRK248 cIts is transformed with the recombinant expression plasmid pRH24. For inducing the expression of the CUSI-I gene lying downstream of the lambda-p L promoter, 200 ml LB-medium (20 μg/ml tetracyline, 50 μg/ml ampicillin) are inoculated with 3 ml of an overnight culture of E. coli K12 MC1061/pRK248 cIts/pRH24 and cultured at 28° C. up to a cell density of 0.7 A 578 units/ml. Then the culture is further shaken at 42° C. In order to carry out protein analyses, before induction of the expression and at different intervals after the induction start, cell samples are taken, cells (about 1×10 9 cells) are filled up per 1 A 578 unit, centrifuged for 3 min at 12,000 g and the cell sediment is frozen at -20° C. until further processing. EXAMPLE 4 Characterization of the Crude Protein Extract after Expression of the CUSI-I Protein in E. coli K12 MC1061/pRK248 cIts/pRH24 (a) Test for immunological cross-reaction with rabbit-anti-HUSI-I antiserum The cell sediments are resuspended in 60 μl disruption buffer (50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 2% Triton-X-100) and 40 μl reduction buffer (4% SDS, 40% β-mercaptoethanol, 20% glycerol, 0.1% bromphenol blue) are added. The samples are subsequently incubated for 5 minutes at 100° C., then for 5 minutes in the ultrasonic bath at room temperature and again for 5 minutes at 100° C. 20 μl of the cell disruption volume are electrophoretically separated in 13.5% SDS-polyacrylamide and transferred onto nitrocellulose for an immunological assay. The nitrocellulose filter is incubated at 37° C. with "blocking" buffer (50 mM Tris-HCl, pH 7.4, 200 mM NaCl, 0.05% Tween 20, 1.5% gelatine) for 1 h in order to saturate non-specific binding sites on the filter. Rabbit-anti-HUSI-I antiserum (1:600 diluted in "blocking" buffer) is used for the first antibody reaction (incubation: 2 h at room temperature) while sheep-anti-rabbit-IgG-peroxidase conjugate is used as second antibody. The substrate reaction of the horseradish peroxidase is carried out with diaminobenzidine. (b) Test for inhibitory activity of the proteinase inhibitor expressed in E. coli Induced (6 h after start of induction) and non-induced cell samples are disrupted and tested. The cell sediments (1 A 578 unit cells) are suspended in 50 μl lysozyme disruption buffer (50 mM Tris-HCL, pH 8.0, 1 mM EDTA, 1 mg/ml lysozyme), incubated for 10 minutes at room temperature, diluted with 150 μl 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, and incubated for 5 min at room temperature in the ultra sonic bath. 20 μl and 80 μl, respectively, of the crude extract of non-induced cells are tested in a chymotrysin inhibition test (39) for inhibitory activity. The results are listed in Table I. TABLE I______________________________________Detection of the inhibitory activity of the CUSI-I proteinexpressed in E. coliInhibitor test chymotrypsin activitysolution E. coli of 2 pmol enzymeextract μl induced non-induced %______________________________________- - - 10020 - + 99.280 - + 89.720 + - 91.280 + - 56.4______________________________________ When comparing the activity of chymotrypsin-non-induced crude extract from E. coli, inhibition by cell extracts of induced cells is higher by 8 and 37%, respectively. EXAMPLE 5 Expression of the C-terminal CUSI-I Domain as β-Galactosidase Fusion Protein in E. coli K12 JM101 As can be seen from FIG. 9, the structure of the CUSI inhibitor may be described as a protein molecule consisting of two domains which are formed by intragenic duplication. For expression of the C-terminal domain in E. coli, the DNA sequence coding for the C-terminal 59 amino acids is ligated in the correct reading frame with the DNA sequence encoding the C-terminus of the β-galactosidase of plasmid pUR290 (25). The cloning scheme is shown in FIG. 10. 10 μg of plasmid pRH31 are cleaved with restriction endonuclease Sau3A, preparatively separated in 5% polyacrylamide gel and the 320 bp CUSI-I partial fragment is eluted from the gel. pUR290 (10 μg) is cleaved with the enzyme BamHI, treated with alkaline phosphatase and ligated with the 320 bp fragment. A third of the ligated DNA is introduced into CaCl 2 -treated E. coli K12 JM101 cells. The clones are selected on LB-amp agar plates (10 g/l casein enzymatically digested (Sigma), 8 g/l NaCl, 5 g/l yeast extract (Sigma), pH 7.5, 100 μg/ml, ampicillin). Since two orientations of the CUSI-I partial fragment are possible in the recombinant plasmid, plasmid rapid analyses are carried out with subsequent HindIII restriction. Clones whose plasmids contain a 165 bp HindIII fragment are further analyzed. One of these plasmids is designated as pRH21. For induction of the fusion protein expression, 100 mg LB medium containing 100 μg/ml ampicllin are inoculated with E. coli K12 JM101 bacteria from an overnight culture which where transformed with plasmid pRH21. The culture is incubated at 37° C. and cell growth is monitored at 578 nm. At an optical density (578 nm) of 0.5 the cultures are adjusted to 500 μmol IPTG and further incubated at 37° C. The induction of the fusion protein is followed in dependence on time and analyzed with an SDS polyacrylamide gel electrophoresis. After induction, first exclusively the CUSI-I-β-galactosidase fusion protein is formed, later also β-galactosidase. In order to show an immunological reaction with anti-CUSI-I antibodies, proteins of the E. coli crude extract separated electrophoretically on an SDS gel are transferred to nitrocellulose. The Western blot analysis for the specific detection of the fusion protein is carried out as described in example 4(a). The fusion protein is isolated and purified as follows: According to (37), the IPTG analogon TPEG is bound to CH-sepharose. For purifying the CUSI-I-β-galactosidase fusion protein the strain E. coli K12 JM101 which contains the plasmid pRH21, is cultivated in 1 liter LB medium with 50 μg/ml ampicillin, and induced at a cell density of 0.5 A 578 units/ml by adjusting the medium to 0.5 mmol IPTG. After 1 h the induction phase is stopped by rapid cooling of the culture to 40° C. The cells are sedimented (5.5 g weight, moist), suspended in the lysis buffer (20 mM Tris-HCl, pH 7.4, 20 mM MgCl 2 , 20 mM β-mercaptoethanol) and disrupted by ultrasonic treatment. The crude extract is adjusted to about 20 mg/ml protein concentrate and 1.6 mol NaCl and subjected to TPEG-Sepharose-chromatography. After washing the column material with 20 mM Tris-HCl, pH 7.4, 10 mM β-mercaptoethanol, 10 mM MgCl 2 , 1.6M NaCl, the CUSI-I-β-galactosidase fusion protein is eluted with 100 mM sodium borate, 10 mM β-mercaptoethanol, pH 10. Chromatography was monitored by the determination of the β-galactosidase activity (43). The 1 liter culture yielded 8 mg pure CUSI-I-β-galactosidase (90%). It was further shown that the purified fusion protein also reacts with anti-HUSI-I antibodies. For cleaving the C-terminal CUSI-I domain, the thus purified fusion protein is dissolved in 10 or 30% acetic acid or 70% formic acid. The presence of an acid-sensitive aspartic acid-proline linkage (see amino acid sequence of CUSI-I) led after a reaction time of 24-36 hours at room temperature to a 40 to 60% removal of the C-terminal CUSI-I domain. After this acid-treatment, this intact CUSI-I domain can be separated by gel filtration with G-75 and purified. The amino acid sequence of the expressed C-terminal CUSI-I domain reads as follows: Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. This sequence is identical with positions 50-107 of the entire CUSI-I protein. EXAMPLE 6 Expression of the C-terminal CUSI-I Domain in E. coli K12 JM101 As can be seen from example 5, the C-terminal CUSI-I domain can be expressed in E. coli K12 JM101 as β-galactosidase-fusion-protein. As shown in FIG. 11, the cDNA encoding the C-terminal 59 amino acids is linked to the signal sequence of the alkaline phosphatase gene of plasmid pSP6 in the reading frame in order to express the C-terminal CUSI-I domain as native protein. Plasmid pSP6 has been deposited with the Deutsche Sammlung fur Mikroorganismen under deposition number DSM 3904. 30 μg of plasmid pRH1810 are cleaved with BamHI and HinfI. The DNA fragments are separated in 8% polyacryl amide gel. The 175 bp CUSI-I-DNA fragment coding for the C-terminal domain is eluted from the gel. The protruding DNA ends are filled up by means of the Klenow fragment of the DNA polymerase. There is obtained a 182 bp double-stranded DNA molecule with blunt ends. 3 μg of the vector pSP6 are cleaved with restriction endonuclease HindIII. The protruding single-stranded DNA ends are degraded with Mungbean nuclease and the 5'-terminal phosphate residues are removed with alkaline phosphatase. 0.3 pmol of the thus treated vector are ligated with 1 pmol of the C-terminal CUSI-I-DNA fragment. Transformation-competent (17) cells of the strain E. coli K12 DH1 are transformed with half of the obtained ligation product. The clones are selected on LB-Amp agar plates. 4 clones are identified by colony hybridization with the oligonucleotide AH12. The plasmid DNA of the clones contains DNA sequences complementary to the used probe. The oligonucleotide AH12 is complementary to the nucleotide sequence 241-258 of the CUSI-I-cDNA clone. It has the sequence 5' CCT GTT GAC ACC CCA AAC 3'. By plasmid rapid analysis and cleavage of the DNA with HindIII and BamHI, a clone is identified containing a 540 bp DNA fragment as insert. This DNA fragment consists of the promoter region P tac , the signal peptide sequence of the alkaline phosphatase and of the cDNA sequence for the C-terminal CUSI-I domain. The plasmid thus constructed is designated pBA17. Then component E. coli K12 JM101 cells are transformed with the DNA of the constructed expression plasmid pBA17. For expressing the C-terminal CUSI-I domain, 250 ml LB-Amp medium are inoculated with the obtained transformants. Then incubation is carried out at 37° C. Cell growth is monitored by determining clouding at 578 nm. At an optical density of 0.97 IPTG is added in a final concentration of 0.5 mM in order to induce expression. An aliquod of 1 A 578 unit cells is taken at different times before and after induction of the expression (see Table II below), centrifuged for 3 minutes at 12,000 g and the cell sediment is stored at -20° C. The expression product has 59 amino acids with the following sequence: Asp-Pro-Val-Asp-Thr-Pro-Asn-Pro-Thr-Arg-Arg-Lys-Pro-Gly-Lys-Cys-Pro-Val-Thr-Tyr-Gly-Gln-Cys-Leu-Met-Leu-Asn-Pro-Pro-Asn-Phe-Cys-Glu-Met-Asp-Gly-Gln-Cys-Lys-Arg-Asp-Leu-Lys-Cys-Cys-Met-Gly-Met-Cys-Gly-Lys-Ser-Cys-Val-Ser-Pro-Val-Lys-Ala-OH. Test for the Inhibitory Activity of the C-terminal CUSI-I Domain Expressed in E. coli The chymotrypsin inhibition test (39) is carried out as described in example 4. The increase in the inhibitory activity of the E. coli crude extract vis-a-vis chymotrypsin is monitored in dependence of time. In each case half of the E. coli lysate (100 μl) is tested for inhibitory activity. The results are listed in table II. TABLE II______________________________________Determination of the inhibitory activity of the C-terminal CUSI-Idomain expressed in E. coli chymotrypsin activity ofSample taken m IU/ml culture 2 pMol enzyme (%)______________________________________before induction(hours)2 0,624 902.5 1.88 753 2.00 77after induction(hours)1 4.83 672 6.57 673 7.24 674 9.56 645 8.00 676 10.66 6021 16.96 37______________________________________ In Table III the microorganisms deposited in accordance with the Budapest Treaty are listed. TABLE III______________________________________Microorganism Depository Deposition Number______________________________________E. coli K12 MC1061 DSM 3631E. coli K12 JM101 ATCC 33876E. coli K12 DH1 ATCC 33849E. coli K12 W6 DSM 3632pBR322 ATCC 31344pUC18 DSM 3424pUR290 DSM 3417pWH701 DSM 3633pRK248cIts ATCC 33766pRH31 DSM 3634pRH34 DSM 3635pSP6 DSM 3904pRH1810 DSM 3905______________________________________ References 1. Bodmer et al., Schweiz. med. Wschr. 144, 1359-1363 (1984) 2. Lewis, D. A., Biochem. Pharmacol. 33, 1705-1714 (1984) 3. Schiessler, H. et al., Bayer Symp. V, Proteinase Inhibitors, (Fritz, H., Tschesche, H., Greene, L. J. Truscheit, E., Eds.), pp. 147-155, Springer Verlag, Berlin (1974) 4. Wallner, O. and Fritz, H., Hoppe-Seyler's Z. Physiol. Chem. 355, 709-711 (1974) 5. Fritz, H. et al. (1975) in: Proteases and Biological Control (Reich, E., Rifkin, D. B. and Shaw, E., Eds.), 737-766, Cold Spring Harbor Laboratory 6. Wallner, O. et al. in: Protides of the Biological Fluids (Peters, H., ed) 23, 177-182, Pergamon Press, Oxford (1975) 7. Chirgwin, J. M. et al., Biochemistry 18, 5294-5299 (1979) 8. Thayer, R. E., Anal. Biochem. 98, 60-63 (1979) 9. Wallace, R. B. et al., Nucl. Acids Res. 9, 879-894 (1981) 10. Clark, L. et al., Meth. Enzymol. 68, 436-442 (1979) 11. Gershoni, J. M. and Palade, G. E. Anal. Biochem. 131, 1-15 (1983) 12. Towbin, H. et al., Proc. Natl. Acad. Sci. USA 76, 4350-4354 (1979) 13. Gubler, U. and Hoffman, B. J. Gene 25, 263-269 (1983) 14. Volkaert, G. et al. in: Advanced Molecular Genetics, Springer Verlag, Berlin, 255-257 (1984) 15. Casadaban, M. J. and Cohen, S. N., J. Mol. Biol. 138, 179-207 (1980) 16. Messing, J. et al., Nucl. Acids Res. 9, 309-321 (1981) 17. Hanahan, D., J. Mol. Biol. 166, 557-580 (1983) 19. McDonnell, M. W. et al., J. Mol. Biol. 110, 119 (1977) 20. Bailey, J. M. and Davidson, N., Anal. Biochem. 70, 75-85 (1976) 21. Laemmli, U. K., Nature 227, 680-685 (1970) 22. Maxam, A. M. and Gilbert, W., Meth. Enzymol. 65, 499-580 (1980) 23. Bolivar, F. et al., Gene 2, 95-113 (1977) 24. Yanish-Perron, C. et al., Gene 33, 103-119 (1985) 25. Ruther, U. Muller-Hill, B. EMBO-J 2, 1791-1794 (1983) 26. C. Gatz, TH Darmstadt, Dissertation, 89-93 (1985) 27. Bernard, H. U. et al., Gene 5, 59-76 (1979) 28. Maniatis, T. et al.: Molecular cloning: A laboratory manual, Cold Spring Harbor Larboratory, Cold Spring Harbor, N.Y., 194 (1982); Bonner, T. I. et al., J. Mol. Biol., 81, 123 (1973) 29. Glisin, V. et al., Biochemistry 13, 2633 (1974) 30. Aviv, H. and Leder, P., Proc. Natl. Acad. Sci. USA 69, 1408 (1972) 31. Thomas, P. S., Proc. Natl. Acad. Sci. USA 77, 5201 (1980) 32. Suggs, S. V. et al., Developmental biology using purified genes (D. Brown, ed.), Academic Press, N.Y., 683 (1981) 33. Mandel, M. and Higa, A., J. Mol. Biol. 53, 159-162 (1970) 34. Hardies, S. C. et al., J. Biol. Chem. 254, 5527-5534 (1979) 35. Holmes, D. S. and Quigley, M. Anal. Biochem. 114, 193-197 (1981) 36. Caruthers, M. H., in Chemical and Enzymatic Gene Synthesis (H. G. Gassen, A. Lang eds.), 1st ed., Verlag Chemie, Weinheim (1982) 37. Ullmann, A., Gene 29, 27-31 (1984) 38. Fritz, H. et al.: Methoden der enzymatischen Analyse (H. U. Bergmeyer, ed.), 3rd ed., 1105, Verlag Chemie, Weinheim (1974) 39. DelMar, E. G. et al., Anal. Biochem. 99, 316-320 (1979) 40. Pelham, R. B. and Jackson, R. J., Eur. J. Biochem. 67, 247-256 (1976) 41. Klasen, E. C. and Kramps, J. A., Biochem. Biophys. Res. Comm. 128, 285-289 (1985) 42. Guarente, L. et al., Science 209, 1428-1430 (1980) 43. Miller, J. H. Experiments in Molecular Genetics, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 433 (1972) 44. Ohlson, K. et al., Hoppe-Seyler's Z. Physiol. Chem. 357, 1241-1244 (1977) 45. Hochstrasser, K. et al., Hoppe-Seyler's Z. Physiol. Chem. 362, 1369-1375 (1981) 46. Smith, C. E. and Johnson, D. A. Biochem. J. 225, 463-472 (1985) 47. Schiessler, H. et al., Neutral Proteinases of Human Polymorphnuclear Leukocytes (Havemann, K. and Janoff. A., eds.), 195-207, Urban and Schwarzenberg, Baltimore, Munich (1978) 48. Fritz, H. in.: Protein Degradation in Health and Disease, Ciba Foundation Symposium 75, 351-379, publ. Excerpta Medica, Elsvier, North Holland (1980) 49. Bernard, H.-U., Methods Enzymol. 68, 482-492 (1979) 50. Machleidt, W., Modern Methods in Protein Chemistry (Tschesche, H., ed.), 267-302, Walter de Gruyter, Berlin, N.Y. (1983)

There are described DNA sequences from the genome of mammals, in particular from the human genome, coding for proteins having the biological activity of HUSI-type I inhibitors. There are further described biotechnological methods of the preparation of proteins having the biological activity of HUSI-type I inhibitors as well as pharmaceutical compositions containing said proteins.

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present invention claims the benefit of commonly-owned, co-pending U.S. Provisional Patent Application Ser. No. 60/408,956 filed Sep. 6, 2002, and is related to U.S. patent Publication Nos. 2002/0194570, 2002/0191712, 2002/0181581, filed on Apr. 22, 2002, Apr. 9, 2002, Feb. 19, 2002, respectively, and to the co-pending, commonly-assigned patent application entitled “PACKET INSERTION MECHANISM FOR AN IMPROVED ATSC DTV SYSTEM,” filed on ______, the entire contents and disclosure of each of which are incorporated by reference as if fully set forth herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a digital signal transmission system and particularly to the transmission of a signal representative of encoded digital data. DISCUSSION OF THE PRIOR ART [0004] The ATSC standard for high-definition television (HDTV) transmission over terrestrial broadcast channels uses a signal that comprises a sequence of twelve (12) independent time-multiplexed trellis-coded data streams modulated as an eight (8) level vestigial sideband (VSB) symbol stream with a rate of 10.76 MHz. This signal is converted to a six (6) MHz frequency band that corresponds to a standard VHF or UHF terrestrial television channel, over which the signal is broadcast at a data rate of 19.39 million bits per second (Mbps). Details regarding the (ATSC) Digital Television Standard and the latest revision A/53 are available at http://www.atsc.org/. [0005] While the existing ATSC 8-VSB A/53 digital television standard is sufficiently capable of transmitting signals that overcome numerous channel impairments such as ghosts, noise bursts, signal fades and interferences in a terrestrial setting, receiving antennas have increasingly been placed indoors, adding to the challenge of delivering a clear signal. There accordingly exists a need for flexibility in the ATSC standard so that streams of varying priority and data rates may be accommodated. [0006] To address these concerns, the present inventors have disclosed enhancements to the A/53 transmitter in U.S. patent Publication Nos. 2002/0194570 (hereinafter “the '570 application”), 2002/0191712 (hereinafter “the 712” application”), 2002/0181581 (hereinafter “the 581 application”) and “PACKET INSERTION MECHANISM FOR AN IMPROVED ATSC DTV SYSTEM” (hereinafter “the Packet Insertion application”) whose disclosures have been incorporated by reference herein. [0007] The present invention is directed to further improvements relating to signal transmission quality and to efficient leverage of existing A/53 infrastructure. SUMMARY OF THE INVENTION [0008] In one aspect, the present invention concerns the encoding of parameters to be embodied within a television broadcast signal for transmission. [0009] In another aspect, the present invention relates to techniques for encoding into a signal parameters to be transmitted and which are needed by a wireless receiver both to correctly ascertain the transmitted signal and to decode data accompanying the parameters in the signal. [0010] In yet another aspect, the present invention concerns leveraging data structures in a standard television protocol to accommodate enhancements to the standard that retain compatibility with existing receivers. [0011] In accordance with preferred embodiments of the invention, there is provided wireless communication of a leading bit string comprising a header and a body, and a trailing bit string comprising a header and a body. For example, a bit string of length N may have a header X 0 , X 1 , . . . X K and a body X K+1 , X K+2 , . . . X N−1 . Data is encoded to form the body of the leading bit string. The header of the trailing bit string is formed to include at least one bit of a parameter to be used by a receiver in decoding the encoded data. A wireless signal representing at the receiver the leading bit string and then the trailing bit string is transmitted to the receiver. [0012] The encoding techniques preferably include applying a fixed code to encode bits of a bit-stream, one-by-one, to create an encoded bit-stream. The encoded bit-stream is modulated to produce a signal whose frequency range at any given time is predetermined independently of the code. The signal, thus modulated, is transmitted within the frequency range. BRIEF DESCRIPTION OF THE DRAWINGS [0013] Details of the invention disclosed herein shall be described below, with the aid of the figures listed below: [0014] FIG. 1 illustrates a block diagram of an exemplary television communication system according with the present invention; [0015] FIG. 2 is a diagram of a circuit used for encoding parameters in the system portrayed in FIG. 1 ; and [0016] FIG. 3 is an exemplary flow diagram representative of processing that data for transmission undergoes in the system of FIG. 1 prior to transmission and after reception. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] FIG. 1 depicts an exemplary embodiment of television communication system 100 in accordance with the invention. The communication system 100 includes an encoder 104 , a transmitter 108 , a receiver 112 and a data decoder 116 . The encoder 104 includes a data encoder 120 , which receives a parameter bit-stream 124 and a data bit-stream 128 , and a parameter encoder 132 . The transmitter 108 is communicatively connected to the encoder 104 and has a modulator 136 and an antenna 140 . The receiver 100 an antenna 144 configured for wireless reception of signaling from the antenna 140 . The receiver 100 further includes a demodulator 148 , a parameter decoder 152 and an equalizer 156 , and is communicatively connected with the data decoder 116 . [0018] FIG. 2 illustrates an example of a sequence generator 200 utilized for bit encoding in accordance with the present invention. The sequence generator 200 includes a four element shift register 204 , which has four delay elements such as D flip-flops 208 , 212 , 216 , 220 . An exclusive-OR gate tap 224 is disposed between the third element 216 and the fourth element 220 . The fourth element 220 has an output terminal 228 which feeds back to an input terminal 232 of the first element 208 and to the tap 224 . [0019] As shown in FIG. 2 , each of the flip-flops 208 - 220 has a pre-loaded bit value and is connected to a common clock (not shown). With the first clock pulse, for example, the output “0” on the fourth flip-flop 220 feeds back to first flip-flop 208 . On that same pulse, the value “1” of the first flip-flop 208 shifts forward to the second flip-flop 212 . Likewise, the value “0” on the second flip-flop 212 shifts forward to the third flip-flop 216 . Again, on that same pulse, the value “0” of the third flip-flop 216 is exclusively-ORed with the output “0” to shift the result, “0”, to the fourth flip 220 . Accordingly, after the first clock pulse, the register contents have changed from “1000” to “0100”. Each subsequent clock pulse changes the register contents, and the sequence starts to repeat after 15 clock pulses. The pre-load followed by 14 clock pulses generates at the output 228 the sequence “000111101011001” which repeats for each subsequent 15 clock pulses. This sequence is a linear recursive sequence, i.e., a periodic sequence of bits generated by shift register with feedback. The above sequence is used in the present invention as a fixed code. In particular, the fixed code is applied to each bit of data to be encoded to produce the same 15-bit fixed code if the bit is zero, or the opposite of the code, i.e., with zeroes becoming ones and ones becoming zeroes, if the bit is one. This can be implemented by, for example, connecting the output 228 and the bit to be encoded to an XOR gate, and the resulting output and the bit value “1” to another XOR gate. Advantageously, the sequence “000111101011001” can be reliably detected at the receiver, because it minimally correlates with a shifted version of itself. In an alternative implementation, the sequence generator 200 can include an additional XOR gate tap between the first element 208 and the second element 212 that is fed by the output 228 . Also, pre-load values other than “1000” can be used. Nor is a sequence generator in accordance with the invention limited to four delay elements. It is further within the intended scope of the invention for the sequence generator 200 to be implemented with an XOR gate or gates in the feedback path rather than embedded within register 204 . [0020] FIG. 3 is an exemplary flow diagram which shows one example of the processing of the parameter and data bit-streams 124 , 128 in the digital television communication system 100 . A frequency range of the signal for transmission is determined ( 304 ) and may, alternatively, be determined at any point before modulation of the signal for transmission. The frequency range of the signal may also be changed or varied, for example in accordance with the type of data being processed, although it is predetermined independently of the fixed code. In step 308 , a fixed code is determined, although it can be determined any time before encoding. [0021] If there is no data for transmission ( 312 ), processing waits. [0022] Otherwise, if the parameter bit-stream 124 is ready for reception by the data encoder 120 , it is received ( 316 ). The parameter bit-stream 124 is time-synchronized with the data bit-stream 128 , and may therefore not be ready for reception if the data bit-stream is not ready. In addition, no parameters may be ready for reception if parameters have not changed, since parameters for the system 100 do not necessarily change in any particular time period. If the parameter bit-stream 124 is received, its bits are encoded bit-by-bit, one bit at a time, by the parameter encoder 132 using the fixed code ( 320 ). A predetermined number of encoded bits are used in forming the headers of two bit strings before a new bit string pair is utilized, each bit string consisting of two parts, a header and a body. One of the two bit strings is a leading bit string and the other one is a trailing bit string. Specific ones of the encoded parameters are allotted the leading bit string header and the other parameters are allotted to the trailing bit string header ( 324 ). [0023] Meanwhile, if the data bit-stream 128 is ready for input, it is received ( 328 ) and encoded ( 332 ). Although the parameter bit-stream 124 is preferably encoded bit-by-bit, one bit at a time, encoding of the data bit-stream would not typically be subject to such restrictions. The data bit-stream 128 is a video interlaced signal, and, as such, represents a frame which divides into two fields, an even field and an odd field. Encoded data from one of the fields is used in forming the body of a leading bit string. Similarly, encoded data from the other field is used in filling the body of a trailing bit string ( 336 ). Processing of the data and parameter bit-streams 124 , 128 is synchronized so that each of the two types of bit strings receives its respective encoded data and encoded parameters that correspond to that data. In one embodiment, although the encoded parameters for a frame are divided into two groups for forming their respective field headers, the encoded parameters apply to the encoded data of the entire frame. [0024] A carrier signal is then modulated by the modulator 136 using the encoded bit string pair for wireless transmission of a signal representing at the receiver the leading bit string and then the trailing bit string ( 340 ). [0025] The received signal is demodulated by the demodulator 148 ( 344 ), and parameters are decoded by the parameter decoder 152 ( 348 ). [0026] The parameters define the number of discrete levels in the digital wireless signal conveying the bit-streams 124 , 128 , and are therefore used by the equalizer 156 in resolving multipath or otherwise converging the signal ( 352 ). The decoded parameters are also utilized in decoding the data bit-stream 128 ( 356 ). [0027] The inventive television communication system 100 can be implemented to enhance an A/53 system proposed by the current inventors and described in the Packet Insertion application. [0028] The Packet Insertion application discusses the use of the following parameters in a parameter bit-stream. TABLE 1 Parameter Definitions Parameter Number Name Definition of bits MODE Modulation type (2-VSB, E-VSB etc) 2 NRS Presence of Backward Compatible Parity Byte 1 Generator (BCPBG) NRP Number of robust packets before encoding 4 TR Coding Rate 1 [0029] The parameters convey the number of levels in the transmitted signal, and since this information is used by the equalizer, the parameters must be decoded before equalization. Therefore, robust methods that can survive severe channel conditions are needed. The present invention expands on the '570 techniques of transmitting these parameters to the receiver in a reliable manner. [0030] In accordance with the A/53 standard, the header of each field contains an 832-bit “data field sync” of specific format. The format includes a 92-bit reserved area (corresponding to symbol numbers 729-820) which the standard recommends be filled with repeated information for extra redundancy. [0031] As shown above in TABLE 1, 8 parameter bits need to be transmitted. Encoding by the sequence generator of FIG. 2 yields 8×15=120 bits, a total which exceeds the 92 bits of reserved space. The inventive technique splits the encoded bits between the two fields of a frame, e.g. 4 bits allocated per field. An extra parity bit is added to each group of 4 bits for an additional level of error detection, bringing the total to 5 bits, or 5×15=75 encoded bits, per field. TABLE 2 below defines the symbols 729-820 for odd and even fields. TABLE 2 Symbol definitions in Field sync Symbol Number Even (odd) Held sync Odd (even) field sync 729-743 LSB of MODE bit0 (LSB) of NRP 744-758 MSB of MODE bit1 of NRP 759-773 MRS bit2 of NRP 774-788 TR bit3 (MSB) of NRP 789-803 Parity bit Parity bit 804-820 Reserved Reserved [0032] As set forth more fully in the Packet Insertion application, if MODE=0, the rest of the parameters are not utilized. Receivers adapted for the enhancements by the current inventors can decode the MODE parameter to identify whether the received signal embodies the enhanced bit-stream formats, and, if so, can decode the other parameters. [0033] While there have been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

Transmission of a digital television signal conveys data parameters along with the encoder data that are utilized by the receiver in equalization and in decoding the encoded data. Leveraging the existing digital television standard data formatting, parameters are split between the two fields of a frame of the interlaced signal. Spread spectrum techniques are employed to robustly convey the parameters in encoded form to the receiver.

This is a division of application Ser. No. 08/026,886, filed Mar. 22, 1993. FIELD OF THE INVENTION The present invention generally relates to semiconductor electronic integrated circuits, and, more particularly, to integrated circuits including bipolar devices. BACKGROUND OF THE INVENTION Without limiting the scope of the invention, its background is described in connection with, bipolar transistors as an example. Heretofore, in this field. GaAs/AlGaAs heterojunction bipolar transistors (HBT) have been fabricated using mesa technology in which the collector, base and emitter epi layers are subsequently grown during a single epitaxial deposition run. The emitter and base epi layer are selectively removed using two etch steps for making contact to the base and collector areas, respectively. These etches result in steps in the GaAs ranging in height between 0.4 and 2.0 microns for a typical mesa HBTs. Although high quality. HBTs can be fabricated in this manner, the resulting mesa structure results in very severe topography making it difficult to incorporate a multilevel metal system as required tier high levels of integration. Planar heterojunction bipolar transistors have been fabricated as elements of integrated circuits in the emitter down configuration (See U.S. Pat. No. 4,573,064). This avoids the mesa topography but this technology requires all of the NPN transistors to be connected in the common emitter configuration which severely limits its applications for analog/linear ICs. Although a single epitaxial deposition run as used in the foregoing mesa HBTs and emitter-down HBTs does simplify the fabrication process, it limits the types of structures which can be integrated together on a single chip. An alternative has been to grow an emitter epilayer onto an implanted base with Zn as the base dopant because of the high mass and low implant range. However, implanted Zn is difficult to activate at low temperatures. Raising the temperature high enough for good activation results in excessive diffusion due to the large diffusion coefficient for Zn, significantly increasing the base width and lateral dimensions and degrading the frequency response. Additionally, this process integrates only a single type of device, the NPN HBT. Improved performance as well as increased circuit flexibility has been made possible by integrating both NPN and PNP bipolar transistors on the same chip. Silicon digital circuits make use of vertical NPN switching transistors and PNP transistors for input logic, current sources and level shifting. Silicon linear circuits are routinely using integrated NPN and PNP transistors for improved circuit performance. SUMMARY OF THE INVENTION The present invention provides devices, integrated circuits and fabrication processes which include more than one epitaxial deposition but provides NPN, PNP or simultaneously both NPN and PNP bipolar transistors. This invention eliminates in conventional mesa heterojunction bipolar transistors the requirement to etch down to the subcollector for making contact and the resulting severe surface topography which can result in poor yields in multilevel metal VLSI circuits. In a preferred embodiment, a GaAs wafer is deposited with an epitaxial film which may be made of several sequential doped layers; the wafer is selectively implanted with suitable dopants and/or etched selectively. After this processing the wafer is preferably cleaned and a second epitaxial layer is deposited. The number of epitaxial layers deposited may be varied as needed. The implant/etch processes followed by epitaxial deposition may be repeated a number of times. The specific epitaxial deposition process may be MOCVD, MBE, MOMBE or other deposition processes. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIGS. 1a-1e are cross-sectional views, at different processing stages, of a first preferred embodiment of this invention; and FIGS. 2a-2e are cross-sectional views, at different processing stages, of a second preferred embodiment of this invention. Corresponding numerals and symbols in the different figures refer to corresponding parts unless otherwise indicated. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A heterojunction bipolar transistor (HBT) is described in the following embodiments as an example of the present invention. However, it should be realized that the processes described may be useful in the fabrication of any bipolar transistor. The steps described could be used when fabricating a bipolar transistor of different materials with different dopants, different dopant concentrations, different layer thicknesses, etc. For example, the processes described could be used to make a silicon bipolar transistor. While the process described in the first embodiment is based on an NPN transistor, the same process could be used to form a PNP transistor. Also, the second embodiment process is described beginning in the same manner as the first embodiment NPN transistor. However, if desired the process could begin with the PNP transistor formation with the NPN transistor being formed in a manner similar to that of the PNP transistor formation in the second embodiment described below. Refer to Table 1 for example values of layer thicknesses and doping levels for both embodiments described below. The process flow of a first preferred embodiment of the present invention is illustrated in FIGS. 1a-e. The process utilizes overgrowth to bring the collector contact area to the surface and shallow etching (≈3000 Å) to contact the base and emitter regions. This process employs overgrowth at the collector-base interface rather than at the more critical emitter-base interface as described in U.S. Pat. No. 5,068,756. The collector of the bipolar transistor of the first preferred embodiment is significantly different from that of the standard microwave HBT process. Referring to FIG. 1(a), the process preferably starts with a semi-insulating GaAs substrate 10 onto which a preferably 1-μm N+ GaAs subcollector 12 and a preferably 0.6-μm N-- GaAs layer 14 are grown, for example by MOCVD. The N-- doping, preferably approximately 5E14-2E16, is chosen such that it will be mostly depleted even at zero collector-base bias. As an example, silicon 15 is selectively implanted into the collector contact area 16 and into the region 18 which will be directly under the emitter contact area to change the N-- doping in these areas to N+. These implanted regions will be extensions of the N+ collector 12. (Note that portions of layers 12, 14, and 20 together form the final N+ collector 12). Referring to FIG. 1(b), after annealing the silicon implants a second N-- collector layer 20 is overgrown using preferably MOCVD. A second silicon implant 21 is used in the collector contact area 16 to bring the N+ region to the top of the surface. As an example, beryllium 23 may be selectively implanted into the surface to form buried P+ extrinsic base regions 22,24 [FIG. 1(c)]. The hole in the donut shaped extrinsic base implant pattern will determine the size of the intrinsic transistor. FIGS. 1(a), 1(b), and 1(c) each show a layer of resist 17, 19, and 21, respectively, that may be used as a mask during implanting steps and later removed. Any comparable method of masking and/or implanting may be used. As an alternative to implanting the buffed P+ layer 22,24, the p-type dopant can be diffused from an appropriate source such as zinc oxide using either of several conventional selective masking techniques. Another alternative is to grow, at this point in the process, a P+ carbon doped GaAs layer as an epi deposition and selectively etching it away except in regions where the buried P+ region 22, 24 is desired. The P+ buffed regions 22,24 may also be selectively grown at this point. Referring to FIG. 1(d), the base 26 and emitter layers 28 are then overgrown onto the waters using, for example. MOCVD. In this example, the base layer 26 is preferably P- carbon doped GaAs and the emitter layer 28 is preferably N AlGaAs. One or more grading layers 30 and an ohmic contact layer 32 may be used to improve emitter contact. In this example, the grading layers 30 are preferably graded from AlGaAs (Al x Ga 1-x As) to GaAs to InGaAs and the ohmic contact layer 32 is preferably N+ InGaAs. From this point in the process the wafers may be processed in a manner similar to mesa HBTs. Referring to FIG. 1(e), the emitter metal contact pattern is preferably aligned to the hole in the extrinsic base implant pattern (buried P+) and using lift off the emitter contact 34 is formed. This metal contact 34 may be used as a mask to etch down to the base layer 26. This etch step is tar less critical than for a microwave mesa base etch step since a buried P+ layer 22 extends the thickness of the base in the contact area 36 allowing for some over etching. After etching the base layer 26 from the field region the collector ohmic contact 38 is made to the N+ implanted collector region 12. The transistor is then preferably isolated using 5 meV oxygen implants 40, for example. Boron 42 may be selectively implanted to improve the isolation between the HBT base and collector contact area and to reduce capacitance. The advantages of the first preferred embodiment process include: Reduced collector-base capacitance without the use of implant damage which can anneal out. The thick n-- epi under the base contact and extrinsic base region will result in lower collector-base capacitance than can be obtained using implant damage. Improved base contact yields because of thicker extrinsic base layer resulting from the buried P+ implant which allows noncritical etching and metal contacts to the base. Improved current gains through the use of a less heavily doped intrinsic base epitaxial layer, since there is reduced base resistance resulting from the buried P+ extrinsic base. Mesa etching down to the N+ collector is not required since an N+ implanted plug brings the N+ collector contact region to the surface. Improved collector-emitter breakdown voltage. The process flow of a second preferred embodiment of the present invention is illustrated in FIGS. 2a-e. As an example, this process provides a complementary NPN/PNP bipolar transistor process that can significantly reduce the power consumption and minimize the thermal gradients within the die for improved SNRs. The use of both high-speed NPNs and PNPs can simplify circuit design, reduce chip size and significantly improve circuit performance. This is illustrated by nearly all high-speed, high resolution silicon bipolar circuits using both high-speed NPNs and moderate-speed PNPs for these reasons. It has been demonstrated that the GaAs/AlGaAs PNP HBT can be fabricated with performance nearly equal to that of its NPN counterpart. The addition of complementary high-speed bipolar circuits will open up the field of high-speed linear GaAs circuits. The complementary bipolar transistor process results in NPN and PNP HBTs that can be integrated into a planar process and used as needed without the requirement that all of one type of transistor appear in only one area of a chip and the second type appear in only a second area. The complementary bipolar transistor process of the second preferred embodiment uses one additional overgrowth process compared to the process of the first preferred embodiment. Starting wafers may be the same as the first preferred embodiment process [FIG. 2(a)]. Referring to FIG. 2(a), the process preferably starts with a semi-insulating substrate 50 onto which a preferably 1-μm N+ GaAs subcollector 52 and a preferably 0.6-μm N-- GaAs layer 54 are grown, for example by MOCVD. The N-- doping, preferably approximately 5E14-2E16, is chosen such that it will be mostly depleted even at zero collector-base bias. As an example, silicon 56 is selectively implanted into the collector contact area 58 and into the region 60 which will be directly under the emitter contact area to change the N-- doping in these areas to N+. These implanted regions will be extensions of the N+ collector 52. (Note that portions of layers 52, 54, and 66 together form the final NPN N+ collector 52 and other portions of the same layers form the final PNP P+ collector 64). In regions where PNP transistors are to be grown, a dopant source such as zinc oxide 52 is preferably selectively patterned and diffused into the waters converting portions of the N-- collector 54 and N+ subcollector 52 to form the P+ subcollector 64. As an alternative to the use of a dopant source and diffusion to convert the N-- collector and N+ collector to a P+ subcollector, selective implantation of a p-type dopant such as beryllium can be used. The first epi overgrowth may be the same as in the first preferred embodiment process. Referring to the NPN portion of FIG. 2(b), after annealing the silicon implants 56 a second N-- collector layer 66 is overgrown using preferably MOCVD. A second silicon implant 68 is used in the collector contact area 58 to bring the N+ region to the top of the surface. As an example, beryllium 70 may be selectively implanted into the surface to form buried P+ extrinsic base regions 72,74. The hole in the donut shaped extrinsic base implant pattern will determine the size of the intrinsic transistor. FIGS. 2(a), 2(b), and 2(c) each show a layer of resist, such as nitride, 57, 76, and 86, respectively, that may be used as a mask during implanting steps and later removed. Any comparable method of masking and/or implanting may be used. Another alternative is to grow, at this point in the process, a P+ carbon doped GaAs layer as an epi deposition and selectively etching it away except in regions where the buried P+ region 72, 74 is desired. The P+ buried regions 72,74 may also be selectively grown at this point. Referring to the PNP portion of FIG. 2(b), similar to the NPN process, beryllium 78 is preferably implanted into the overgrowth layer 66 forming the P+ plug 80 for the PNP collector 64 surface contact. Silicon 82 is preferably implanted into the PNP extrinsic base region forming a buried N+ region 84,86 similar to the buried P+ region 72,74 in the NPN. The alternative methods described for forming the P+ buried regions 72,74 may be used to form the N+ buried regions 84,86. Referring to FIG. 2(c), the NPN HBTs are then preferably selectively covered by a material 88 such as nitride exposing the field and the PNP HBTs. The PNP base 90, preferably Si doped N- GaAs, and emitter 92, preferably carbon doped AlGaAs, epitaxial layers are preferably grown by MOCVD. A grading layer 94 graded from AlGaAs to GaAs may be used to improve emitter contact formation. Referring to FIG. 2(d), after removing the protective nitride 88 over the NPNs, the PNP HBTs are protected, preferably with nitride 96, and the NPN HBT base 98, and emitter 100 layers are grown preferably by MOCVD. In this example, the base layer 98 is preferably P- carbon doped GaAs and the emitter layer 100 is preferably N AlGaAs. One or more grading layers 102 and an ohmic contact layer 104 may be used to improve emitter contact, In this example, the grading layers 30 are preferably graded from AlGaAs (Al x Ga 1-x As) to GaAs to InGaAs and the ohmic contact layer 32 is preferably N+ InGaAs. Excellent selectivity has been demonstrated using this process. After growth of NPN and PNP HBT layers the emitter, base and collector layers are preferably contacted in the same manner as described in the first preferred embodiment process. Referring to FIG. 2(e), the emitter metal contact pattern is preferably aligned to the hole in the extrinsic base implant pattern (buried P+ and N+) and using lift off the emitter contacts 106, 108 are formed. These metal contacts 106,108 may be used as a mask to etch down to the base layers 90,98. This etch step is far less critical than for a microwave mesa base etch step since a buried P+ 72 and N+ 84 layer extends the thickness of the base 90,98 in the contact areas 110, 112 allowing for some over etching. After etching the base layers 90,98 from the field region the collector ohmic contacts 114, 116 are made to the implanted collector regions 52,64. The transistor is then preferably isolated using, for example, oxygen implants 118 and boron 120. The advantages of the planar NPN/PNP bipolar transistor process over the standard mesa approach include: Access to the NPN and PNP collector contacts can be obtained without etching mesas down to the collectors for improved interconnect yields. Enhanced NPN because of reduced c-b capacitance. Improved yields because of thicker extrinsic base layer tier etching and contacting the base. This is particularly important tier the PNPs which typically utilize thinner base layers than NPNs to improve performance. A preferred embodiment has been described in detail hereinabove. It is to be understood that the scope of the invention also comprehends embodiments different from those described, yet within the scope of the claims. For example, the buried P+ and/or buried N+ regions can be omitted from the process for process simplification. Additionally, the N type dopant, while preferably silicon, could be a material such as S, or Se. Alternatives for the P type dopant include, for example, carbon and zinc. Similarly, the GaAs could be replaced with a material such as InGaAs, InP, or GaInP and the AlGaAs could be replaced with GaInP or InP. In addition, the use of implantation and diffusion from appropriate sources can be used interchangeably as the technologies evolve. Alternatively, this invention could be realized in other materials, silicon for example. While the epitaxial deposition process suggested above is MOCVD, other processes may be used, for example, MBE or MOMBE. Words of inclusion are to be interpreted as nonexhaustive in considering the scope of the invention. While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the an upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments. TABLE 1______________________________________ LAYER DOPANTELEMENT LAYER THICKNESS LEVELNO. NAME (μM) (cm.sup.3)______________________________________12, 52 N + subcollector 0.6-2.0 1E18-1E1914, 54 1st N-- collector 0.3-1.0 1E15-5E1620, 66 2nd N-- collector 0.3-1.0 1E15-5E1626, 98 NPN base .02-0.2 1E18-1E2028, 100 NPN emitter .02-0.2 1E17-5E1830, 102 NPN cap layer .05-0.4 1E18-1E1932, 104 InGaAs cap layer .02-0.1 1E18-1E2090 PNP base .02-0.2 1E18-5E1892 PNP emitter .02-0.2 1E17-1E2094 PNP cap layer .05-0.4 1E18-1E20______________________________________

This is a method of forming a bipolar transistor comprising: forming a subcollector layer, having a doping type and a doping level, on a substrate; forming a first layer, of the same doping type and a lower doping level than the subcollector layer, over the subcollector layer; increasing the doping level of first and second regions of the first layer; forming a second layer, of the same doping type and a lower doping level than the subcollector layer, over the first layer; increasing the doping level of a first region of the second layer which is over the first region of the first layer, whereby the subcollector layer, the first region of the first layer and the first region of the second layer are the collector of the transistor; forming a base layer over the second layer of an opposite doping type than the subcollector layer; and forming an emitter layer of the same doping type as the subcollector layer over the base layer. Other devices and methods are also disclosed.

TECHNICAL FIELD [0001] The present invention relates to a method for pretreating green coffee beans before roasting to improve flavor and taste of coffee; green coffee beans pretreated by the method; a method for preparing a coffee extract including extracting the thus-prepared green coffee beans with hot-water; and a coffee extract prepared by the method. BACKGROUND ART [0002] Coffee is a popular drink and is the most widely distributed and consumed drink in the world. It is sold or consumed in the form of instant coffee, mixed coffee, canned coffee, and brewed coffee. Green coffee or green coffee beans refers to dried seeds of the coffee cherries, which are obtained by removing the pericarp and the pulp of the coffee cherries followed by drying, upon harvesting. The green coffee beans are prepared into powder (i.e., roasted and ground coffee) by roasting and grinding, and added with hot water to obtain a liquid extract containing the ingredients present in the powder, which is the brewed coffee we drink. [0003] Coffee is cultivated in areas located from latitude 25° south to latitude 25° north, the so-called coffee zone or coffee belt, and its flavor is known to vary according to various factors, such as coffee species, characteristics of cultivation areas, methods of cultivation, weather conditions, methods of harvesting, methods of drying, roasting, grinding, etc. [0004] Coffee species are largely classified into Arabica coffee ( Coffea arabica ) and Robusta coffee ( Coffea canephora ). Arabica coffee, which is mainly cultivated in cool alpine areas with an altitude of 800 m or higher in South America, Central America, and some African countries such as Ethiopia, accounts for about 65% of the global coffee production. Arabica coffee is a premium quality coffee with excellent flavor quality and a harmony of pleasant sour taste and bitter taste, and thus is used in premium brew coffeehouses. On the other hand, Robusta coffee accounts for about 35% of the global coffee production, and is cultivated in high-temperature and high-humidity areas with an altitude of 600 m or lower in Southeast Asia, such as Vietnam, India Indonesia, Thailand, etc., and most African countries, such as Uganda, Republic of the Cote d'Ivoire, etc. Robusta coffee has a less desirable flavor with a harsh and strong rubber-burning smell, a weak sour taste and a strong bitter taste, and is cheap, and thus is mainly used as a raw material for instant coffee or thick espresso. While, Brazil produces 30% or more of global coffee production, and among them. Arabica coffee accounts for 80%. However, 20% or more of the total production of Brazilian coffee, although they are Arabica coffee, has been poorly evaluated due to the presence of a particular odor, the so-called “Rioy defect”, characterized by an acrid and powerful off-odor or strong phenolic, medicinal antiseptic-type smell. [0005] In particular, green coffee beans can be dried largely by a dry processing method and a wet processing method. The dry processing method, which is also called the natural drying method, proceeds with roughly a three-step process (washing-drying-peeling). The dry processing method includes removing impurities from the coffee fruits harvested in areas with insufficient water but with good sunlight, washing the coffee fruits with flowing water, primarily drying in spacious areas with the full sunlight for about from 2 weeks to 4 weeks according to the weather conditions, removing the dried cherry fruit flesh, and drying the resultant so that the final water content of the seeds can be in the range from 10% to 12%. The dry processing method is widely used in Brazil, Ethiopia, Ecuador, Indonesia, Vietnam, etc. The wet processing method, which is also called washing and drying method, includes removing the epicarp of the coffee fruits using a mechanical device, removing the mucilage covering the endocarp via natural fermentation by soaking in water for 10 hours to 24 hours, washing to adjust the average water content to about 57%, drying by hot air drying or natural drying so that the average water content to be about from 10% to 13%. Such a wet processing method requires many facilities and labor, however, the quality of green coffee beans prepared by the method is known to have a higher quality than the quality of those prepared by the dry processing method. In Colombia, Jamaica, Hawaii, and Guatemala, etc., premium Arabica coffee is produced using the wet processing method. The dried coffee is stored/maintained in the state of parchment green beans removed from epicarp in a polishing factory, and at the time of sales, the endocarp is removed and the green coffee beans are classified according to the size after sorting out defective green coffee beans, packed, and sent out for sales. [0006] Roasting, which is an important step in a coffee processing procedure, is a process of applying heat on green coffee beans until appropriate color and flavor develop, and various physicochemical reactions that can determine the quality of final brewed coffee during the process. During the roasting process, a rapid expansion occurs inside the green coffee beans due to the pressure caused by water and carbon dioxide along with a chemical reaction the heat applied thereon, and part of the volatile components generated therein become volatilized to the outside. Coffee aroma is the most important factor in coffee quality, and the low molecular weight saccharides and amino acids or proteins present in green coffee beans react alone or with each other by the heat treatment (these reactions are classified into three different types of reactions; Caramellization, Maillard reaction, and Strecker degradation) and generate a few hundred kinds of volatile aromatic materials. As such, coffee can have various tastes and flavors according to the species, areas of production, drying methods, roasting methods, etc., and thus, continuous studies are conducted on the methods of cultivation, processing of green coffee beans, roasting, etc., for the improvement of coffee flavors. [0007] Although Robusta coffee has low quality flavor and taste, it grows well in areas under 600 m in elevation instead of high alpine regions, tolerates well drought, is resistant to damages by diseases and insects, and enables mechanization thus having a 2- to 3-fold higher harvest compared to that of Arabica . However, Robusta coffee has problems in that it has a 2-fold higher caffeine content than that of Arabica (1.7% to 2.5%), has a weak or harsh flavor, and in the case of light roasting, it often releases a earthy smell, a fungus smell, a beany smell, and has a bitter and astringent taste. In the case of a mild or dark roasting, as a way to solve the problems, Robusta coffee has a problem in that it releases a very strong taste of bitterness and astringency along with a pungent rubber-burning smell. Additionally, in the case of dark roasting, a large amount of carcinogens, such as acrylamide, furan, etc., can be generated due to carbonization. Reportedly, coffee contains the highest amount of furan among the foods. [0008] Furan is known to be produced by pyrolysis of saccharides or amino acids and thermal oxidation of polyvalent unsaturated fatty acids or vitamin C, during the roasting process. To solve the problem, large coffee manufacturing companies, such as Nestle and Kraft, have focused their studies on the processes and methods for improving the quality of Robusta coffee. However, they have not yet found any fundamental solution to the problem. [0009] Attempts to improve the flavors of Robusta coffee were already initiated in early 1970s (U.S. Pat. No. 3,640,726), and the American General Foods Corporation (the current U.S. Kraft Foods Group, Inc.) developed a technology for roasting to remove the rough and bitter taste of Robusta coffee by drying the green Robusta coffee beans after steaming them under high temperature and high pressure (U.S. Pat. No. 4,540,591) in 1985. Additionally, in 1991, the Swiss Jacobs Suchard (the current U.S. Kraft Foods Group, Inc.) developed a method for reducing the “earthy smell” and “fungi smell” of Robusta coffee to improve the quality of the Robusta coffee flavor by increasing the water content of the raw Robusta coffee beans to a range from 30% to 45% under high pressure (3 atm. to 4 atm.) with steaming at a temperature from 135° C. to 140° C. (U.S. Pat. No. 5,019,413). However, these two representative methods for treating green Robusta coffee beans under high-temperature and high-pressure steaming have disadvantages in that they require a large-scale steam-generating apparatus under high-temperature and high-pressure and release off-flavors along with the cooked beany smell due to the pyrolysis of green coffee beans by heat treatment at high temperature, and thus other types of off-flavors may be generated although the original off-flavors of Robusta coffee may be reduced. [0010] Additionally. Japanese Application Publication No. 2003-009767 discloses that when green coffee beans are added with 2.5 to 10 times of water relative to the weight of the green coffee beans at from 10° C. to 60° C. and soaked therein at the same water temperature for 4 hours to 24 hours, the flavor of the green coffee beans can be improved. Additionally, International Publication No. WO 2008-029578 discloses a method for germinating fresh coffee beans, which includes sufficiently immersing the green coffee beans in water at a temperature from 5° C. to 50° C., maintaining the water temperature at a temperature from 20° C. to 40° C. for the germination of the green coffee beans, washing impurities from the germinated green coffee beans with water, and drying the green coffee beans to have a water content of about 11%. However, these two methods have a serious problem in that the immersion of a large amount of the green coffee beans in warm water for a long period of time results in the loss of a large amount of low molecular weight water-soluble flavor precursors such as saccharides (i.e., sucrose, glucose, and fructose) and water-soluble amino acids, which are very important for the expression of coffee flavors during the roasting process, thus deteriorating the development of coffee flavors. [0011] Additionally, the temperature range (20° C. to 40° C.) for immersing the green coffee beans can cause a serious problem in terms of sanitation and safety in that a large amount of nutrients are leached out from the immersed green coffee beans, thus providing a condition suitable for the growth of molds which produce ochratoxin A, a highly toxic carcinogen. [0012] Additionally, Korean Pat. No. 10-1060203 discloses a method for preparing coffee with good flavor by steaming the green coffee beans at a temperature from 90° C. to 106° C. for 5 hours to 9 hours, drying the resultant at a temperature from 50° C. to 70° C. for 12 hours to 24 hours, and age the resultant beans at room temperature for 1 day to 7 days. Additionally, Korean Pat. No. 10-1448184 discloses a method which can increase the γ-aminobutyric acid (GABA) content by completely immersing the green coffee beans by adding magnetized water to a water tank equipped with a thermostat and germinating at a temperature from 40° C. to 85° C. for 3 hours to 9 hours. However, both methods include a process of immersing green coffee beans into an excess amount of hot water for 4 hours to 24 hours, and flavor components are generated during the roasting process, and it is unavoidable that a large amount of water-soluble flavor precursors such as saccharides and amino acid materials, which are essential for the expression of coffee flavors during the roasting process, is lost, and thus the amount of good flavors is absolutely lowered during the roasting step thereby becoming fatal to the quality of the coffee produced therefrom. [0013] U.S. Application Publication No. 2009-0220645, which relates to a method for preparing the green coffee beans with flavor characteristic similar to that of “Kopi Luwak”, which is in vogue at present, includes adding an enzyme capable of decomposing the components of the green coffee beans in a state where the green coffee beans are submerged to a hydrochloric acid bath with a pH 1.7, thereby decomposing the saccharides and the proteins contained in the green coffee beans at a temperature from 30° C. to 45° C. for a maximum of 24 hours, drying, followed by roasting. However, the method is very inappropriate to be utilized in reality because the submerging of the green coffee beans in strong hydrochloric acid would trigger a negative customer reaction due to the use of a chemical agent and also, there is a problem in that a large amount of flavor precursor materials, which are important for the expression of coffee flavor, can be lost by the use of hydrochloric acid. DISCLOSURE Technical Problem [0014] The present inventor has endeavored to develop a method for resolving the problems described above and improving flavors and tastes of coffee, and as a result, have discovered that roasting the green coffee beans after pretreating them can improve flavors and tastes of coffee, increase extraction efficiency, and reduce the amount of carcinogens, thereby completing the present invention. Technical Solution [0015] An object of the present invention is to provide a method for pretreating green coffee beans, including: germinating water-absorbed green coffee beans in an incubator or a dark room at a temperature from 10° C. to 20° C. or from 40° C. to 60° C. for 1 day to 3 days; and drying the green coffee beans germinated in step (a). [0016] Another object of the present invention is to provide a method for pretreating green coffee beans, including: germinating the water-absorbed green coffee beans in an incubator or a dark room at a temperature from 10° C. to 20° C. for 1 day to 3 days; germinating the green coffee beans that went through with step (a) in an incubator or a dark room at a temperature from 40° C. to 60° C. for 1 day to 3 days; and drying the green coffee beans germinated in step (b). [0017] Still another object of the present invention is to provide green coffee beans pretreated by the above method. [0018] Still another object of the present invention is to provide a method for preparing a coffee extract including extracting the green coffee beans with hot-water. [0019] Still another object of the present invention is to provide a coffee extract prepared by the above method of preparing the coffee extract. Advantageous Effects of the Invention [0020] According to the pretreatment method of the present invention, the method can reduce the rough and strong smells of low quality coffee, in particular, a Robusta species coffee, increase the desirable aroma while reducing bitter taste and increasing sour taste, thereby significantly improving the taste. Additionally, in the case of Brazilian coffee, which is an Arabica coffee, the taste quality can be improved by increasing the sweet and nutty flavors while reducing the bad smell of a disinfectant. Accordingly, the method of pretreating green coffee beans of the present invention can improve the taste and flavors, increase extraction efliciency, and prepare coffee with a reduced amount of carcinogens, and thus can be widely applied to coffee industry. BRIEF DESCRIPTION OF THE DRAWINGS [0021] FIG. 1 shows a chart comparing the methods for pretreating green coffee beans until hot air drying in Preparation Examples 1 to 5. [0022] FIG. 2 shows the representative results of analysis of volatile aroma components of Robusta coffee (Vietnam), obtained in the present invention, performed using the Gas chromatography-Flame Ionization Detector (GC-FID). Specifically, (A) represents the control group, (B) represents coffee obtained by low temperature germination, and (C) represents coffee obtained by enzyme-added germination. The components corresponding to each peak are analyzed in Table 1. [0023] FIG. 3 shows the representative results of analysis of volatile aroma components of Arabica coffee (Brazil), obtained in the present invention, performed using the Gas chromatography-Flame Ionization Detector (GC-FID). Specifically, (A) represents the control group. (B) represents coffee obtained by low temperature germination, and (C) represents coffee obtained by enzyme-added germination. The components corresponding to each peak are analyzed in Table 2. [0024] FIG. 4 shows the images of roasted Robusta coffee (Vietnam) at 300× magnification under an electron microscope. [0025] FIG. 5 shows the images of roasted Arabica coffee (Brazil) at 500× magnification under an electron microscope. BEST MODE OF APPLICATIONS INVENTED [0026] An aspect of the present invention provides a method for pretreating green coffee beans before roasting for the improvement of aroma and taste of coffee. Specifically, the method for pretreating green coffee beans may include (a) germinating the water-absorbed green coffee beans in an incubator or a dark room at from 10° C. to 20° C. or 40° C. to 60° C. for 1 day to 3 days; and drying the green coffee beans germinated in step (a). [0027] The method of pretreating green coffee beans of the present invention can improve aroma and taste quality of coffee and reduce carcinogens and thus can be effectively used in the coffee industry. [0028] As used herein, the term “green coffee or green coffee beans” generally refers to coffee beans taking on a green color, that is, the coffee in a state obtained from coffee cherries by a wet process, a dry process, etc., but the method to obtain the coffee is not limited thereto as long as the germinability can be maintained. [0029] Germination of all species is affected by temperature, moisture content, oxygen, and sunlight, and among them, moisture content and temperature are considered to be most important. During the early process of germination, various kinds of enzymes are biosynthesized and activated, and polymer materials such as proteins and polysaccharides are decomposed into smaller units of peptides and amino acids, and oligosaccharides or monosaccharides, etc. Additionally, in the case of green coffee beans, many phenolic compounds, which are different from the original compounds, are produced by enzymatic or chemical reactions. The present inventor has discovered that the production of new compounds and changes therein by all biochemical or chemical reactions occurring during the early germination process eventually become the precursors of good volatile aroma components developed while roasting green coffee beans, and simultaneously the components of bitter taste become reduced, thereby completing the present invention. [0030] The present invention increased the precursors capable of expressing good aroma components during the coffee-roasting process and simultaneously reduced the precursors for generating bad odors or bitter taste, thereby improving flavor and taste quality of coffee. [0031] Unlike the conventional method of soaking green coffee beans in an excess amount of hot water, the pretreating method of the present invention is a method for germinating green coffee beans by allowing a suitable amount of water for germination to be absorbed into the green coffee beans, and the loss of a large amount of low molecular weight flavor precursors, i.e., saccharides (e.g., sucrose, glucose, fructose, and water-soluble amino acid materials), can be prevented, thereby improving aroma and taste of coffee. [0032] In the present invention, the water content of the water-absorbed green coffee beans in step (a) belongs to the scope of the present invention as long as the water content is sufficient for the germination of green coffee beans, and specifically, water may be absorbed in the range from 40% to 60% relative to the total weight of the green coffee beans, and more specifically, from 45% to 55%, but is not limited thereto. [0033] Additionally, specifically, the incubation temperature in step (a) may be in the range from 12° C. to 20° C. or from 40° C. to 58° C., but is not limited thereto. [0034] Additionally, in the present invention, the water temperature of the water-absorbed green coffee beans in step (a) will belong to the scope of the present invention as long as green coffee beans can be germinated thereat, and specifically, the temperature may be 15° C. to 25° C., but is not limited thereto. [0035] In step (a) of the pretreatment method of the present invention, the purpose of allowing the green coffee beans to absorb water to have a water content in the range from 40% to 60%, followed by germinating the water-absorbed green coffee beans in an incubator maintained at from 10° C. to 20° C. or 40° C. to 60° C. for 1 day to 3 days was for preventing the major germination process while allowing the initiation of the biochemical metabolism for the early germination of green coffee beans at an appropriate level, and furthermore, for avoiding the temperature range of from 20° C. to 40° C., which is the most suitable temperature for the proliferation of bacteria or fungi. Accordingly, regarding the degree of germination in step (a), it is sufficient that radicals slightly pop out of the green coffee beans, or there is a movement of germination by the enzyme action of the green coffee beans themselves inside the green coffee beans. Conventionally, the germination rate that can be achieved in the present invention may be in the range from 50% to 80%, but is not limited thereto. [0036] The green coffee beans immediately processed upon harvest generally have 90% or higher of germination rate. However, the germination rate of green coffee beans varies a lot depending on the states of the harvested coffee cherries, and conditions of processing and storage. In particular. Robusta coffee is mostly grown in African countries or Asian regions under poor growth conditions with hot and humid weather. Therefore, the vitality of green coffee beans is deteriorated during the storage period after bean processing. Furthermore, since the green coffee beans must go through with the sea transport under a hot and humid environment until they arrive at the final place for consumption, the germination rate of green coffee beans will be rapidly deteriorated, thus the production of flavor precursors via germination process may not be sufficient. [0037] Accordingly, the present invention may be performed by adding an enzyme for effective decomposition of the various constituting components of the endosperm of green coffee beans, which are difficult to germinate due to the deterioration in vitality. In the case of adding such an enzyme, the method of pretreatment of the present invention may be performed by adding an appropriate amount of an enzyme to water to be absorbed into green coffee beans in step (a) and allowing the green coffee beans to absorb the enzyme solution using the water for incubation. Additionally, low-temperature germination and enzyme-added germination may be performed in series depending on the types of green coffee beans and the environment. The enzyme-added germination refers to performing germination by adding an enzyme to green coffee beans. [0038] The non-limiting example of the enzymes to be absorbed into green coffee beans may include protease, carbohydrase, armvlase, glucosidase, dextranase, mannase, etc., and a complex enzyme containing at least one of these enzymes may also be used. [0039] The pH range of water, to which the enzyme is added in the present invention, may not be limited as long as the enzyme can exhibit its activity in the given pH range, and specifically, the pH range may be from pH 3.0 to pH 8.0 in which the flavor precursors important for the expression of coffee flavors are not significantly lost, but is not limited thereto. [0040] Additionally, at least one flavor precursors of green coffee beans selected from the group consisting of sucrose, glucose, and fructose, may be added to water before green coffee beans absorb water so that at least one selected saccharide is absorbed into the water-absorbed green coffee beans, in step (a) of the present invention, and specifically, the flavor precursors may be added in an amount of from 0.05% to 30% relative to the total weight of green coffee beans, and more specifically, from 0.1% to 15%, but is not limited thereto. [0041] Additionally, in step (a), sucrose, glucose, and fructose, which are the flavor precursors of green coffee beans, for being absorbed into the green coffee beans may be added into water with a mixed weight ratio of 1 to 6:1 to 6:1 to 6 relative to the weight, and specifically 3:1:1, but is not limited thereto. [0042] In an exemplary embodiment of the present invention, 200 g of green coffee beans washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C. was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. After sealing, the zipper bag was placed in a 15° C. incubator for from 24 hours to 72 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination (Preparation Example 1). [0043] Additionally, in an exemplary embodiment of the present invention, 200 g of green coffee beans washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C., in which a complex enzyme containing protease and carbohydrase was contained in an amount of 0.2% relative to the total weight of the green coffee beans, was poured thereinto and mixed well, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. Then, the complex enzyme was absorbed into the green coffee beans. After sealing, the zipper bag was placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination (Preparation Example 2). [0044] Additionally, the method for pretreating green coffee beans of the present invention may include: (a) germinating the water-absorbed green coffee beans in an incubator or a dark room at 10° C. to 20° C. for 1 day to 3 days; (b) germinating the green coffee beans germinated in step (a) in an incubator or a dark room at 40° C. to 60° C. for 1 day to 3 days; and drying the green coffee beans germinated in step (b). [0045] In step (a), the green coffee beans are allowed to absorb water so that the water content of the green coffee beans can be in the range from 40% to 60% relative to the total weight, and more specifically from 45% to 55%, but is not limited thereto. [0046] In the present invention, the water content of the water-absorbed green coffee beans in step (a) will belong to the scope of the present invention as long as the water content is sufficient for the germination of green coffee beans, and specifically, water may be absorbed in the range from 40% to 60% relative to the total weight of the green coffee beans, and more specifically, from 45% to 55%, but is not limited thereto. [0047] Additionally, the culture temperature may be in the range from 12° C. to 20° C. in step (a) or from 40° C. to 58° C. in step (b), but is not limited thereto. [0048] Additionally, the method of the present invention may be performed by adding an enzyme which can effectively decompose the various components in the endosperm of green coffee beans. In the case of adding the enzyme, regarding the pretreatment method of the present invention, the green coffee beans may be cultured in step (a) using water, which is to be absorbed to the green coffee beans, by adding an appropriate amount of an enzyme thereto; or in step (b), by adding an appropriate amount of an enzyme to the green coffee beans, which went through step (a), and allowing the enzyme solution to be absorbed into the green coffee beans. Additionally, specifically, the green coffee beans may be cultured at a temperature from 50° C. to 60° C. by adding the green coffee beans, which went through step (a), in step (b) and allowing the enzyme solution to be absorbed into the green coffee beans. The non-limiting examples of the enzyme and the pH range of the water to which the enzyme is added are the same as described above. [0049] Additionally, in the present invention, at least one flavor precursor of green coffee beans, which is selected from the group consisting of sucrose, glucose, and fructose, may be added to be absorbed into the green coffee beans, and specifically, the flavor precursor may be added in an amount of from 0.05% to 30% relative to the total weight of the green coffee beans, and more specifically from 0.1% to 15%, but is not limited thereto. [0050] Additionally, in step (a), sucrose, glucose, and fructose, which are the flavor precursors of green coffee beans, for being absorbed into the green coffee beans may be added into water with a mixed weight ratio of 1 to 6:1 to 6:1 to 6 relative to the weight, and specifically 3:1:1, but is not limited thereto. [0051] In an exemplary embodiment of the present invention, 200 g of green coffee beans washed by a conventional washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C. was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. In a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours to 48 hours, added with a complex enzyme containing protease and carbohydrase prepared for the effective decomposition of the green coffee beans, in an amount of 0.2% relative to the total weight of the green coffee beans and sealed; and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination (Preparation Example 3). [0052] Additionally, in an exemplary embodiment of the present invention, 200 g of green coffee beans washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C., in which an enzyme and flavor precursor materials (sucrose, glucose, and fructose in an amount of 3 g, 1 g, and 1 g, respectively) were contained, was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% relative to the total weight of the green coffee beans, and a complex enzyme containing protease and carbohydrase was added to the green coffee beans in an amount of 0.2% relative to the total weight of the green coffee beans to be absorbed thereinto. Then, in a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours, and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination (Preparation Example 4). [0053] Additionally, in an exemplary embodiment of the present invention, 200 g of green coffee beans washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C., in which an enzyme and flavor precursor materials (sucrose, glucose, and fructose in an amount of 6 g, 2 g, and 2 g, respectively) were contained, was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% relative to the total weight of the green coffee beans, and a complex enzyme containing protease and carbohydrase was added to the green coffee beans in an amount of 0.2% relative to the total weight of the green coffee beans to be absorbed thereinto. Then, in a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours, and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination (Preparation Example 5). [0054] In the present invention, the pretreated green coffee beans may be used for roasting after drying. Specifically, the green coffee beans may be dried so that the water content of the green coffee beans can be in an amount of from 8%0/to 14%, but is not limited thereto. Additionally, specifically, the temperature suitable for drying is in a range from 35° C. to 70° C., and more specifically, from 50° C. to 60° C., but is not limited thereto. [0055] In an exemplary embodiment of the present invention, a pretreated green coffee beans sample was well spread over an aluminum tray and placed in a 55° C. incubator with hot air drying oven and dried until the water content of the green coffee beans reached a range from 10% to 12% (Preparation Example 1). [0056] The green coffee beans, which were pretreated by the pretreatment method of the present invention, can be prepared into coffee through processes such as roasting (at 230° C. to 240° C. for 6 min to 15 min). During the roasting process performed at 200° C. or higher, a large amount of gas generated inside the green coffee beans due to the reactions of organic compounds, such as saccharides and amino acids, along with the water vapor pressure by high heat is released, thereby increasing the pressure. In this regard, during the roasting process, honeycomb-shaped porous structures are formed inside the beans by the rapid change in pressure therein, and carbon dioxide and flavor components are stored inside the numerous pores. Accordingly, the shape and the size of pores are closely related to the preservation of coffee flavor components and extraction efficiency. That is, as the pore size becomes more uniform and the number of pores increases the amount of flavor preservation increases, and as the thickness of pore wall becomes thinner the extraction efficiency becomes higher. [0057] The green coffee beans which underwent the pretreatment of the present invention have uniform pores and an increased number of pores when roasted compared to that of the control group, and thus can capture more flavor components thereby improving both aroma and taste of coffee. The green coffee beans have thinner walls compared to the control group and thus extraction efficiency can be increased and very effectively used in the coffee industry. [0058] Additionally, the method of the present invention may further include washing the green coffee beans before the green coffee beans are allowed to absorb water, and this is for removing impurities, bacteria, fungi, etc., on bean surfaces, which can be harmful to humans, and the washing process may be performed, for example, in such a manner of washing with a brush under the flowing water with a certain degree of pressure, for 2 minutes to 5 minutes, although not particularly limited thereto. [0059] Additionally, the method of the present invention may further include sterilizing green coffee beans before the green coffee beans are allowed to absorb water, and this may be performed using the conventional UV, low temperature plasma, etc., either alone or in combination, although not particularly limited thereto. [0060] In an exemplary embodiment of the present invention, green coffee beans were pretreated according to the methods of Preparation Examples 1 to 5 using Robusta coffee (product of Vietnam) or Arabica coffee (product of Brazil), roasted, and the volatile flavor components were compared and analyzed. As a result, the Robusta coffee species showed increases in the sweet and nutty malty flavor and chocolate flavor, 3-methyl butanal (peak no. 4) and 2-methyl butanal (peak no. 5), in the direction from the control group (A) to low-temperature germination (B), enzyme-added germination (C), and enzyme-addition after low-temperature germination (D). [0061] Additionally, the coffee prepared under saccharide- and enzyme-added germination (E and F) showed a significant increase in 3-methyl butanal and 2-methyl butanal compared to the control group (A) ( FIG. 2 and Table 1). In particular, peak nos. 13, 21, and 22, which represent unconfirmed components, are nutty flavor components and were discovered only in the coffee prepared by enzyme treatment of Robusta green coffee beans. Additionally, all treated groups (B to F) showed a decrease in 2-methoxyphenol (peak no. 33), which is the representative compound causing a burnt smell and a disinfectant smell, in 2-furanmethanol (peak no. 12) and furfuryl alcohol (peak no. 24), which are components for a harsh odor and a bitter taste. Additionally, furan (peak no. 1), which is classified as a potential carcinogen causing a potential health risk, was significantly decreased in all treated groups (B to F) compared to the control group (A). These results could be obtained not only in Robusta coffee but also in Arabica coffee ( FIG. 3 and Table 2). [0062] From the above, it was confirmed that the coffee prepared by low-temperature germination, enzyme-added germination, enzyme addition after low-temperature germination, and saccharide- and enzyme-added germination has an increase in nutty malty and chocolate flavors, a decrease of a burnt smell, a disinfectant smell, and components for a bitter taste, and a decrease in furan, a carcinogen. Since the method of pretreating coffee of the present invention can improve flavor quality of coffee and reduce the amount of carcinogens and thus the method can be very effectively used in the coffee industry. [0063] In an exemplary embodiment of the present invention, sensory evaluations were performed using coffee extracts from 6 different species (control group (A), low-temperature germination (B), enzyme-added germination (C), enzyme-addition after low-temperature germination (D), saccharide- and enzyme-added germination 1 (E), and saccharide- and enzyme-added germination 2 (F)) of Robusta coffee (Vietnam) in Table 1. As a result, it was confirmed that there was an increase in a nutty flavor, a sweet flavor, and a sweet taste and a sour taste which are either not present or weak in Robusta coffee, which are positive factors for flavor quality, whereas there was a decrease in negative factors, such as a harsh flavor, a rubbery smell, a bitter taste, and an astringent taste, in the direction from the control group (A) to low-temperature germination (B), enzyme-added germination (C), enzyme-addition after low-temperature germination (D), and saccharide- and enzyme-added germination (E) (Table 3). The results of these sensory evaluations were overall in line with the result of flavor analysis performed using an analytical instrument (Table 1) and the result of pH analysis which shows acidity (Table 4). [0064] In an exemplary embodiment of the present invention, sensory evaluations were performed using coffee extracts from 6 different species (control group (A), low-temperature germination (B), enzyme-added germination (C), enzyme-addition after low-temperature germination (D), saccharide- and enzyme-added germination 1 (E), and saccharide- and enzyme-added germination 2 (F)) of Arabica coffee (Brazil) in Table 2. As a result, as is the case with the Robusta coffee, it was confirmed in Arabica coffee that there was an increase in the nutty flavor, a sweet flavor, and a sweet taste and a sour taste, which are positive factors for flavor quality, whereas there was a decrease in negative factors, such as a harsh flavor, a rubbery smell, a bitter taste, and an astringent taste, in the direction from the control group (A) to low-temperature germination (B), enzyme-added germination (C), enzyme-addition after low-temperature germination (D), and saccharide- and enzyme-added germination (E) (Table 5). The results of these sensory evaluations were overall in line with the result of flavor analysis performed using a device (Table 2) and the result of pH analysis which shows acidity (Table 6). [0065] From the foregoing, it was confirmed that coffee prepared by low-temperature germination, coffee prepared by enzyme-added germination, coffee prepared by enzyme-addition after low-temperature germination, and coffee prepared by saccharide- and enzyme-added germination showed an increase in positive factors for flavor quality while showing a decrease in negative factors. In this regard, the method of pretreating green coffee beans of the present invention can improve both aroma and taste of coffee and thus can be very effectively used in the coffee industry. [0066] In an exemplary embodiment of the present invention, for the measurement of internal physical changes of pretreated green coffee beans, the electron microscopic images of roasted coffee after pretreatment were observed. As a result, it was confirmed that roasted Robusta coffee (Vietnam) or Arabica coffee (Brazil) have more uniform pores and thinner pore walls in low-temperature germination coffee (B) and enzyme-added germination coffee (C) compared to the control group (A) ( FIGS. 4 and 5 ). These results indicate that the coffee samples prepared by low-temperature germination or enzyme-added germination have more uniform pores and a larger number of pores and thus can capture a larger amount of flavor components and also the thinner pore walls can provide improved extraction efficiency. [0067] From the above, it was confirmed that coffee prepared by low-temperature germination, coffee prepared by enzyme-added germination, coffee prepared by enzyme-addition after low-temperature germination, and coffee prepared by saccharide- and enzyme-added germination have more flavor components captured therein and have improved extraction efficiency. Therefore, the method of pretreating green coffee beans of the present invention can improve both flavor and taste of coffee and also extraction efficiency, and thus can be very effectively used in the coffee industry. [0068] In another aspect, the present invention provides green coffee beans pretreated by the method described above. [0069] As used herein, the term “pretreated green coffee beans” refers to green coffee beans in a state where a part of the components of the green coffee beans are biochemically/chemically converted by allowing water to be absorbed into green coffee beans, followed by germination and drying. During the water absorption into green coffee beans, an enzyme which can decompose green coffee beans and a flavor precursor may be also absorbed. The green coffee beans pretreated for the purpose of the present invention have an increase of precursors of various flavor components, a decrease of a rubbery smell, which is unique to Robusta coffee, and also a decrease of bitter taste components, thereby significantly improving the flavor of the Robusta coffee. Additionally, in the case of Arabica coffee, the rio-off flavor, which is a unique smell of a disinfectant, was effectively reduced while the sweet caramel flavor and nutty flavor increased. Additionally, in the case of the Arabica coffee, the rio-off flavor unique to a disinfectant was effectively reduced, and on the contrary, the sweet caramel flavor and the nutty flavor also increased. Additionally, the pretreated green coffee beans have more uniform pores and a larger number of pores than the green coffee beans in the control group, thus having a larger amount of flavor components, and also the thinner pore walls of the pretreated green coffee beans increased the extraction efficiency. [0070] A further aspect of the present invention provides a method for preparing a coffee extract by roasting the green coffee beans, grinding, and hot-water extraction, and a coffee extract prepared by the method. [0071] The coffee extract may be prepared by roasting the pretreated green coffee beans, grinding, followed by an extraction with hot-water, and preferably, by a series of steps of roasting the pretreated green coffee beans, grinding, and hot-water extraction according to a conventional method. In particular, since the overall conditions, such as the degree of roasting of green coffee beans, the degree of grinding of roasted green coffee beans, a weight ratio between water and ground green coffee beans, water temperature, extraction time, etc., can vary according to the user's preference, and the extraction is preferably performed according to the conditions conventionally known in the art, although the conditions are not particularly limited thereto. DETAILED DESCRIPTION OF THE INVENTION [0072] Hereinafter, the present invention will be described in more detail with reference to the following Examples. However, these Examples are for illustrative purposes only, and the invention is not intended to be limited by these Examples. Example 1 Preparation of Coffee Beans Using Pretreated Green Coffee Beans Preparation Example 1 [0073] Green coffee beans (200 g) washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C. was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. After sealing, the zipper bag was placed in a 15° C. incubator for from 24 hours to 72 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination. The thus-germinated green coffee bean sample was well spread over an aluminum spray and dried in a 55° C. hot-air drying oven to adjust the water content of the green coffee beans in the range from 10% to 12%. The thus-pretreated green coffee beans were roasted according to a conventional method. The roasting was performed using the drum-type Sample Roaster (Probat REI, Germany). When the internal temperature of the roasting drum reached 235° C., the sample (200 g) of the green coffee beans was added thereinto and roasted at an intermediate level for 11 minutes to 12 minutes (lightness, L=23 to 25: a=4: b=10 to 11). Preparation Example 2 [0074] Green coffee beans (200 g) washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C., in which a complex enzyme containing protease and carbohydrase was contained in an amount of 0.2% relative to the total weight of the green coffee beans, was poured thereinto and mixed well, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. Then, the complex enzyme was absorbed into the green coffee beans. After sealing, the zipper bag was placed in a 55° C. incubator for from 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination. The drying and roasting after cultivation were performed in the same manner as in Preparation Example 1. Preparation Example 3 [0075] Green coffee beans (200 g) washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C. was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans. In a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours to 48 hours, added with a complex enzyme containing protease and carbohydrase prepared for the effective decomposition of the green coffee beans, in an amount of 0.2% relative to the total weight of the green coffee beans and sealed; and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination. The drying and roasting after cultivation were performed in the same manner as in Preparation Example 1. Preparation Example 4 [0076] Green coffee beans (200 g) washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C., in which an enzyme and flavor precursor materials (sucrose, glucose, and fructose in an amount of 3 g, 1 g, and 1 g, respectively) were contained, was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% (about 50%) relative to the total weight of the green coffee beans, and a complex enzyme containing protease and carbohydrase was added to the green coffee beans in an amount of 0.2% relative to the total weight of the green coffee beans to be absorbed thereinto. Then, in a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours, and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination. The drying and roasting after cultivation were performed in the same manner as in Preparation Example 1. Preparation Example 5 [0077] Green coffee beans (200 g) washed by a conventional water washing process were added into a zipper bag and then 150 mL of drinking water at from 15° C. to 25° C. in which an enzyme and flavor precursor materials (sucrose, glucose, and fructose in an amount of 6 g, 2 g, and 2 g, respectively) were contained, was poured thereinto, and the water content of the green coffee beans was adjusted in the range from 40% to 60% relative to the total weight of the green coffee beans, and a complex enzyme containing protease and carbohydrase was added to the green coffee beans in an amount of 0.2% relative to the total weight of the green coffee beans to be absorbed thereinto. Then, in a sealed state, as a primary treatment, the zipper bag was placed in a 15° C. incubator for 24 hours, and as a secondary treatment, placed in a 55° C. incubator for 24 hours to 48 hours for the germination of the green coffee beans. During the germination, the green coffee beans were pretreated by frequently opening the zipper bag to supply oxygen necessary for germination. The drying and roasting after cultivation were performed in the same manner as in Preparation Example 1. [0078] The methods of pretreating green coffee beans prior to hot-air drying illustrated in Preparation Examples 1 to 5 were compared and the results are shown in FIG. 1 . Example 2 Analysis and Quality Evaluation of Flavor Components 2-1. Measurement of Roasting Intensity [0079] The measurement of coffee chromaticity was indicated in terms of value L (which represents lightness), value a (which represents redness), and value b (which represents yellowness) using a colorimeter after grinding the coffee beans to a medium size, and the measurement was performed 5 times repeatedly. 2-2. Analysis of Flavor Components of Roasted Coffee [0080] After grinding the roasted coffee to medium-size particles, the ground coffee particles in an amount of 1 g were respectively added into 16 mL SPME (Solid Phase MicroExtraction) vials, added with 5 mL of drinking water at 35° C. closed with a lid, and the flavor components were allowed to adsorb to SPME fiber (50/30 μm DVBiCarboxen/PDMS) exposed thereto while stirring at 500 rpm in a temperature-controlled magnetic stirrer, thereby analyzing the flavor components. The analysis was performed 3 times repeatedly. 2-3. Result of Analysis of Flavor Components [0081] Green coffee beans of Robusta coffee (product of Vietnam) or Arabica coffee (product of Brazil) were respectively pretreated according to the methods of Preparation Examples 1 to 5, roasted, and the volatile flavor components thereof were compared and analyzed. The content of flavor components was analyzed by GC peak area comparison, and the Robusta coffee (product of Vietnam) or Arabica coffee (product of Brazil) without any treatment were compared and analyzed after roasting. The results are shown in FIGS. 2 to 3 and Tables 1 and 2. [0000] TABLE 1 Robusta Coffee (Product of Vietnam) GC Peak Area Control Prep. Ex. 3 Prep. Ex. 4 Prep. Ex. 5 Group Prep. Ex. 1 Prep. Ex. 2 Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Peak Group Germination Germination Germination Germination 1 Germination 2 No. Compound (A) (B) (C) (D) (E) (F) 1 Furan 382 276 301 272 295 274 2 Unknown 311 297 451 380 298 297 3 Unknown 1237 729 984 745 941 771 4 3-Methyl butanal 537 580 898 924 836 870 5 2-Methyl butanal 1053 1284 1450 1495 1356 1392 6 Unknown 931 585 452 505 446 630 7 Unknown 246 132 243 65 272 138 8 Unknown — 417 114 150 261 414 9 Dihydro-2-methyl- 118 93 66 36 75 100 3(2H)-furanone 10 2-Methyl pyrazine 692 696 443 288 511 728 11 Furfural 950 1160 1241 1334 1279 1259 12 2-Furanmethanol 2813 2515 2431 2303 2407 2442 13 Unknown — — 327 481 355 341 14 2-Furfurylformate 625 417 454 391 381 390 15 1-(2-Furanyl)-ethanone 1049 1147 855 760 898 1198 16 2-Ethyl pyrazine 643 610 473 358 374 615 17 2,3-Dimethyl pyrazine 183 192 85 337 330 212 18 3-Methyl-2-buten-1-ol 39 46 15 20 23 39 19 Benzaldehyde 106 114 103 110 111 107 20 Unknown 1182 1436 1385 1263 1253 1294 21 Unknown — — 494 497 376 324 22 Unknown — — 308 364 382 374 23 2-Pentyl furan 416 368 384 319 387 401 24 Furfuryl alcohol 3651 2835 2787 2858 2608 2735 25 Trimethyl pyrazine 221 239 250 222 230 251 26 1-Methyl-1H-pyrrole- 411 474 550 532 381 487 2-carboxaldehyde 27 N-(2-Cyanoethyl)-pyrrole 138 127 90 61 112 127 28 Benzene acetaldehyde 100 135 139 127 144 118 29 1-(1H-pyrrole-2-yl)- 155 209 222 125 136 146 ethnaone 30 1-(1-Methyl-pyrrole- 145 127 128 109 123 126 2-yl)-ethanone 31 Unknown 354 384 294 285 332 396 32 Unknown 440 302 390 339 321 318 33 2-Methoxy phenol 456 332 387 314 322 315 34 Unknown 251 160 304 254 183 155 35 3,5-Diethyl-2-methyl 84 85 78 72 76 88 pyrazine 36 1-(2-Furanyl methyl)- 435 467 611 540 493 458 1H-pyrrole [0082] As can be confirmed in FIG. 2 and Table 1, in the case of the Robusta species coffee, there was an increase in the content of 3-methyl butanal (peak no. 4) and 2-methyl butanal (peak no. 5), which are sweet and nutty malty flavor and chocolate flavor, in the direction from the control group (A) to low-temperature germination (B), enzyme-added germination (C), and enzyme-addition after low-temperature germination (D). Additionally, the coffee prepared by saccharide- and enzyme-added germination (E and F) showed a significant increase in the content of 3-methyl butanal and 2-methyl butanal, compared to the control group (A). [0083] In particular, unidentified components represented by peak nos. 13, 21, and 22 are nutty flavor components and were discovered only in the coffee prepared by enzyme-treatment of Robusta green coffee beans (C to F). [0084] Additionally, all the treated groups (B to F) showed a decrease in the content of 2-methoxyphenol (peak no. 33), which is a representative material for a burnt smell and a disinfectant smell, and 2-furanmethanol (peak no. 12) and furfuryl alcohol (peak no. 24), which represent a harsh smell and a bitter taste, compared to the control group (A). Additionally, there was a significant decrease of furan (peak no. 1), which is known to have a potential health risk, in all the treated groups (B to F), compared to the control group (A). [0085] There results could be obtained not only form Robusta coffee but also in Arabica coffee ( FIG. 3 and Table 2). [0000] TABLE 2 Arabica Coffee (Product of Brazil) GC Peak Area Control Prep. Ex. 3 Prep. Ex. 4 Prep. Ex. 5 Group Prep. Ex. 1 Prep. Ex. 2 Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Peak Group Germination Germination Germination Germination 1 Germination 2 No. Compound (A) (B) (C) (D) (E) (F) 1 Furan 270 246 230 213 235 235 2 Unknown 204 294 547 510 287 423 3 Unknown 500 462 498 527 621 605 4 3-Methyl butanal 379 781 1662 1894 1081 1415 5 2-Methyl butanal 824 1111 1734 1650 1446 1658 6 Unknown 392 359 227 296 308 254 7 Unknown 126 102 282 275 159 122 8 Unknown 195 125 100 101 131 124 9 Unknown 264 257 96 29 167 147 10 Dihydro-2-methyl- 127 167 73 97 110 86 3(2H)-furanone 11 2-Methyl pyrazine 487 513 311 276 435 319 12 Furfural 2361 2776 2575 2672 2528 2485 13 Ethyl benzene 74 72 80 96 97 84 14 2-Furanmethanol 2195 2553 1517 1458 2258 1961 15 Unknown 127 186 558 561 64 168 16 2-Furfurylformate 479 500 287 316 428 363 17 1-(2-Furanyl)-ethanone 935 1123 634 597 912 735 18 2-Ethyl pyrazine 405 461 305 280 317 339 19 2,3-Dimethyl pyrazine 115 114 155 158 230 89 20 3-Methyl-2-buten-1-ol 60 55 52 50 44 48 21 Benzaldehyde 79 124 71 77 108 110 22 Unknown 1814 2497 1736 1929 1954 1929 23 Unknown — — 941 880 950 1150 24 Unknown — — 361 326 550 — 25 2-Pentyl furan 157 132 157 157 175 203 26 Furfuryl alcohol 2508 2036 1802 1766 2173 1973 27 Trimethyl pyrazine 196 156 337 306 136 99 28 1-Methyl-1H-pyrrole- 296 378 316 296 317 314 2-carboxaldehyde 29 N-(2-Cyanoethyl)-pyrrole 74 73 40 39 65 153 30 Benzene acetaldehyde 96 126 100 103 133 123 31 1-(1H-pyrrole-2-yl)- 138 159 111 135 116 147 ethnaone 32 1-(1-Methyl-pyrrole- 117 141 43 78 66 45 2-yl)-ethanone 33 Unknown 288 252 205 99 199 114 34 Unknown 215 216 199 199 230 179 35 2-Methoxy phenol 143 106 126 114 101 120 36 Unknown 164 168 169 196 150 104 37 3,5-Diethyl-2-methyl 60 49 36 29 46 32 pyrazine 38 1-(2-Furanyl methyl)- 264 321 348 311 341 441 1H-pyrrole [0086] That is, in the case of Arabica coffee, there was an increase in the content of 3-methyl butanal (peak no. 4) and 2-methyl butanal (peak no. 5), which are sweet and nutty malty flavor and chocolate flavor, in the direction from the control group (A) to low-temperature germination (B), enzyme-added germination (C), and enzyme-addition after low-temperature germination (D), whereas 2-furanmethanol (peak no. 14) and furfuryl alcohol (peak no. 26), which represent harsh and bitter taste components, decreased as a whole. In contrast, the unidentified nutty flavor component, represented by peak no. 15, was also discovered in the control group (A), but it was further increased in low-temperature germination (B) and significantly increased in coffee prepared by enzyme-treatment of green coffee beans (C and D). Additionally, unidentified nutty flavor components represented by peak no. 23 and 24 were discovered only in coffee prepared by enzyme-treatment of green coffee beans (C to F). [0087] From the foregoing, it was confirmed that coffee prepared by low-temperature germination, germination by enzyme-addition, enzyme-addition after low-temperature germination, and saccharide- and enzyme-added germination of green coffee beans showed an increase in nutty malty and chocolate flavors while showing a decrease in components for a burnt smell, a disinfectant smell, a harsh smell, and a bitter taste. Accordingly, it was confirmed that the method of pretreating green coffee beans according to the present invention can improve the quality of coffee flavor while reducing carcinogens contained therein, and thus can be very effectively used in the coffee industry. Example 3 Result of Sensory Evaluation of Flavors and Tastes 3-1. Result of Sensory Evaluation of Robusta Coffee [0088] Sensory evaluation was performed by providing a panel of 15 people with coffee extracts of 6 different species of Robusta coffee (Vietnam) (control group (A), low-temperature germination (B), enzyme-added germination (C), enzyme addition after low-temperature germination (D), saccharide- and enzyme-added germination 1 (E), saccharide- and enzyme-added germination 2 (F)) shown in Table 1. The sensory evaluation on coffee was performed in such a manner that the evaluation on flavors regarding four different kinds of coffee aromas (nutty, sweet, harsh, and rubbery flavors) was performed first and then the evaluation on tastes regarding four different kinds of coffee tastes (bittemess, sourness, sweetness, and astringency) was performed. The result of each sensory evaluation is shown in Table 3. [0000] TABLE 3 Result of Sensory Evaluation of Robusta Coffee (Vietnam) Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Group Germination Germination Germination Germination 1 Germination 2 Type of Flavors (A) (B) (C) (D) (E) (F) Aroma nutty 4.14 4.93 5.69 5.85 5.89 5.85 sweet 2.46 3.08 4.00 4.12 4.81 4.85 harsh 5.57 4.71 4.53 4.62 4.45 4.73 rubbery 5.29 4.50 4.00 3.89 4.13 3.74 Taste bitter 6.27 5.00 5.20 5.15 5.37 4.92 sour 3.36 3.00 3.29 3.52 3.73 3.64 sweet 2.07 2.21 2.29 2.81 3.02 2.96 astringent 4.40 4.00 4.20 4.12 4.05 4.01 [0089] As a result, as can be seen in Table 3, regarding the flavors of Robusta coffee, nutty and sweet flavors increased in the direction from control group (A) to low-temperature germination (B), enzyme-added germination (C), enzyme addition after low-temperature germination (D), and saccharide- and enzyme-added germination 1 (E), whereas negative flavors, such as harsh and rubbery flavors, generally decreased in the same direction. [0090] Additionally, regarding the tastes of Robusta coffee, sweetness increased in the direction from control group (A) to low-temperature germination (B), enzyme-added germination (C), enzyme addition after low-temperature germination (D), and saccharide- and enzyme-added germination 1 (E), whereas bitterness and astringency decreased in the direction from control group (A) to enzyme-added germination (C), enzyme addition after low-temperature germination (D), saccharide- and enzyme-added germination 1 (E), and low-temperature germination (B). As a result of the overall sensory evaluation, positive factors for quality flavor, such as a nutty aroma, a sweet aroma, and a sweet taste and a sour taste which are either not present or weak in Robusta coffee increased, whereas negative factors, such as a harsh aroma, a rubbery smell, a bitter taste, and an astringent taste, showed a general trend of decrease in the same direction. The results of sensory evaluation were generally in consistent with the flavor analysis result (Table 1) and the pH analysis result showing acidity (Table 4) obtained using analytical devices. [0000] TABLE 4 Result of pH Measurement of Robusta Coffee (Vietnam) Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Group Germination Germination Germination Germination 1 Germination 2 (A) (B) (C) (D) (E) (F) 5.64 5.53 5.41 5.40 5.38 5.37 3-2. Result of Sensory Evaluation of Arabica Coffee [0091] Sensory evaluation was performed by providing a panel of 15 people with coffee extracts of 6 different species of Arabica coffee (Brazil) (control group (A), low-temperature germination (B), enzyme-added germination (C), enzyme addition after low-temperature germination (D), saccharide- and enzyme-added germination 1 (E), saccharide- and enzyme-added germination 2 (F)) shown in Table 2. The sensory evaluation on coffee was performed in the same manner as in Example 3-1, and the result is shown in Table 5. [0000] TABLE 5 Result of Sensory Evaluation of Arabica Coffee (Brazil) Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Group Germination Germination Germination Germination 1 Germination 2 Type of Flavors (A) (B) (C) (D) (E) (F) Aroma nutty 5.00 5.47 6.07 6.13 6.17 6.08 sweet 3.64 4.57 4.79 4.80 4.95 4.85 harsh 4.47 3.87 4.13 4.21 4.11 4.18 rubbery 4.29 3.93 4.29 3.78 3.82 3.89 Taste bitter 4.53 4.21 3.45 3.22 3.78 3.85 sour 5.07 4.80 6.67 6.94 6.42 6.12 sweet 2.87 3.33 3.60 3.84 3.92 3.87 astringent 3.47 3.13 2.80 2.61 2.68 2.64 [0092] As can be seen in Table 5, as in the case of Robusta coffee, Arabica coffee showed an increase of positive factors for flavor quality (i.e., a nutty aroma, a sweet aroma, a sweet taste, and a sour taste) in the direction from control group (A) to low-temperature germination (B), enzyme-added germination (C), enzyme addition after low-temperature germination (D), and saccharide- and enzyme-added germination 1 (E), whereas negative flavors (i.e., harsh aroma, rubbery aroma, bitter taste, and sour taste), generally decreased in the same direction. The results of sensory evaluation were generally in consistent with the flavor analysis result (Table 2) and the pH analysis result showing acidity (Table 6) obtained using analytical devices. [0000] TABLE 6 Result of pH Measurement of Arabica Coffee (Brazil) Enzyme-addition Sugar- and Sugar- and Control Low-temp Enzyme-added after Low-temp Enzyme-added Enzyme-added Group Germination Germination Germination Germination 1 Germination 2 (A) (B) (C) (D) (E) (F) 5.06 5.03 4.86 5.01 4.92 4.95 [0093] From the above, it was confirmed that the coffee prepared by low-temperature germination, enzyme-added germination, enzyme addition after low-temperature germination, and saccharide- and enzyme-added germination has an increase in positive factors for flavor quality while having a decrease in negative factors. Accordingly, the method of pretreating green coffee beans of the present invention can improve both flavor and taste of coffee and thus can be very effectively used in the coffee industry. Example 4 Internal Physical Change of Pretreated Green Coffee Beans [0094] For the measurement of physical changes in the interior of pretreated green coffee beans, the images of roasted coffee after the pretreatment in Example 2-3 were observed under an electron microscope. [0095] As a result, it was confirmed that the roasted Robusta coffee (Vietnam), which was prepared by low-temperature germination (B) or by enzyme-added germination (C), has more uniform pores and thinner pore walls than the coffee of the control group (A) as shown in FIG. 4 . Further, it was confirmed that the roasted Arabica coffee (Brazil), which was prepared by low-temperature germination (B) or by enzyme-added germination (C), has more uniform pores and thinner pore walls than the coffee of the control group (A) as shown in FIG. 5 , as is the case with the Robusta coffee. [0096] These results suggest that the coffee samples prepared by low-temperature germination or by enzyme-added germination have more uniform pores and a larger number of pores thus capable of capturing more flavor components and also have an improved extraction efficiency due to thinner pore walls. [0097] Conclusively, from the above, it was confirmed that coffee, which was prepared by low-temperature germination, by enzyme-added germination, by enzyme-addition after low-temperature germination, and by saccharide- and enzyme-added germination, has more flavor components captured therein and improved extraction efficiency. Accordingly, the method of pretreating green coffee beans of the present invention can improve both flavor and taste of coffee and thus can be very effectively used in the coffee industry. [0098] From the foregoing, a skilled person in the art to which the present invention pertains will be able to understand that the present invention may be embodied in other specific forms without modifying the technical concepts or essential characteristics of the present invention. In this regard, the exemplary embodiments disclosed herein are only for illustrative purposes and should not be construed as limiting the scope of the present invention. On the contrary, the present invention is intended to cover not only the exemplary embodiments but also various alternatives, modifications, equivalents and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

The present invention relates to a method for pretreating green coffee beans before roasting to improve flavor and taste of coffee; green coffee beans pretreated by the method; a method for preparing a coffee extract including extracting the thus-prepared green coffee beans with hot-water; and a coffee extract prepared by the method. According to the pretreatment method of the present invention, coffee can be prepared with improved taste and flavor, increased extraction efficiency, and a reduced amount of carcinogenic materials, and thus the method of the present invention can be widely applied in the coffee industry.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic blackboard for processing image information which corresponds to the image or the like displayed on the writing surface and its accessories such as writing tools. 2. Prior Art Hitherto, there is a conventional electronic blackboard apparatus (called "an electromagnetic coupled type" hereinafter) arranged such that a multiplicity of sensing lines are, in both x and y directions, formed on the reverse side of the writing surface thereof and a writing tool comprising a felt pen or the like is provided with a coil as to generate flux change when an electronic current is passed so that the thus-generated flux change is detected by the sensing lines or the other end of the coil so that the position of the writing tool on the writing surface is detected and thereby image information which corresponds to the image displayed on the writing surface can be processed. Another type of the electronic blackboard apparatus called "a photoelectric transfer type" hereinafter) is known which is arranged such that an image written on a whiteboard or a flexible seat with a writing tool such as a felt pen or the like is scanned by a scanner which can move along the surface of this whiteboard or by a stationary scanner with this seat wound up as to be photoelectrically transferred to image information. The other conventional electronic blackboard apparatus (called "a pressure sensing type" hereinafter) is known in which two resistance plates provided with electrodes on the opposing sides thereof are fastened to the reverse side of a writing surface made of a flexible material. The various parts are laminated to each other. These two resistance plates are fastened to the electrodes in such a manner that these electrodes are positioned in the vertical or lateral direction. Therefore, a displacement current is generated between an electrode on one resistance plate and the electrode on the other resistance plate when the writing tool is moved along the surface of the writing surface with an electric current being passed through either of the two resistance plates. On the basis of the thus-generated displacement current, the position of the writing tool on the writing surface is detected so that image information corresponding to the image displayed on the writing surface is processed. However, the above-described electromagnetic coupling type apparatus has a problem in that, a cord needs to be provided between the control unit for detecting position and a coil provided for the writing tool. The thus-provided cord readily deteriorates in handling the writing tool. In the photoelectrically transfer type apparatus, the writing tool can be arranged to be a cord-less type. However, another problem arises in that information corresponding to the displayed image cannot be obtained during writing of the image on the writing surface, that is a real-time image cannot be obtained since image information can be first obtained when the scanner is moved or the seat is wound up. In the pressure sensing type apparatus, the writing tool can be arranged to be a cord-less type and the information corresponding to the image which is being written can be obtained. However, a problem arises in that the thickness and the weight become excessive since the structure needs to be formed to withstand the pressure applied with the writing tool to the writing surface. SUMMARY OF THE INVENTION A first object of the present invention is to provide an electronic blackboard apparatus capable of using a cordless accessary such as an instruction rod, a marker, or an eraser (called a "writing tool" hereinafter in this specification), obtaining realtime image information which corresponds to the image formed on the writing surface, and exhibiting a thin structure and light weight. In accordance with one aspect of the invention, an electronic blackboard apparatus comprises a writing surface, in combination with a tool for modifying an image on the surface, wherein the tool includes a tuned circuit having a predetermined resonant frequency. A sensor for an electric wave having plural frequencies, one of which is the resonant frequency, and an electrical wave detector for an electric wave reflected by the tuned circuit is provided. The sensor includes coordinate detection means responsive to the electric waves reflected from the tool and generated by the generating means for detecting a coordinate corresponding to the position of the tool. Image information processing means processes, on the basis of the thus-detected coordinate, image information corresponding to an image formed by the tool on the surface. Another aspect of the invention is directed to the combination of a position sensing tablet a two coordinate direction coil arrangement, a two coordinate direction display superposed with the tablet, a marker for the display and an eraser for the display. The marker and eraser each include a tuned circuit respectively having first and second resonant frequencies. AC energy is supplied at the first and second resonant frequencies to the coil arrangement. The tuned circuits on the marker and the eraser, when the marker or eraser is placed in proximity to the tablet and coil arrangement, respectively cause changes in currents flowing in the coil arrangement at the first and second frequencies. The changes in the current flowing in the coil arrangement at the first and second frequencies are sensed. In response to the current changes at the first and second frequencies there is derived a signal indicative of the position of markings by the marker on the display as modified by the eraser. In accordance with still a further aspect, the invention is directed to the combination of a position sensing tablet, a two coordinate direction coil arrangement associated with the tablet and multiple implements for movement relative to the table. Each of the implements has a different characteristic associated therewith and includes a tuned circuit having a different resonant frequency. AC energy at the different resonant frequencies is supplied to the coil arrangement. The tuned circuits on the implements, when the implements are placed in proximity to the tablet and coil arrangement, cause changes in the currents flowing in the coil arrangement at the different frequencies. Changes in current flowing in the coil arrangement at the different frequencies are sensed. In response to the current changes at the frequencies there is derived a signal indicative of the position and characteristics of the implements on the tablet. A further aspect of the invention is directed to a method of identifying a characteristic and position of an implement on a position sensing tablet having a two coordinate direction coil arrangement associated therewith, wherein the implement has one of plural characteristics and includes a tuned circuit having one of plural different resonant frequencies. The method comprises supplying AC energy at the plural different resonant frequencies to the coil arrangement. The tuned circuit on the implement, when placed in proximity to the tablet and coil arrangement, causes changes in current flowing in the coil arrangement at the one frequency. Changes in the current flowing in the coil arrangement at the different frequencies are sensed. In response to current changes at the frequencies there is derived a signal indicative of the position and characteristic of the implement on the tablet. Still another aspect of the invention is directed to an eraser for supplying a signal to an electronic display and for removing a marking from a surface of a visual display. The eraser comprises a housing including: a surface for erasing the marking, first and second tuned circuits each having a reactance positioned in proximity to first and second opposite edges of the erasing surface, as well as first and second switches which when activated respectively cause the first and second tuned circuits to have different first and second resonant frequencies. The first and second switches are positioned and arranged so that the first and second switches are respectively activated in response to the first and second edges of the eraser being pushed against the display surface. Still a further aspect of the invention is directed to the combination of a position sensing tablet, a two-coordinate direction coil, a two-coordinate direction display superposed with the tablet, and multiple implements for modifying markings of the display. Each implement has a different characteristic associated therewith and includes a tuned circuit having a different resonant frequency for each characteristic. AC energy at the different resonant frequencies is supplied to the coil arrangements. The tuned circuits on the implements, when the implements are placed in proximity to the tablet and coil arrangement, respectively cause changes in the currents flowing in the coil arrangement at the different frequencies. Changes in the current flowing in the coil arrangement at the different frequencies are sensed. In response to current changes at the frequencies there is derived a signal indicative of the position and characteristics of markings by the implements on the display. Still a further aspect of the invention is directed to the combination of a position sensing tablet, a two-coordinate coil arrangement associated with the tablet, a two-coordinate direction display superposed with the tablet and plural markers for the display. Each of the markers is for a different color on the display. Each of the markers includes a tuned circuit having a different resonant frequency. AC energy at the different resonant frequencies is supplied to the coil arrangement. The tuned circuits on the markers, when the markers are placed in proximity to the tablet and coil arrangement, cause changes in currents flowing in coils of the coil arrangement at the different frequencies. In response to energy coupled between the tablet and markers there is derived a signal indicative of the position of the colors of markings by the markers on the display by sensing changes in current flowing in the coil arrangement at the different frequencies. Yet an additional aspect of the invention is directed to a method of displaying a polychromatic image by marking a first two-coordinate direction display with plural markers each having a different color and a tuned circuit with a different resonant frequency thereon. Plural frequencies are supplied to a two-coordinate direction coil arrangement. The coil arrangement couples the plural frequencies to each marker as it is marking the first display. The coil arrangement is activated so it is responsive to an interaction of each applied frequency and each tuned circuit to provide an indication of the color and position of the mark being made by each marker on the first display. By responding to the indication there is displayed on a second two-coordinate direction display the position and color of the mark made by each marker on the first display. Another aspect of the invention concerns a method of indicating the position of an image on a two-coordinate direction display by marking the display with a marker and erasing from the display at least a portion of marks made by the marker. The marker and eraser respectively have tuned circuits with first and second resonant frequencies. A two-coordinate direction coil arrangement is activated so it applies the first and second resonant frequencies to the marker and the eraser as they respectively mark and erase the display. The coil arrangement is activated to be responsive to an interaction of the applied first and second frequencies with the tuned circuits to derive an indication of the position of the marking on the display as modified by the eraser. Still an additional aspect of the invention is directed to an eraser for supplying a signal to an electronic display and for removing a marking from a surface of a visual display. The eraser has a housing including: a surface for erasing the marking, a tuned circuit having a reactance positioned immediately behind the eraser surface, and switch means activated in response to the erasing surface being pressed against the display surface for connecting elements including the reactance of the tuned circuit together so they have a predetermined resonant frequency while the erasing surface is pressed against the display surface. A second object of the present invention is to provide an electronic blackboard apparatus capable of identifying the type and the state of the writing tool which is being used and to thereby obtain image information which corresponds to the thus-identified type or state of the writing tool. A third object of the present invention is to provide an electronic blackboard apparatus including two writing surfaces. A fourth object of the present invention is to provide a writing tool such exhibiting a simple structure, light weight, and easy handling capability, that is, an instruction rod, a marker, and an eraser. Other objects and features of the present invention will become more apparent in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a first embodiment of an electronic blackboard apparatus according to the present invention; FIG. 2 is a structural view of loop coil groups in X and Y directions of a sensing portion; FIG. 3 is a cross-sectional view of an instruction rod; FIG. 4 is a cross-sectional view of a marker; FIG. 5 is a cross-sectional view of an eraser; FIG. 6 is a block diagram of the electronic blackboard apparatus according to the present invention; FIG. 7 is a schematic block diagram of tuning circuits for a writing tool and details of a control unit for a sensing portion; FIG. 8 is a series of waveforms used for describing the circuit of FIG. 7; FIG. 9 is a timing diagram used to describe the circuit of FIG. 7; FIG. 10 is a flow chart of the coordinate-detection action performed by a control unit of the sensing portion; FIGS. 11A, 11B, and 11C are further waveforms used for describing coordinate detection action performed by the control unit of the sensing portion; FIG. 12 is a waveform of the levels of the detected voltage obtainable from each of the loop coils when coordinate detection action is performed; FIG. 13 is a block diagram of a data processing unit used with the present invention; FIG. 14 is a flow chart for processing of image information performed by the data processing unit; FIG. 15 is a view of a second embodiment of the electronic blackboard apparatus according to the present invention; FIG. 16 is a view of a partial cross-sectional view of a frame according to the second embodiment; FIG. 17 is a flow chart of a program for the data processing unit according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a view of a first embodiment of an electronic blackboard apparatus according to the present invention, wherein reference numeral 1 represents a main blackboard body, 2 represents an instruction rod, 3 represents a marker, 4 represents an eraser, and 5 represents a control box. The main blackboard body 1 is formed such that legs 13 are fastened to a frame 12 a portion of which corresponds to the front surface of a sensing portion 11 is made of a non-metallic material having a flat surface so as to form a writing surface 14 which can be repeatedly used with the marker 3 and the eraser 4. Alternatively, the portion of the frame 12 which corresponds to the front surface of the sensing portion 11 may be formed by applying paint to which magnetic dust is mixed to the plate made of the non-metallic material or by laminating a film sheet such as a magnet sheet and a plastic sheet on the same plate for the purpose of realizing a writing surface to which sheet in which intended frames or figures are written can be temporally fastened by metal pieces or magnets. In FIG. 2 are illustrated a loop coil group 11x in x-direction and a loop coil group 11y in y-direction which form the sensing portion 11. The loop coil group 11x in x-direction comprises a multiplicity of, for example, 48 loop coils 11x-1, 11x-2, . . . , 11x-48 so as to be arranged in parallel to each other and to overlap each other. The loop coil group 11y in y-direction comprises a multiplicity of, for example, 30 loop coils 11y-1, 11y-2, . . . , 11y-30 so as to be arranged in parallel to each other and to overlap each other. The loop coil group 11x in x-direction and the loop coil group 11y in y-direction overlap each other with positioned closely contact with each other (in order to readily understand the structure, they are drawn in a separated manner). Alternative to the structure employed here in which each of the loop coils is formed by one turn, the loop coils may be formed by a plurality of turns if necessary. In FIG. 3 is illustrated a first embodiment of the writing tool and so on according to the present invention, in which the structure of the instruction rod 2 is illustrated. This instruction rod 2 is made of a synthetic resin, wood or the like and is formed in such a manner that a tuning circuit 22 comprising a coil 221 which includes a core and a capacitor 222 is accommodated in a recessed portion 21a formed at the front end portion of a column-like main body 21 made of a synthetic resin or wood in such a manner that the axis of this coil 221 substantially meets the longitudinal direction of the main body 21 (frame), and this recessed portion 21a is covered with a cap 23 made of the similar material to that for the main body 21. The main body 21 may comprise a telescopic rod. The coil 221 and the capacitor 222 are, as shown in FIG. 7, connected to each other in series so as to form a known resonant circuit. The inductance of this coil 221 and the capacity of the capacitor 222 are determined as to make the resonant (tuned) frequency thereof substantially a predetermined frequency f0, for example, 600 kHz. FIG. 4 is a view of a second embodiment of the writing tool according to the present invention, in which the structure of a marker 3 is in detail illustrated. This marker 3 comprises: a pen shaft 31 formed by two portions 31a and 31b made of a non-metallic material such as a synthetic resin and to be screw-coupled with each other; a pen body 32 such as a black felt pen on the market or the like; a push switch 331; a coil 332 including a core; a tuning circuit 33 comprising capacitors 333 and 334; and a cap 34 for the pen body 32. The pen body 32 is accommodated in a space formed by a stopper 31a' formed in the portion 31a of the pen shaft 31 and the switch 331 accommodated in the portion 31b such that the same can be slightly moved therein. The coil 332 is accommodated in the portion at the front end of the portion 31a of the pen shaft 31 such that the axial direction thereof is substantially coincident with the longitudinal direction of the pen shaft 31 (frame). As shown in FIG. 7, the coil 332 and the capacitor 333 are connected to each other in series so as to form a known resonant circuit. The inductance of this coil 332 and the capacity of the capacitor 333 are so determined as to make the resonant (tuned) frequency thereof substantially a predetermined frequency f0, for example, 600 kHz. The capacitor 334 is in parallel connected to the two ends of the capacitor 333 via the switch 331 so that the same acts to change the tuned frequency in the resonant circuit from the predetermined frequency f0 to another frequency f1, for example, 550 kHz when the above-described switch 331 is switched on. This switch 331 is arranged to be switched on when it is abutted by the rear end of the pen body 32 which has been pushed into the pen shaft 31 as a result of abutting the front end of the pen body 32 against the writing surface 14 or the like with the pen shaft 31 held by the hand or the like. Although the front end of the pen body is made project over the writing surface as to enable the writing according to this embodiment, it may be arranged to be capable of projecting only when used. The marker is so designed that the pen body 32 included therein can be replaced by so arranging the pen shaft 31 that it can be divided and coupled to each other. In FIG. 5 is illustrated a third embodiment of the writing tool or the like according to the present invention, in which the structure of the eraser 4 is illustrated in detail. This eraser 4 comprises: a case 41 made of a non-metallic material such as a synthetic resin or the like; a movable plate 42 comprising a pair of members 42a and 42b each of which has a shape corresponding to the bottom surface of the case 41 and which are arranged to be detachable to each other; a pair of springs 43a and 43b inserted between the movable plate 42 and the case 41; a stopper 44 disposed in an inner portion 41a of the case 41 and capable of supporting a securing portion 42b' which projects in the direction of the member 42b perpendicular to the drawing sheet for the purpose of restricting the position of the movable plate 42 with respect to the case 41; an erasing member 45 made of felt or the like and fastened to the outer surface of the member 42a of the movable plate 42; a first tuning circuit 46 comprising a switch 461 accommodated in the inner portion 41a of the case 41, a capacitor 462 and a capacitor 463 which includes a core and is held between the members 42a and 42b at the position corresponding to the spring 43a of the movable plate 42 such that the axial direction thereof and the erasing surface formed by the erasing member 45 are substantially perpendicular to each other; and a second tuning circuit 47 comprising a switch 471, a capacitor 472, and a coil 473 which includes a core and is held between the members 42a and 42b at the position corresponding to the spring 43b such that the axial direction thereof and the erasing surface formed by the erasing member 45 are substantially perpendicular to each other. This movable plate 42 is held such that the same can move slightly with respect to the case 41 so that the switch 463 and/or 473 can be operated. The coil 463 and the capacitor 462 are connected to each other in series via the switch 461 as shown in FIG. 7 so that a known resonant circuit is actuated when this switch 461 is switched on. The inductance of this coil 463 and the capacity of the capacitor 462 are determined as to make the resonant (tuned) frequency thereof substantially another frequency f2, for example, 500 kHz. The coil 473 and the capacitor 472 are connected to each other in series via the switch 471 as shown in FIG. 7 so that a known resonant circuit is actuated when this switch 471 is switched on. The inductance of this coil 473 and the capacity of the capacitor 472 are determined as to make the resonant (tuned) frequency thereof substantially other frequency f3, for example, 450 kHz. These switches 461 and 471 are switched off when the eraser 4 is not operated, while either or both of the switches 461 and 471 are switched on by being pressed by the member 42b of the movable plate 42 when the erasing member 45 of the movable plate 42 is pushed into the case 41 by abutting this erasing member 45 against the writing surface 14 or the like with the case 41 held by the hand or the like. The tuning circuit for the writing tool or the like of the type described above is so arranged that it can be synchronized with the energy of the electric wave discharged from the electric wave generating means in the sensing portion and discharge this energy to the electric wave detection means in the sensing portion for the purpose of meeting the conditions required to perform indication of the position to be measured to the sensing portion. The control box 5 is provided with, on the front surface thereof, various control switches 51 and an outlet 52 through which printed sheets are discharged, this control box 5 including, as shown in FIG. 6, the sensing portions control unit 6, the data processing unit 7, and a printer 8. In FIG. 7 is illustrated the sensing portion control unit 6 together with the instruction rod 2, the marker 3, the tuning circuits 22, 33, 46, and 47 for the eraser 4. Referring to this drawing, reference numeral 601 represents a control circuit, 602 represents a signal generating means (circuit), 603x and 603y respectively represent selection means (circuit) in x-direction and y-direction, 604x an 604y represent transmission and reception switch circuits, 605 represents a XY switch circuit, and 606 represents a reception timing switch circuit, whereby connection switch means is formed. Reference numeral 607 represents a BPF (Band-Pass Filter) which forms a signal detection means. Reference numeral 608 represents a detector and 609 represents an LPF (Low-Pass Filter) which form coordinate detection means and writing tool or the like identification means in which a process performed by the control circuit 601 to be described later is included. Reference numerals 610 an 611 represent drive circuits, 612 and 613 represent amplifiers, and 614 represents an inverter. The operation of the sensing portion control unit 6 with the structure thereof will be described. First, the signal transmission and receipt between the sensing portion 11 and the writing tool or the like and the thus-obtained signals will be described with reference to FIG. 8. The control circuit 601 comprises a known type of a microprocessor or the like. It acts to: supply a frequency switch signals p1 and P2 (quadrual counter data) and a timing signal (start pulse) p3 to the signal generating circuit 602 in accordance with a flow chart to be described later: control the switching of the loop coils in the sensing portion 11 via the selection circuits 603x and 603y; control the switching of the coordinate detection direction performed by the XY switch circuit 605 and the reception timing switch circuit 606; analog-digital (A/D) convert the output data from the low pass filter 609 for the purpose of obtaining the coordinate of the writing tool or the like by performing calculations to be described later; and supply the frequency switch signals p1 and p2 when the above-described coordinate is obtained to the data processing unit 7, these frequency switch signals p1 and p2 serving information representing the type or the state (a state of the switch for the marker 3) of the writing tool or the like. The signal generating circuit 602 comprises a rectangular signal generators 602a, 602b, 602c, 602d, and 602e, and a multiplexer 602f for respectively generating predetermined frequencies f0, f1, f2, f3, and fk. The rectangular signals having frequencies from f0 to f3 are arranged to be input to the multiplexer 602f whose switching is controlled in response to the switch signals p1 and p2. When the switching signals p1 and P2 are "00" , the signal having the frequency f0 is output, when the same are "01", the signal having the frequency fl is output, when the same are "10", the signal having the frequency f2 is output, and when the same are "11", the signal having the frequency f3 is output, the thus-generated signal being output in the form of a rectangular signal A. The thus-output rectangular signal A is converted to a sine-wave signal by a low-pass filter (omitted from illustration), and is then supplied to either the drive circuit 610 or 611 via the XY switch circuit 605. A rectangular signal having the frequency fk, for example, 18.75 kHz, is transmitted to the transmission and reception switch circuits 604x and 604y in the form of a transmission and reception switch signal B, and is simultaneously inverted via the inverter 614 as to be transmitted to the reception timing switch circuit 606 in the form of a reception timing signal C. The rectangular signal generator 602e is reset by the start pulse p3. The selection circuit 603x successively selects a loop coil from the x-direction loop coil group 11x, while the selection circuit 603y successively selects a loop coil from the y-direction loop coil group 11y, each of these selection circuits 603x and 603y acting in response to information supplied from the control circuit 601. The transmission and reception switch circuit 604x alternately connect the thus-selected x-direction loop coil to the drive circuit 610 and the amplifier 612. The transmission and reception switch circuit 604y alternately connect the thus-selected y-direction loop coil to the drive circuit 611 and the amplifier 613. These transmission and reception switch circuits 604x and 604y act in accordance with the transmission and receipt switch signal B. It is assumed that "00" has been, together with the start pulse p3, supplied from the control circuit 601 to the signal generating circuit 602 in the form of the switch signals p1 and p2 and information to select x-direction has been input to the XY switch circuit 605 and the reception timing switch circuit 606, the sine-wave signal having the frequency f0 is supplied to the drive circuit 610 in which it is converted to an equilibrium signal before being supplied to the transmission and reception switch circuit 604x. Since this transmission and reception switch circuit 604x switches and connects either of the drive circuit 610 or the amplifier 612 in response to the transmission and reception switch signal B, a signal to be output from the transmission and reception switch circuit 604x to the selection circuit 603x becomes a signal D which intermittently outputs a sine-wave signal 600 kHz every time period T (=1/2 fk), where it is substantially 27 μsec here. This signal D is transmitted to the x-direction loop coil 11x-i (i=1, 2, . . . , 48) in the sensing portion 11 via the selection circuit 603x, this loop coil 11x-i generating an electric wave on the basis of the signal D. In this state, when the writing tool, for example, the marker 3 is held substantially vertically on the writing surface 14 of the main blackboard body 1 with the switch 331 switched off, the above-described electric wave excites the coil 332 of the marker 3 so that an induced voltage E synchronized with the signal D is generated in the tuning circuit 33 of the coil 332. When the state of the signal D is then brought to a no-signal period, that is, signal reception period and simultaneously the loop coil 11x-i is switched to the amplifier 612, the electric wave from this loop coil 11x-i is immediately eliminated. On the other hand, the above-described induced voltage E is gradually damped in accordance with loss in the tuning circuit 33. On the other hand, the electric current passing through the tuning circuit 33 in accordance with this induced voltage E causes the coil 332 to transmit an electric wave. Since the thus-transmitted electric wave excites the loop coil 11x-i connected to the amplifier 612 on the contrary, an induced voltage on the basis of the electric wave from the coil 332 is generated. The thus-generated induced voltage is transmitted from the transmission and reception switch circuit 604x to the amplifier 612 during only the signal reception period so that it is amplified to become a reception signal F, and is then transmitted to the reception timing switch circuit 606. Either of the selection information in x-direction or y-direction, the x-direction selection information and the reception timing signal C in this case, are input to the reception timing switch circuit 606. When this signal C is at the high (H) level, a reception signal F is output, while no signal is output when the same is at the low (L) level. Therefore, a signal G (substantially the same as the reception signal F) is obtained at the output of the reception timing switch circuit 606. Since this signal F is transmitted to the band-pass filter 607 which is a filter including the frequency f0 to f3 in its band-pass region, a signal H (strictly, in the state in which a plurality of signals G have been input to and converged in the band-pass filter 607) having an amplitude h in accordance with energy of the frequency components from f0 to f3 in the above-described signal G transmitted to the detector 608. The signal H input to the detector 608 is detected and rectified as to be made a signal I. Then, this signal I is converted into a direct current J having a voltage level corresponding to a half of the above-described amplitude h, for example, Vx by a low-pass filter 609 with a sufficiently low cut-off frequency as to be transmitted to the control circuit 601. The voltage level Vx of the signal J relates to the distance between the marker 3 and the loop coil 11x-i, where it is a value in inverse proportion to substantially the fourth power of the distance between the marker 3 and the loop coil 11x-i. Therefore, when the loop coil 11x-i is switched, this voltage Vx of the signal J is varied. As a result, the x-coordinate of the marker 3 can be obtained by converting, in the control circuit 601, the voltages Vx obtained for each of the loop coils into digital values and by having the thus-obtained digital values subjected to the arithmetic process to be described later. The y-coordinate of the marker 3 can be obtained similarly. On the other hand, when the marker 3 and the writing surface 14, that is the sensing portion 11, are disposed away from each other, or when the marker 3 is disposed substantially in parallel to the sensing portion 11, the electric wave transmitted from the loop coil in the sensing portion 11 does not excite the coil 332 of the marker 3. Therefore, no induced voltage E is generated in the turned circuit 33. In this state, since also no electric wave is transmitted from the coil 332 of the tuning circuit 33, no induced voltage F is generated in the loop coil of the sensing portion during signal reception so that the coordinate cannot be detected (practically, a slight level of induced voltage is generated in both the tuned circuit and the loop coil in the sensing portion, their levels are insufficient to perform the coordinate detection). The above-described frequency switch signals p1 and p2 are the values counted by the quadrual ring counter formed by a program or the like in the control circuit 601. This counter is stepped to "1" when no reception signal, that is, no induced voltage is obtained in the control circuit 601 and the detection of the coordinate is thereby impossible to be performed. The value counted at this time is, together with the start pulse p3, arranged to be transmitted in the form of the switch signals p1 and p2 to the signal generating circuit 602. Therefore, during the period in which no reception signal is obtained, the frequency of the AC signal is successively switched from f0 to f3 so that the detection of the coordinate is performed by repeating this switching of the frequency. If any reception signal is obtained, the x and y-coordinates can be obtained as described above. At this time, if the switch signal p1 and p2 are "00" or "01", that is if the frequency of the AC signal is f0 or f1, the above-described counter is not stepped so that the frequencies of the switch signals p1 and p2, that is the frequency of the AC signal is maintained intact. On the other hand, if the switch signal p1 and p2 are "10" or "11", that is if the frequency of the AC signal is f2 or f3, the above-described counter is stepped by "1" so that the frequencies of the switch signals p1 and p2, that is the frequency of the AC signal is successively switched. As described above, when the tuning circuit 22 and 20 the switch 331 of the instruction rod 2 are turned off, the tuned frequency of the tuning circuit 33 of the marker 3 is f0, when the switch 331 is switched on, the tuned frequency of the tuning circuit 33 of the marker 3 is f1, when the switch 461 is switched on, the tuned frequency of the tuning circuit 46 of the eraser 4 is f2, and when the switch 471 is switched on, the tuned frequency of the tuning circuit 47 of the eraser 4 is f3. Therefore, if the switch signals p1 and p2 representing the frequency of the AC signal are "00" when the reception signal can be obtained, a fact can be detected that the apparatus is used such that the instruction rod 2 or the pen body 32 of the marker 3 is not positioned in contact with the writing surface 14 and thereby the switch 331 is switched off. If the switch signals p1 and p2 are "01", a fact can be detected that the apparatus is used such that the pen body 32 of the marker 3 is positioned in contact with the writing surface 14 and thereby the switch 331 is switched on, that is, a fact can be detected that image is being written on the writing surface 14. If the switch signals p1 and p2 are "10" or "11", a fact can be detected that the apparatus is used such that the erasing member 45 of the eraser 4 is positioned in contact with the writing surface 14 and thereby the switch 416 or 471 is switched on, that is, a fact can be detected that the image on the writing surface is being erased. Therefore, the switch signals p1 and p2 representing the frequencies of the AC signal when the above-described reception signal is obtained serve identification information representing the type or the state of use of the writing tool which is being used on the writing surface 14. FIG. 9 is a timing diagram of an example of transition of the switch signals p1 and p2. First, when the writing tool or the like is positioned away from the writing surface 14, the switch signals p1 and p2 are successively switched as "00", "01", "10", and "11". When the writing tool or the like, for example, the marker 3 is allowed to come closer to the writing surface 14 with substantially erected, the coordinate is detected by the AC signal having the frequency f0, causing the AC signal having the frequency f0 to be generated repeatedly. Then, when the pen body 32 is brought into contact with the writing surface 14 (brought to a pen down state) between the time point t3 and t4, that is, when the switch 331 is switched on, the coordinate detection by means of the AC signal having the frequency f1 is repeatedly performed. Furthermore, when the pen body 32 of the marker 3 is moved away from the writing surface 14 (brought to a pen up state), that is, when the switch 331 is switched off, the coordinate detection by means of the AC signal having the frequency f1 is stopped. Then, a transition to frequency f2 and f3 is, similarly to the above-description, realized. The data of the switch signals p1 and p2 are, together with the obtained x and y-coordinate data, supplied to the data processing unit 7. As described above, when the switch signals p1 and p2 representing the frequency of the AC signal are "00" or "01" at the time of obtaining the reception signal, the frequency of the switch signal, that is, the frequency of the AC signal is maintained intact. The reason for this lies in that the cycle of detecting the coordinate when the instruction rod 2 or the marker 3 is used is intended to be shortened as possible for the purpose of improving following-up performance. On the other hand, when the switch signals p1 and p2 representing the frequency of the AC signal are "10" or "11" at the time of obtaining the reception signal, the frequency of the switching signal, that is, the frequency of the AC signal is successively switched. The reason for this lies in that two tuning circuits 46 and 47 having individual frequencies are sometimes operated and their coordinates thereby need to be simultaneously detected when the eraser 4 is used. In addition, the significantly excellent following-up capability is not needed with respect to the marker 3 or the like which writes image. The structure may be arranged such that the signals f0 to f3 are always and repeatedly generated regardless of the results of the coordinate detection although the coordinate-detection speed is slightly reduced. Then, the operation of the sensing portion control unit 6 will be in detail described with reference to FIGS. 10 to 12. The control circuit 601 resets the above-described quadrual counter (step sp1), transmits the thus-obtained counter data, that is, the switch signals p1 and p2 with the start pulse p3 to the signal generating circuit 602 (step sp2). transmits information for selecting x-direction to the XY switch circuit 605 and the transmission and reception switch circuit 606, transmits information for selecting the first loop coil 11x-1 from the x-direction loop coils from 11x-1 to 11x-48 in the sensing portion 11 to the selection circuit 603x, and connects the thus-selected loop coil 11x-1 to the transmission and reception switch circuit 604x. The transmission and reception switch circuit 604x alternately connects the loop coil 11x-1 to the drive circuit 610 and the amplifier 61 in response to the above-described transmission and reception switch signal B. At this time, the drive circuit 610 transmits 16 sine wave signals of 600 kHz as shown in FIG. 11A to the loop coil 11x-1 during the signal reception time period of substantially 27 μsec. The above-described switching between signal transmission and signal reception are, as shown in FIG. 11B, repeated 7 times for one loop coil, where it is 11x-1. The time period in which the signal transmission and signal reception are repeated 7 times corresponds to the selection period for one loop coil. At this time, an induced voltage can be obtained at the output of the amplifier 612 for one loop coil every reception time period of 7 times. The thus-obtained induced voltages are, as described above, transmitted to the band-pass filter 607 via the reception timing switch circuit 606, wherein the same is averaged and then is transmitted to the control circuit 601 via the detector 608 and the low-pass filter 609. The control circuit 601 inputs the output value from the above-described low-pass filter 609 after A/D converting the same as to store the same as the detected voltage related to the distance between the writing tool or the like and the loop coil 11x-1, for example as Vx1. Then, the control circuit 601 transmits information for selecting the loop coil 11x-2 to the selection circuit 603x, connects this loop coil 11x2 to the transmission and reception switch circuit 604x, obtains and stores the detection voltage Vx2 relating to the distance between the writing tool or the like and the loop coil 11x-2, successively and similarly connects the loop coils 11x-3 to 11x-48 to the transmission and reception switch circuit 604x, and stores the detection voltages Vx1 to Vx48 (however, FIG. 11C illustrates only a part of the voltages in an analog-like manner) relating to each of the distances between each of the loop coils as shown in FIG. 11C and the writing tool or the like in x-direction (step sp3). The practical detected voltages are, as shown in FIG. 12, obtained in several loop coils centering the position (xp) of the writing tool. Then, the control circuit 601 transmits y-direction selection information to the XY switch circuit 605 and the reception timing switch circuit 606, similarly switches the selection circuit 603y and the transmission and reception switch circuit 604y, and temporally stores the detected voltage relating to each of the distances between the writing tool or the like and each of the loop coils 11y-1 to 11y-30 in y-direction and obtained by A/D-converting the output value from the low-pass filter 609 (step sp4). Then, the control circuit 601 determines whether or not the level of the detected voltage which has been stored exceeds a predetermined level (step sp5). If it is below the predetermined level, the quadrual counter is stepped by "1" (step sp6), and the above-described steps sp2 to sp5 are repeated. If the same exceeds the predetermined level, the x and y-coordinates of the writing tool or the like are calculated from the thus-stored voltage level in a manner to be described later (step sp7), transmits the thus-calculated coordinates with the switch signals p1 and p2 to the data processing unit 7 (step sp8), and determines whether or not the switching signals p1 and p2 is "00" or "01" at this time (step sp9). If the same are "00" or "01", the process according to steps sp2 to sp9 are repeated with the quadrual counter maintained intact. If the same are "10" or "11", the quadrual counter is stepped by "1" (step sp6), and the processes according to steps sp2 to sp9 are repeated. As a method for calculating the x or y-coordinate, for example, the above-described coordinate xp, there is a method in which the waveforms in the vicinity of the maximal values of the above-described detected voltages Vx1 to Vx48 are approximated by an appropriate function and the coordinates of the maximal value of this function are calculated. For example, referring to FIG. 11C, when the detected voltage Vx3 of the maximal value and the detected voltages Vx2 and Vx4 disposed on both sides of the former are approximated by a quadratic function, the coordinates can be calculated as follows (where it is provided that the coordinates of the central position of each of the loop coils 11x-1 to 11x-48 are x1 to x48 and the distances between the central positions are Δx): first, from each of the voltages and the coordinates, Vx2=a(x2-xp).sup.2 +b (1) Vx3=a(x3-xp).sup.2 +b (2) Vx4=a(x4-xp).sup.2 +b (3) where a and b represent constants (a>0). Furthermore, the following equations holds: x3-x2=Δx (4) x4-x2=2Δx (5) Substituting Equations (4) and (5) into Equations (2) and (3) before rearrangement, the following equation holds: xp=x2+Dx/2 {3Vx2-4Vx3+Vx4)/(Vx2-2Vx3+Vx4)} (6) Therefore, the coordinate xp of the writing tool or the like can be calculated by performing the calculation expressed in Equation (6) by using the detected voltage of the maximal value and the detected voltages in the vicinity of this maximal value which have been obtained at the above-described level check extracted from the detected voltages Vx1 to Vx48 and the coordinates (known) of the loop coil which is disposed forward by one from the loop coil at which the detected voltage of the above-described maximal value has been obtained. FIG. 13 is a block diagram of the data processing unit 7, wherein reference numeral 71 represents a microprocessor (CPU), 72 represents a frame memory, 73 represents a overlay memory, 74, 75, 76, and 77 represent interface circuits which respectively corresponds to the operation switch 51, sensing portion control unit 6, printer 8, and display (omitted from illustration). FIG. 14 is a flow chart of the program relating to processing of image information in the data processing unit 7. Image information processing means is formed by this program and the microprocessor 71. The operation of the data processing unit 7 will now be described. The microprocessor 71 receives data comprising the x and y-coordinates and the identification information from the sensing portion control unit 6 via the interface circuit 75 (step s1), and determines whether or not the thus-received information is "00" (step s2). If the identification information is "00", the microprocessor 71 determines that the coordinates at this time are temporal positional data, and causes the character generator (omitted from illustration) to generate a cursor pattern ,for example, an arrow "↑" as to be written in an address in the overlay memory 73 which corresponds to the above-described coordinates (step s3). Since the contents of the overlay memory 73 can be lost if no data is written within a predetermined time period (usually several ms), the above-described address in which the cursor has been written is changed in accordance with the change of the coordinates transmitted from the sensing portion control unit 6. If the identification information is not "00", it is determined whether or not the same is "01" (step s4). If the identification information is "01", it is determined that the data corresponds to the image drawn on the writing surface 14 by the marker 3 so that bit "1" is written in the address in the frame memory 72 corresponding to the above-described coordinates (step s5). Contents written in the frame memory 72 can be retained if no other data is written therein. If the identification information is neither "00" nor "01", it is determined that the data is the data for determining a predetermined range on the writing surface 14 to be erased by the eraser 4 so that bit "0" is written in the address in the frame memory 72 corresponding to the predetermined range to be erased and determined by the above-described coordinates (step s6), and the image information is deleted. When a printing-out switch (omitted from illustration) of the above-described operation switches 51 is operated, the microprocessor 71 transmits the contents of the frame memory 73 to the printer 8 via the interface circuit 76 so that these contents are subjected to a hard copying process. When a display device is connected, the microprocessor 71 simultaneously reads out the contents of the frame memory 72 and the overlay memory 73 via the interface circuit 77 and simultaneously converts the contents to a video signal as to be transmitted to and displayed on the display device. When the marker 3 or the eraser 4 is used along the writing surface 14, the contents of the frame memory 72 are rewritten in accordance with the coordinates at that time. When the instruction rod 2 is used on the writing surface 14, or when the marker 3 is used such that the same does not come contact with the writing surface 14, the cursor is written in the overlay memory 73 in accordance with the coordinates at that time. Therefore, image corresponding to the image written on the writing surface 14 is displayed by dots on the frame of the display device, and the position of the instruction rod 2 or the marker 3 pointing an optional position on the writing surface 14 is indicated by the cursor. Furthermore, data received from the sensing portion control unit 6 can be transmitted to the other electronic blackboard connected by means of an interface circuit, a MODEM and communication lines for the purpose of display the similar image or cursor on the display device of the other electronic blackboard. As an alternative to the above-described embodiment in which only one type of marker comprising a black felt pen is used, a multiplicity of markers comprising the other color felt pens, for example, red, blue and so on and tuning circuits each of which having individual frequencies may be prepared, these markers being identified from the above-described identification information as to be processed on frame memories corresponding to the multiplicity of colors. FIG. 15 is a diagram of a second embodiment of the electronic blackboard according to the present invention, in which an example of a structure in which two writing surfaces are provided is illustrated. Referring to this drawing, reference numeral 15 represents a frame supported as to be rotatable with respect to the legs 16 with a support shaft 17. Each of the obverse side and the reverse side of this frame 15 can be optionally made face the direction of the surface of this drawing sheet. The frame 15 is, as shown in FIG. 16, provided with, on both sides of the sensing portion 11 thereof, honeycomb members 151 and 152 made of a non-metallic material such as a synthetic resin or the like, and boards 153 and 154 which are similarly made of a non-metallic material are disposed on both sides of the above-described honeycomb members 151 and 152. The boards 153 and 154 respectively have corresponding writing surfaces 18 and 19 which can be repeatedly used. The frame 15 and the legs 16 respectively includes couplers 91, 92, and 93 for the purpose of transmitting information therebetween. These couplers 91 to 93 are arranged such that when either of the two writing surfaces, for example, the writing surface 18 is made face the surface of this drawing sheet, the couplers 91 and 92 confront each other, while when the other one, that is, the writing surface 19 is made face the surface of this drawing sheet, the couplers 91 and 93 confront each other. These couplers 91 to 93 include, for example, light emitting diodes or phototransistors for the purpose of transmitting information by means of optical signals. According to this embodiment, the sensing portion control unit 6 is disposed within the frame 15 (for example, in the circumferential portion of the sensing portion 11) so that information to be transmitted by means of the couplers 91 to 93 becomes the above-described coordinates or identification information. A metallic member 94 and non-contact sensors 95 and 96 are respectively disposed adjacent to the above-described positions at which the couplers 91 to 93 are positioned in the frame 15 and the legs 16 so that when the writing surface 18 is made face the surface of this drawing sheet, the metallic member 94 and the non-contact sensor 95 confront each other, while when the other one, that is, the writing surface 19 is made face the surface of this drawing sheet, the metallic member 94 and the non-contact sensor 96 confront each other so that detection of the fact which one of the writing surfaces 18 and 19 is being positioned to face the surface of this drawing sheet can be readily performed, that is, a fact that which one is being used can be readily detected. The outputs from the non-contact sensors 95 and 96 are transmitted to the data processing unit 7 via an interface circuit (omitted from illustration). The power for the sensing portion control unit 6 in the frame 16 is arranged to be supplied through a mechanical and electric contact (omitted from illustration) disposed similarly to the couplers 91 to 93. According to the above-described apparatus, the vertical positions of the sensing portions 11 are made inverse between the case in which the writing surface 18 is made to face the surface of this drawing sheet and the case in which the writing surface 19 is made to face the same. Therefore, even if the same image has been written, coordinates whose vertical positions are different are output from the sensing portion control unit 6. FIG. 17 is a flow chart of a program employed in the data processing unit 7 according to the present invention. When data from the sensing portion control unit 6 is received, a fact that which one of the writing surface of the frame 15 faces the surface of this drawing sheet is detected on the basis of the outputs from the non-contact sensors 95 and 96 (step s7) and the vertical coordinate, for example, y-coordinate is used intact or is converted into a value obtained by subtracting this coordinate from the maximal value in the subject direction (step s8). Therefore, according to the present invention, both of the writing surfaces can be used in the same manner regardless of consciousness of recognizing the writing surface. According to this embodiment, the metallic member 94 and the non-contact sensor 95 and 96 form means for detecting the writing surface which is being used, while, the program and microprocessor 71 shown in FIG. 17 form coordinate conversion means. The sensing portion described in the first and second embodiments is usually formed by an insulating substrate having a printed conductive pattern as to correspond to the positions of the above-described x and y-direction loop coils. Alternatively, a structure may be employed which is arranged such that a member in which a multiplicity of conductive wires are, at predetermined intervals, held between two insulating films and the thus-held conductive wires are connected to each other so as to correspond to the positions of the x and y-direction loop coils. The most preferable example is described upon the electronic blackboard apparatus according to the present invention. For example, the loop coil for generating the electric wave and the loop coil for detecting the electric wave may be individually provided. In this case, the structure may be arranged to always generate the electric wave. Although the structure of the above-described embodiments is arranged in such a manner that one sensing portion performs both the transmission function and receiving function, a structure may be formed such that a transmitting sensing portion and a receiving sensing portion may be individually provided. It is not necessarily critical for the transmission and the reception to be subjected to the time-division treatment. For example, a structure may be arranged such that the transmission side continues the transmission and the reception side detects a predetermined electric wave from the transmission side by switching only the coils of the tuning circuit. In the foregoing, the present invention may be subject to various arrangements, modifications and detailed changes in range that they do not deviate from the spirit. Therefore, the invention should not be understood within the limited meanings without adhering to the disclosed embodiment in the specification and drawings. The present invention is in the scope of the claims and further protected in the range that it agrees with the spirit.

A characteristic and the position of an implement with a tuned circuit having one of plural resonant frequencies are determined. AC energy at the plural different resonant frequencies is supplied to a two-coordinate direction coil arrangement of a position sensing tablet. The tuned circuit changes the current flowing in the coil arrangement at the implement resonant frequency. The current change is used to signal the implement position and characteristic. The implement may be an eraser for supplying a signal to an electronic display and for removing a mark from a surface of a visual display overlaying the tablet of the eraser. A housing includes a surface for erasing the marking and two tuned circuits each having a reactance positioned close to opposite edges of the erasing surface. Two switches, when activated, cause the tuned circuits to have different resonant frequencies. The switches are respectively activated when opposite eraser edges are being pushed against the display surface. The implement may also be one of a plurality of markers, each for a different color. Another display responds to the signals to display the position and colors of the markings and selectively remove markings from areas corresponding to the eraser position.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority from and is related to the following prior application: “Enhanced Transport Layer Security Handshake For Mobile Communication Devices,” U.S. Provisional Application No. 60/227,946, filed Aug. 25, 2000. This prior application, including the entire written description and drawing figures, is hereby incorporated into the present application by reference. BACKGROUND [0002] 1. Field of the Invention [0003] This invention relates generally to the field of computer network security protocols. More particularly, the invention provides an enhanced transport layer security (“ETLS”) protocol that is especially well-suited for use with mobile communication devices, such as Personal Digital Assistants, cellular telephones, and wireless two-way e-mail communication devices (collectively referred to hereinafter as “mobile devices”). [0004] 2. Description of the Related Art [0005] Security protocols for establishing a secure connection to a computer network, such as the Internet, are known. A security protocol commonly used to securely connect to an Internet host is the Transport Layer Security (“TLS”) protocol, which was formerly known as the Secure Socket Layer (“SSL”) protocol. [0006] [0006]FIG. 1 is a signal flow diagram 10 illustrating the basic steps typically used to establish a secure connection between a client 12 and an Internet server 14 using the TLS protocol. In step 16 , an initial datagram is transmitted from the client 12 to the server 14 to establish contact and to identify the algorithms or languages that the client 12 is capable of supporting. Once the initial datagram is received, the server 14 typically accepts the connection and replies with a datagram that identifies the algorithms or languages that the server will support (step 18 ). In addition, the reply datagram from the server 14 typically includes a public key in a digital certificate that authenticates the identity of the server 14 . The digital certificate is generally acquired from a trusted third-party, such as VeriSign™ or some other certificate authority, which verifies that the public key belongs to the server 14 . In addition, the public key typically has an associated private key that is maintained only by the server 14 , whereby data encrypted with the public key can only be decrypted using the private key. [0007] In steps 20 and 22 , the client 12 negotiates a session key with the server 14 . The session key is typically a random number generated by the client 12 that is used for only one fetch-response operation between the client 12 and server 14 . The random session key is typically first used to encrypt some random data as “proof of the key.” The session key and the data are then encrypted with the public key and transmitted to the server in step 20 . The session key and “proof of key” data are decrypted by the server using its private key. The “proof of key” data is then further decrypted with the session key. Then, in step 22 , the server typically transmits the “proof of key” data back to the client 12 to establish that it has properly received and decrypted the session key. [0008] Once the TLS public key has been exchanged and a session key has been negotiated, a secure TLS socket is established, and application data may be securely transmitted between the client 12 and server 14 using the session key (step 24 ). By utilizing this four-pass handshake between a client and a server each time a communication is initiated, the TLS protocol ensures both the authenticity of the server and the originality of the transmission. For example, to illustrate the importance of originality, if a user has communicated with a bank server via a client to electronically transfer money from an account, the four-pass TLS handshake prevents the transfer operation from being repeated by “replaying” the same encrypted message from either the same client or another client if the communication was intercepted. [0009] Although the TLS protocol provides a secure connection to a server, this protocol is not well-suited for mobile applications because the datagrams transferred in the TLS four-pass handshake typically contain a relatively large amount of data that cannot be quickly transferred over a wireless network. Therefore, in order to reduce the number of datagrams transferred over the wireless network, mobile applications commonly utilize a Wireless Application Protocol (“WAP”) to establish a secure connection with an Internet server. [0010] [0010]FIG. 2 is a block diagram illustrating a typical mobile communication system 30 utilizing the Wireless Application Protocol (WAP). In this system 30 , a service request from a mobile device 32 that is addressed to a server 34 is encoded using a Wireless Transport Layer Security (WTLS) protocol and transmitted through a wireless gateway 36 to a WAP Gateway 38 , which typically acts as a proxy to the Internet. The wireless gateway and WAP gateway may or may not be co-located. Typically, the WAP Gateway 38 has its own digital certificate, signed by a trusted third-party that is used by the mobile device 32 to validate its authenticity. Once the WTLS-encrypted service request is received, the WAP Gateway 38 generally establishes a TLS connection over the Internet with the server 34 . The service request is then decrypted by the WAP Gateway 38 , re-encrypted using the TLS protocol and sent over the Internet to the server 34 . To respond to the service request, the server 34 typically transmits TLS-encrypted data to the WAP Gateway 38 , which is then decrypted and re-encrypted using the WTLS protocol and transmitted to the mobile device 32 . Although this system 30 is typically faster than the TLS protocol for mobile applications, it leaves a gap in the secure link, thereby risking that data may be intercepted while it is in plaintext format in the WAP Gateway 38 . SUMMARY [0011] A system and method for implementing an enhanced transport layer security (ETLS) protocol is provided. The system includes a primary server, an ETLS servlet and an ETLS software module. The primary server operates on a computer network and is configured to communicate over the computer network using a non-proprietary security protocol. The ETLS servlet also operates on the computer network and is securely coupled to the primary server. The ETLS servlet is configured to communicate over the computer network using an ETLS security protocol. The ETLS software module operates on a mobile device, and is configured to communicate over the computer network using either the nonproprietary security protocol or the ETLS security protocol. Operationally, the ETLS software module initially contacts the server over the computer network using the non-proprietary security protocol, and subsequently contacts the server through the ETLS servlet using the ETLS security protocol. BRIEF DESCRIPTION OF THE DRAWINGS [0012] [0012]FIG. 1 is a signal flow diagram illustrating the basic steps typically used to establish a secure connection between a client and an Internet server using the TLS protocol; [0013] [0013]FIG. 2 is a block diagram illustrating a typical mobile communication system utilizing a Wireless Application Protocol (WAP); [0014] [0014]FIG. 3 is a signal flow diagram illustrating a wireless communication between a client and a server using an enhanced transport layer security (“ETLS”) protocol; [0015] [0015]FIG. 4 is a block diagram of an exemplary ETLS system illustrating a secure connection between a mobile device and an HTTP server using the ETLS protocol; and [0016] [0016]FIG. 5 is a flow diagram of an exemplary method for securely communicating between a mobile device and a network server using the ETLS protocol. DETAILED DESCRIPTION [0017] Referring now to the remaining drawing figures, FIG. 3 is a signal flow diagram 40 illustrating a wireless communication between a client 42 and a server 44 using an enhanced transport layer security (“ETLS”) protocol. The client 42 may be any system operating on a mobile device that is capable of wirelessly accessing a computer network. The server 44 preferably includes a primary server, such as an HTTP server 46 , and an ETLS servlet 48 , both operating on a computer network, such as the Internet. The ETLS servlet 48 , discussed in more detail below with reference to FIG. 4, is preferably a JAVA™ servlet operating on the HTTP server 46 , but could alternatively be some other server-side mechanism such as a CGI script. The ETLS servlet 48 is preferably installed on the HTTP server 46 with its own uniform resource locator (URL), which is added to a custom HTTP response header along with an ETLS public key. [0018] In step 50 , the client 42 attempts to open a secure connection with the server 44 . At this point, the client 42 has not yet detected the ETLS servlet 48 , and, therefore, uses a non-proprietary security protocol such as the TLS protocol. The TLS four-pass handshake, discussed above with reference to FIG. 1, is performed in steps 50 - 56 . In steps 50 and 52 , the client 42 and the server 44 determine which operations or languages they have in common, and a TLS public key in a digital certificate is transferred to the client 42 . In steps 54 and 56 , a random TLS session key is negotiated. Then, in step 58 the initial service request from the client 42 is encrypted with the TLS session key and transmitted to the HTTP server 46 . The HTTP server 46 decrypts the service request and transmits its initial encrypted response in step 60 . Along with the encrypted data, the initial response 60 from the HTTP server 46 also includes the custom HTTP response header with the URL of the ETLS servlet 48 and the ETLS public key. The ETLS public key is preferably generated by the ETLS servlet 48 , and has an associated ETLS private key that is maintained exclusively by the ETLS servlet 48 . The client 42 preferably stores the ETLS public key and associated URL in a memory location on the mobile device. Thereafter, each time the client 42 establishes a secure connection to the server 44 , it uses the ETLS public key and associated URL to communicate through the ETLS servlet 48 . [0019] Steps 62 - 68 illustrate two secure ETLS transmissions between the client 42 and the server 44 after the ETLS public key and associated URL have been received and stored by the client 42 . To establish a secure connection using the ETLS protocol, the client 42 first establishes a random ETLS session key and encrypts it with the ETLS public key received from the custom HTTP response header. The client 42 then uses the ETLS session key to encrypt the bulk data that makes up its service request to the server 44 and also to encrypt a digital time-stamp. In step 62 , the client 42 transmits the data to the ETLS servlet, preferably in the form of an HTTP POST request that includes the encrypted session key, service request and time-stamp. Once the ETLS servlet 48 has received the HTTP POST request, the request is decrypted and compared to a connection log to establish that the transmission is original. At this point, the security of the communication has been established, and the ETLS servlet 48 may perform a fetch-response operation with the HTTP server 46 . Then, once a response from the HTTP server 46 has been returned, the ETLS servlet 48 encrypts the response with the ETLS session key and transmits it to the client 42 in step 64 . The ETLS protocol, including the operations of the digital time-stamp and the connection log, are discussed in more detail below with reference to FIG. 4. [0020] Steps 66 and 68 illustrate that each subsequent communication between the client 42 and the server 44 may be performed using the same two-step ETLS handshake described above with reference to steps 62 and 64 . In this manner, the ETLS protocol enables secure communications between a mobile device and an Internet server without requiring the lengthy, multiple transmissions commonly associated with non-proprietary security protocols, such as the TLS protocol. [0021] [0021]FIG. 4 is a block diagram of an exemplary ETLS system 70 illustrating a secure connection between a mobile device 72 and an primary server 74 using the ETLS protocol. Cross-referencing FIGS. 3 and 4, the ETLS system 70 shown in FIG. 4 illustrates the ETLS connections made in steps 62 - 68 of FIG. 3, and after the initial TLS connection shown in steps 50 - 60 of FIG. 3. The ETLS system 70 includes the mobile device 72 , the primary server 74 , a wireless gateway 76 , the ETLS servlet 78 and the connection log 80 . The primary server 74 , ETLS servlet 78 and connection log 80 are located on a computer network, such as the Internet, and are preferably protected behind a common firewall 82 . Communications between the mobile device 72 and the computer network are preferably made through the wireless gateway 76 using any known Web browser-type software designed for use on a mobile device. The mobile device 72 preferably also includes an ETLS software module 71 that is configured to establish a secure connection with the computer network using either the ETLS protocol or a nonproprietary security protocol such as the TLS protocol. [0022] To send a service request to the primary server 74 using the ETLS protocol, the mobile device 72 preferably establishes a random ETLS session key that it uses to encrypt the service request, and encrypts the session key using the stored ETLS public key for the ETLS Servlet 78 . In addition, to protect against “replay” communications, an electronic time-stamp is also preferably generated by the mobile device and encrypted using the ETLS session key. Then, the encrypted service request, session key and time-stamp are all bundled in an HTTP POST request, or some other suitable transfer mechanism, and transmitted through the wireless gateway 76 to the ETLS servlet 78 . [0023] When the HTTP POST request is received at the ETLS servlet 78 , the ETLS session key is preferably decrypted with the ETLS private key that is maintained by the ETLS servlet 78 . The ETLS session key is then used by the ETLS servlet 78 to decrypt the service request and time-stamp. Preferably, a digital certificate from the primary server 74 was received and stored by the mobile device 72 when it first contacted the primary server 74 using a nonproprietary security protocol. Therefore, the identity of the primary server 74 has already been verified. The link is not yet secure, however, because a multi-pass handshake, such as the TLS handshake, was not used to negotiate the ETLS session key and establish that the transmission is original. The ETLS servlet 78 thus preferably protects against “replay” communications by comparing the decrypted service request and time-stamp with previous transmissions stored in the connection log 80 . In this manner, if the ETLS servlet 78 receives an encrypted HTTP POST request that includes a service request and time-stamp that is identical to that of a previous transmission stored in the communication log, then the servlet 78 will recognize that the service request is not an original communication, and will preferably ignore the service request. In a preferred embodiment, the communication log stores all of the service requests and time-stamps received by the ETLS servlet 78 within a pre-determined time period. Alternatively, the ETLS servlet 78 may save only the time-stamps or some other data, such as an ordinal number, indicating the originality of the transmission. [0024] Once the HTTP POST request has been decrypted by the ETLS servlet 78 and compared with the previous transmissions stored in the connection log 80 , a secure link between the mobile device and the ETLS servlet 78 has been established. The decrypted service request may then be transmitted from the ETLS servlet 78 to the primary server 74 , which performs the desired operation and returns a response to the ETLS servlet 78 . Because the ETLS servlet 78 and the primary server 74 operate behind the common firewall 82 , the non-encrypted data may be securely transferred using a standard transfer protocol, such as HTTP. Once the response from the primary server 74 is received by the ETLS servlet 78 , it is encrypted with the ETLS session key and transmitted through the wireless gateway 76 to the mobile device 72 . At the mobile device 72 , the response is decrypted with the session key. Then, if a new service request is desired, a new session key may be generated by the mobile device 72 , and the above described process repeated. [0025] [0025]FIG. 5 is a flow diagram of an exemplary method for securely communicating between a mobile device and a network server using the ETLS protocol. The method begins at step 92 in which communication is established between a mobile device and a network server operating on a computer network, such as the Internet. Once communication with the computer network has been established, the mobile device preferably accesses an internal memory location at step 100 to determine if an ETLS public key and an ETLS servlet URL have previously been saved for the particular network server. If so, then the mobile device recognizes that a secure link may be established using an ETLS servlet operating in connection with the server, and an ETLS handshake is performed starting at step 108 . If the mobile device does not have a stored ETLS URL and public key for the server, however, then a secure socket should preferably be opened with the server using a non-proprietary security protocol, such as the TLS protocol (step 102 ). After a secure socket has been negotiated with the server, the mobile device may then send an encrypted service request to which the server may respond with an encrypted TLS response (step 104 ). If the server is equipped with an ETLS servlet (step 106 ), then the TLS response sent by the server in step 104 will preferably include a custom HTTP response header that identifies the ETLS public key and the associated URL for the ETLS servlet, which is stored on the device in step 107 . The device then waits for a request for the next connection at step 109 . If the server is not equipped with an ETLS servlet (step 106 ), however, the device preferably waits until the device requests the next connection at step 109 . [0026] At step 108 , the mobile device preferably begins the ETLS handshake by generating a session key and encrypting it with the ETLS public key previously received from the server in the custom HTTP response header. At step 110 , the service request from the mobile device and a digital time-stamp are both encrypted using the session key (step 110 ). The digital time-stamp preferably includes the time and date that the transmission takes place. Then, at step 112 , the encrypted service request, time-stamp and session key are transmitted to the ETLS servlet, preferably in the form of an HTTP POST request or some other suitable transfer mechanism. [0027] When the HTTP POST request is received by the ETLS servlet, the ETLS session key is decrypted using a private key maintained exclusively by the ETLS servlet, and the decrypted session key is then used to decrypt the service request and digital time-stamp (step 114 ). At step 116 , the digital time-stamp is compared with those of previous transmissions stored in a connection log that is maintained by the ETLS servlet. If the time-stamp matches that of a previous transmission stored in the connection log, then the transmission is not original (step 118 ), and the service request is preferably ignored by the ETLS servlet (step 120 ). If the transmission is original (step 118 ), however, then the digital time-stamp is saved to the connection log (step 122 ) to prevent the transmission from being “replayed” in subsequent communications. In alternative embodiments, both the time-stamp and service request may be stored in the connection log and compared with the HTTP POST request, or the time-stamp may be replaced with some other means for determining that the request is original, such as an ordinal number. [0028] In step 124 , a secure link has been established and a fetch-response operation is performed between the ETLS servlet and the server to perform the function indicated in the service request from the mobile device. Then, in step 126 the response from the server is encrypted by the ETLS servlet using the session key and is transmitted to the mobile device. The response is decrypted by the mobile device at step 128 , and a new service request may then be initiated by the mobile device at step 109 . [0029] The embodiments described herein are examples of structures, systems or methods having elements corresponding to the elements of the invention recited in the claims. This written description may enable those skilled in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. The intended scope of the invention thus includes other structures, systems or methods that do not differ from the literal language of the claims, and further includes other structures, systems or methods with insubstantial differences form the literal language of the claims.

A system and method for implementing an enhanced transport layer security (ETLS) protocol is provided. The system includes a primary server, an ETLS servlet and an ETLS software module. The primary server operates on a computer network and is configured to communicate over the computer network using a non-proprietary security protocol. The ETLS servlet also operates on the computer network and is securely coupled to the primary server. The ETLS servlet is configured to communicate over the computer network using an ETLS security protocol. The ETLS software module operates on a mobile device, and is configured to communicate over the computer network using either the non-proprietary security protocol or the ETLS security protocol Operationally, the ETLS software module initially contacts the server over the computer network using the non-proprietary security protocol, and subsequently contacts the server through the ETLS servlet using the ETLS security protocol.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method and system for capturing signals and to associated signal processing techniques. This invention further relates to a method and system for hands free operation of mobile or non-mobile phones. 2. Background Art In any system for capturing signals, the goal is to capture the desired signal while rejecting undesired signals. Signal processing techniques are employed to process a received input signal to enhance the desired signal while removing the undesired signals. One particular problem faced in systems for hands free operation of mobile or non-mobile phones is the acoustic echo cancellation (AEC) problem. The AEC problem is a well known problem, and it can be described as shown in FIG. 1 , where the far-end received signal (x(n)) is sent to a loud speaker inside of a car (for example). This signal is propagated by the interior of the automobile through the acoustic path (q(n)), and is fed back into the microphone generating the echo signal (c(n)). To cancel the echo signal an adaptive filter is used, where the objective is to identify the acoustic echo path (q(n)) with the adaptive filter (g(n)), and then to subtract the resultant signal (y(n)) from the microphone signal. If (g(n)=q(n)) then (y(n)=c(n)), and the subtraction of the output signal of the adaptive filter from the microphone signal will cancel the echo signal. This AEC problem has been addressed in existing applications by using different types of adaptive filter algorithms such as least mean square algorithm (LMS), normalized least mean square algorithm (NLMS), data reuse normalized least mean square algorithm (DRNLMS), recursive least square algorithm (RLS), affine projection algorithm (APA), and others. Another related problem is that an adaptive filter algorithm needs some type of control to prevent the divergence of the algorithm when far-end send and near-end receive signals are present at the same time. This divergence problem has been addressed in existing applications by introducing a double talk detector (DTD). The DTD restricts the conditions under which the adaptive filter algorithm may adapt. One particular requirement of any system is that the system must perform well in the presence of a noise signal (v(n)). In attempts to meet this requirement, a noise cancellation algorithm (NC) has been introduced. Various different approaches have been taken for implementing the NC algorithm including approaches based on spectral subtraction, Kalman filters, neural networks, and others. In another aspect, existing applications have introduced a non-linear processor (NLP). The NLP attempts to compensate for the practical problem of the adaptive filter algorithm not achieving its minimum mean square error (MSE) and for system non-linearity particularly where one of the sources is the non-linear loud speaker. Overall, existing applications have taken a variety of approaches to address acoustic echo, adaptive algorithm divergence, noise, and system non-linearity. The initial problem of acoustic echo cancellation has developed into an evolving complex problem involving a number of different design aspects. Although various approaches have been taken in addressing specific issues, the overall evolving complex problem has yet to be fully addressed. Background information may be found in S. Haykin, Adaptive Filter Theory , Prentice Hall, Upper Saddle River, N.J., 4th Edition, 2002; P.S.R. Diniz, Adaptive Filtering—Algorithms and Practical Implementation , Kluwer Academic Publishers, Dordrecht, The Netherlands, 2nd Edition, 2002; P. P. Vaidyanathan, Multirate Systems and Filter Banks , Prentice Hall Signal Processing Series, Englewood Cliffs, N.J., 1993; R. E. Crochiere, L. R. Rabiner, Multirate Digital Signal Processing , Prentice Hall, Englewood Cliffs, N.J.; S. T. Gay, J. Benesty, Acoustic Signal Processing for Telecommunication , Kluwer Academic Publishers, Dordrecht, The Netherlands, 2000; S. F. Boll, “Suppression of acoustic noise in speech using spectral subtraction,” IEEE Trans. Acoust., Speech, Signal Proc ., vol. ASSP-27, April 1979; R. B. Jeannes, P. Scalart, G. Faucon, C. Beaugeant, “Combined noise and echo reduction in hands free systems: A survey,” IEEE Trans. Speech Audio Processing , vol. 9, pp 808-820, November 2001; R. Martin, J. Altenhoner, “Coupled Adaptive Filters for Acoustic Echo Control and Noise Reduction,” Proc. ICASSP 95, pp. 3043-3046, May 1995; M. R. Petraglia, R. G. Alves, P. S. R. Diniz, “New Structures for Adaptive Filtering in Subbands with Critical Sampling,” IEEE Transactions on Signal Processing , Vol. 48, No. 12, December 2000; M. R. Petraglia, R. G. Alves, P. S. R. Diniz, “Convergence Analysis of an Oversampled Subband Adaptive Filtering Structure with Local Errors,” Proc. IEEE Int. Symp. on Circuits and Systems (ISCAS), May 2000. For the foregoing reasons, there is a need for an improved method and system for clear signal capture that provides a practical solution to this evolving complex problem. SUMMARY OF THE INVENTION It is an object of the invention to provide an improved method and system for clear signal capture. The improved method and system comprehend several individual aspects that address specific problems in improved ways. In addition, the improved method and system also comprehend a hands free implementation that is a practical solution to a very complex problem. In carrying out the invention, a method and system for clear signal capture are provided. The method and system comprehend several individual aspects that address specific problems in improved ways. In one aspect of the invention, an improved technique is used to implement acoustic echo cancellation (AEC) and noise cancellation (NC). This aspect involves using a frequency domain approach for both AEC and NC. Preferably, the input microphone signal and the speaker signal are split into subbands for independent processing. More specifically, a method of acoustic echo cancellation (AEC) and noise cancellation (NC) is provided. A microphone signal resulting from an unobservable signal corrupted by additive background noise (the near-end component) and an acoustic echo (the far-end component which is the speaker signal modified by the acoustic path) is processed in an attempt to restore the unobservable signal. At a more detailed level, the original microphone signal in the time domain is processed by an analysis filter bank to result in a frequency domain representation of the microphone signal. The speaker signal is also processed by an analysis filter bank to result in a frequency domain representation of the speaker signal. The (frequency domain) speaker signal is processed by an adaptive filter that models the echo path. The (frequency domain) microphone signal is processed by a noise cancellation filter. The output of the adaptive filter is processed by a copy of the noise cancellation filter. The outputs of the noise cancellation filter and filter copy are compared using subtraction to determine an error, and the adaptive filter that models the echo path is adapted based on the error. This approach allows the converging adaptive filter to have the benefit of noise cancelling before comparing so that the adaptive filter can better model the echo path. A second noise cancellation filter is applied to an echoless signal that is obtained by directly comparing the adaptive filter output to the microphone signal. In this way, the adaptive filter tracking benefits from the first noise cancellation filter and its copy, and the second noise cancellation filter is applied to an echoless signal obtained via direct comparison to provide the estimation of the unobservable signal. In one aspect of the invention, an improved technique is used to implement noise cancellation. A method of frequency domain-based noise cancellation is provided. A noisy signal resulting from an unobservable signal corrupted by additive background noise is processed in an attempt to restore the unobservable signal. The method comprises estimating background noise power with a recursive noise power estimator having an adaptive time constant, and applying a filter based on the background noise power estimate in an attempt to restore the unobservable signal. Preferably, the background noise power estimation technique considers the likelihood that there is no speech power in the current frame and adjusts the time constant accordingly. In this way, the noise power estimate tracks at a lesser rate when the likelihood that there is no speech power in the current frame is lower. In any case, since background noise is a random process, its exact power at any given time fluctuates around its average power. To avoid musical or watery noise that would occur due to the randomness of the noise particularly when the filter gain is small, the method further comprises smoothing the variations in a preliminary filter gain to result in an applied filter gain having a regulated variation. Preferably, an approach is taken that normalizes variation in the applied filter gain. To achieve an ideal situation, the average rate should be proportional to the square of the gain. This will reduce the occurrence of musical or watery noise and will avoid ambiance. In one approach, a pre-estimate of the applied filter gain is the basis for normalizing the adaption rate. In one aspect of the invention, an improved technique is used to address the divergence of the adaptive filter algorithm. A method of acoustic echo cancellation (AEC) is provided. A microphone signal resulting from an unobservable signal corrupted by additive background noise (the near-end component) and an acoustic echo (the far-end component which is the speaker signal modified by the acoustic path) is processed in an attempt to restore the unobservable signal. The speaker signal is processed by an adaptive filter that models the echo path. The output of the adaptive filter and the microphone signal are compared by subtraction to determine an error, and the adaptive filter that models the echo path is adapted based on the error to allow the adaptive filter to converge. The approach of this method allows the converging adaptive filter to achieve an optimal balance between dynamic tracking ability and filter divergence control. In addition, gain control may be independently performed in each subband. The method comprises controlling the adaption gain of the adaptive filter based on the ratio of far-end energy to total energy. This requires an approximation of the far-end component (or equivalently the near-end component). The result is that when far-end echo dominates, tracking occurs quickly to achieve dynamic tracking, and when near-end speech or noise dominates, tracking occurs more slowly to achieve divergence control. At a more detailed level, a preferred approach to far-end energy approximation considers the correlation between the microphone signal and the filter output signal. The preferred adaptation gain is based on a ratio of this correlation to the expected total microphone signal energy. In more detail, the adaptation gain should be proportional to the square of this ratio. In a most preferred approach, the adaptation gain control method includes further arrangements for handling exception conditions that may be present in certain applications. In these exceptions, what happens is that the far-end energy is underestimated. This could happen at system reset or when the echo path gain suddenly increases. Exception conditions are handled by assuring that the adaption rate is not overly diminished due to the resultant underestimation of the energy ratio. In another aspect of the invention, a method of residual echo reduction (RERF) is provided. This method is performed after the initial acoustic echo cancellation is performed. The target signal to the residual echo reduction filter is the main AEC filter output. The RERF is also an adaptive filter algorithm and the RERF input signal is the system input signal or alternatively a function thereof that hastens convergence of the RERF adaptation. In this way, the RERF gain effectively converges toward zero when the system input signal is mostly far-end echo causing the AEC output to converge toward zero. On the other hand, when the microphone input is mostly speech, the AEC output reflects the system input and the RERF effectively approaches unity (in the case where RERF input is the same as the microphone input). The resultant gain of the RERF is then applied directly to the AEC output signal to reduce residual echo present at the AEC output signal. At a more detailed level, this aspect of the invention comprehends controlling the RERF adaptation rate. The method comprehends a RERF adaptation rate step size control applied to the filter gain constant. The step size control is based on a weighted average of the previous gain and a look ahead. The weighting of the look ahead increases as frequency increases and provides greater flexibility at higher frequencies. In yet another aspect of the invention, a divergence control method protects the output of the system from rare divergence of the adaptive algorithm. The method is based on conservation of energy. The method may be used at any of the adaptive filters. At a more detailed level, the method involves comparing the energy of the filter output signal to the energy of the target signal. The filter output signal should have less energy than the target signal. In the event that it is concluded based on the energy comparison that the filter has diverged, the target signal bypasses the error signal and becomes the stage output. In another aspect of the invention, a hands-free implementation may involve any combinations of the various individual aspects that address specific problems. But it is to be appreciated that these individual aspects each are useful alone, as well as in combinations. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a prior art hands free implementation; FIG. 2 illustrates a subband adaptive filter structure; FIG. 3 illustrates a noise cancellation algorithm; FIG. 4 illustrates an arrangement that optimizes the AEC algorithm performance; FIG. 5 illustrates an arrangement that optimizes the AEC and NC algorithms performance; FIG. 6 illustrates main and auxiliary adaptive filters in an arrangement that overcomes deficiencies of a traditional DTD arrangement; FIG. 7 illustrates a residual echo reduction filter; FIG. 8 illustrates a divergence control system; FIGS. 9A-9B illustrate a non-linear processor implementation; and FIG. 10 illustrates a method and system for a clear signal capture in the preferred embodiment which incorporates preferred embodiments of the improved individual features. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 2 illustrates a subband adaptive filter structure. The adaptive filter algorithm used is the second-order DRNLMS in the frequency domain. The noise cancellation algorithm is illustrated in FIG. 3 , and is also implemented in the frequency domain. In this way, both the speaker and microphone signals are split into frequency subbands, the AEC and NC are implemented in frequency domain, and the output signal is transformed back to the time domain. With continuing reference to FIG. 2 , the subband adaptive filter structure used to implement the NLMS in subbands consists of two analysis filter banks, which split the speaker (x(n)) and microphone (d(n)) signals into M bands each. The subband signals are modified by an adaptive filter, after being decimated by a factor L, and the coefficients of each subfilter (G i ) are adapted independently using the individual error signal of the corresponding band (E i ). In order to avoid aliasing effects, this structure uses a down-sampling factor L smaller than the number of subbands M. The analysis and synthesis filter banks can be implemented by uniform DFT filter banks, so that the analysis and synthesis filters are shifted versions of the low-pass prototype filters, i.e. H i ( z )= H 0 ( zW M i ) F i ( z )= F 0 ( zW M i ) with i=0, 1, . . . , M−1, where H 0 (z) and F 0 (z) are the analysis and synthesis prototype filters, respectively, and W M = ⅇ - j ⁢ 2 ⁢ ⁢ π M . Uniform filter banks can be efficiently implemented by the Weighted Overlap-Add (WOA) method. The coefficient update equation for the subband structure of FIG. 2 , based on the NLMS algorithm, is given by: G i ( k+ 1)= G i ( k )+μ i ( k )[ X i *( k ) E i ( k )] where ‘*’ represents the conjugate value of X i (k), and: E i ⁡ ( k ) = D i ⁡ ( k ) - Y i ⁡ ( k ) Y i ⁡ ( k ) = X _ i T ⁡ ( k ) ⁢ G _ i ⁡ ( k ) μ i ⁡ ( k ) = μ P i ⁡ ( k ) are the error signal, the output of the adaptive filter and the step-size in each subband, respectively. Note that the step size appears normalized by the power of the reference signal. Note also that μ is a constant real value, and P i (k) is the power estimate of the reference signal X i (k), which can be obtained recursively by the equation: P i ( k+ 1)=β P i ( k )+(1−β)| X i ( k )| 2 for 0<β<1. A few observations of the illustrated subband adaptive filter can be made. If the system to be identified has N coefficients in fullband, each subband adaptive filter ( G i (k)) will be a column vector with N/L complex coefficients, as well as X i (k). D i (k), X i (k), Y i (k) and E i (k) are complex numbers. The choice of N is related to the tail length of the echo signal to cancel, for example, if fs=8 kHz, and the desired tail length is 64 ms, N=8000*0.064=512 coefficients, for the time domain fullband adaptive filter. β is related to the number of coefficients of the adaptive filter ((N−L)/N). The number of subbands for real input signals is M=(Number of FFT points)/2+1. The previous equations describe the NLMS in subband, to obtain the DRNLMS it is required to compute the “new” error signal (E i (k)) using the updated values of the subband adaptive filter coefficients, and to update again the coefficients of the subband adaptive filters, it is: Y i j ⁡ ( k ) = X _ i T ⁡ ( k ) ⁢ G _ i j - 1 ⁡ ( k ) E i j ⁡ ( k ) = D i ⁡ ( k ) - Y i j ⁡ ( k ) μ i j ⁡ ( k ) = μ j P i ⁡ ( k ) G _ i j ⁡ ( k ) = G _ i j - 1 ⁡ ( k ) + μ i j ⁡ ( k ) ⁡ [ X _ i * ⁡ ( k ) ⁢ E i j ⁡ ( k ) ] where j=2, . . . R represents the number of reuses that are in the algorithm, also known as order of the algorithm. Observe that G i 1 ( k )= G i ( k )μ i 1 ( k )=μ i ( k ) E i 1 ( k )= E i ( k ) and Y i 1 ( k )= Y i ( k ) With continuing reference to FIG. 3 , the noise cancellation algorithm considers that a speech signal s(n) is corrupted by additive background noise v(n), so the resulting noisy speech signal d(n) can be expressed as d ( n )= s ( n )+ v ( n ). Ideally, the goal of the noise cancellation algorithm is to restore the unobservable s(n) based on d(n). Unlike the AEC problem, where what needs to be removed from the microphone signal is unambiguous, the noise cancellation problem is usually not as well defined. For the purpose of this noise cancellation algorithm, the background noise is defined as the quasi-stationary noise that varies at a much slower rate compared to the speech signal. The noise cancellation algorithm is a frequency-domain based algorithm. With a DFT analysis filter bank with length (2M−2) DFT, the noisy signal d(n) is split into M subband signals, D i (k), i=0, 1 . . . , M−1, with the center frequencies uniformly spaced from DC to Nyquist frequency. Except the DC and the Nyquist bands (bands 0 and M−1, respectively), all other subbands have equal bandwidth which equals to 1/(M−1) of the overall effective bandwidth. In each subband, the average power of quasi-stationary background noise is tracked, and then a gain is decided accordingly and applied to the subband signals. The modified subband signals are subsequently combined by a DFT synthesis filter bank to generate the output signal. When combined with other frequency-domain modules (AEC for example), the DFT analysis and synthesis banks are moved to the front and back of all modules, respectively. Because it is assumed that the background noise varies slowly compared to the speech signal, its power in each subband can be tracked by a recursive estimator P NZ , i ⁡ ( k ) = ⁢ ( 1 - α NZ ) ⁢ P NZ , i ⁡ ( k - 1 ) + α NZ ⁢  D i ⁡ ( k )  2 = ⁢ P NZ , i ⁡ ( k - 1 ) + α NZ ⁡ (  D i ⁡ ( k )  2 - P NZ , i ⁡ ( k - 1 ) ) where the parameter α NZ is a constant between 0 and 1 that decides the weight of each frame, and hence the effective average time. The problem with this estimation is that it also includes the power of speech signal in the average. If the speech is not sporadic, significant over-estimation can result. To avoid this problem, a probability model of the background noise power is used to evaluate the likelihood that the current frame has no speech power in the subband. When the likelihood is low, the time constant α NZ is reduced to drop the influence of the current frame in the power estimate. The likelihood is computed based on the current input power and the latest noise power estimate: L NZ , i ⁡ ( k ) =  D i ⁡ ( k )  2 P NZ , i ⁡ ( k - 1 ) ⁢ exp ( 1 -  D i ⁡ ( k )  2 P NZ , i ⁡ ( k - 1 ) ) and the noise power is estimated as P NZ,i ( k )= P NZ,i ( k− 1)+(α NZ L NZ,i ( k ))(| D i ( k )| 2 −P NZ,i ( k− 1)). It can be observed that L NZ,i (k) is between 0 and 1. It reaches 1 only when |D i (k)| 2 is equal to P NZ,i (k−1), and reduces towards 0 when they become more different. This allows smooth transitions to be tracked but prevents any dramatic variation from affecting the noise estimate. In practice, less constrained estimates are computed to serve as the upper- and lower-bounds of P NZ,i (k). When it is detected that P NZ,i (k) is no longer within the region defined by the bounds, it is adjusted according to these bounds and the adaptation continues. This enhances the ability of the algorithm to accommodate occasional sudden noise floor changes, or to prevent the noise power estimate from being trapped due to inconsistent audio input stream. In general, it can be assumed that the speech signal and the background noise are independent, and thus the power of the microphone signal is equal to the power of the speech signal plus the power of background noise in each subband. The power of the microphone signal can be computed as |D i (k| 2 . With the noise power available, an estimate of the speech power is P SP,i ( k )=max(| D i ( k )| 2 −P NZ,i ( k ),0) and therefore, the optimal Wiener filter gain can be computed as G T , i ⁡ ( k ) = max ⁡ ( 1 - P NZ , i ⁡ ( k )  D i ⁡ ( k )  2 , 0 ) . However, since the background noise is a random process, its exact power at any given time fluctuates around its average power even if it is stationary. By simply removing the average noise power, a noise floor with quick variations is generated, which is often referred to as musical noise or watery noise. This is the major problem with algorithms based on spectral subtraction. Therefore, the instantaneous gain G T,i (k) needs to be further processed before being applied. When |D i (k)| 2 is much larger than P NZ,i (k), the fluctuation of noise power is minor compared to |D i (k)| 2 , and hence G T,i (k) is very reliable. On the other hand, when |D i (k)| 2 approximates P NZ,i (k), the fluctuation of noise power becomes significant, and hence G T,i (k) varies quickly and is unreliable. In accordance with an aspect of the invention, more averaging is necessary in this case to improve the reliability of gain factor. To achieve the same normalized variation for the gain factor, the average rate needs to be proportional to the square of the gain. Therefore the gain factor G oms,i (k) is computed by smoothing G T,i (k) with the following algorithm: G oms,i ( k )= G oms,i ( k− 1)+(α G G 0,i 2 ( k ))( G T,i ( k )− G oms,i ( k− 1)) G 0,i ( k )= G oms,i ( k− 1)+0.25×( G T,i ( k )− G oms,i ( k− 1)) where α G is a time constant between 0 and 1, and G 0,i (k) is a pre-estimate of G oms,i (k) based on the latest gain estimate and the instantaneous gain. The output signal can be computed as Ŝ ( k )= G oms,i ( k )× D i ( k ). It can be observed that G oms,i (k) is averaged over a long time when it is close to 0, but is averaged over a shorter time when it approximates 1. This creates a smooth noise floor while avoiding generating ambient speech. FIG. 4 illustrates the subband adaptive filter structure and the noise cancellation algorithm arranged to optimize AEC performance. Considering the prior art system shown in FIG. 1 , the adaptive filter algorithm comes first and the noise cancellation implementation follows. It is realized in this way because historically the adaptive filter algorithm is realized in time domain, and the noise cancellation algorithm is realized in frequency domain. Changing the order of the adaptive filter and the noise cancellation algorithms would introduce a delay at the microphone signal path caused by the NC algorithm and would also introduce a non-linearity caused by the NC algorithm. The adaptive filter cannot compensate non-linearity (because it is a linear system (FIR filter)). The arrangement of FIG. 4 overcomes these limitations by implementing the NC algorithm first and then the adaptable filter algorithm second. In this way, environmental noise is removed and the convergence rate of the adaptive filter algorithm and also the maximum echo return loss enhancement (ERLE) obtained by the system will be increased. By placing a copy of the OMS gain coefficients at the output of the subband adaptive filters, the non-linearity introduced by the OMS gain coefficients at the microphone input is compensated. In addition, by implementing the subband adaptive filter structure and noise cancellation algorithm in the frequency domain, time delay problems can be avoided. FIG. 5 illustrates the subband adaptive filter structure and the noise cancellation algorithm arranged to optimize AEC and NC performance. FIG. 4 illustrates the AEC improvement achieved by placing the NC algorithm before the AEC algorithm, but from the NC algorithm point of view, the NC algorithm could perform better if applied after removal of the echo. The FIG. 5 arrangement optimizes both algorithms at the same time. As shown, a second NC algorithm (OMS 2 block) is performed in an echoless signal. That is, the adaptive filter benefits from the presence of the OMS 1 and OMS 1 copy blocks while the OMS 2 block benefits from the adaptive filter. In this way, the output from the OMS 2 block benefits significantly in terms of AEC and NC performance. From the acoustic model illustrated in FIG. 5 , the microphone signal d(n) can be decomposed as d ( n )= d ne ( n )+ d fe ( n ) where the near-end component d ne (n) is the sum of the near-end speech s(n) and background noise v(n), and the far-end component d fe (n) is the acoustic echo, which is the speaker signal modified by the acoustic path: c(n)=q(n){circle around (x)}(n). The NLMS filter estimates the acoustic path by matching the speaker signal (x(n)) to the microphone signal (d(n)) through correlation. Because it is assumed that both near-end speech and background noise are uncorrelated to the reference signal, the adaptive filter should converge to the acoustic path q(n). However, since the NLMS is a gradient-based adaptive algorithm that approximates the actual gradients by single samples, the filter coefficients drift around the ideal solutions even after the filter converges. The range of drifting, or misadjustment, depends mainly on two factors: adaptation gain constant μ and the energy ratio between near-end and far-end components. The misadjustment plays an important role in AEC performance. When near-end speech or background noise is present, this increases the near-end to far-end ratio, and hence increases the misadjustment. Thus the filter coefficients drift further away from the ideal solution, and the residual echo becomes louder as a result. This problem is usually referred to as divergence. Traditional AEC algorithms deal with the divergence problem by deploying a state machine that categorizes the current event into one of four categories: silence (neither far-end nor near-end speech present), receive-only (only far-end speech present), send-only (only near-end speech present), and double-talk (both far-end and near-end speech present). By adapting filter coefficients during the receive-only state and halting adaptation otherwise, the traditional AEC algorithm prevents divergence due to the increase in near-end to far-end ratio. Because the state machine is based on the detection of voice activities at both ends, this method is often referred to as double-talk detection (DTD). Although working nicely in many applications, the DTD inherits two fundamental problems. First of all, it completely ignores the near-end background noise as a factor. Secondly, it only allows filter adaptation in the receive-only state, and thus cannot handle any echo path variation during other states. The DTD can get away with these problems when the background noise level is ignorable and the near-end speech is sporadic. However, when background noise becomes significant, not only the accuracy of state detection suffers, the balance between dynamic tracking and divergence prevention also becomes difficult. Therefore, a lot of tuning effort is necessary for a traditional DTD-based system, and system robustness is often a problem. Furthermore, the traditional DTD-based system often manipulates the output signal according to the detected state in order to achieve better echo reduction. This often results in half-duplex like performance in noisy conditions. To overcome the deficiency of the traditional DTD, a more sophisticated double-talk control is used in order to achieve better overall AEC performance. As discussed above, the misadjustment mainly depends on two factors: adaptation gain constant and near-end to far-end ratio. Therefore, using adaptation gain constant as a counter-balance to the near-end to far-end ratio can keep the misadjustment at a constant level and thus reduce divergence. To achieve this, it is necessary that μ ∝ ( far ⁢ - ⁢ end ⁢ ⁢ energy total ⁢ ⁢ energy ) 2 = ( E ⁢ {  d fe ⁡ ( n )  2 } E ⁢ {  d ⁡ ( n )  2 } ) 2 . When there is no near-end component, the filter adaptation is allowed to proceed at full speed. As the near-end to far-end ratio increases, the filter adaptation slows down accordingly. Finally, when there is no far-end component, the filter adaptation is halted since there is no information about the echo path available. Theoretically, this strategy achieves optimal balance between dynamic tracking ability and filter divergence control. Furthermore, because the adaptive filter in each subband is independent from the filters in other subbands, this gain control decision can be made independent in each subband and becomes more efficient. The major obstacle of this strategy is the availability of the far-end (or equivalently, near-end) component. With access to these components, there would be no need for an AEC system. Therefore, an approximate form is used in the adaptation gain control: μ i ⁢  E ⁢ { D i ⁡ ( k ) ⁢ Y i * ⁡ ( k ) }  2 E ⁢ {  D i ⁡ ( k )  2 } 2 ⁢ γ where γ is a constant that represents the maximum adaptation gain. When the filter is reasonably close to converging, Y i (k) would approximate the far-end component in the i-th subband, and therefore, E{D i (k)Y* i (k)} would approximate the far-end energy. In practice, it should be noted that the energy ratio should be limited to its theoretical range bounded by 0 and 1 (inclusively). This gain control decision works effectively in most conditions, with two exceptions which will be addressed in the subsequent discussion. From the discussion above, E{D i (k)Y* i (k)} approximates the energy of the far-end component only when the adaptive filter converges. This means that over- or under-estimation of the far-end energy can occur when the filter is far from convergence. However, increased misadjustment, or divergence, is a problem only after the filter converges, so over-estimating the far-end energy actually helps accelerating the convergence process without causing a negative trade-off. On the other hand, under-estimating the far-end energy slows down or even paralyzes the convergence process, and therefore is a concern with the aforementioned gain control decision. Specifically, under-estimation of far-end energy happens when E{D i (k)Y* i (k)} is much smaller than the energy of far-end component, E{|D fe,i (k)| 2 }. By analyzing all possible scenarios, under-estimating mainly happens in the following two situations: (1) When the system is reset, with all filter coefficients initialized as zero, Y i (k) would be zero. This leads to the adaptation gain μ being zero and the adaptive system being trapped as a result. (2) When the echo path gain suddenly increases, the Y i (k) computed based on the earlier samples would be much weaker than the actual far-end component. This can happen when the distance between speaker and microphone is suddenly reduced. Additionally, if the reference signal passes through an independent volume controller before reaching the speaker, the volume control gain would also figure into the echo path. Therefore turning up the volume would also increase echo path gain drastically. For the first situation, the adaptation gain control is suspended for a short interval right after the system reset, which helps kick-start the filter adaptation. For the second situation, an auxiliary filter ( G ′ i ((k)) is introduced to relieve the under-estimation problem. The auxiliary filter is a plain subband NLMS filter which is parallel to the main filter, as illustrated in FIG. 6 , and with the number of taps being enough to cover the main echo path. Its adaptation gain constant should be small enough such that no significant divergence would result without any adaptation gain or double-talk control mechanism. After each adaptation, the 2-norms of the main and auxiliary filters in each subband are computed: SqGa i ( k )=∥ G i ( k )∥ 2 SqGb i ( k )=∥ G ′ i ( k )∥ 2 which are estimates of echo path gain from both filters, respectively. Since the auxiliary filter is not constrained by the gain control decision, it is allowed to adapt freely all of the time. The under-estimation factor of the main filter can be estimated as RatSqG i = min ⁡ ( SqGa i ⁡ ( k ) SqGb i ⁡ ( k ) , 1 ) and the double-talk based adaptation gain control decision can be modified as μ i = min ⁡ (  E ⁢ { D i ⁡ ( k ) ⁢ Y i * ⁡ ( k ) }  2 E ⁢ {  D i ⁡ ( k )  2 } 2 × RatSqG i , 1 ) ⁢ γ . It can be observed that the auxiliary filter only affects system performance when its echo path gain surpasses that of the main filter. Furthermore, it only accelerates the adaptation of the main filter because RatSqG i is limited between 0 and 1. As discussed previously, the acoustic echo cancellation problem is approached based on the assumption that the echo path can be modeled by a linear finite impulse response (FIR) system, which means that the far-end component received by the microphone is the result of the speaker signal transformed by an FIR filter. The AEC filter uses a subband NLMS-based adaptive algorithm to estimate the filter from the speaker and microphone signals in order to remove the far-end component from the microphone signal. It can be observed that a residual echo is usually left in the output of the adaptive filter. Many factors can contribute to this. First of all, the linear FIR model might not be exactly satisfied. In addition, the echo path might be time-varying, which makes the adaptive filter lag behind no matter how fast it adapts. Finally, the misadjustment of the adaptive filter results in filter estimation error even if the model is perfect, the echo path is time-invariant, and the algorithm is fully converged. This residual echo usually makes the AEC performance unsatisfactory. Therefore, further attenuating the residual echo without significantly damaging the near-end speech is desired. A residual echo reduction (RER) filter is illustrated in FIG. 7 and is used to achieve this goal. Following the overall system structure, it works in each subband independently. For each subband, a one-tap NLMS filter is implemented with the main AEC filter output (E i (k)) as the ideal signal. If the microphone signal (D i (k)) is used as the reference signal, the one-tap filter will converge to G r , i ⁡ ( k ) = E ⁢ { E i ⁡ ( k ) ⁢ D i * ⁡ ( k ) } E ⁢ {  D i ⁡ ( k )  2 } . When the microphone signal contains mostly far-end component, most of it should be removed from E i (k) by the main AEC filter and thus the absolute value of G r,i (k) should be close to 0. On the other hand, when the microphone signal contains mostly near-end component, E i (k) should approximate D i (k), and thus G r,i (k) is close to 1. Therefore, by applying |G r,i (k)| as a gain on E i (k), the residual echo can be greatly attenuated while the near-end speech is mostly intact. To further protect the near-end speech, the input signal to the one-tap NLMS filter can be changed from D i (k) to F i (k), which is a weighted linear combination of D i (k) and E i (k) defined as F i ( k )=(1− R NE,i ( k )) D i ( k )+ R NE,i ( k ) E i ( k ) where R NE,i (k) is an instantaneous estimate of the near-end energy ratio. With this change, the solution of G r,i (k) becomes G r , i ⁡ ( k ) = E ⁢ { E i ⁡ ( k ) ⁢ F i * ⁡ ( k ) } E ⁢ {  F i ⁡ ( k )  2 } . It can be observed that when R NE,i (k) is close to 1, F i (k) is effectively E i (k), and thus G r,i (k) is forced to stay close to 1. On the other hand, when R NE,i (k) is close to 0, F i (k) becomes D i (k), and G r,i (k) returns to the previous definition. Therefore, the RER filter preserves the near-end speech better with this modification while achieving similar residual echo reduction performance. Because |G r,i (k)| is applied as the gain on E i (k), the adaptation rate of the RER filter affects the quality of output signal significantly. If adaptation is too slow, the on-set near-end speech after echo events can be seriously attenuated, and near-end speech can become ambient as well. On the other hand, if adaptation is too fast, unwanted residual echo can pop up and the background can become watery. To achieve optimal balance, an adaptation step-size control (ASC) is applied to the adaptation gain constant of the RER filter: μ r , i ⁡ ( k ) = A ⁢ ⁢ S ⁢ ⁢ C i ⁡ ( k ) ⁢ γ r A ⁢ ⁢ S ⁢ ⁢ C i ⁡ ( k ) = ( 1 - α A ⁢ ⁢ S ⁢ ⁢ C , i ) ⁢  G r , i ⁡ ( k - 1 )  2 + α A ⁢ ⁢ S ⁢ ⁢ C , i ⁢ min ⁡ (  E i ⁡ ( k )  2  F i ⁡ ( k )  2 , 1 ) . It can be observed that ASC i (k) is decided by the latest estimate of |G r,i | 2 plus a one-step look ahead. The frequency-dependent parameter α ASC,i , which decides the weight of the one-step look ahead, is defined as α ASC,i =1−exp(− M /(2 i )),i=0,1, . . . ,( M/ 2) where M is the DFT size. This gives more weight to the one-step look-ahead in the higher frequency subbands because the same number of samples cover more periods in the higher-frequency subbands, and hence the one-step look-ahead there is more reliable. This arrangement results in more flexibility at higher-frequency, which helps preserve high frequency components in the near-end speech. The divergence control system basically protects the output of the system from rare divergence of the adaptive algorithm and it is based on the conservation of energy theory for each subband of the hands free system. FIG. 8 presents the block diagram of the divergence control system and it compares in each subband the power of the microphone signal (D i (k)) with the power of the output of the adaptive filter (Y i (k)). Because energy is being extracted (the echo) from the microphone signal, the power of the adaptive filter output has to be smaller than or equal to the power of the microphone signal in each subband, if this does not happen it means that the adaptive subfilter is adding energy to the system and the assumption will be that the adaptive algorithm diverged, if it occurs the output of the subtraction block (E i (k)), is replaced by the microphone signal D i (k)). The divergence control system is also used for the subtraction blocks after OMS1 and before the RER calculation to improve the performance of the RER in case of divergence of the main adaptive filter. The objective of the comfort noise generator (CNG) is to compensate for the irregularities at the noise floor in the output signal caused by the residual echo reduction. Basically for each subband an estimate of the magnitude of the noise floor before the residual echo reduction block is made, and compared with the magnitude of the signal after the residual echo reduction block. If the magnitude of the signal after the RER block is smaller than the magnitude of the signal before the RER block, a signal with the magnitude of the result of the difference between these two signals and random phase is added to the output signal, otherwise nothing is added. Observe that the CNG proposed also can compensate existing discontinuities in frequency domain on the microphone signal, which will provide an audible improvement on the quality of the system output signal. The center-clipping also known as the non linear processor (NLP) is implemented to remove some residual echo that is still present at the output signal, it works in time domain and it basically puts to zero the samples that have absolute value smaller than a predefined threshold (Th). There are two different approaches, and they are presented in FIGS. 9A-9B . The block diagram of the complete system is presented in FIG. 10 . FIG. 10 illustrates how the different parts of the system are implemented together. The block TD-CC represents the center-clipping implementation in time domain. The block CNG represents the comfort noise generator and it is implemented in frequency domain after the RER algorithm represented by the Gr 1 . . . M−1 Copy block. While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

A method and system for clear signal capture comprehend several individual aspects that address specific problems in improved ways. In addition, the method and system also comprehend a hands-free implementation that is a practical solution to a very complex problem. Individual aspects comprehended related to echo and noise reduction, and divergence control.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This U.S. non-provisional patent application claims priority to: U.S. Provisional Application No. 62/248,463, filed on Oct. 30, 2015; U.S. Provisional Application No. U.S. 62/252,017, filed on Nov. 6, 2015; Korean Patent Application No. 10-2015-0156254, filed on Nov. 7, 2015; Korean Patent Application No. 10-2015-0156255, filed on Nov. 7, 2015; Korean Patent Application No. 10-2015-0156256, filed on Nov. 7, 2015; Korean Patent Application No. 10-2015-0156257, filed on Nov. 7, 2015; Korean Patent Application No. 10-2015-0156258, filed on Nov. 7, 2015; Korean Patent Application No. 10-2015-0185841, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185846, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185850, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185854, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185856, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185857, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185864, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185869, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0185876, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0186044, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0186153, filed on Dec. 24, 2015; Korean Patent Application No. 10-2015-0191540, filed on Dec. 31, 2015; Korean Patent Application No. 10-2016-0037235, filed on Mar. 28, 2016; Korean Patent Application No. 10-2016-0037246, filed on Mar. 28, 2016; Korean Patent Application No. 10-2016-0037255, filed on Mar. 28, 2016; U.S. Provisional Application No. U.S. 62/355,118, filed on Jun. 27, 2016; Korean Patent Application No. 10-2016-0083053, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083054, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083061, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083062, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083066, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083071, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083074, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083081, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083087, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083106, filed on Jun. 30, 2016; Korean Patent Application No. 10-2016-0083227, filed on Jul. 1, 2016; Korean Patent Application No. 10-2016-0113455, filed on Sep. 2, 2016; Korean Patent Application No. 10-2016-0113456, filed on Sep. 2, 2016; Korean Patent Application No. 10-2016-0121745, filed on Sep. 22, 2016; Korean Patent Application No. 10-2016-0129309, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129310, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129311, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129312, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129313, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129314, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129315, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129316, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129317, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129318, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129319, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129320, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129321, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129322, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129323, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129324, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0129355, filed on Oct. 6, 2016; Korean Patent Application No. 10-2016-0135195, filed on Oct. 18, 2016; and Korean Patent Application No. 10-2016-0139828, filed on Oct. 26, 2016, the entire contents of which are hereby incorporated by reference. [0002] This U.S. non-provisional patent application is directed to an air conditioning apparatus, which may include a combination(s) of one or more of any embodiment or feature disclosed in U.S. patent application Ser. Nos. 15/337,304; 15/337,451; 15/337,575; 15/337,895; 15/337,906; 15/337,914; 15/337,926; 15/337,930; 15/337,944; 15/337,974; 15/338,015; 15/338,065; 15/338,067; 15/338,093; 15/338,112; 15/338,136; 15/338,137; 15/338,146; 15/338,153; 15/338,160; 15/338,163; 15/338,257; 15/338,261; 15/338,264; 15/338,267; 15/338,270; 15/338,283; 15/338,286; and Ser. No. 15/338,292, which were filed on Oct. 28, 2016 in the United States Patent and Trademark Office, the entire contents of which are hereby incorporated by reference for any and all purposes thereof. BACKGROUND OF THE INVENTION [0003] The present invention disclosed herein relates to an apparatus for both humidification and air cleaning. [0004] Air conditioning apparatuses include air conditioners that control the temperature of air, air cleaners that remove foreign substances from air to maintain air cleanliness, humidifiers that increase humidity in the air, and dehumidifiers that reduce humidity in the air. [0005] Typical humidifiers are classified into a vibration type which atomizes water on a vibrating plate and discharges it into air and a natural evaporation type that evaporates water in a humidification filter. [0006] The natural evaporation type of humidifier is classified into a disc type of humidifier which rotates a disc using a driving force and allows water to naturally evaporate from the surface of the disc in the air and a humidification filter type of humidifier which allows water to naturally evaporate from a wet humidification medium by flowing air. [0007] In a typical humidifier, a portion of flowing air during the humidification process is filtered by a filter. [0008] However, since a typical humidifier is used only in a low humidity season and an air cleaner has no humidification function, a user needs to purchase both products. [0009] Also, since a typical humidifier has an air cleaning function as an additional function in addition to a humidification function as a main function, the air cleaning function is weak. [0010] Furthermore, there is a limitation in that a typical humidifier or air cleaner cannot separately operate the humidification or air cleaning function. SUMMARY OF THE INVENTION [0011] The present invention provides a humidification and air cleaning apparatus which can separately operate a humidification function and an air cleaning function. [0012] The present invention also provides a humidification and air cleaning apparatus which allows a user to check water drops formed on a humidification flow passage with his/her eyes and to intuitively know the humidification state. [0013] The present invention also provides a humidification and air cleaning apparatus which includes an air wash module performing humidification and disposed in an air clean module performing air cleaning, and can supply filtered air of the air clean module to the air wash module through a connection flow passage. [0014] The present invention also provides a humidification and air cleaning apparatus in which filtering and humidification of air are performed until suctioned air is discharged and in which the flow direction of air is minimized. [0015] The present invention also provides a humidification and air cleaning apparatus which can sufficiently secure the flow rate by supplying filtered air in all directions of 360 degrees when filtered air is humidified. [0016] The present invention also provides a humidification and air cleaning apparatus in which filtered air is humidified while passing a water tank humidification medium disposed at an inlet of a humidification flow passage and in which filtered air is additionally humidified while passing a discharge humidification medium disposed at an outlet of the humidification flow passage. [0017] The present invention also provides a humidification and air cleaning apparatus which washes filtered air by scattering water drops when a humidification medium is wetted. [0018] The present invention also provides a humidification and air cleaning apparatus in which a humidification medium is disposed to be spaced from water of a water tank and can maintain a dry state when humidification mode does not operate. [0019] The objectives of the present invention are not limited to the above-mentioned objectives, and other objectives that are not mentioned will be clearly understood by persons skilled in the art from the following description. [0020] Embodiments of the present invention provide humidification and air cleaning apparatuses comprising: an air clean module suctioning external air and generating filtered air by filtering suctioned external air; and an air wash module separably placed on the air clean module, supplied with filtered air from the air clean module, and humidifying filtered air, wherein: the air clean module comprises: an intake flow passage suctioning air; a filtering flow passage connected to the intake flow passage, allowing air suctioned through the intake flow passage to be filtered, and allowing filtered air to flow therein; and a clean connection flow passage connected to the filtering flow passage and providing filtered air to the air wash module; the air wash module comprises: a humidification connection flow passage to which filtered air is provided; a humidification flow passage connected to the humidification connection flow passage and supplying moisture to filtered air in order to form humidified air; and a discharge flow passage connected to the humidification flow passage and discharging humidified air to the outside; and when the air wash module is placed on the air clean module, the humidification connection flow passage and the clean connection flow passage are connected to each other. [0021] In some embodiments, the filtering flow passage may be formed in upward and downward directions and external air flows from a lower side to an upper side; the humidification flow passage is formed in upward and downward directions and filtered air flows from a lower side to an upper side; and an air guide is disposed in at least one of the clean connection flow passage and the humidification connection flow passage to change a flow direction of filtered air. [0022] In some embodiments, the air wash module may further comprises a water tank forming at least a portion of the humidification flow passage and communicating with the humidification connection flow passage, and the air guide forms at least a portion of the clean connection flow passage, and guides filtered air to the humidification connection flow passage. [0023] In some embodiments, when the air wash module is placed on the air clean module, the air guide may be disposed to cover the water tank, and the air guide may guide filtered air in all directions of 360 degrees of the water tank, and filtered air guided by the air guide may be guided to the humidification flow passage. [0024] In some embodiments, the air wash module may further comprise an air wash inlet communicating with the humidification connection flow passage and guiding filtered air to the humidification flow passage, and when the air wash module is placed on the air clean module, the humidification flow passage and the clean connection flow passage are connected to each other through the air wash inlet. [0025] In some embodiments, the air wash module may further include a water tank storing water and forming the humidification flow passage; the air clean module has a water tank insertion space receiving at least a portion of the water tank; and when the water tank is inserted into the water tank insertion space and the air wash module is placed on the air clean module, the humidification flow passage and the clean connection flow passage may be connected to each other through the air wash inlet. [0026] In some embodiments, the air wash module may further include a water tank humidification medium spaced from water stored in the water tank, and the water tank humidification medium is disposed at the air wash inlet and provides moisture to filtered air flowing to the humidification flow passage through the air wash inlet when the water tank humidification medium is wetted by being supplied with water stored in the water tank. [0027] In some embodiments, the air wash module may further include a discharge humidification medium disposed between the humidification flow passage and the discharge flow passage, and the water tank humidification medium may provide moisture to filtered air flowing from the humidification flow passage to the discharge flow passage when the water tank humidification medium is wetted by being supplied with water stored in the water tank. [0028] In some embodiments, the air wash module may further include a water supply flow passage supplied with water and guiding supplied water to the humidification flow passage, and the water supply flow passage may be disposed separately from the discharge flow passage. [0029] In some embodiments, the discharge flow passage and the water supply flow passage may be disposed at an upper part of the air wash module, and the water supply flow passage may be disposed inside the discharge flow passage. [0030] In some embodiments, the air wash module may include: a water tank storing water; an air wash inlet communicating with the humidification connection flow passage and guiding filtered air to the humidification flow passage; a watering unit spraying water stored in the water tank; and a water tank humidification medium disposed at the air wash inlet, spaced from water stored in the water tank, and wetted by water sprayed from the watering unit, and when the water tank humidification medium is wetted, may provide moisture to filtered air flowing to the humidification flow passage through the air wash inlet. [0031] In some embodiments, the air wash module may further include a discharge humidification medium disposed between the humidification flow passage and the discharge flow passage, and the water tank humidification medium may provide moisture to filtered air flowing from the humidification flow passage to the discharge flow passage when the water tank humidification medium is wetted by water sprayed from the watering unit. [0032] In some embodiments, the air clean module may have a water tank insertion space receiving at least a portion of the water tank, and when the water tank is inserted into the water tank insertion space and the air wash module is placed on the air clean module, the humidification flow passage and the clean connection flow passage may be connected to each other through the air wash inlet. [0033] In some embodiments, the humidification and air cleaning apparatus may further include an air guide disposed in at least one of the clean connection flow passage and the humidification connection flow passage and changing a flow direction of filtered air. Here, when the air wash module is placed on the air clean module, the air guide may be disposed outside the water tank insertion space, may cover the water tank insertion space, and may guide filtered air to the inside of the water tank insertion space. [0034] In some embodiments, when the air wash module is placed on the air clean module, the air guide may be disposed to cover the water tank, and the air guide may guide filtered air in all directions of 360 degrees of the water tank, and filtered air guided by the air guide may be guided to the humidification flow passage. [0035] In some embodiments, the air wash inlet may be formed in all directions of 360 degrees, and the water tank humidification medium may be disposed to cover all directions of 360 degrees in which the air wash inlet is formed. [0036] In some embodiments, the air wash module may further include a water supply flow passage supplied with water and guiding supplied water to the humidification flow passage, and the water supply flow passage may be disposed separately from the discharge flow passage. [0037] In some embodiments, the discharge flow passage and the water supply flow passage may be disposed at an upper part of the air wash module, and the water supply flow passage may be disposed inside the discharge flow passage. [0038] In some embodiments, the air wash module may further include a top cover assembly in which the discharge flow passage and the water supply flow passage are formed; the discharge flow passage may be formed in all directions of 360 degrees along an edge of the top cover assembly, and the water supply flow passage is disposed at a center of the top cover assembly; and the discharge flow passage and the water supply flow passage may all communicate with the humidification flow passage. [0039] In some embodiments, the air clean module may further include an air blowing unit allowing air to flow and comprising an air blowing flow passage formed therein, and the air blowing flow passage may be disposed between the filtering flow passage and the humidification flow passage. [0040] Embodiments of the present invention provide humidification and air cleaning apparatuses including: an air clean module suctioning external air and generating filtered air by filtering suctioned external air; and an air wash module combined with the air clean module, supplied with filtered air from the air clean module, and humidifying filtered air, wherein: the air clean module comprises: an intake flow passage suctioning air; a filtering flow passage connected to the intake flow passage, allowing air suctioned through the intake flow passage to be filtered, and allowing filtered air to flow therein; and a clean connection flow passage connected to the filtering flow passage and providing filtered air to the air wash module; the air wash module comprises: a humidification connection flow passage to which filtered air is provided; a humidification flow passage connected to the humidification connection flow passage and supplying moisture to filtered air in order to form humidified air; and a discharge flow passage connected to the humidification flow passage and discharging humidified air to the outside; and the humidification connection flow passage and the clean connection flow passage are connected to each other. BRIEF DESCRIPTION OF THE DRAWINGS [0041] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the drawings: [0042] FIG. 1 is a perspective view illustrating a humidification and air cleaning apparatus according to a first embodiment of the present invention; [0043] FIG. 2 is an exploded perspective view of FIG. 1 ; [0044] FIG. 3 is an exploded front view of FIG. 1 ; [0045] FIG. 4 is an exploded cross-sectional view of FIG. 3 ; [0046] FIG. 5 is a view illustrating an air flow of the humidification and air cleaning apparatus according to the first embodiment of the present invention; [0047] FIG. 6 is a view illustrating an air flow of the humidification and air cleaning apparatus shown in FIG. 4 ; [0048] FIG. 7 is a view illustrating an air flow of the lower body shown in FIG. 6 ; [0049] FIG. 8 is a view illustrating an air flow of the upper body shown in FIG. 6 ; and [0050] FIG. 9 is a view illustrating an air flow of the air wash module shown in FIG. 6 . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0051] Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. [0052] Hereinafter, it will be described about an exemplary embodiment of the present invention in conjunction with the accompanying drawings. [0053] Advantages and features of the present invention, and implementation methods thereof will be clarified through following embodiments described with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Further, the present invention is only defined by scopes of claims. Like reference numerals refer to like elements throughout. [0054] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. [0055] FIG. 1 is a perspective view illustrating a humidification and air cleaning apparatus according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of FIG. 1 . FIG. 3 is an exploded front view of FIG. 1 . FIG. 4 is an exploded cross-sectional view of FIG. 3 . [0056] A humidification and air cleaning apparatus according to an embodiment of the present invention may include an air clean module 100 and an air wash module 200 disposed over the air clean module 100 . [0057] The air clean module 100 may take in and filter external air, and may provide filtered air to the air wash module 200 . The air wash module 200 may be supplied with filtered air, may perform humidification to provide moisture, and may discharge humidified air to the outside. [0058] The air wash module 200 may include a water tank 300 for storing water. The water tank 300 may be separable from the air clean module 100 when the air wash module 200 is separated. The air wash module 200 may be disposed over the air clean module 100 . [0059] A user can separate the air wash module 200 from the air clean module 100 , and can clean the air wash module 200 that is separated. A user may also clean the inside of the air clean module 100 from which the air wash module 200 is separated. When the air wash module 200 is separated, the upper surface of the air clean module 100 may be opened to a user. [0060] The air clean module 100 may include a filter assembly 10 described later, and may be cleaned after the filter assembly 10 is separated from a base body 110 . [0061] A user may supply water into the air wash module 200 . The air wash module 200 may have a water supply flow passage 109 formed therein to supply water from the outside to the water tank 300 . [0062] The water supply flow passage 109 may be configured to be separated from a discharge flow passage 107 from which air is discharged. The water supply flow passage 109 may be configured to supply water into the water tank 300 at any moment. For example, even when the air wash module 200 is operating, water can be supplied through the water supply flow passage. For example, even when the air wash module 200 is coupled to the air clean module 100 , water can be supplied through the water supply flow passage. For example, even when the air wash module 200 is decoupled from the air clean module 100 , water can be supplied through the water supply flow passage. [0063] The air clean module 100 and the air wash module 200 may be connected to each other through a connection flow passage 103 . Since the air wash module 200 is separable, the connection flow passage 103 may be distributedly disposed at the air clean module 100 and the air wash module 200 . Only when the air wash module 200 is placed over the air clean module 100 , the flow passage of the air wash module 200 and the flow passage of the air clean module 100 may communicate with each other through the connection flow passage 103 . [0064] The connection flow passage formed in the air clean module 100 may be defined as a clean connection flow passage 104 , and the connection flow passage formed in the air wash module 200 may be defined as a humidification connection flow passage 105 . [0065] The flow of air passing through the air clean module 100 and the air wash module 200 will be described in more detail later. [0066] Hereinafter, the air clean module 100 and the air wash module 200 will be described in more detail. [0067] The air clean module 100 may include a base body 110 , a filter assembly 10 that is disposed in the base body 110 and filters air, and an air blowing unit 20 that blows air. [0068] The air wash module 200 may include a water tank 300 , a watering unit 400 , a humidification medium 50 , a visual body 210 , and a top cover assembly 230 . The water tank 300 may store water for humidification, and may be detachably disposed over the air clean module 100 . The watering unit 400 may be disposed in the water tank 300 , and may spray water in the water tank 300 . The humidification medium 50 may be wetted with water sprayed from the watering unit 400 , and may provide moisture to flowing air. The visual body 210 may be coupled to the water tank 300 , and may be formed of a transparent material. The top cover assembly 230 may be detachably disposed over the visual body 210 , and may include a discharge flow passage 107 through which air is discharged and a water supply flow passage 109 through which water is supplied. [0069] The air clean module 100 may include an intake flow passage 101 , a filtering flow passage 102 , an air blowing flow passage 108 , and a clean connection flow passage 104 disposed therein. Air suctioned through the intake flow passage 101 may flow to the clean connection flow passage 104 via the filtering flow passage 102 and the air blowing flow passage 108 . [0070] The air wash module 200 may include a humidification connection flow passage 105 , a humidification flow passage 106 , a discharge flow passage 107 , and a water supply flow passage 109 disposed therein. [0071] When the air wash module 200 is placed over the air clean module 100 , the clean connection flow passage 104 of the air clean module 100 and the humidification connection flow passage 105 of the air wash module 200 may be connected to each other. [0072] Filtered air supplied through the humidification connection flow passage 105 of the air wash module 200 may be discharged into the indoor via the humidification flow passage 106 and the discharge flow passage 107 . The water supply flow passage 109 may be manufactured into a structure in which air is not discharged and only water is supplied while communicating with the humidification flow passage 106 . [0073] First, each configuration of the air clean module 100 will be described. [0074] The base body 110 may include an upper body 120 and a lower body 130 . The upper body 120 may be disposed on the lower body 130 , and the upper body 120 and the lower body 130 may be assembled. [0075] Air may flow into the base body 110 . [0076] The intake flow passage 101 , the filtering flow passage 102 , and the air blowing flow passage 108 may be disposed in the lower body 130 , and structures that define the intake flow passage 101 , the filtering flow passage 102 , and the air blowing flow passage may be disposed in the lower body 130 . [0077] A portion of the connection flow passage 103 may be disposed in the upper body 120 , and structures for guiding filtered air to the air wash module 200 and structures for supporting the air wash module 200 may be disposed in the upper body 120 . [0078] The base body 110 may include the lower body 130 defining the exterior thereof and having an inlet hole 110 formed in the undersurface thereof, and the upper body 120 defining the exterior thereof and coupled to the upper side of the lower body 130 . [0079] The filter assembly 10 may be detachably assembled in the base body 110 . [0080] The filter assembly 10 may provide the filtering flow passage 102 , and may filter external air. The filter assembly 10 may have a structure that is detachable from the base body 110 in a horizontal direction. The filter assembly 10 may be disposed so as to cross the flowing direction of air that flows upstream in a vertical direction. The filter assembly 10 may slide in a horizontal direction, and may filter air that flows upward in a vertical direction. The filter assembly 10 may be disposed in a horizontal direction, and may form the filtering flow passage 102 in a vertical direction. [0081] The filter assembly 10 may slide in a horizontal direction with respect to the base body 110 . [0082] The filter assembly 10 may include a filter housing 11 disposed in the lower body 130 and forming the filtering flow passage 102 , and a filter 14 separably coupled to the filter housing 11 and filtering air passing the filtering flow passage 102 . [0083] The filter housing 12 may communicate with the intake flow passage 101 at the lower side thereof, and may communicate with the air blowing flow passage 108 at the upper side thereof. Air suctioned through the intake flow passage 101 may flow to the air blowing flow passage 108 via the filtering flow passage 102 . [0084] The filter housing 12 may be opened at one side thereof in a direction crossing the filtering flow passage 102 . The filter 14 may be detachably coupled through the opened surface of the filter housing 12 . The opened surface of the filter housing 12 may be formed in a lateral direction. The opened surface of the filter housing 12 may be disposed on the outer surface of the lower body 130 . Accordingly, the filter 14 may be inserted through the side surface of the lower body 130 , and may be located inside the filter housing 12 . The filter 14 may be disposed to cross the filtering flow passage 102 , and may filter air passing the filtering flow passage 102 . [0085] The filter 14 may be an electric duct collecting filter that collects foreign substances in the air by electrifying the filter using applied power. The filter 14 may be formed of a material that collects foreign substances in the air through a filter medium. The filter 14 may be disposed in various structures. The scope of the inventive invention is not limited to the filtering method or the filter medium of the filter 14 . [0086] The filtering flow passage 102 may be disposed in the same direction as the main flowing direction of the humidification and air cleaning apparatus. In this embodiment, the filtering flow passage 102 may be disposed in a vertical direction, and may allow air to flow in the opposite direction to gravity. That is, the main flowing direction of the humidification and air cleaning apparatus may be formed so as to direct from bottom to top. [0087] The air blowing unit 20 may be disposed over the filter housing 12 . [0088] The upper side surface of the filter housing 12 may be opened, and air passing the filtering flow passage 102 may flow to the air blowing unit 20 . [0089] The air blowing unit 20 may generate flowing of air. The air blowing unit 20 may be disposed inside the base body 110 , and may allow air to flow from the lower side to the upper side. [0090] The air blowing unit 20 may include a blower housing 150 , a blower motor 22 , and a blower fan 24 . In this embodiment, the blower motor 22 may be disposed at an upper side, and the blower fan 24 may be disposed at a lower side. The motor shaft of the blower motor 22 may direct to bottom, and may be coupled to the blower fan 24 . [0091] The blower housing 150 may be disposed inside the base body 110 . The blower housing 150 may provide a flow passage of flowing air. The blower motor 22 and the blower fan 24 may be disposed in the blower housing 150 . [0092] The blower housing 150 may be disposed over the filter assembly 10 , and may be disposed under the upper body 120 . [0093] The blower housing 150 may form the air blowing flow passage 108 therein. The blower fan 24 may be disposed in the air blowing flow passage 108 . The air blowing flow passage 108 may connect the filtering flow passage 102 and the clean connection flow passage 104 . [0094] The blower fan 24 may be a centrifugal fan, and may suction air from the lower side thereof and discharge air to the outside in a radial direction. The blower fan 24 may discharge air to the upper side and the outside in a radial direction. The outer end of the blower fan 24 may be disposed to direct to the upper side in a radial direction. [0095] The blower motor 22 may be disposed over the blower fan 24 to minimize contact with flowing air. The blower motor 22 may be installed so as to be covered by the blower fan 24 . The blower motor 22 may not be located on the airflow passage by the blower fan 24 , and may not generate a resistance against air flowing by the blower fan 24 . [0096] The upper body 120 may include an upper outer body 128 forming the exterior of the base body and coupled to the lower body 130 , an upper inner body 140 disposed inside the upper outer body 128 , having the water tank 300 inserted therein, and providing the connection flow passage 103 , and an air guide 170 coupling the upper inner body 140 and the upper outer body 128 and guiding air to the water tank 300 . [0097] Since the upper body 120 is disposed to separate the connection flow passage and the water tank insertion space, water of the water tank 300 flowing into the connection flow passage can be minimized. Particularly, since the connection flow passage is divided by the upper inner body 140 and disposed outside a space in which water is stored, water can be inhibited from flowing into the connection flow passage. [0098] The upper inner body 140 may be formed to be opened at the upper side thereof, and may receive the water tank 300 . The upper inner body 140 may form a portion of the clean connection flow passage 104 into which filtered air flows. [0099] The upper inner body 140 may have an upper inlet 121 formed therein and corresponding to an air wash inlet 31 . The upper inlet 121 may not be an essential component. It may be sufficient if the upper body 120 has a shape that exposes the air wash inlet 31 to the connection flow passage 103 . [0100] The air guide 170 may guide air supplied through the clean connection flow passage 104 to the upper inlet 121 . The air guide 170 may collect air rising along the outside of the base body 110 toward the inside. The air guide 170 may change the flowing direction of air flowing from the lower side to the upper side. However, the air guide 170 may minimize the flow resistance of air by minimizing the change angle of the flow direction of air. [0101] The air guide 170 may cover the outside of the upper inner body 140 360 degrees of a circumference of the upper inner body 140 . The air guide 170 may guide air to the water tank 300 in all directions of 360 degrees of a circumference of the water tank 300 . The air guide 170 may inwardly collect air guided along the outside of the lower body 130 , and may supply the collected air to the water tank 300 . Through this structure, the flow rate of air supplied to the water tank 300 can be sufficiently secured. [0102] Accordingly, the air guide 170 may include a guide part 172 formed in the flowing direction of air, and a change part 174 that is connected to the guide part 172 and changes the flow direction of guided air. [0103] The air guide 170 may form the connection flow passage 103 . [0104] The guide part 172 may be formed in the substantially same direction as the filtering flow passage 102 , and in this embodiment, may be formed in a vertical direction. The change part 174 may be formed in a direction crossing the filtering flow passage 102 , and in this embodiment, may be formed in a substantially horizontal direction. [0105] The change part 174 may be disposed at an upper side of the air guide 170 . The change part 174 may be connected to the guide part 172 through a curved surface. [0106] Although the change part 174 is formed in a horizontal direction, air passing the connection flow passage 103 may upwardly flow in a substantially oblique direction. The flow resistance of air can be reduced by allowing the change angle of the connection flow passage 103 and the filtering flow passage 102 to be similar to the straightly traveling direction. [0107] The lower end of the guide part 172 may be fixed to the upper outer body 128 . The upper end of the change part 174 may be fixed to the upper inner body 140 . [0108] A portion of the clean connection flow passage 104 may be formed outside the upper inner body 140 . The air guide 170 may form a portion of the clean connection flow passage 104 . Air passing the clean connection flow passage 104 may flow into the water tank 300 through the upper inlet 121 and the air wash inlet 31 . [0109] The upper inner body 140 may have a basket shape on the whole. The upper inner body 140 may have a circular shape in horizontal section, and the clean connection flow passage 104 may be formed in all directions of 360 degrees of a circumference of the upper inner body 140 . [0110] The air guide 170 may be a component for guiding filtered air to the clean connection flow passage 104 , and may be omitted in accordance with embodiments. The air guide 170 may combine the upper inner body 140 or the upper outer body 128 . [0111] The air guide 170 may be formed to cover the upper inner body 140 . Particularly, the air guide 170 may be formed to cover the upper inlet 121 , and may guide filtered air to the upper inlet 121 . When viewed from top, the air guide 170 may have a donut shape. [0112] In this embodiment, the upper end of the air guide 170 may adhere closely to the upper end of the upper inner body 140 . [0113] When viewed from top, the upper side surface of the air guide 170 may coincide with the upper side surface of the upper inner body 140 . In this embodiment, an upper inner body ring 126 may be disposed on the upper end of the upper inner body 140 to be coupled to or adhere closely to the air guide 170 . [0114] An inner body extension part 148 may be disposed to connect the upper inner body 140 and the upper inner body ring 126 . The inner body extension part 148 may be disposed in plurality. An upper inlet 121 may be formed between the inner body extension part 148 and the upper inner body ring 126 . [0115] The inner body extension part 148 may correspond to a water tank body extension part 380 . When the water tank 300 is placed, the water tank body extension part 380 may be located inside the inner body extension part 148 . The inner body extension part 148 and the water tank body extension part 380 may overlap each other inside and outside. [0116] The upper end of the air guide 170 may adhere closely to or be coupled to the upper inner body ring 126 . The lower end of the air guide 170 may adhere closely to or be coupled to the upper outer body 128 . [0117] Accordingly, air flowing through the clean connection flow passage 104 between the upper inner body 140 and the upper outer body 128 may be guided to the upper inlet 121 . [0118] The diameter of the upper inner body ring 126 and the diameter of the upper end of the air guide 170 may be the same as or similar to each other. The air guide 170 and the upper inner body ring may adhere closely to each other to prevent leakage of filtered air. The upper inner body ring 126 may be disposed inside the air guide 170 . [0119] A grip 129 may be formed on the upper outer body 128 . The air wash module 200 may be placed in the upper body, and the whole of the humidification and air cleaning apparatus can be lifted through the grip 129 . [0120] The upper inner body 140 may have the water tank insertion space 125 formed therein so as to receive the water tank 300 . [0121] The clean connection flow passage 104 may be disposed outside the upper inlet 121 , and the water tank insertion space 125 may be disposed inside the upper inlet 121 . Air flowing along the clean connection flow passage 104 may pass through the upper inlet 121 . When the water tank 300 is placed in the water tank insertion space 125 , filtered air passing through the upper inlet 121 may flow into the water tank 300 . [0122] Meanwhile, an outer visual body 214 may be coupled to the upper side of the upper body 120 . [0123] The outer visual body 214 may be a component of the visual body 210 , but in this embodiment, may be fixed to the upper body 120 . Unlike this embodiment, the outer visual body 214 may also be fixed to the air wash module 200 . Unlike this embodiment, the outer visual body 214 may be omitted. [0124] The outer visual body 214 may be fixed to the upper body 120 . In this embodiment, the outer visual body 214 may be coupled to the upper outer body 128 . The outer visual body 214 and the outer surface of the upper outer body 128 may form a continuous surface. [0125] The outer visual body 214 may be formed of a material through which a user can see the inside of the outer visual body 214 . The outer visual body 214 may be formed of a transparent or translucent material. [0126] A display module 160 may be disposed in at least one of the air clean module 100 or the air wash module 200 to display the operational state to a user. In this embodiment, the display module 160 may be disposed in the base body 110 to display the operational state of the humidification and air cleaning apparatus to a user. [0127] The display module 160 may be disposed inside the outer visual body 214 . The display module 160 may be disposed to adhere closely to the inner side surface of the outer visual body 214 . When viewed from top, the display module 160 may have a donut shape. The water tank 300 may be inserted into the display module 160 . [0128] The display module 160 may be supported by the outer visual body 214 . The inner edge of the display module 160 may be supported by the upper inner body ring 126 . The display module 160 may be disposed over the air guide 170 . The display module 160 may be manufactured integrally with a connector 260 . [0129] The display module 160 may be disposed over the air guide 170 . The display module 160 may be disposed between the upper outer body 128 and the upper inner body 140 . The display module 160 may cover the upper outer body 128 and the upper inner body 140 such that a user cannot see a gap between the upper outer body 128 and the upper inner body 140 . The inside and the outside of the display module 160 may be sealed to prevent water from permeating between the upper outer body 128 and the upper inner body 140 . [0130] The inside of the display module 160 may be supported by the upper inner body 140 , and the outside of the display module 160 may be supported by the outer visual body 218 . [0131] In this embodiment, the display 160 may have a ring shape. Unlike this embodiment, the display 160 may be formed into an arc shape. The surface of the display 160 may be formed of a material that can reflect light, or may be coated with a material that can reflect light. [0132] Accordingly, when water drops are formed on the visual body 210 , water drops formed on the visual body 210 may be projected onto or reflected by the surface of the display 160 . When the water drops formed on visual body 210 flows down, the same effect is also shown on the display 160 . [0133] This effect may give a visual stimulus to a user, and a user may intuitively recognize that humidification is being performed. The water drop image projected on the display 160 may give a refreshment feeling to a user, and may allow a user to know the humidification state. [0134] The upper side surface of the display 160 may be obliquely formed. The display 160 may be obliquely disposed toward a user. Accordingly, the inside of the display 160 may be high, and the outside thereof may be low. [0135] Hereinafter, each configuration of the air wash module 200 will be described. [0136] The air wash module 200 may increase humidity in the filtered air. The air wash module 200 may implement a rain view in the humidification flow passage 106 . The air wash module 200 may spray and circulate water in the water tank 300 . The air wash module 200 may change water into small-sized droplets, and may again wash filtered air through scattered droplets. When filtered air is washed through scattered droplets, humidification and filtering may be performed once again. [0137] The air wash module 200 may include the humidification connection flow passage 105 , the humidification flow passage 106 , the discharge flow passage 107 , and the water supply flow passage 109 . [0138] The air wash module 200 may include the water tank 300 , the watering unit 400 , the humidification medium 50 , the visual body 210 , the top cover assembly 230 , and a handle 180 . [0139] The handle 180 may be coupled to the visual body 210 , may rotate in the visual body 210 , and may be held in the visual body 210 . A user may simply lift up only the air wash module 200 through, and may separate the air wash module 200 from the air clean module 100 . [0140] The humidification connection flow passage 105 may be disposed outside the water tank 300 , and may guide air into the water tank 300 . The humidification connection flow passage 105 may be disposed outside the visual body 210 , and may guide air into the visual body 210 . [0141] The humidification connection flow passage 105 may be disposed at the outside of at least one of the water tank 300 and the visual body 210 , and may guide air into one of the water tank 300 and the visual body 210 . [0142] The discharge flow passage 107 may be disposed between the top cover assembly 230 and the visual body 210 . The discharge flow passage 107 may be disposed in at least one of the top cover assembly 230 and the visual body 210 . [0143] In this embodiment, the discharge flow passage 107 may be disposed at the outer edge of the top cover assembly 230 , and the water supply flow passage 109 may be disposed at the center of the inside of the top cover assembly 230 . [0144] In the humidification and air cleaning apparatus according to this embodiment, a power source may be connected to the air clean module 100 , and the air wash module 200 may be supplied with power through the air clean module 100 . [0145] Since the air wash module 200 has a structure separable from the air clean module 100 , the air clean module 100 and the air wash module 200 may be provided with a separable power supply structure. [0146] Since the air clean module 100 and the air wash module 200 are separably assembled through the upper body 120 , a connector 260 may be disposed in the upper body 120 to provide power for the air wash module 200 . [0147] The top cover assembly 230 of the air wash module 200 may be provided with a control part and a display which requires power. A top connector 270 may be disposed in the air wash module 200 , and may be separably connected to the connector 260 . The top connector 270 may be disposed in the top cover assembly 230 . [0148] In this embodiment, since the top cover assembly 230 is separable, the inner side surface of the visual body 210 or the inner side surface of the water tank 300 can be conveniently cleaned. [0149] The top cover assembly 230 may include the water supply flow passage 109 formed therein, and may form the discharge flow passage 107 with the visual body 210 in between. The top cover assembly 230 may be installed separably from the visual body 210 . The top cover assembly 230 may include the top connector 270 disposed therein and electrically connected to the connector 260 . [0150] When the top cover assembly 230 is placed, the top connector 270 may be disposed over the connector 260 . The top cover assembly 230 may be supplied with electricity from the connector 260 via the top connector 270 . [0151] A water level display part (not shown) may be disposed around the water supply flow passage 109 to display the water level of the water tank 300 . Thus, a user can check the water level of the water tank 300 when supplying water. By disposing the water level display part on the movement line of water supply, a user can be prevented from excessively supplying water, and the water tank 300 can be prevented from overflowing. [0152] The water level display part may be disposed in the top cover assembly 230 . The separable power supply structure of the top connector 270 and the connector 260 may achieve effective upper water supply. [0153] The water tank 300 may be separably placed in the upper body 120 . The watering unit 400 may be disposed inside the water tank 300 , and may rotate inside the water tank 300 . [0154] The water tank 300 may include a water tank body 320 storing water, an air wash inlet 31 formed at the side surface of the water tank body 320 , and a water tank body extension part 380 upwardly extending from the water tank body 320 and coupled to the visual body 210 . [0155] In this embodiment, the water tank body 320 may be formed into a cylindrical shape with an opened upper side. Unlike this embodiment, the water tank body 320 may be formed into various shapes. [0156] The water tank body extension part 380 may upwardly extend from the water tank 300 . The water tank body extension part 380 may form the air wash inlet 31 . The air wash inlet 31 may be formed between the water tank body extension parts 380 . [0157] The air wash inlet 31 may be formed in the side surface of the water tank body 320 . The air wash inlet 31 may be formed on the water tank body 320 in all directions of 360 degrees of a circumference of the water tank body 320 . The air wash inlet 31 may communicate with the humidification connection flow passage 105 . [0158] The water tank body extension part 380 may guide water flowing down from the inner side surface of the visual body 210 into the water tank 300 . The noise of dropping water can be minimized by guiding water flowing down from the visual body 210 . [0159] The water tank body extension part 380 may be coupled to the lower end of the visual body 210 . [0160] In this embodiment, the air wash inlet 31 may be formed by the configuration of the water tank body 320 . Unlike this embodiment, the air wash inlet 31 may also be formed by disposing the water tank body extension part 380 in the visual body 210 . Also unlike this embodiment, a portion of a plurality of water tank body extension parts 380 may be disposed in the water tank 300 , and other water tank body extension parts 380 may be disposed in the visual body 210 to configure the air wash inlet 31 . Unlike this embodiment, the air wash inlet 31 may also be formed in a separate configuration distinguished from the visual body 210 and the water tank 300 . Unlike this embodiment, the air wash inlet 31 may also be formed in the visual body 210 and in the water tank 300 . [0161] That is, the air wash inlet 31 may be disposed in at least one of the water tank 300 and the visual body 210 . The air wash inlet 31 may be formed by combining the water tank 300 and the visual body 210 . The air wash inlet 31 may be disposed in a separate configuration distinguished from the water tank 300 and the visual body 210 , and then the separate configuration may be disposed between the water tank 300 and the visual body 210 . The air wash inlet 31 may be formed by combination of the water tank 300 and the visual body 210 . [0162] The air wash inlet 31 may be disposed at the side of the air wash module 200 , and may be connected to the humidification flow passage 106 . The air wash inlet 31 may communicate or connect with the humidification connection flow passage 105 . [0163] The watering unit 400 may have a function of supplying water to the humidification medium 50 . The watering unit 400 may have a function of visualizing the humidification process. The watering unit 400 may have a function of implementing a rain view inside the air wash module 200 . [0164] The watering unit 400 may suction water inside the water tank 300 by rotating a watering housing 800 , may upwardly pump suctioned water, and then may spray pumped water toward the outside in a radial direction. The watering unit 400 may include the watering housing 800 that suctions water, upwardly pumps suctioned water, and then sprays pumped water toward the outside in a radiation direction. [0165] In this embodiment, the watering housing 800 may be rotated in order to spray water. Unlike this embodiment, water may also be sprayed using a nozzle instead of the watering housing. Water may be supplied to the humidification medium 50 by spraying water from the nozzle, and the rain view may be similarly implemented. According to embodiments, water may be sprayed from the nozzle, and the nozzle may be rotated. [0166] Water sprayed from the watering housing 800 may wet the humidification medium 50 . Water sprayed from the watering housing 800 may be sprayed toward at least one of the visual body 210 and the humidification medium 50 . [0167] Water sprayed toward the visual body 210 may implement a rain view. Water sprayed toward the humidification medium 50 may be used to humidify filtered air. The rain view may be implemented by spraying water toward the visual body 210 , and then water flowing down from the visual body 210 may be used to wet the humidification medium 50 . [0168] In this embodiment, a plurality of nozzles having different heights may be disposed on the watering housing 800 . Water discharged out of any one nozzle may form droplets on the inner side surface of the visual body 210 to implement a rain view, and water discharged out of another nozzle may wet the humidification medium 50 to be used for humidification. [0169] The watering housing 800 may spray water to the inner side surface of the visual body 210 , and sprayed water may flow down along the inner side surface of the visual body 210 . Droplets formed in a form of water drop may be formed on the inner side surface of the visual body 210 , and a user can see droplets through the visual body 210 . [0170] Particularly, water flowing down from the visual body 210 may wet the humidification medium 50 to be used for humidification. The humidification medium 50 may be wetted with water sprayed from the watering housing 800 and water flowing down from the visual body 210 . [0171] The visual body 210 may be coupled to the water tank 300 , and may be located over the water tank 300 . At least a portion of visual body 210 may be formed of a material through which a user can see the inside. [0172] A display module 160 may be disposed outside the visual body 210 . The display module 160 may be coupled to any one of the visual body 210 and the upper body 120 . [0173] The display module 160 may be disposed on a location where a user can observe a rain view. In this embodiment, the display module 160 may be disposed at the upper body 120 . [0174] When the air wash module 200 is placed, the outer surface of the visual body 210 may adhere closely to the display module 160 . At least a portion of the surface of the display module 160 may be formed of or coated with a material that reflects light. [0175] Droplets formed on the visual body 210 may also be projected onto the surface of the display module 160 . Accordingly, a user can observe the motion of droplets at both visual body 210 and display module 160 . [0176] The water tank 300 may include the air wash inlet 31 which is formed thereon and through which air passes. The air wash inlet 31 may be located between the connection flow passage 103 and the humidification flow passage 106 . The air wash inlet 31 may be an outlet of the connection flow passage 103 , and may be an inlet of the humidification flow passage 106 . [0177] Filtered air supplied from the air clean module 100 may flow into the air wash module 200 through the air wash inlet 31 . [0178] The humidification medium 50 may include a water tank humidification medium 51 disposed at the inlet of the humidification flow passage 106 , and a discharge humidification medium 55 disposed at the outlet of the humidification flow passage 106 . The outlet of the humidification flow passage 106 and the inlet of the discharge flow passage 107 may be connected to each other. Accordingly, the discharge humidification medium 55 may be disposed at the discharge flow passage 107 . [0179] Since the connection flow passage 103 , the humidification flow passage 106 , and the discharge flow passage 107 are not formed of structures such as duct, it may be difficult to clearly distinguish the boundaries thereof. However, the humidification flow passage 106 in which humidification is performed is defined as between the water tank humidification medium 51 and the discharge humidification medium 55 , the connection flow passage 103 and the discharge flow passage 107 may be naturally defined. [0180] The connection flow passage 103 may be defined as between the blower housing 150 and the water tank humidification medium 51 . The discharge flow passage 107 may be defined as after the discharge humidification medium 55 . [0181] In this embodiment, the water tank humidification medium 51 may be disposed at the air wash inlet 31 of the water tank 300 . [0182] The water tank humidification medium 51 may be located in at least one of the same plane, the outside, and the inside of the air wash inlet 31 . Since the water tank humidification medium 51 is wetted with water for humidification, it may be desirable that the water tank humidification medium 51 is located at the inside of the air wash inlet 31 . [0183] Water flowing down after wetting the water tank humidification medium 51 may be stored in the water tank 300 . Water flowing down after wetting the water tank humidification medium 51 may be configured so as not to flow out of the water tank 300 . [0184] Thus, the water tank humidification medium 51 may humidify filtered air passing through the air wash inlet 31 . [0185] Water that is naturally evaporated from humidification medium 50 may humidify filtered air. The natural evaporation means that water evaporates in a state where separated heat is not applied to water. As contact with air increases, as the flow velocity of air increases, as the pressure in the air decreases, the natural evaporation may be promoted. The natural evaporation may also be referred to as natural vaporization. [0186] The humidification medium 50 may promote the natural evaporation of water. In this embodiment, the humidification medium 50 may be wetted with water, but may not be immersed in the water tank 300 . [0187] Since disposed separately from water stored in the water tank 300 , the water tank humidification medium 51 and the discharge humidification medium 55 may not be always wet even though there is water stored in the water tank 300 . That is, the water tank humidification medium 51 and the discharge humidification medium 55 may become wet only during the operation of humidification mode, and the water tank humidification medium 51 and the discharge humidification medium 55 may be maintained at a dry state during the operation of air cleaning mode. [0188] The water tank humidification medium 51 may cover the air wash inlet 31 , and air may penetrate the water tank humidification medium 51 to flow into the water tank 300 . [0189] The discharge humidification medium 55 may be disposed at the outlet of the humidification flow passage 106 or at the inlet of the discharge flow passage 107 . [0190] In this embodiment, the discharge humidification medium 55 may be disposed so as to cover the upper part of the visual body 210 . The discharge humidification medium 55 may be placed on the visual body 210 . Unlike this embodiment, the discharge humidification medium 55 may be coupled to the undersurface of the top cover assembly 230 . [0191] The discharge humidification medium 55 may cover the discharge flow passage 107 , and humidified air may penetrate the discharge humidification medium 55 and then flow to the discharge flow passage 107 . [0192] On the other hand, while the separable structure of the air wash module and the air clean module has been described in this embodiment, the air wash module and the air clean module may have a combined structure in another embodiment, Also in the combined state of the air wash module and the air clean module, filtered air may be provided to the humidification flow passage through the humidification connection flow passage and the clean connection flow passage according to this embodiment. That is, the air flow passages according to this embodiment may propose an effective flow passage which can provide filtered air to the humidification flow passage. [0193] Hereinafter, the flow of air will be described with reference to the accompanying drawings. [0194] When the air blowing unit 20 operates, external air may flow into the base body 110 through the intake flow passage 101 formed at a lower side of the base body 110 . Air suctioned through the intake flow passage 101 may sequentially pass the air clean module 100 and the air wash module 200 while moving upward, and may be discharged to the outside through the discharge flow passage 107 formed at an upper side of the air wash module 200 . [0195] Air suctioned to the intake flow passage 101 may pass the filtering flow passage 102 of the filter assembly 10 , and the filter assembly 10 may filter external air. [0196] Air passing the filtering flow passage 102 may flow to the connection flow passage through the air blowing unit 20 . Air passing the filtering flow passage 102 may flow into the air blowing flow passage 108 . [0197] The filtered air may be pressurized by the blower fan 24 in the air blowing flow passage 108 , and then may flow to the clean connection flow passage 104 . [0198] Since the air blowing unit 20 is disposed next to the filtering flow passage 102 , the air blowing unit 20 may pressurize and blow filtered air. Through the arrangement relation of the filter assembly 10 and the air blowing unit, adherence of foreign substances like dust on the blower fan 24 can be minimized. [0199] When the air blowing unit 20 is disposed at the front of the filtering flow passage 102 , external air may first contact the blower fan 24 , and thus the possibility that foreign substances adhere to the blower fan 24 may increase. When the blower fan 24 is contaminated with foreign substances, a user needs to periodically clean the blower fan 24 , and a structure for cleaning the blower fan 24 may be needed. [0200] Since the air blowing unit 20 according to this embodiment blows filtered air from which foreign substances are removed, a separate cleaning may not be needed. [0201] Also, since the air blowing unit 20 is disposed at the front of the humidification flow passage 106 , adherence of moisture on the surface of the blower fan 24 can be minimized. When moisture adheres to the surface of the blower fan 24 , foreign substances may adhere to the surface of the blower fan 24 or molds grow on the blower fan 24 . [0202] Since the air blowing unit 20 is disposed at the rear of the filtering flow passage 102 and at the front of the humidification flow passage 106 , the contamination of the air blowing unit 20 can be minimized. [0203] The connection flow passage 103 may include the clean connection flow passage 104 formed in the air clean module 100 and the humidification connection flow passage 105 formed in the air wash module 200 . [0204] When the air wash module 200 is placed on the upper body 120 , the clean connection flow passage 104 and the humidification connection flow passage 105 may be connected to each other. When the air wash module 200 is in a separated state, the clean connection flow passage 104 and the humidification connection flow passage 105 may be exposed to the outside. [0205] The clean connection flow passage 104 may be formed in the upper body 120 , and the humidification connection flow passage 105 may be formed in the air wash module 200 . [0206] The clean connection flow passage 104 and the humidification connection flow passage 105 may also be formed in a form of duct to form a clear flow passage. In this embodiment, the connection flow passage 103 may distributedly disposed in the structure of the upper body 120 and the structure of the water tank 300 . [0207] The connection flow passage 103 may also be formed using a configuration such as duct. However, when air is supplied into the water tank 300 through a structure such as duct, the flow resistance may significantly increase due to the duct, and it may be difficult to secure a sufficient flow rate. When the flow rate supplied into the water tank 300 is limited, RPM of the blower fan 24 needs to increase, and thus power consumption and noise may increase. [0208] In this embodiment, the connection flow passage 103 may provide air to the water tank 300 in all directions of 350 degrees, thereby securing a sufficient flow rate. [0209] Filtered air passing the air blowing flow passage 108 may flow into the clean connection flow passage 104 formed in the upper body 120 . The air guide 170 may be disposed in the clean connection flow passage 104 of the upper body 120 to minimize the change of the flow direction of filtered air. The air guide 170 may minimize the change angle of filtered air that flows. [0210] In this embodiment, since the upper inner body 140 forming the water tank insertion space 125 is disposed in the upper body 120 , the clean connection flow passage 104 may be directly connected to the air wash inlet 31 . [0211] Unlike this embodiment, when the height of the upper inner body 140 is small or zero, the outer wall of the water tank 300 may provide the humidification connection flow passage 105 . In other words, when there is only the bottom 141 of the upper inner body 140 and no side wall of the upper inner body 140 , the outside of the side wall of the water tank 300 may provide the humidification connection flow passage 105 , and the inner side of the air guide 170 may provide the clean connection flow passage 104 . Also, when the water tank 300 is placed on the bottom 141 , the connection flow passage 103 may be connected. [0212] In this embodiment, filtered air of the clean connection flow passage 104 may sequentially pass the upper inlet 121 and the air wash inlet 31 , and then may pass the water tank humidification medium 51 to flow into the humidification flow passage 106 . [0213] The humidification flow passage 106 may be a section in which moisture is supplied to filtered air. In this embodiment, the humidification flow passage 106 may be a flow passage or a space from the water tank humidification medium 51 to the discharge humidification medium 55 . [0214] In the humidification flow passage 106 , humidification may be performed through various paths. [0215] First, in a process where filtered air passes the water tank humidification medium 51 , moisture of the water tank humidification medium 51 may be naturally evaporated, and filtered air may be supplied with moisture. [0216] Second, filtered air may be supplied with moisture by water drops scattered from the watering unit 400 . [0217] Third, humidification may be performed by moisture that is evaporated in the water tank 300 . [0218] Fourth, also in a process where filtered air passes the discharge humidification medium 55 , water wetting the discharge humidification medium 55 may be naturally evaporated, and thus filtered air may be supplied with moisture. [0219] Thus, when passing the humidification flow passage 106 , filtered air may be supplied with moisture through various paths. [0220] Air passing the discharge humidification medium 55 may be exposed to the outside through the discharge flow passage 107 . [0221] Air that is filtered and humidified may be discharged through the discharge flow passage 107 . The discharge flow passage 107 may discharge air in all directions of 360 degrees with respect to the upper side and inclined direction. [0222] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The preferred embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention. [0223] A humidification and air cleaning apparatus according to an exemplary embodiment of the present invention has at least one of the following effects. [0224] First, filtered air is generated in the filtered air, and the filtered air is supplied to perform humidification in the air wash module. Also, when a user wants, the air wash module can be separated from the air clean module. [0225] Second, scattering water drops can wash air passing the humidification flow passage. [0226] Third, the air guide can be disposed in the connection flow passage to guide filtered air to the humidification flow passage, and the change angle of air can be minimized through the air guide. Thus, the flow resistance of air can be minimized. [0227] Fourth, the air clean module for filtering air and the air wash module for humidification of air can be separably configured, and only the air wash module that contacts water can be separated for cleaning. [0228] Fifth, a user can check water drops formed on the humidification flow passage with his/her eyes, and thus can intuitively recognize that humidification is being performed. [0229] Sixth, the flow direction of air can form a substantially straight line in the intake flow passage, the filtering flow passage, the humidification flow passage and the discharge flow passage, and the change of the flow direction of air can be minimized in the connection flow passage, thereby minimizing the flow resistance of air. [0230] Seventh, the humidification medium for humidifying filtered air may be spaced from water, and the humidification medium can be maintained at a dry state when humidification mode is not used. [0231] Eighth, the humidification mediums are disposed at both inlet and outlet of the humidification flow passage, and filtered air can be allowed to pass each humidification medium, thereby securing sufficient humidification. [0232] Ninth, since filtered air is supplied in all directions of 360 degrees of the humidification flow passage, the flow rate of air can be sufficiently secured. [0233] Tenth, when the watering unit disposed in the humidification flow passage operates, a rain view effect can be implemented as if it rains in the humidification flow passage, and a user can directly check the rain view with his/her eyes. [0234] Eleventh, when a rain view effect is implemented, a sound as if it actually rains can be created, thereby stabilizing the mind and body. [0235] Twelfth, since the discharge flow passage and the water supply flow passage are separated, water can be prevented from scattering to the outside together with discharged air even though water is supplied when humidification is performed. [0236] The effects of the present invention are not limited to the above; other effects that are not described herein will be clearly understood by the persons skilled in the art from the following claims. [0237] The above-disclosed subject matter is to be considered illustrative and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an air cleaner and an air washer coupled to the air cleaner.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the carpentry art and, more particularly, to the fabrication of wood joints. 2. Description of the Prior Art Conventional types of wood joints include butt, miter, rabbet, tongue and groove, mortise and tenon, and dado. Each type of joint has a particular use depending upon material, cost, and desired appearance. The butt, rabbet, and miter joints are inexpensive to fabricate and may be utilized with virtually any kind of wood material. However, they tend to be weak. The tongue and groove, mortise and tenon, and dado joints are more expensive and complicated to produce and require the use of solid woods. However, they are strong and stable and thus far superior to the butt, miter, and rabbet joints. The increasing use of laminated materials has presented additional problems to carpenters because laminates tend to separate in the joints no matter what type of joint is used. The mortise and tenon, tongue and groove, and dado joints are virtually eliminated from use with laminated woods because of the tendency of the laminates to separate when the necessary angular cuts are made in the materials. The butt, miter, and rabbet joints have therefore become the standard types of joints where laminated materials are brought together. As noted above, these types of joints tend to be weak and are unsatisfactory where strong connections are required. The increasing scarcity of solid woods has forced the use of laminated wood products. One of the major reasons for the increasing scarcity of solid woods is that higher utilization of a given log may be achieved by peeling the log into thin veneers and then forming the veneers together into stiff laminated boards instead of by cutting the log into solid wood planks. Thus, economic necessity has forced the utilization of increasing amounts of laminates and in turn created an increasing demand for a strong joint to connect two laminated pieces of wood together. Another problem with conventional joints is that they tend to destroy the aesthetic harmony of the wood structure as a whole by their practical requirements. Only the miter joint disappears into the materials of the joint. The problem with the miter joint is that it is relatively weak and unstable. All of the other joints present unsightly lines in the finished product. SUMMARY OF THE INVENTION Accordingly, it is the primary object of the present invention to provide an improved laminated wood joint. It is another object of the present invention to create a joint for laminated woods having a strength equal to that of the laminated woods themselves. It is another object of the invention to provide a joint for laminated woods which is aesthetically pleasing. It is another object of the invention to provide a joint for laminated woods which minimizes the separation of the laminates in the joint. It is still another object of the present invention to provide a joint for laminated woods which is easy to fabricate. It is another object of the invention to provide a joint for laminated woods which is inexpensive to fabricate. These and other objects of the present invention are realized in the preferred embodiment as described in detail hereinafter. In the preferred embodiment, the laminated wood coupling arrangement is fabricated by selecting wood strips having predetermined thicknesses and widths and then interweaving them together in a predetermined pattern in the joint area to produce a strong and attractive joint. For purposes of illustration simple wood strips having square ends are described. Complicated angular relationships between the wood strips to form joints having angles of intersection other than 90° are also possible. The joints may be carved into any desired shape such as a curve after lamination. A minimum of four wood strips are selected each having upper, lower, front, rear, first side, and second side planar surfaces. In the preferred embodiment the front surfaces are perpendicular to the sides and upper and lower surfaces. The upper and lower planar surfaces are perpendicular to the side surfaces. In order to fabricate the joint, the wood strips in the same layer across the joint must have the same thickness. Likewise, the wood strips in each leg on either side of the joint should have the same width unless a desired visual effect is sought. The construction of the joint is best described by an explanation of the fabrication steps. As each strip is placed against another strip or on top of another strip, a bonding means such as glue is added to create a unitary structure which is cured by heat and pressure after the building process is completed. Thus, if four wood strips are utilized, the resulting wood coupling arrangement has two layers of lamination. The initial fabrication step is to place the first strip down on a suitable surface. The second strip is then placed at 90° to the first strip with the front surface of the first strip aligned with the second side surface of the second strip and with the rear surface of the second strip abutting the first side surface of the first strip. A simple L configuration is created by the placement of the two wood strips. The first layer of the lamination is thereby created. The second layer of the lamination is made by laying the sixth wood strip (the numbering of the wood strips is determined by the most complicated structure which is described below) on top of the second wood strip and over the front end of the first wood strip of the first layer so that the sixth wood strip covers the butt joint between the two wood strips in the first layer. The sixth wood strip extends to the second side surface of the first wood strip of the layer below. A fifth wood strip is then placed on top of the first wood strip and abutting the first side surface of the sixth wood strip. The second layer of the wood lamination is thereby created with the second layer superimposed on and aligned with the first layer. Additional layers may be added to create any desired strength or aesthetic appearance. All additional layers repeat the pattern of the first two layers. For purposes of further description of the invention, all layers which are identical to the first layer are identified as the first portion of the lamination. All layers which are identical to the second layer are identified as the second portion of the lamination. Thus, as the lamination is constructed, the initial first portion is first laid down. The initial second portion is placed on next. If desired, a new first portion is placed on top of the second portion. Then if desired, an additional second portion is added on top of the new first portion. Additional first and second portions may be added in an alternating arrangement to create any desired number of layers. A five layer arrangement has many advantages over other combinations for several reasons: 1. two intersecting wood strips from one leg are bound on the outside by two intersecting wood strips from the other leg thereby providing equal strength in the joint from each leg; 2. the central layer is surrounded on either side by an equivalent amount of material which provides an aesthetic balance; 3. a minimum number of separate layers is utilized to achieve the desired strength characteristics and aesthetic balance in comparison to 7, 9, or 11 layer combinations; and 4. the central layer may be provided with a colored edge to create an attractive aesthetic appearance or, alternatively, the paired second and fourth or first and fifth layers may be colored to create this desired balanced appearance. If desired, an additional finish layer may be placed on the outside with the grain all running in the same direction. The two legs are thus made to appear to be cut from one piece of wood. This finish layer may be an extremely thin veneer of natural wood or it may be plastic. A similar thin finish layer may be placed on the opposite side with the grain running in the same direction to create a similar appearance. To this point, the preferred embodiment of the present invention has been described as a simple L structure. Instead of an L structure, the wood strips may be assembled into a V structure having any desired angular relationship between the two legs of the V. An additional third leg may be added to one of the legs of the L to create a wood form in the shape of the letter U. The addition of a fourth leg connecting the first and third legs creates a structure having the shape of a square letter O. Any other combination is also possible requiring the connection of two or more pieces of wood. Bending of the laminates as they are constructed makes possible the creation of three dimensional structures. It would be possible, for example, to construct the entire frame for a chair from a unitarily laminated wood composition combining the present state of the art bending techniques and the unique wood coupling arrangement of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of the assembly of wood strips in accordance with the present invention. FIG. 2 is a side elevational view perpendicular to the rignt side of FIG. 1. FIG. 3 is a perspective view of the assembled embodiment illustrated in FIGS. 1 and 2. FIG. 4 is a perspective view of another embodiment of the present invention. FIG. 5 is an exploded view of another embodiment of the present invention. FIG. 6 is a perspective view of the embodiment shown in FIG. 5. FIG. 7 is an exploded view of another embodiment of the present invention. FIG. 8 is a perspective view of the embodiment shown in FIG. 7. FIG. 9 is a perspective view of another embodiment of the present invention. FIG. 10 is a perspective view of another embodiment of the present invention. FIG. 11 is an enlarged side elevational view of the embodiment shown in FIG. 9 in the direction of arrows 11. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the various figures of the drawing, there is illustrated in FIGS. 1, 2, and 3 a preferred embodiment of a laminated wood coupling arrangement generally designated 10 of the present invention showing an assembly of a plurality of layers 12. FIG. 1 shows an exploded view of arrangement 10. First portion 14 of said plurality of layers 12 has first wood strip 16 and second wood strip 18. Second portion 20 has fifth wood strip 22 and sixth wood strip 24 (the numbering of the wood strips is determined by the most complicated structure shown in FIG. 7 below). As shown in FIGS. 1 and 2, first portion 14 is repeated three times in arrangement 10. Second portion 20 is repeated two times in arrangement 10. Each first portion 14 is identical to every other first portion 14 and every second portion 20 is identical to every other second portion 20. While a total of five first and second portions 14 and 20 are illustrated in FIGS. 1 and 2, at least one of each is required to have the laminated wood coupling arrangement 10 and any number could be added depending upon the desired strength requirement and aesthetic appearance. If there are only two layers, either portion may be above or below the other. Each of the wood strips 16, 18, 22, and 24 have an upper planar surface 26, a lower planar surface 28 spaced a transverse distance from and parallel to upper planar surface 26 with the transverse distance defining the thickness 30 of the given wood strip. All of the upper planar surfaces shown on all of the wood strips in FIGS. 1 through 3 of the drawing are upper planar surface 30 as designated only on first wood strip 16. Likewise, all lower planar surfaces of all the wood strips in FIGS. 1 through 3 are lower planar surfaces 28 as is designated only on first wood strip 16. Thus, while each upper and lower planar surface throughout all of the figures could have been designated with the appropriate number, only first wood strip 16 is actually marked with a numerical designation in order to avoid confusion and unnecessary clutter in the figures. Front surface 32 is longitudinally spaced from rear surface 34 with the longitudinal distance defining the length 36 of any given wood strip. As noted in the immediately preceeding paragraph, for purposes of clarity only first wood strip 16 has been marked with the numerical designations of front surface 32, rear surface 34, and length 36. All other wood strips in FIGS. 1 through 3 could have been marked. Rear surface 34 is always encountered first when the figure is viewed in a clockwise direction. Front surface 32 is the ending surface as the eye travels along any given wood strip in the clockwise direction through the figure. Thus, using sixth wood strip 24 as an example, rear surface 34 is first encountered when the eye moves in a clockwise direction from fifth wood strip 22 onto sixth wood strip 24. As the eye moves along sixth wood strip 24, it leaves at front surface 32. First side surface 38 is spaced a lateral distance from second side surface 40 with the lateral distance defining the width 42 of any given wood strip. Again, for purposes of clarity all of the wood strips illustrated in FIGS. 1 through 3 are not given designations for first and second side surfaces. Only first wood strip 16 is marked. For any given wood strip, when the eye moves in a clockwise direction, the first side surface 38 is always toward the inside of the circle. The second side surface 40 is always toward the outside of the circle. Thus, again using sixth wood strip 24 as a sample, second side surface 40 is on the outside and first side surface 38 is on the inside as the eye moves in a clockwise direction. Wood fibers 44 creating the grain of the wood in any given wood strip run substantially along the length 36 from the front surface 32 to the rear surface 34. Again, only first wood strip 16 is marked with the designation for wood fibers 44. However, the direction of the wood fibers 44 is clearly illustrated on all the other wood strips. Arrangement 10 has 7 layers: the first finish layer 46, first layer 48, second layer 50, third layer 52, fourth layer 54, fifth layer 56, and second finish layer 58. First, third, and fifth layers 48, 52, and 56 are all first portions 14 with identical wood strip arrangements. Second and fourth layers 50 and 54 are all second portions 20 with the alternative wood strip arrangement. Thickness 30 of the two wood strips in any given layer must be identical in order for the next layer to lie flat on top of the previously layer. Thus, first and second wood strips 16 and 18 in the first layer 48 must have the same thickness. Likewise, fifth and sixth wood strips 22 and 24 in second layer 50 must have the same thickness. However, the thickness of the wood strips in first layer 48 need not be the same as the thickness of the wood strips in second layer 50. The width 42 of first wood strip 16 need not be the same as the width of fifth wood strip 22 immediately above it. Nor does width 42 of first wood strip 16 have to be the same as the width of second wood strip 18. The width of any given wood strip is determined merely by strength and aesthetic consideration. If a smooth outer appearance is desired, identical widths of all of the wood strips is selected. If indentation on one or more layers of the plurality of layers 12 is desired, a narrower width can be selected for one or more of the wood strips. The actual interlocking of all the wood strips in the laminated wood coupling arrangement 10 is achieved by the intricate relationship between the first wood strip 16 and second wood strip 18 in first portion 14, fifth wood strip 22 and sixth wood strip 24 in second portion 20, and the alternating relationship between first portion 14 and second portion 20. Additional first portions 14 and second portions 20 have additional wood strips arranged in the same intricate manner as the original first portion 14 and second portion 20 and the first and second portions 14 and 20 alternate with each other. Thus, in first portion 14 the front surface 32 of first strip 16 is aligned with second side surface 40 of second wood strip 18. Rear surface 34 of second wood strip 18 abutts first side surface 38 of first wood strip 16. In addition, lower surfaces 28 of first and second strips 16 and 18 are substantially coplanar. Since first wood strip 16 and second wood strip 18 have the same thickness 30, the upper planar surfaces 26 are also substantially coplanar. In second portion 20, front surface 32 of fifth wood strip 22 abutts first side surface 38 of sixth wood strip 24. Rear surface 34 of sixth wood strip 24 is aligned with second side surface 40 of fifth wood strip 22. Lower surfaces 28 of fifth and sixth wood strips 22 and 24 are substantially coplanar. Since fifth and sixth wood strips 22 and 24 have the same thickness 30, upper planar surfaces 26 of fifth and sixth wood strips 22 and 24 are substantially coplanar. In the superimposed vertical relationship between first and second portions 14 and 20, rear surface 34 of sixth wood strip 24 is aligned vertically with second side surface 40 of first wood strip 16. Front surface 32 of first wood strip 16 is aligned with second side surface 40 of sixth wood strip 24. Second portion 20 is superimposed on and in aligned relationship with first portion 14. As noted above, depending upon the relative width 42 of the given wood strips and the desire to have precise vertical alignment, the first side surfaces 38 and second side surfaces 40 of the given wood strips in the various layers may or may not be in precise vertical alignment. As illustrated in FIGS. 1 through 3, the first and second side surfaces 38 and 40 of the given wood strips are in precise vertical alignment. However, they need not be in precise vertical alignment in order for the laminated wood coupling arrangement 10 to be effective as long as the plurality of layers 12 are substantially superimposed and substantially aligned with each other. In order for the arrangement 10 to obtain maximum strength, first portion 14 and second portion 20 are in the alternating relationship described above. Obviously, if there are only two layers, first portion 14 and second portion 20 must be alternating because there are only one of each. As additional first and second portions 14 and 20 are added, it would be possible to stack any number of first portions 14 or second portions 20 together. However, such an arrangement would have no greater strength than two boards with their ends glued together. The strength inherent in the present invention lies in the alternating relationship between first portions 14 and second portions 20. It should be noted that no difference in strength exists between having the second portion 20 on top of the first portion 14 or the first portion 14 on top of the second portion 20. As completed, arrangement 10 has a first joint 60 wherein end portions adjacent rear surface 34 of sixth wood strip 24 are in superimposed relationship to end portions adjacent front surface 32 of first wood strip 16. A first leg 62 extends in a first direction indicated by arrow 64 away from first joint 60. A second leg 66 extends in a second direction indicated by arrow 68 different from the first direction away from first joint 60. If desired, first and second finish layers 46 and 58 may be placed on the top or the bottom of arrangement 10 to produce a uniform surface texture such as the appearance of wood grain running substantially the same direction on both legs. An extremely thin layer of veneer may be utilized for this purpose. Alternatively, artificial plastic veneers may be utilized for both decorative and protective purposes. While two finished layers are shown in FIG. 1, only one finish layer such as second finish layer 58 may be needed where only one side of arrangement 10 is visible. Throughout the fabrication process, a glue or bonding means 70 is placed on the wood strips as they are assembled at the locations where they touch other woods strips. Once the arrangement 10 is assembled, heat and pressure are applied to laminate the plurality of layers 12 into a single unitary mass. The preferred heat and pressure laminating technique utilizes a radio frequency generator to create the required heat and wooden molds to hold arrangement 10 during the curing process. Depending upon the overall thickness of arrangement 10, only 30 seconds to 21/2 minutes are required at a frequency of 13.5 megacycles to complete the laminating process. The preferred type glue is a combination of CR-5h resin and F-132 catalist manufactured by Borden Chemical Division of Borden, Inc. Alternatively, the laminated wood coupling arrangement 10 may be cured in a standard heat oven. However, additional time is required to penetrate to the center of arrangement 10 and cooling jigs must be utilized for cooling for several hours to prevent warping. FIG. 2 is a side elevational view perpendicular to the right side of FIG. 1. The spacing between the various elements of FIG. 1 has been diminished somewhat in order to compress the height of the drawing. The uniform direction of the wood grain in first portions 14 is clearly illustrated. The identical wood grain direction is also illustrated in fifth wood strip 22 of second portion 20. However, as soon as sixth wood strips 24 are reached moving from right to left, rear surfaces 34 of sixth wood strips 24 appear and the direction of the wood grain turns perpendicular into the page. Joint 60 occurs where the alternating wood grain is shown between first portions 14 and second portions 20. First leg 62 is the portion of FIG. 2 where the wood grain is all in the same direction parallel to the surface of the drawing. FIG. 3 is perspective view of arrangement 10 illustrated in FIGS. 1 and 2 after it has been compressed together and laminated into a single unit. The result is a unitary L shaped structural element having first joint 60, first leg 62, and second leg 66. The arrangement 10 illustrated in FIGS. 1, 2, and 3 is unadorned by extra coloration material such as paint. The simple wood grain of the wood comprising each wood strip is the only decoration. Thus, along first leg 62 the grain of the wood all runs in the same direction of arrow 64. Likewise, along second leg 66 the g side elevational view perpendicular to the right side of FIG. 1. The spacing between the various elements of FIG. 1 has been diminished somewhat in order to compress the height of the drawing. The uniform direction of the wood grayers of wood have grains perpendicular to each other throughout. The appearance of the grain of the wood along the edge of laminated wood coupling arrangement 10 is, therefore, vastly superior to the edge presented by a piece of ordinary plywood. If desired, one or more of the plurality of layers 12 may be stained or painted prior to assembly. For example, an attractive design may be created by providing third layer 52 with edge coloration. The mass of natural wood on either side of third layer 52 may be made equal and symetrical by having all of the layers equal in width to the width of the third layer. Another possibility is to leave third layer 52 clear so that the natural wood grain shows through and then color second and fourth layers 50 and 54 prior to assembly. Again, a harmonious and aesthetic geometric appearance is created. The advantage of coloring one layer of the laminated wood coupling arrangement 10 prior to assembly is readily apparent. No smearing of coloration on adjacent layers is possible because there are no adjacent layers at the time of coloration. A fine color line results between natural wood layers in the final product. Alternatively, a layer such as third layer 52 may be made with wood strips having a width less than the width of the wood strips in second layer 50 and fourth layer 54. As arrangement 10 is assembled, the second side surface 40 of first wood strip 16 of the third layer 52 can be indented in comparison to the second side surfaces 40 of the wood strips in adjacent layers. A fine groove along first leg 60 results when arrangement 10 is laminated together. FIG. 4 is a perspective view of another embodiment 72 of the present invention. Embodiment 72 is identical to arrangement 10 of FIGS. 1, 2, and 3 except that curve 74 has be routed or cut along the forward face 76 of first joint 60. After arrangement 10 has been laminated, it is a single unitary piece and it can be cut, sanded, drilled, or otherwise worked as a normal piece of wood. Those skilled in the art will recognize numerous possibilities for creating different shapes in addition to the simple curve 74 illustrated in FIG. 4. FIGS. 5 and 6 illustrate another embodiment 78 of the present invention. FIG. 5 is an exploded view of embodiment 78. First portion 80 is similar to first portion 14 shown in FIGS. 1 and 2. First portion 80 has a first wood strip 82, a second wood strip 84, and a third wood strip 86. First wood strip 82 is identical to first wood strip 16 illustrated in FIGS. 1 and 2. Second wood strip 84 is similar to second wood strip 18 of arrangement 10. First wood strip 82 and second wood strip 84 are assembled in exactly the same manner as described in conjunction with the description of the assembly of first wood strip 16 and second wood strip 18 into first portion 14 of arrangement 10. The only new element is third wood strip 86. Second portion 88 is similar to second portion 20 of arrangement 10. Second portion 88 of embodiment 78 has a fifth wood strip 90, a sixth wood strip 92, and a seventh wood strip 94. Fifth wood strip 90 is identical to fifth wood strip 22 of arrangement 10. Sixth wood strip 92 is similar to sixth wood strip 24 of arrangement 10. Fifth and sixth wood strips 90 and 92 are assembled in exactly the same manner as fifth and sixth wood strips 22 and 24 of arrangement 10. The only new element is the addition of seventh wood strip 94. Third wood strip 86 has the same thickness as first and second wood strips 82 and 84. Seventh wood strip 94 has the same thickness as fifth and sixth wood strips 90 and 92. Front surface 96 of second strip 84 is aligned with second side surface 98 of third strip 86. Rear surface 100 of third strip 86 abutts first side surface 102 of second strip 84. Lower surfaces 104 of first, second, and third strips 82, 84, and 86 are substantially coplanar. Front surface 96 of sixth strip 92 abutts first side surface 102 of seventh strip 94. Rear surface 100 of seventh strip 94 is aligned with second side surface 98 of sixth strip 92. Lower surfaces 104 of fifth, sixth, and seventh strips 90, 92, and 94 are substantially coplanar. FIG. 6 illustrates first portion 80 and second portion 88 bonded together. First joint 106 is identical to first joint 60 of arrangement 10 illustrated in FIG. 3. First leg 108 is identical to first leg 62 of arrangement 10 and extends in a first direction indicated by arrow 110. Second leg 112 is similar to second leg 66 of embodiment 10 and extends in a second direction indicated by arrow 114 different from the first direction indicated by arrow 110. A second joint 116 is created by the interrelationship of first portion 80 and second portion 88. A third leg 118 extends from second joint 116 in a third direction indicated by arrow 120 different from the second direction indicated by arrow 114. Second joint 116 is formed where end portions adjacent rear surface 100 of seventh wood strip 94 are superimposed on end portions adjacent front surface 96 of second wood strip 84. FIGS. 7 and 8 illustrate another embodiment 122 of the present invention. FIG. 7 is an exploded view of embodiment 122. First portion 124 is similar to first portion 80 of embodiment 78 shown in FIGS. 5 and 6 and first portion 14 of arrangement 10 shown in FIGS. 1, 2, and 3. First portion 124 has first wood strip 126, second wood strip 128, third wood strip 130, and fourth wood strip 132. First and second wood strip 126 and 128 are identical to first and second wood strips 82 and 84 of embodiment 78. First wood strip 126 and second wood strip 128 are assembled in exactly the same manner as described in conjunction with the description of the assembly of first wood strip 16 and second wood strip 18 in first portion 14 of arrangement 10. Third wood strip 130 is similar to third wood strip 86 of embodiment 78. Third wood strip 130 is assembled to second wood strip 128 in exactly the same manner as described in conjunction with the description of the assembly of second wood strip 84 to third wood strip 86 of embodiment 78. The new addition to the first portion 124 of embodiment 122 is fourth wood strip 132 which completes the square. Second portion 134 is similar to second portion 88 of embodiment 78 shown in FIGS. 5 and 6 and second portion 20 shown in FIGS. 1, 2, and 3. Second portion 134 has fifth wood strip 136, sixth wood strip 138, seventh wood strip 140, and eighth wood strip 142. Fifth wood strip 136 is similar to fifth wood strip 90 of embodiment 78. Sixth and seventh wood strips 138 and 140 are identical to sixth and seventh wood strips 92 and 94 of embodiment 78. The new element of second portion 134 is eighth wood strip 142. Fifth and sixth wood strips 136 and 138 are assembled in exactly the same manner as fifth and sixth wood strips 90 and 92 of embodiment 78 and fifth and sixth woods strips 22 and 24 of arrangement 10. Seventh wood strip 140 is assembled to sixth wood strip 138 in exactly the same manner as seventh wood strip 94 is assembled to sixth wood strip 92 in embodiment 78. Fourth wood strip 132 has the same thickness as first, second, and third wood strips 126, 128, and 130. Eighth wood strip 142 has the same thickness as fifth, sixth, and seventh wood strips 136, 138, and 140. Front surface 144 of third strip 130 is aligned with second side surface 146 of fourth strip 132. Rear surface 148 of fourth strip 132 abutts first side surface 150 of third strip 130. In addition, front surface 144 of fourth strip 124 is aligned with second side surfaces 146 of first strip 126. Rear surface 148 of first strip 126 abutts first side surface 150 of fourth strip 132. Lower surfaces 152 of first, second, third, and fourth wood strips 126, 128, 130, and 132 are substantially coplanar. Front surface 144 of seventh strip 140 abutts first side surface 150 of eighth strip 142. Rear surface 148 of eighth strip 142 is aligned with second side surface 146 of seventh strip 140. In addition, front surface 144 of eighth strip 142 abutts first side surface 150 of fifth strip 136. Rear surface 148 of fifth strip 136 is aligned with second side surface 146 of eighth strip 142. Lower surfaces 152 of fifth, sixth, seventh, and eighth wood strips 136, 138, 140, and 142 are substantially coplanar. FIG. 8 illustrates first portion 124 and second portion 134 bonded together. First joint 154 is identical to first joint 106 of embodiment 78 illustrated in FIG. 6 and first joint 60 of arrangement 10 illustrated in FIG. 3. First leg 156 is similar to first leg 108 of arrangement 78 and first leg 62 of arrangement 10 and extends in a first direction indicated by arrow 158. Second leg 160 is identical to second leg 112 of embodiment 78 and is similar to second leg 66 of embodiment 10. Second leg 160 extends in a second direction indicated by arrow 162 different from the first direction indicated by arrow 158. Second joint 164 is identical to second joint 116 of embodiment 78. Third leg 166 is similar to third leg 118 of embodiment 78 and extends from second joint 164 in a third direction indicated by arrow 168 different from the second direction indicated by arrow 162. A third joint 170 and a fourth joint 174 are created by the interrelationship of first portion 124 and second portion 134. A fourth leg 172 extends from third joint 170 to fourth joint 174. Third joint 170 is formed where end portions adjacent rear surface 148 of eighth wood strip 142 are superimposed on end portions adjacent front surface 144 of third wood strip 130. Fourth joint 174 is formed where end portions adjacent rear surface 140 of fifth wood strip 136 are superimposed on end portions adjacent front surface 144 of fourth wood strip 132. FIGS. 9 and 11 are illustrations of another embodiment 176 of the present invention. FIG. 9 is a perspective view of embodiment 176. Embodiment 176 is identical to arrangement 10 shown in FIG. 3 with the addition of first curve 178 in first leg 180 and second curve 182 in second leg 184. The results is a complicated three dimentional stuctural element. FIG. 11 is an enlarged side elevational view of embodiment 176 of FIG. 9 in the direction of arrows 11. First joint 186 is fabricated in exactly the same manner as first joint 60 of arrangement 10 shown in FIGS. 1 and 2. Exactly the same number of plurality of layers 188 are shown as are shown in the plurality of layers 12 of arrangement 10. However, the front surfaces 190 of first leg 180 are shown instead of front surfaces 32 of second leg 66 of arrangement 10. FIG. 11 at second curve 182 clearly shows the nature of a laminated wood arrangement at a curve. The first layer 192 toward the center of the curve has a much shorter radius than does fifth layer 194 at the outside of the curve. The intermediate layers have intermediate radii. The result is an extremely strong curve in comparison to a bent curve in a solid piece of wood. Any curve requires the compression of wood fibers toward the center of the curve and the stretching of the wood fibers toward the outside of the curve. The wood fibers in the various layers of embodiment 176 are compressed and stretched only minimally in comparison to the wood fibers in a similar piece of solid wood with the same thickness. Also solid wood can only be bent up to certain limited radii depending upon the thickness and type of wood. Laminated wood curves, on the other hand, can be made with virtually any radius and thickness. The combination of the curve fabricating technique illustrated in second curve 182 and the laminated wood coupling arrangement of the present invention as shown in first joint 186 results in a method for making attractive, versatile, and extremely strong wood laminated structures. FIG. 10 is a perspective view of another embodiment 196 of the present invention. Embodiment 196 is identical to embodiment 78 shown in FIG. 6 with the addition of first curve 198 in first leg 200 and second curve 202 in third leg 204. First and second curves 198 and 202 are formed in the same manner as second curve 182 of embodiment 176 shown in FIG. 11. The result is another complicated three dimentional structural element which might possibly be utilized for a portion of a chair frame. Those skilled in the art will realize that a wide variety of embodiments may be employed in producing structures in accordance with the present invention. In many instances, such embodiments may not even resemble those depicted here and may be used for applications other than those shown and described. Nevertheless, such embodiments will employ the spirit and scope of the invention as set forth in the following claims.

A laminated wood coupling arrangement for fabricating unitary laminated wood joints. Two sets of multiple layers of thin wood strips placed at a 90° angle to each other overlap ends in alternating layers. Glue placed between all adjacent surfaces retains the laminate together. The bottom layer has two strips. One strip butts against the end of the side of the other strip. The second layer above also has two strips with one crossing over the butt joint of the first layer. The other strip in the second layer butts against the end of the side of the cross over strip. Additional layers may be added in this alternating arrangement to achieve any desired strength or aesthetic appearance.

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. application Ser. No. 11/982,238, filed Oct. 31, 2007, now issued as U.S. Pat. No. 7,991,463 (the contents being incorporated herein by reference), which is a continuation of U.S. patent application Ser. No. 10/830,189, filed Apr. 21, 2004, now issued as U.S. Pat. No. 7,963,927 (the contents being incorporated herein by reference), which is a divisional of U.S. application Ser. No. 09/722,070, filed Nov. 24, 2000, now issued as U.S. Pat. No. 7,470,236 (the contents being incorporated herein by reference), which claims priority from U.S. Provisional Application Ser. No. 60/167,416 filed Nov. 24, 1999 (the contents being incorporated herein by reference). TECHNICAL FIELD [0002] The present invention relates to electromyography (EMG) and to systems for detecting the presence of nerves during surgical procedures. BACKGROUND OF THE INVENTION [0003] It is important to avoid unintentionally contacting a patient's nerves when performing surgical procedures, especially when using surgical tools and procedures that involve cutting or boring through tissue. Moreover, it is especially important to sense the presence of spinal nerves when performing spinal surgery, since these nerves are responsible for the control of major body functions. However, avoiding inadvertent contact with these nerves is especially difficult due to the high nerve density in the region of the spine and cauda equina. [0004] The advent of minimally invasive surgery offers great benefits to patients through reduced tissue disruption and trauma during surgical procedures. Unfortunately, a downside of such minimally invasive surgical procedures is that they tend to offer a somewhat reduced visibility of the patient's tissues during the surgery. Accordingly, the danger of inadvertently contacting and/or severing a patient's nerves can be increased. [0005] Systems exist that provide remote optical viewing of a surgical site during minimally invasive surgical procedures. However, such systems cannot be used when initially penetrating into the tissue. Moreover, such optical viewing systems cannot reliably be used to detect the location of small diameter peripheral nerves. [0006] Consequently, a need exists for a system that alerts an operator that a particular surgical tool, which is being minimally invasively inserted into a patient's body, is in close proximity to a nerve. As such, the operator may then redirect the path of the tool to avoid inadvertent contact with the nerve. It is especially important that such a system alerts an operator that a nerve is being approached as the surgical tool is advanced into the patient's body prior to contact with the nerve, such that a safety distance margin between the surgical tool and the nerve can be maintained. [0007] A variety of antiquated, existing electrical systems are adapted to sense whether a surgical tool is positioned adjacent to a patient's nerve. Such systems have proven to be particularly advantageous in positioning a hypodermic needle adjacent to a nerve such that the needle can be used to deliver anesthetic to the region of the body adjacent the nerve. Such systems rely on electrifying the needle itself such that as a nerve is approached, the electrical potential of the needle will depolarize the nerve causing the muscle fibers coupled to the nerve to contract and relax, resulting in a visible muscular reaction, seen as a “twitch”. [0008] A disadvantage of such systems is that they rely on a visual indication, being seen as a “twitch” in the patient's body. During precision minimally invasive surgery, uncontrollable patient movement caused by patient twitching, is not at all desirable, since such movement may itself be injurious. In addition, such systems rely on the operator to visually detect the twitch. Accordingly, such systems are quite limited, and are not particularly well adapted for use in minimally invasive surgery. SUMMARY OF THE INVENTION [0009] The present invention provides methods and apparatus for informing an operator that a surgical tool or probe is approaching a nerve. In preferred aspects, the surgical tool or probe may be introduced into the patient in a minimally invasive cannulated approach. In alternate aspects, the surgical tool or probe comprises the minimally invasive cannula itself. [0010] In a first aspect, the present invention provides a system for detecting the presence of a nerve near a surgical tool or probe, based upon the current intensity level of a stimulus pulse applied to the surgical tool or probe. When a measurable neuro-muscular (EMG) response is detected from a stimulus pulse having a current intensity level at or below a pre-determined onset level, the nerve is considered to be near the tool or probe and thus, detected. [0011] In an optional second aspect of the invention, the onset level (i.e.: the stimulus current level at which a neuro-muscular response is detected for a particular nerve) may be based on EMG responses measured for a probe at a predetermined location relative to the nerve. Specifically, onset levels may first be measured for each of a plurality of spinal nerves, (yielding an initial “baseline” set of neuro-muscular response onset threshold levels), which are then used in the first (nerve detection) aspect of the invention. Therefore, in accordance with this optional second aspect of the invention, a system for determining relative neuro-muscular onset values (i.e.: EMG response thresholds), for a plurality of spinal nerves is also provided. Accordingly, the pre-determined onset level may be compared to the current level required to generate a measurable EMG response for a tool or probe being advanced toward one or more nerves of interest. [0012] In alternate aspects, however, the neuro-muscular onset values that are used to accomplish the first (nerve detection) aspect of the invention are not measured for each of the patient's plurality of spinal nerves. Rather, pre-determined levels of current intensity (below which neuro-muscular responses are detected in accordance with the first aspect of the invention) can instead be directly pre-set into the system. Such levels preferably correspond to specific expected or desired onset threshold values, which may have been determined beforehand by experimentation on other patients. [0013] In the aspect of the invention where initial “baseline” neuro-muscular onset values are determined prior to nerve detection, such onset values can optionally be used to calibrate the present nerve-detection system (which in turn operates to detect whether an minimally invasive surgical tool or probe is positioned adjacent to a spinal nerve). [0014] It is to be understood, therefore, that the present invention is not limited to systems that first determine relative neuro-muscular onset values, and then use these neuro-muscular onset values to detect the presence of a nerve. Rather, the present invention includes an optional system to first determine relative neuro-muscular onset values and a system to detect the presence of a nerve (using the neuro-muscular onset values which have been previously determined). As such, the present invention encompasses systems that also use fixed neuro-muscular onset values (which may simply be input into the system hardware/software by the operator prior to use) when performing electromyographic monitoring of spinal nerves to detect the presence of a spinal nerve adjacent a tool or probe. [0015] In optional aspects, the preferred method of sensing for the presence of a nerve may be continuously repeated as the probe/surgical tool is physically advanced further into the patient such that the operator is warned quickly when the probe/surgical tool is closely approaching the nerve. [0016] In the first (nerve sensing) aspect of the invention, the present nerve-detection system comprises an electrode or electrodes positioned on the distal end of the surgical tool or probe, with an electromyographic system used to detect whether a spinal nerve is positioned adjacent to the surgical tool or probe. A conclusion is made that the surgical tool or probe is positioned adjacent to a spinal nerve when a neuro-muscular (e.g.: EMG) response to a stimulus pulse emitted by the electrode or electrodes on the surgical tool or probe is detected (at a distant myotome location, such as on the patient's legs) at or below certain neuro-muscular response onset values (i.e.: pre-determined current intensity levels) for each of the plurality of spinal nerves. The stimulus pulse itself may be emitted from a single probe, but in an optional aspect, the stimulus pulse may be emitted from separate left and right probes with the signals being multiplexed. As stated above, such pre-determined levels may be pre-input by the operator (or be pre-set into the system's hardware or software) and may thus optionally correspond to known or expected values. (For example, values as measured by experimentation on other patients). [0017] In accordance with the optional second (neuro-muscular response onset value determination) aspect of the invention, the neuro-muscular response onset values used in nerve detection may instead be measured for the particular patient's various nerves, as follows. [0018] Prior to attempting to detect the presence of a nerve, an EMG stimulus pulse is first used to depolarize a portion of the patient's cauda equina. This stimulus pulse may be carried out with a pulse passing between an epidural stimulating electrode and a corresponding skin surface return electrode, or alternatively, between a pair of electrodes disposed adjacent to the patient's spine, or alternatively, or alternatively, by a non-invasive magnetic stimulation means. It is to be understood that any suitable means for stimulating (and depolarizing a portion of) the patient's cauda equina can be used in this regard. [0019] After the stimulus pulse depolarizes a portion of the patient's cauda equina, neuro-muscular (i.e., EMG) responses to the stimulus pulse are then detected at various myotome locations corresponding to a plurality of spinal nerves, with the current intensity level of the stimulus pulse at which each neuro-muscular response is first detected being the neuro-muscular response “onset values” for each of the plurality of spinal nerves. [0020] It is to be understood that the term “onset” as used herein is not limited to a condition in which all of the muscle fibers in a bundle of muscle fibers associated with a particular nerve exhibit a neuro-muscular response. Rather, an “onset” condition may comprise any pre-defined majority of the muscle fibers associated with a particular nerve exhibit a neuro-muscular response. [0021] In an additional aspect of the invention, the relative neuro-muscular response onset values can be repeatedly re-determined (at automatic intervals or at intervals determined by the operator) so as to account for any changes to the response onset values caused by the surgical procedure itself. Accordingly, a further advantage of the present invention is that it permits automatic re-assessment of the nerve status, with the relative neuro-muscular response onset values for each of the plurality of spinal nerves being re-determined before, during and after the surgical procedure, or repeatedly determined again and again during the surgical procedure. This optional aspect is advantageous during spinal surgery as the surgery itself may change the relative neuro-muscular response onset values for each of the plurality of nerves, such as would be caused by reducing the pressure on an exiting spinal nerve positioned between two adjacent vertebrae. This periodic re-determination of the onset values can be carried out concurrently with the nerve sensing function. [0022] Accordingly, an advantageous feature of the present invention is that it can simultaneously indicate to an operator both: (1) nerve detection (i.e.: whether the surgical tool/probe is near a nerve); and (2) nerve status changes (i.e.: the change in each nerve's neuro-muscular response onset values over time). The surgeon is thus able to better interpret the accuracy of nerve detection warnings by simultaneously viewing changes in the various onset levels. For example, should the surgeon note that a particular onset value (i.e.: the current level of a stimulus pulse required to elicit an EMG response for a particular nerve) is increasing, this would tend to show that this nerve pathway is becoming less sensitive. Accordingly, a “low” warning may be interpreted to more accurately correspond to a “medium” likelihood of nerve contact; or a “medium” warning may be interpreted to more accurately correspond to a “high” likelihood of nerve contact. [0023] Optionally, such re-assessment of the nerve status can be used to automatically re-calibrate the present nerve detection system. This can be accomplished by continually updating the onset values that are then used in the nerve detection function. [0024] In preferred aspects, the neuro-muscular response onset values for each of the plurality of spinal nerves are measured at each of the spaced-apart myotome locations, and are visually indicated to an operator (for example, by way of an LED scale). Most preferably, the measuring of each of the various neuro-muscular response onset values is repeatedly carried out with the present and previously measured onset value levels being simultaneously visually indicated to an operator such as by way of the LED scale. [0025] Accordingly, in one preferred aspect, for example, different LED lights can be used to indicate whether the value of each of the various neuro-muscular response onset values is remaining constant over time, increasing or decreasing. An advantage of this optional feature of the invention is that a surgeon operating the device can be quickly alerted to the fact that a neuro-muscular response onset value of one or more of the spinal nerves has changed. Should the onset value decrease for a particular nerve, this may indicate that the nerve was previously compressed or impaired, but become uncompressed or no longer impaired. [0026] In a particular preferred embodiment, example, a blue LED can be emitted at a baseline value (i.e.: when the neuro-muscular response onset value remains the same as previously measured); and a yellow light can be emitted when the neuro-muscular response onset value has increased from that previously measured; and a green light being emitted when the neuro-muscular response onset value has decreased from that previously measured. [0027] In an alternate design, different colors of lights may be simultaneously displayed to indicate currently measured onset values for each of the plurality of spinal nerve myotome locations, as compared to previously measured onset values. For example, the present measured onset value levels for each of the plurality of spinal nerve myotome locations can appear as yellow LED lights on the LED scale, with the immediately previously measured onset value levels simultaneously appearing as green LED lights on the LED scale. This also allows the operator to compare presently measured (i.e. just updated) neuro-muscular response onset values to the previously measured neuro-muscular response onset values. [0028] In preferred aspects, the present system also audibly alerts the operator to the presence of a nerve. In addition, the volume or frequency of the alarm may change as the probe/tool moves closer to the nerve. [0029] In a preferred aspect of the present invention, the neuro-muscular onset values, (which may be detected both when initially determining the relative neuro-muscular response onset values in accordance with the second aspect of the invention, and also when detecting a neuro-muscular onset response to the emitted stimulus pulse from the probe/tool in accordance with the first aspect of the invention), are detected by monitoring a plurality of distally spaced-apart myotome locations which anatomically correspond to each of the spinal nerves. Most preferably, these myotome locations are selected to correspond to the associated spinal nerves that are near the surgical site. Therefore, these myotome locations preferably correspond with distally spaced-apart on the patient's legs (when the operating site is in the lower vertebral range), but may also include myotome locations on the patient's arms (when the operating site is in the upper vertebral range). It is to be understood, however, that the present system therefore encompasses monitoring of any relevant myotome locations that are innervated by nerves in the area of surgery. Therefore, the present invention can be adapted for use in cervical, thoracic or lumbar spine applications. [0030] During both the optional initial determination of the relative neuro-muscular response onset values for each of the plurality of spinal nerves (i.e.: the second aspect of the invention) and also during the detection of neuro-muscular onset responses to the stimulus pulse from the surgical probe/tool (i.e.: the first aspect of the invention), the emission of the stimulus pulse is preferably of a varying current intensity. Most preferably, the stimulus pulse is incrementally increased step-by-step in a “staircase” fashion over time, at least until a neuro-muscular response signal is detected. The stimulus pulse itself may be delivered either between a midline epidural electrode and a return electrode, or between two electrodes disposed adjacent the patient's spine, or from an electrode disposed directly on the probe/tool, or by other means. [0031] An important advantage of the present system of increasing the level of stimulus pulse to a level at which a response is first detected is that it avoids overstimulating a nerve (which may cause a patient to “twitch”), or cause other potential nerve damage. [0032] In optional preferred aspects, the “steps” of the staircase of increasing current intensity of the stimulus pulse are carried out in rapid succession, most preferably within the refractory period of the spinal nerves. An advantage of rapidly delivering the stimulus pulses within the refractory period of the spinal nerves is that, at most, only a single “twitch” will be exhibited by the patient, as opposed to a muscular “twitching” response to each level of the stimulation pulse as would be the case if the increasing levels of stimulus pulse were instead delivered at intervals of time greater than the refractory period of the nerves. [0033] In another optional preferred aspect, a second probe is added to the present system, functioning as a “confirmation electrode”. In this optional aspect, an electrode or electroded surface on the second probe is also used to detect the presence of a nerve, (using the same system as was used for the first probe to detect a nerve). Such a second “confirmation electrode” probe is especially useful when the first probe is an electrified cannula itself, and the second “confirmation electrode” probe is a separate probe that can be advanced through the electrified cannula. For example, as the operating (electrified) cannula is advanced into the patient, this operating cannula itself functions as a nerve detection probe. As such, the operating cannula can be advanced to the operating site without causing any nerve damage. After this cannula has been positioned at the surgical site, it may then be used as the operating cannula through which various surgical tools are then advanced. At this stage, its nerve-sensing feature may be optionally disabled, should this feature interfere with other surgical tools or procedures. Thereafter, (and at periodic intervals, if desired) the second “confirmation electrode” probe can be re-advanced through the operating cannula to confirm that a nerve has not slipped into the operating space during the surgical procedure. In the intervals of time during which this second “confirmation electrode” probe is removed from the operating cannula, access is permitted for other surgical tools and procedures. The second “confirmation electrode” probe of the present invention preferably comprises a probe having an electrode on its distal end. This confirmation electrode may either be mono-polar or bi-polar. [0034] In an optional preferred aspect, the second “confirmation electrode” probe may also be used as a “screw test” probe. Specifically, the electrode on the secondary “confirmation” probe may be placed in contact with a pedicle screw, thereby electrifying the pedicle screw. Should the present invention detect a nerve adjacent such an electrified pedicle screw, this would indicate that pedicle wall is cracked (since the electrical stimulus pulse has passed out through the crack in the pedicle wall and stimulated a nerve adjacent the pedicle). [0035] An advantage of the present system is that it may provide both nerve “detection” (i.e.: sensing for the presence of nerves as the probe/tool is being advanced) and nerve “surveillance” (i.e.: sensing for the presence of nerves when the probe/tool had been positioned). [0036] A further important advantage of the present invention is that it simultaneously monitors neuro-muscular responses in a plurality of different nerves. This is especially advantageous when operating in the region of the spinal cord due to the high concentration of different nerves in this region of the body. Moreover, by simultaneously monitoring a plurality of different nerves, the present system can be used to indicate when relative nerve response onset values have changed among the various nerves. This information can be especially important when the surgical procedure being performed can alter the relative nerve response onset value of one or more nerves with respect to one another. [0037] A further advantage of the present system is that a weaker current intensity can be applied at the nerve detecting electrodes (on the probe) than at the stimulus (i.e.: nerve status) electrodes. BRIEF DESCRIPTION OF THE DRAWINGS [0038] FIG. 1 is an illustration of various components of the present invention in operation. [0039] FIG. 2 shows a current intensity staircase for an electromyographic stimulation (nerve status) electrode. [0040] FIG. 3 shows a current intensity staircase for an electromyographic stimulation pulse for a nerve detection electrode disposed on a probe. [0041] FIG. 4 corresponds to FIG. 1 , but also shows exemplary “high”, “medium” and “low” warning levels corresponding to exemplary neuro-muscular response onset levels. [0042] FIG. 5 shows a patient's spinal nerves, and corresponding myotome monitoring locations. [0043] FIG. 6 is an illustration of the waveform characteristics of a stimulus pulse and a corresponding neuro-muscular (EMG) response as detected at a myotome location. [0044] FIG. 7 is a schematic diagram of a nerve detection system. [0045] FIG. 8A is an illustration of the front panel of one design of the present nerve status and detection system. [0046] FIG. 8B is an illustration of the front panel of another design of the present nerve status and detection system. DESCRIPTION OF THE PREFERRED EMBODIMENT [0047] The present invention sets forth systems for detecting when a nerve is near or adjacent to an electrified surgical tool, probe, cannula, or other surgical instrument. The present invention also involves optional systems for simultaneously determining the “status” (e.g.: sensitivity) of a plurality of nerves. [0048] As will be explained, the present system involves applying a signal with a current level to a probe near a nerve and determining whether an electromyographic “EMG” (i.e.: neuro-muscular) response for a muscle coupled to the nerve is present. [0049] In preferred aspects, the present system applies a signal with a known current level (mA) to a “probe” (which could be midline probe, a cannula, a needle, etc.) Depending on the current level, distance to the nerve, and health of the nerve, an EMG may be detected in a muscle coupled to the nerve. In accordance with preferred aspects, an EMG response is determined to have been detected when the peak-to-peak response of the EMG signal is greater than some level (mVolts). In other words, an EMG response is determined to have been detected when the stimulus current level generates an EMG having a peak-to-peak value greater than a pre-determined level (for example, 60 mV or 80 mV in spinal nerve applications.) Such stimulus current level at which an EMG response is detected is termed the “onset” current level for the nerve. [0050] In optional aspects, the present invention also sets forth systems for determining these onset current values (i.e.: determining the stimulus current level at which an EMG response is detected with a maximum peak-to-peak value greater than a predetermined level). Such onset values may be determined for a plurality of nerves either in absolute terms, or in relation to one another. [0051] The first aspect of the present invention involves nerve detection. In the optional second aspect of the invention, nerve status information may be used to aid nerve detection. The nerve status aspect determines the minimum current level of a signal applied to a probe near a nerve needed to generate onset EMG response for a muscle coupled to a nerve of interest. The present invention may use this determined minimum current level when determining whether a probe is near the same nerve. [0052] In optional aspects, the present invention may involve determining an initial set of “baseline” neuro-muscular response onset values for a plurality of different spinal nerve pathways. This optional second (nerve status) aspect of the present invention is preferably carried out prior to the first (nerve detection) aspect of the invention, with the initial set of “baseline” neuro-muscular onset values then optionally being used in the nerve detection function, as will be explained below. As the optional second aspect of the invention is carried out prior to carrying out the first aspect of the invention, it will be described first. [0053] In the nerve status determination, the minimum current level of a signal applied to a probe needed to generate an onset neuro-muscular response (i.e.: EMG response) is first determined for each of a plurality of nerves, as follows. Referring to FIG. 1 , a patient's vertebrae L1, L2, L3, L4, L5, and S1 are shown. In a preferred aspect of the present invention, a portion of the patient's cauda equina is stimulated (i.e. depolarized). This depolarization of a portion of the patient's cauda equina may be achieved by conducting a stimulus pulse having a known current level between an epidural stimulating electrode 11 and a patient return electrode 13 . Electrodes 11 and 13 are referred to herein as “status” electrodes, as they assist in determining the initial status of the various nerve pathways). The epidural electrode is placed in the epidural space of the spine. Alternatively, the depolarization of a portion of the patient's cauda equina may be achieved by conducting a stimulus pulse having a known current level between a pair of status (baseline) electrodes 12 and 14 , which may be positioned adjacent the (thoracic/lumbar) T/L junction (above vertebra L1), as shown. Status electrodes 12 and 14 may be positioned in-line at the T/L junction, (as shown in FIG. 1 ). Status electrodes 12 and 14 could also be positioned on opposite lateral sides of the T/L junction. [0054] In a preferred aspect, neuro-muscular (i.e., EMG), responses to the stimulus pulse by muscles coupled to nerves near the stimulating electrode are detected by electrodes positioned at each of a plurality of myotome locations MR 1 , MR 2 , and MR 3 on the patient's right leg, and myotome locations ML 1 , ML 2 , and ML 3 on the patient's left leg. The sensing of neuro-muscular responses at these locations may be performed with needle electrodes, or electrodes placed on the surface of the patient's skin, as desired. An EMG response at each location MR 1 to MR 6 is detected when the maximum peak-to-peak height of the EMG response to the stimulus pulse is greater than a predetermined mV value (called “onset”). Accordingly, the current level required to elicit an onset EMG response is called the “onset” current level. As described below, the current level of the stimulus pulse or signal applied to the electrode 11 or electrodes 12 , 14 may be incremented from a low level until an onset EMG response is detected for one or more of the myotome locations MR 1 to ML 3 . [0055] It is to be understood that myotome sensing may be carried out at more than the three distal locations illustrated on each of the patient's legs in FIG. 1 . Generally, as greater numbers of distal myotome locations are monitored, a greater number of spinal nerves corresponding to each of these myotome locations can be individually monitored, thereby enhancing the present system's nerve detection ability over a larger section of the patient's spinal column. [0056] It is also to be understood that the present invention can be easily adapted to cervical or thoracic spinal applications (in addition to the illustrated lumbar application of FIG. 1 ). In this case an appropriate portion of the spinal column is depolarized and myotome-sensing locations are selected according to the physiology of the associated nerves for portion of the spinal column of interest. In exemplary aspects, therefore, preferred myotome-sensing locations may therefore include locations on the patient's arms, anal sphincter, bladder, and other areas, depending upon the vertebrae level where the spinal surgery is to be performed. [0057] In a preferred aspect, the current level of the stimulus signal conducted between status electrodes 11 and 13 (or 12 and 14 ) is incrementally increased in a staircase fashion as shown in the current staircase of FIG. 2 from a low value until an onset EMG response is detected at one or more myotome locations. In a preferred embodiment, onset EMG response peak-to-peak value is between 60 mV and 80 mV. (It is noted, however, that depending on the location the stimulating electrode relative to the nerve corresponding to a myotome and the nerve health/status, an onset EMG response may not be detected as the current level is incremented from the lowest level to the highest level shown in FIG. 2 .) In the illustrated exemplary aspect, the current level is shown as increasing from 4 mA to 32 mA, in eight 4 mA increments where the current level is incremented until an onset EMG response is detected. The present invention is not limited to these values and other current ranges (and other numbers “steps” in the staircase) may also be used, as is desired. [0058] At lower current levels, an onset neuro-muscular (i.e., EMG) responses to the stimulus pulse may not be detected at each myotome ML 1 to MR 3 location. However, as the current level of the stimulus signal is incrementally increased (i.e.: moving up the staircase, step-by-step), an onset neuro-muscular (i.e., EMG) response may eventually be detected at each of the various myotome locations ML 1 through MR 3 for each of the six associated spinal nerves. As noted whether an onset EMG response is detected for myotome depends on the location of the electrode relative to the corresponding nerve and the nerve status/health. For example, when a nerve is compressed or impaired, the current level required to generate an onset EMG response may be greater than the similar, non-compressed nerve at a similar distance from the stimulating electrode. Accordingly, he onset neuro-muscular response for each of the various myotome ML 1 to MR 3 locations may be elicited at different stimulus current levels due at least in part to the various individual spinal nerves being compressed, impaired, etc., and also due simply to differences in the individual nerve pathway sensitivities. [0059] For example, referring to the example illustrated in FIG. 1 , a stimulus signal having an initial current level is conducted between electrodes 11 and 13 (or between electrodes 12 and 14 ). The current level of the stimulus pulse is increased step-by-step according to the intensity staircase shown in FIG. 2 until an onset EMG response is detected at one or more selected myotomes. In particular, a response to the increasing current level stimulus pulse is detected at each of the various myotome locations ML 1 through MR 3 . Because each of the spinal nerve paths corresponding to the various myotome locations ML 1 through MR 3 may have different sensitivities (as noted), different onset EMG responses may be detected at the different onset current levels for different myotome locations. [0060] For example, Table 1 illustrates the current level required to elicit an onset EMG response for myotome location. As seen in Table 1, myotome location ML 1 detected an onset EMG response to the stimulus pulse for a current level of 4 mA. Similarly, myotome MR 2 detected an onset neuro-muscular/EMG response to the stimulus pulse for a current level of 24 mA, etc. Summarizing in tabular form: [0000] TABLE 1 Stimulus Current Level at Which Onset EMG Response is Detected: ML1 - 4 mA MR1 - 16 mA ML2 - 16 mA MR2 - 24 mA ML3 - 20 mA MR3 - 12 mA [0061] The above detected stimulus current levels may then be optionally scaled to correspond to stimulus staircase levels 1 through 8, with the maximum signal strength of 32 mA corresponding to “8”, as follows, and as illustrated for each of Myotome locations ML 1 to MR 3 , as shown in Table 2 based on the levels shown in Table 1. [0000] TABLE 2 Scaled Neuro-muscular Response Onset Values: ML1 - 1 MR1 - 4 ML2 - 4 MR2 - 6 ML3 - 5 MR3 - 3 [0062] Accordingly, by depolarizing a portion of the patient's cauda equina and by then measuring the current amplitude at which an onset neuro-muscular (i.e., EMG) response to the depolarization of the cauda equina is detected in each of a plurality of spinal nerves, (i.e.: at each of the myotome locations corresponding to each of the individual spinal nerves), a method for determining the relative neuro-muscular response for each of the plurality of spinal nerves is provided. As such, the relative sensitivities of the various spinal nerve pathways with respect to one another can initially be determined. This information may represent the relative health or status of the nerves coupled to each myotome location where the stimulating electrode is approximately the same distance from each of the corresponding nerves. For example, the nerve corresponding to myotome location MR 2 required 24 mA to elicit an onset EMG response in the corresponding muscle. Accordingly, this nerve may be compressed or otherwise physiologically inhibited. [0063] These respective stimulus pulse current levels at which an onset neuro-muscular response is detected for each of myotome locations ML 1 through MR 3 are detected may then be electronically stored (as an initial “baseline” set of onset EMG response current levels). In a preferred aspect, these stored levels may then be used to perform nerve detection for a probe at a location other than the midline as will be explained. As noted, once an onset neuro-muscular or EMG-response has been detected for each of the myotome locations, it is not necessary to apply further increased current level signals. As such, it may not be necessary for the current level of the signal to reach the top of the current level staircase (as shown in FIG. 2 ) (provided a response has been detected at each of the myotome locations). [0064] By either reaching the end of the increasing current amplitude staircase, (or by simply proceeding as far up the staircase as is necessary to detect a response at each myotome location), the present system obtains and stores an initial “baseline” set of current level onset values for each myotome location. These onset values may be stored either as absolute (i.e.: mA) or scaled (i.e.: 1 to 8) values. As noted these values represent the baseline or initial nerve status for each nerve corresponding to one of the myotome locations. This baseline onset current level may be displayed as a fixed value on a bar graft of LEDs such as shown in FIG. 8A or 8 B. At a later point, the nerve status of the nerves corresponding to the myotomes may be determined again by applying a varying current level signal to the midline electrodes. If a procedure is being performed on the patient, the onset current level for one or more of the corresponding nerves may change. [0065] When the onset current level increases for a nerve this may indicate that a nerve has been impacted by the procedure. The increased onset current level may also be displayed on the bar graft for the respective myotome (FIG. 8 A/ 8 B). In one embodiment, the baseline onset current level is shown as a particular color LED in the bar graph for each myotome location and the increased onset current level value is shown as a different color LED on the bar graph. When the onset current level decreases for a nerve this may indicate that a nerve has been aided by the procedure. The decreased onset current level may also be displayed on the bar graft for the respective myotome. In a preferred embodiment, the decreased onset current level value is shown as a third color LED on the bar graph. When the onset current level remains constant, only the first color for the baseline onset current level is shown on the bar graph. In one embodiment, a blue LED is depicted for the baseline onset current level, an orange LED is depicted for an increased (over the baseline) onset current level, and a green LED is depicted for a decreased onset current level. In one embodiment when the maximum current level in the staircase does not elicit an onset EMG response for a myotome, the baseline LED may be set to flash to indicate this condition. Accordingly, a clinician may periodically request nerve status (midline stimulation) readings to determine what impact, positive, negative, or neutral, a procedure has had on a patient. The clinician can make this assessment by viewing the bar graphs on the display shown in FIG. 8 for each of the myotome locations. [0066] The above determined initial set baseline neuro-muscular response onset current levels for each nerve pathway (myotome location) may then be used in the first (i.e.: nerve sensing) aspect of the present invention, in which a system is provided for detecting the presence of a spinal nerve adjacent to the distal end of a single probe 20 , or either of probes 20 or 22 . (It is to be understood, however, that the forgoing nerve status system (which may experimentally determine neuro-muscular response onset values) is an optional aspect of the present nerve detection system. As such, it is not necessary to determine such relative or absolute neuro-muscular response baseline onset current levels as set forth above prior to nerve detection. Rather, generally expected or previously known current onset levels may instead be used instead. Such generally expected or previously known current onset levels may have been determined by experiments performed previously on other patients. [0067] In accordance with the first aspect of the present invention, nerve detection (performed as the surgical tool or probe is advancing toward the operative site), or nerve surveillance (performed in an ongoing fashion when the surgical tool or probe is stationary has already reached the operative site) may be carried out, as follows. [0068] The first (nerve detection/surveillance) aspect of the invention will now be set forth. [0069] Returning to FIG. 1 , a system is provided to determine whether a nerve is positioned closely adjacent to either of two probes 20 and 22 . In accordance with the present invention, probes 20 and 22 can be any manner of surgical tool, including (electrified) cannulae through which other surgical tools are introduced into the patient. In one aspect of the invention only one probe (e.g.: probe 20 ) is used. In another aspect, as illustrated, two probes (e.g.: 20 and 22 ) are used. Keeping within the scope of the present invention, more than two probes may also be used. In one preferred aspect, probe 20 is an electrified cannula and probe 22 is a “confirmation electrode” which can be inserted through cannula/probe 20 , as will be explained. Probes 20 and 22 may have electrified distal ends, with electrodes 21 and 23 positioned thereon, respectively. (In the case of probe 20 being a cannula, electrode 21 may be positioned on an electrified distal end of the cannula, or alternatively, the entire surface of the electrified cannula may function as the electrode). [0070] Nerve detection is accomplished as follows. A stimulus pulse is passed between electrode 21 (disposed on the distal end of a probe 20 ) and patient return electrode 30 . In instances where a second probe ( 22 ) is also used, a stimulus pulse is passed between electrode 23 (disposed on the distal end of a probe 22 ) and patient return electrode 30 . In one aspect, electrodes 21 or 23 operate as cathodes and patient return electrode 30 is an anode. In this case, probes 20 and 22 are monopolar. Preferably, when simultaneously using two probes ( 20 and 22 ) the stimulus pulse emitted by each of electrodes 21 and 23 is multiplexed, so as to distinguish between their signals. [0071] It should be understood that electrodes 21 and 23 could be replaced by any combination of multiple electrodes, operating either in monopolar or bipolar mode. In the case where a single probe has multiple electrodes (replacing a single electrode such as electrode 21 ) probe 20 could instead be bi-polar with patient return electrode 30 no longer being required. [0072] Subsequent to the emission of a stimulus pulse from either of electrodes 21 or 23 , each of myotome locations ML 1 through MR 3 are monitored to determine if they exhibit an EMG response. [0073] In a preferred aspect, as shown in FIG. 3 , the intensity of the stimulus pulse passing between electrodes 21 and 30 or between 22 and 30 is preferably varied over time. Most preferably, the current intensity level of the stimulus pulse is incrementally increased step-by-step in a “staircase” fashion. As can be seen, the current may be increased in ten 0.5 mA steps from 0.5 mA to 5.0 mA. This stimulus pulse is preferably increased one step at a time until a neuro-muscular (i.e., EMG) response to the stimulus pulse is detected in each of myotome locations ML 1 through MR 3 . [0074] For myotome locations that exhibit an EMG response as a result of the stimulus pulse, the present invention then records the lowest amplitude of current required to elicit such a response. Subsequently, this stimulus level is interpreted so as to produce an appropriate warning indication to the user that the surgical tool/probe is in close proximity to the nerve. [0075] For example, in a simplified preferred aspect, the staircase of stimulus pulses may comprise only three levels, (rather than the 8 levels which are illustrated in FIG. 3 ). If an EMG response is recorded at a particular myotome location for only the highest level of stimulation (i.e.: the third step on a 3-step staircase), then the system could indicate a “low” alarm condition (since it took a relatively high level of stimulation to produce an EMG response, it is therefore unlikely that the tool/probe distal tip(s) are in close proximity to a nerve). If an EMG response is instead first recorded when the middle level of stimulation (i.e.: the second step on the 3-step staircase) is reached, then the system could indicate a “medium” alarm condition. Similarly, if an EMG response is recorded when the lowest level of stimulation (i.e.: the first step on the 3-step staircase) is reached, then it is likely that the probe tips(s) are positioned very close to a nerve, and the system, could indicate a “high” alarm condition. [0076] As can be appreciated, an important advantage of increasing the stimulus current intensity in a “staircase” function, increasing from lower to higher levels of current intensity is that a “high” alarm condition would be reached prior to a “low” alarm condition being reached, providing an early warning to the surgeon. Moreover, as soon as a “high” alarm condition is reached, the present invention need not continue through to the end (third step) of the staircase function. In preferred aspects, when the current level of the applied signal to the probe ( 20 or 22 ) elicits an EMG response greater than the pre-determined onset EMG response, the current level is not increased. [0077] In the above-described simplified (only three levels of stimulation) illustration of the invention, it was assumed that all nerves respond similarly to similar levels of stimulation, and the proximity (nerve detection) warning was based upon this assumption. Specifically, in the above-described simplified (three levels of stimulation) illustration, there was an assumed one-to-one (i.e. linear) mapping of the EMG onset value data onto the response data when determining what level of proximity warning indication should be elicited, if any. However, in the case of actual spinal nerve roots, there is not only a natural variability in response onset value threshold, but there is often a substantial variation in neuro-muscular response onset values between the nerve pathways caused as a result of certain disease states, such as nerve root compression resulting from a herniated intervertebral disc. [0078] Accordingly, in a preferred aspect of the present invention, the initial “baseline” neuro-muscular EMG response onset value data set which characterizes the relative EMG onset values of the various nerve roots of interest, (as described above), is used to guide the interpretation of EMG response data and any subsequent proximity warning indication, as follows. [0079] Referring back to FIG. 1 and Table 1, the stimulation staircase transmitted between electrodes 11 and 13 (or 12 and 14 ) resulted in measures neuro-muscular (i.e.: EMG) response onset values of 4, 16, 20, 16, 24 and 12 mA at myotome locations ML 1 , ML 2 , ML 3 , MR 1 , MR 2 and MR 3 , respectively. As can be seen, twice the intensity of current was required to produce a neuro-muscular response at MR 2 as was required to produce a neuro-muscular response at MR 3 (since “24” mA is twice as big as “12” mA). Thus, the nerve pathway to MR 3 is more “sensitive” than to MR 2 (since MR 3 is able to exhibit a neuro-muscular response at ½ of the current intensity required to exhibit a neuro-muscular response at MR 2 ). Consequently, during nerve detection, when electrode 21 or 23 (positioned on the distal end of tool/probe 20 or 22 ) is positioned adjacent the nerve root affiliated with MR 3 , twice the current stimulation intensity was required to produce an EMG response. In contrast, when electrode 21 or 23 (on the distal end of tool/probe 20 or 22 ) was positioned adjacent to the nerve root affiliated with MR 2 , the same level of stimulation that produced a response at MR 3 would not produce a response at MR 2 . [0080] In accordance with preferred aspects of the present invention, the sensitivities of the various spinal nerve pathways (to their associated myotomes) are incorporated into the nerve detection function of the invention by incorporating the various neuro-muscular response onset values, as follows. [0081] A decision is made that either of electrodes 21 or 23 are positioned adjacent to a spinal nerve when a neuro-muscular response is detected at a particular myotome location at a current intensity level that is less than, (or optionally equal to), the previously measured or input EMG response onset value for the particular spinal nerve corresponding to that myotome. For example, referring to myotome location ML 1 , the previously determined neuro-muscular response onset level was 4 mA, as shown in Table 1. Should a neuro-muscular response to the stimulus pulse be detected at a current intensity level at or below 4 mA, this would signal the operator that the respective probe electrode 21 (or 23 ) emitting the stimulus pulse is in close proximity to the spinal nerve. Similarly, the neuro-muscular response onset value for myotome location ML 2 was determined to be 16 mA, as shown in Table 1. Accordingly, should a neuro-muscular response be detected at a current intensity level of less than or equal to 16 mA, this would indicate that respective probe electrode 21 (or 23 ) emitting the stimulus pulse is in close proximity to the spinal nerve. [0082] In addition, as illustrated in FIG. 4 , “high”, “medium” and “low” warning levels may preferably be mapped onto each stimulation staircase level for each myotome location. For example, the neuro-muscular onset level for ML 1 was 4 mA, corresponding to the first level of the 8-level status electrode current staircase of FIG. 2 . Thus, the first (4 mA) step on the staircase is assigned a “high” warning level. Level two (8 mA) is assigned a “medium” warning level and level three (12 mA) is assigned a “low” warning level. Thus, if an EMG response is recorded at ML 1 at the first stimulation level, (4 mA), a “high” proximity warning is given. If a response is detected at the second level (8 mA), then a “medium” proximity warning is given. If a response is detected at the third level (12 mA), then a “low” proximity warning is given. If responses are detected only above the third level, or if no responses are detected, than no warning indication is given. [0083] Similarly, for ML 2 , with a onset value of 16 mA, (i.e.: the fourth level in the status electrode current staircase sequence), the “high”, “medium” and “low” warning levels are assigned starting at the fourth step on the status electrode current staircase, with the fourth step being “high”, the fifth level being “medium” and the sixth level being “low”, respectively, as shown. Accordingly, if an EMG response is detected for ML 2 at (or above) the first, second, third, or fourth surveillance levels, (i.e.: 4, 18, 12 or 16 mA), then a “high” warning indication will be given. For a response initially detected at the fifth level (i.e.: 20 mA), then a “medium” warning indication is given. If a response is not detected until the sixth level (i.e.: 24 mA), then a “low” warning indication is given. If responses are detected only above the sixth level, or not at all, then no indication is given. Preferably, each of myotome locations ML 1 through MR 3 are monitored at conditions indicating “high”, “medium” and “low” likelihood of a nerve being disposed adjacent the surgical tool/probe. [0084] As can be seen in FIG. 4 , ten levels are shown for each of the myotome locations, whereas the illustrated status electrode current staircase has only eight levels. These optional levels “9” and “10” are useful as follows. Should scaled level 8 be the minimum onset level at which a neuro-muscular response is detected, levels “9” and “10” can be used to indicate “medium” and “low” warning levels, respectively. [0085] As explained above, the various neuro-muscular response current onset levels used in detection of spinal nerves may either have been either determined in accordance with the second aspect of the present invention, or may simply correspond to a set of known or expected values input by the user, or pre-set into the system's hardware/software. In either case, an advantage of the present system is that different neuro-muscular response onset value levels may be used when simultaneously sensing for different nerves. An advantage of this is that the present invention is able to compensate for different sensitivities among the various spinal nerves. [0086] As can be seen comparing the current intensities of stimulus electrodes 11 and 13 (or 12 and 14 ) as shown in FIG. 2 (i.e.: up to 32 mA) to the current intensities of probe electrodes 21 and 23 as shown in FIG. 3 (i.e.: up to 5.0 mA), the current intensities emitted by probe electrodes 21 and 23 are less than that of electrodes 12 and 14 . This feature of the present invention is very advantageous in that electrodes 21 and 23 are positioned much closer to the spinal nerves. As such, electrodes 21 and 23 do not depolarize a large portion of the cauda equina, as do electrodes 12 and 14 . In addition, the placement of electrode 11 in the epidural space ensures that the electrode is at a relatively known distance from the spinal nerves. [0087] In an optional preferred aspect of the invention, if a neuro-muscular response (greater than the onset EMG response) is detected for all six myotome sensing locations ML 1 through MR 3 before all of the steps on the staircase is completed, the remaining steps need not be executed. [0088] Moreover, if it has been determined that a maximal level of stimulation is required to elicit an EMG response at a particular myotome sensing location, then only the top three stimulation levels need to be monitored during the neuro-muscular response detection sequence. In this case, the top three monitored levels will correspond to “high”, “medium”, and “low” probabilities of the surgical tool/probe being disposed adjacent the a nerve. In another optional aspect, if any of the myotome locations do not respond to the maximum stimulation level (i.e.: top step on the staircase), they are assigned the maximum scale value (i.e.: a “low” warning indication). [0089] Preferably, each of the spinal nerves monitored at myotome locations ML 1 through MR 3 will correspond to nerves exiting from successive vertebrae along the spine. For example, as shown in FIG. 5 , a main spinal nerve 50 will continuously branch out downwardly along the spinal column with spinal nerve 51 exiting between vertebrae L2 and L3 while nerve 52 passes downwardly. Spinal nerve 53 exits between vertebrae L3 and L4 while spinal nerve 54 passes downwardly to L4. Lastly, spinal nerve 55 will exit between vertebrae L4 and L5 while spinal nerve 56 passes downwardly. As can be seen, neuro-muscular (i.e., EMG) response measurements taken at myotome location MR 1 will correspond to EMG signals in spinal nerve 51 , response measurements taken at myotome location MR 2 correspond to EMG signals in spinal nerve 53 , and response measurements taken at myotome location MR 3 correspond to EMG signals in spinal nerve 55 . [0090] In accordance with the present invention, the detection of a neuro-muscular (EMG) response, whether in accordance with the first (i.e.: nerve detection), or second (i.e.: establishing initial “baseline” neuro-muscular response onset values) aspect of the invention, may be accomplished as follows. [0091] Referring to FIG. 6 , an illustration of the waveform characteristics of a stimulus pulse and a corresponding neuro-muscular (EMG) response as detected at a myotome location is shown. An “EMG sampling window” 200 may be defined at a fixed internal of time after the stimulus pulse 202 is emitted. The boundaries of window 200 may be determined by the earliest and latest times that an EMG response may occur relative to stimulus pulse 202 . In the case of stimulation near the lumbar spine, these times are, for example, about 10 milliseconds and 50 milliseconds, respectively. [0092] During EMG sampling window 101 , the EMG signal may optionally be amplified and filtered in accordance with guidelines known to those skilled in the art. The signal may then be rectified and passed through a threshold detector to produce a train of pulses representing the number of “humps” of certain amplitudes contained in the EMG waveform. A re-settable counting circuit may then count the number of humps and a comparator may determine whether the number of pulses is within an acceptable range. By way of example only, the number of acceptable pulses for EMG responses elicited by stimulation in the lumbar spine region may range from about two to about five. If only one pulse is counted, then it is unlikely that a true EMG response has occurred, since true EMG waveforms are typically biphasic (having at least one positive curved pulse response and one negative curved pulse response) resulting in at least two pulses. This pulse-counting scheme helps to discriminate between true EMG waveforms and noise, since noise signals are typically either sporadic and monophasic (and therefore produce only one pulse) or repetitive (producing a high number of pulses during the EMG sampling window). [0093] In a further optional refinement, a separate noise-sampling window may be established to remove noise present in the EMG responses to increase the ability of the system to discriminate between true EMG responses and false responses caused by noise. The boundaries of noise sampling window are chosen such that there is no significant change of a true EMG signal occurring during the window. For example, it may be deemed acceptable that one curved pulse of an EMG response may be comprised primarily of noise, but if more than one curved pulse of an EMG response is primarily comprised of noise, an alarm would be triggered indicating that excess noise is present on that particular channel. [0094] In preferred aspects of the present invention, both the optional second aspect of determining the neuro-muscular response onset values for each of the plurality of spinal nerves and the first aspect of sensing to detect if a nerve is positioned adjacent to a surgical tool/probe are repeated over time. Preferably, the sensing of whether a nerve is positioned adjacent to a surgical tool/probe is continuously repeated in very short intervals of time, such that the operator can be warned in real time as the surgical tool/probe is advanced toward the nerve. The present system of determining the neuro-muscular response onset values for each of the plurality of spinal nerves is also preferably repeated, and may be repeated automatically, or under operator control. [0095] Typically, the above two aspects of the present invention will not be carried out simultaneously. Rather, when the neuro-muscular response onset values are being determined (using electrodes 11 and 13 or 12 and 14 ), the operation of probe electrodes 21 and 23 will be suspended. Conversely, when sensing to determine whether a nerve is positioned adjacent either of probes 20 or 22 , the operation of stimulation electrodes 11 and 13 or 12 and 14 will be suspended. A standard reference electrode 32 may be used for grounding the recording electrodes at the myotomes. [0096] FIG. 6 depicts a particular exemplary embodiment of the present invention. Other embodiments are also possible, and are encompassed by the present invention. Pulse generator 100 creates pulse trains of an appropriate frequency and duration when instructed to do so by controller 118 . By way of example, the pulse frequency may be between 1 pulse-per-second and 10 pulses-per-second, and the pulse duration may be between 20 μsec and 300 μsec. Pulse generator 100 may be implemented using an integrated circuit (IC), such as an ICL75556 (Intensity) or generated by a software module. Amplitude modulator 102 produces a pulse of appropriate amplitude as instructed by controller 118 , and may comprise a digital-to-analog converter such as a DAC08 (National Semiconductor). The output of amplitude modulator 102 drives output stage 103 , which puts out a pulse of the desired amplitude. Output stage 103 may comprise a transformer coupled, constant-current output circuit. The output of output stage 103 is directed through output multiplexer 106 by controller 118 to the appropriate electrodes, either to status (baseline) electrodes 11 and 13 , or to a combination of screw test probe 109 , probe electrode 21 , 23 and patient return electrode 13 . Impedance monitor 104 senses the voltage and current characteristics of the output pulses and controller 118 elicits an error indication on error display 127 if the impedance falls above or below certain pre-set limits. Input keys 116 may be present on a front panel of a control unit of the present invention, as depicted in FIG. 8 , to allow the user to shift between modes of operation. [0097] EMG inputs 128 to 138 comprise the six pairs of electrodes used to detect EMG activity at six different myotome locations. It will be appreciated that the number of channels may vary depending upon the number of nerve roots and affiliated myotomes that need to be monitored. A reference electrode 140 may also be attached to the patient at a location roughly central to the groupings of EMG electrodes 128 to 138 to serve as a ground reference for the EMG input signals. Electrodes 128 to 140 may either be of the needle-type or of the gelled foam type, or of any type appropriate for detecting low-level physiological signals. EMG input stage 142 may contain input protection circuit comprising, for example, gas discharge elements (to suppress high voltage transients) and/or clamping diodes. Such clamping diodes are preferably of the low-leakage types, such as SST-pads (Siliconix). The signal is then passed through amplifier/filter 144 , which may amplify the signal differentially using an instrumentation amplifier such as an AD620 (Analog Devices). The overall gain may be on the order of about 10,000:1 to about 1,000,000:1, and the low and high filter bands may be in the range of about 1-100 Hz and 500 to 5,000 Hz, respectively. Such filtering may be accomplished digitally, in software, or with discrete components using techniques well known to those skilled in the art. The amplified and filtered signal then passes through rectifier 141 , which may be either a software rectifier or a hardware rectifier. The output of rectifier 146 goes to threshold detector 147 which may be implemented either in electronic hardware or in software. The output of threshold detector 147 then goes to counter 148 which may also be implemented by either software or hardware. [0098] Controller 118 may be a microcomputer or microcontroller, or it may be a programmable gate array, or other hardware logic device. Display elements 120 to 127 may be of any appropriate type, either individually implemented (such as with multicolor LEDs) or as an integrated display (such as an LCD).

Methods for determining structural integrity of a bone within the spine of a patient, the bone having a first aspect and a second aspect, wherein the second aspect separated from the first aspect by a width and located adjacent to a spinal nerve. The methods involve (a) applying an electrical stimulus to the first aspect of the bone; (b) electrically monitoring a muscle myotome associated with the spinal nerve to detect if an onset neuro-muscular response occurs in response to the application of the electrical stimulus to the first aspect of the bone; (c) automatically increasing the magnitude of the electrical stimulus to until the onset neuro-muscular response is detected; and (d) communicating to a user via at least one of visual and audible means information representing the magnitude of the electrical stimulus which caused the onset neuro-muscular response.

The present application is based on Japanese patent application No. 2004-080756, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to grinding abrasive grains suitable for grinding semiconductor wafers such as compound semiconductor wafers (e.g., GaAs wafers), silicon wafers, etc., an abrasive containing the abrasive grains, an abrasive solution containing the abrasive grains, a method for preparing the abrasive solution, a grinding method by the abrasive solution, and a semiconductor device fabrication method using the abrasive solution. 2. Description of the Related Art In recent years, the flatness of compound semiconductor wafers or semiconductor wafers has been strictly required with remarkable high integration and high capacity, so that still more excellent-precision machining technology has been required. In the grinding step of a wafer fabrication process, there are many problems of removing shape irregularities, removing thickness variations, removing machining strains, adjusting flatness, etc. In general, combined chemical and mechanical grinding is applied to the grinding step, and abrasive is a consumable item which largely affects wafer quality. In the chemical and mechanical grinding of semiconductor wafers such as compound semiconductor wafers, silicon wafers, etc., it is important to balance a chemical factor which serves to reduce machining strains and a mechanical factor which affects flatness and surface quality. Both chemical and mechanical factors are largely related to grinding characteristics of abrasive. In other words, the grinding step of semiconductor wafers such as compound semiconductor wafers, silicon wafers, etc., comprises the primary step of forming an oxide film on a surface, the secondary step of grinding the oxide film by abrasive grains, and the third step of dissolving the ground oxide to increase grinding speed. The primary and third steps affect a chemical factor, and the secondary step affects a mechanical factor. Of these steps, the secondary step of grinding the oxide film by abrasive grains largely affects a wafer surface state, shape and flatness, and determines wafer quality. Abrasive grain form affects all grinding characteristics including grinding speed. Accordingly, the most important factor in abrasive that affects wafer quality is abrasive grains. Abrasive grains are largely divided into abrasive grains which disperse in water as primary grains, and abrasive grains which disperse as secondary grains consisting of a plurality of aggregated primary grains. Which of the primary and secondary grains to use, or what ratio to mix them depends on objects to be ground or machining purposes. On the other hand, for the purpose of enhancement in grinding characteristics, various suggestions which focus on abrasive grain shapes have been made by each material maker. Japanese patent application laid-open No. 7-221059 describes that, in grinding a semiconductor wafer, grinding speed is faster by grinding a colloidal silica shape observed by an electron microscope with non-spherical abrasive grains defined by minor to major axes ratios. As a result of examination on this by the present inventor, the grinding speed of amorphous abrasive grains typically tends to be faster than that of spherical abrasive grains. Even though abrasive grains are amorphous, however, its grinding speed is not necessarily faster. Also, when abrasive grains are observed with an electron microscope, unlike a dispersed state in an actual solution, tertiary grains consisting of a plurality of aggregated secondary grains or quaternary grains consisting of a plurality of aggregated tertiary grains are observed, which causes many errors, and are not efficient. Japanese patent application laid-open No. 2001-11433 describes that the grinding speed of abrasive grains consisting of spherical colloidal silica grains linked within one plane by adding a divalent or trivalent metal oxide to the spherical colloidal silica grains is faster, and that a flat smooth surface is obtained with high precision. In this case, however, added metal ions are an impurity which adversely affects a wafer surface. Japanese patent application laid-open No. 9-296161 discloses an abrasive using abrasive grains for reducing defects (e.g., flaws), in which water is caused to intervene between primary grains to form elastic secondary grains by heating a high-purity fumed silica solution. However, control of grain size and secondary grain shape is difficult, and stable grinding characteristics cannot be obtained, which results in no effect on some objects to be ground. Japanese patent application laid-open No. 2002-338232 discloses an abrasive composition using aggregated spherical colloidal silica grains with its uneven surface as abrasive grains, aggregated by a flocculant and aggregation aid. It describes use of polyaluminum chloride as the flocculent, however, such added metals are a kind of impurities, which results in a contaminated wafer surface to be ground. Compound semiconductor wafers and semiconductor wafers are fabricated by means of primary grinding (rough grinding) and secondary grinding (mirror finish). Typically, the primary grinding is performed by pressing a wafer on a soft abrasive pad of a nonwoven cloth or a suede type, and exerting a constant pressure, dripping an abrasive consisting of abrasive grains, oxidizer, alkali reagent, etc. Large problems with the primary grinding step lie in ensuring a wafer shape is of a stable precision, and realizing high-speed grinding. In particular, wafer shape is important, where failure to ensure a wafer shape with a stable precision would affect the subsequent secondary grinding step. The secondary grinding step is the mirror finish step by smoothing wafer surface roughness, often using an abrasive without abrasive grains, which results in no shape correction capability. In other words, it is necessary to constantly ensure a wafer shape with a stable precision in the primary grinding step. In particular, a soft abrasive pad of a nonwoven cloth or a suede type typically tends to cause peripheral dripping in the wafer, compared to a abrasive pad made of foamed polyurethane used in CMP (Chemical Mechanical Polishing), which results in difficulty in obtaining good flatness. Also, there is the large problem that the above soft abrasive pad degrades fast, grinding characteristics changing with the degradation of the abrasive pad, which results in more remarkable peripheral dripping in a wafer peripheral portion. As a method for improving malfunction caused by the abrasive pad, there is the method for improving flatness by increasing the elasticity of the abrasive pad, but using this would rather increase the incidence of flaws. On the other hand, in the research and development of abrasives, as described in the above patent references, various researches have been made on grinding speed, surface roughness, and the reduction of defects (e.g., flaws), but as it stands, there are no disclosures about techniques for enhancing flatness by preventing peripheral dripping, or enhancing wafer shape stability over time. SUMMARY OF THE INVENTION It is an object of the invention to provide abrasive grains that can ensure enhancement in grinding speed, flatness, and wafer shape stability over time, and can ensure stable grinding characteristics. It is a further object of the invention to provide an abrasive containing the abrasive grains, an abrasive solution containing the abrasive grains, a method for preparing the abrasive solution, a grinding method by the abrasive solution, and a semiconductor device fabrication method using the abrasive solution. (1) According to one aspect of the invention, Abrasive grains comprises mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain. It is preferred that the roundness is 0.55 or more and 0.72 or less. In detail, the roundness is a roundness when a medium containing the grains is agitated to disperse them while being irradiated with ultrasound. It is preferred that the grains comprise a plurality of aggregated primary grains with an average grain size of 0.005 μm or more and 0.1 μm or less. It is preferred that the average grain size of the aggregated primary grains is 1 μm or more and 30 μm or less. It is further preferred that the average grain size of the aggregated primary grains is 3 μm or more and 20 μm or less. In detail, the average grain size of the aggregated primary grains is an average grain size when a medium containing the grains is agitated to disperse them while being irradiated with ultrasound. (2) According to another aspect of the invention, an abrasive comprises: abrasive grains that comprise mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain; and at least one of an oxidizer, an oxide solution, an abrasive grain dispersion agent and a basic compound. It is preferred that the oxidizer is sodium dichloroisocyanurate, the oxide solution is sodium tripolyphosphate; the abrasive grain dispersion agent is sodium sulfate; and the basic compound is sodium carbonate or sodium hydroxide. (3) According to another aspect of the invention, an abrasive solution comprises: abrasive grains that comprise mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain; and water or hydrophilic substance. It is preferred that the abrasive grain content is 10 wt % or more and 40 wt % or less when the total amount of the solid content in the abrasive solution is 100 wt %. It is preferred that the abrasive grain content is 0.5 wt % or more and 5 wt % or less when the total amount of the abrasive solution is 100 wt %. It is preferred that the abrasive solution further comprises at least one of an oxidizer, an oxide solution, an abrasive grain dispersion agent and a basic compound. It is preferred that the oxidizer is sodium dichloroisocyanurate, the oxide solution is sodium tripolyphosphate, the abrasive grain dispersion agent is sodium sulfate, and the basic compound is sodium carbonate or sodium hydroxide. It is preferred that the abrasive solution is used for grinding group III-V compound semiconductor material or semiconductor material. (4) According to another aspect of the invention, a method for preparing an abrasive solution comprises the steps of: adding an abrasive to a medium, wherein the abrasive comprises: abrasive grains that comprise mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain; and at least one of an oxidizer, an oxide solution, an abrasive grain dispersion agent and a basic compound; and and agitating the medium while irradiating it with ultrasound. (5) According to another aspect of the invention, a grinding method comprises the step of: grinding an object to be ground at a grinding pressure of 2-10 kPa, using an abrasive solution, wherein the abrasive solution comprises: abrasive grains that comprise mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain; and water or hydrophilic substance. (6) According to another aspect of the invention, a method for fabricating a semiconductor device comprises the steps of: grinding a surface of a substrate comprising a compound semiconductor wafer or a semiconductor wafer by using an abrasive solution that comprises: abrasive grains that comprise mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain; and water or hydrophilic substance; etching a ground damage layer of the surface of the substrate; forming semiconductor layers sequentially and forming ohmic contact; diffusing impurities and implanting ions; forming a substrate protection film; and cutting the substrate. <Advantages of the Invention> The invention can provide an excellent-shape wafer without peripheral dripping, while realizing high-speed grinding. Also, the invention is suitable for grinding wafers having a poor mechanical strength and a strong cleavage. BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiments according to the invention will be explained below referring to the drawings, wherein: FIG. 1 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 1 in Example 1; FIG. 2 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 2 in Example 1; FIG. 3 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 3 in Example 1; FIG. 4 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 4 in Example 1; FIG. 5 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 5 in Example 1; FIG. 6 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 6 in Example 1; FIG. 7 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 7 in Example 1; FIG. 8 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 8 in Comparative Example 1; FIG. 9 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 9 in Comparative Example 1; FIG. 10 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 10 in Comparative Example 1; FIG. 11 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 11 in Comparative Example 1; FIG. 12 is a graph showing change over time of grain-size distribution against homogenizer dispersion time of No. 12 in Comparative Example 1; FIG. 13 is a graph showing change of roundness against dispersion time by the homogenizer, concerning abrasive grains Nos. 1 - 7 of Example 1 and abrasive grains Nos. 8 - 12 of Comparative Example 1; FIG. 14 is a diagram illustrating collision of abrasive grains with a wafer side surface during grinding using abrasive grains of Comparative Example 1; FIG. 15 is a diagram illustrating collision of abrasive grains with a wafer side surface during grinding using abrasive grains of Example 1; FIG. 16 is a graph showing the relationship between grinding speed and roundness of commercial abrasive grains Nos. 3 - 7 of Example 1 and of abrasive grains No. 12 of Comparative Example 1; and FIG. 17 is a graph showing effects of grinding speed on the concentration of sodium tripolyphosphate which is the abrasive content, when a GaAs wafer was ground by an abrasive using abrasive grains No. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is a technique for controlling a wafer shape and grinding speed with abrasive grain characteristics (roundness, cohesion, average grain size, grain-size distribution). The invention is explained in further detail below. <Grinding Characteristics of Abrasive Grains> Grinding characteristics of grains dispersing as primary grains depend on average grain size only. However, the state of ground aggregated grains is varied according to dispersion conditions, and during grinding, aggregated grains are ground by grinding pressure, so that their grain size and grain shape are also varied. For this reason, grinding characteristics of the aggregated grains cannot be determined from shape observation by an electron microscope before dispersion, and are also difficult to be determined from shape observation after dispersion using both ultrasonic irradiation and agitation because it may be an apparent shape. It is not clear in which process the characteristics of the aggregated grains affect grinding characteristics, but the characteristics of the aggregated grains immediately before or during grinding affect grinding characteristics. Accordingly, in order to best bring aggregated grains into such a state, they were dispersed using both ultrasonic irradiation and agitation, and a homogenizer was applied to form an artificial state of aggregated grains immediately before or during grinding. As a result of then examining the relationships between the characteristics of the aggregated grains (roundness, cohesion, average grain size, grain-size distribution) and grinding characteristics [grinding speed and wafer shape (TTV: Total Thickness Variation)], the present inventors found out strong correlations between the roundness of aggregated grains and grinding speed and wafer shape. <Roundness> Roundness is a value that shows the difference of shape relative to a sphere, and is generally assessed using the following formulae 1 and 2. Formula 1 is the ratio of the circumference of a circle having the same area as that of a grain projection image, to the perimeter of the grain projection image, and Formula 2 is the ratio of the area of a grain projection image to the area of a circle whose diameter is the longest diameter of the grain projection image. Both are the quantification of a two-dimensional image, and approach one as it approaches a perfect circle, while they become less than one as it is more different from a perfect circle. Formula 1: Roundness=(the circumference of a circle having the same area as that of the projected grain)/(the perimeter of the projected grain) Formula 2: Roundness=(the area of the projected grain)/((diameter of a circle which is the longest diameter of the projected grain)/2) 2 π The shape of abrasive grains when they affect the wafer surface and side surfaces during grinding is important. Accordingly, roundness is preferred when abrasive grains are assumed to be as close as possible to a state during grinding. However, roundness before dispersion into a medium, roundness during dispersion by ultrasonic irradiation and agitation in the medium, and roundness during dispersion or grinding by a homogenizer for a constant time may be entirely different dependent on kinds of abrasive grains (in particular, in the case of aggregated grains with weak cohesion). Accordingly, roundness is preferred in the medium when abrasive grains are first dispersed by ultrasonic irradiation and agitation, and then dispersed or ground by a homogenizer for a constant time. Roundness in the invention is based on Formula 1 which is remarkable in significant difference compared to roundness calculated by Formula 2. Specifically, it uses results measured by commercial grain image analyzers equipped with both a grain image photography mechanism and an image analysis device by microscope observation in the medium, and is calculated by Formula 3. Also, roundness in the invention is preferably average roundness of one body when a plurality of aggregated primary grains are measured as one body. Further, average grain size of abrasive grains in the invention is preferred when they are dispersed using both ultrasonic irradiation and agitation. Formula 3: Roundness=(the circumference of a circle having the same area as that of the projected grain)/(the perimeter of the projected grain) <Aggregated Grains> Aggregated grains according to the invention may be any silica of commercial colloidal silica, fumed silica, precipitated silica, and gel-type silica, regardless of kinds of silica. Also, two or more of the above silica may be mixed or aggregated. Any preparation method for aggregated grains may be used: grains may be aggregated by causing water to intervene therebetween, or by adsorbing, to the surface of primary grains, aliphatic esters, methyl or ethyl esters such as octanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, etc., which serve as lubrication. <Average Grain Size of Abrasive Grains> When the average grain size of abrasive grains is selected, the surface shape of an abrasive pad has to be taken into consideration. Dependent on kinds of abrasive pads used, the space between fibers of a nonwoven cloth is larger than that of abrasive pads made of foamed polyurethane for general CMP (Chemical Mechanical Polishing), and the average grain size needs to be 1 μm or more, preferably 3 μm or more. In case the average grain size is less than 3 μm, the grain size is smaller than the space between fibers of the abrasive pad surface, which results in no abrasive grains being held on the abrasive pad and no abrasive grain effects being exhibited. As a consequence, exhibited are only chemical effects, which results in a reduction of grinding speed, peripheral dripping, and a deterioration of wafer shape. On the other hand, in case the average grain size is 30 μm or more, abrasive grains with strong cohesion cannot be used because of the high incidence of flaws, chips, etc. Thus, the average grain size is 30 μm or less, preferably 20 μm or less. <Medium> As the medium, pure water is typically used, but the invention is not limited thereto. Also, the abrasive grain content of an abrasive solution of the invention is preferably 10 wt % or more and 40 wt % or less when the total amount of the solid content is 100 wt %. In the case of less than 10 wt %, sufficient grinding speed may be not obtained. In the case of exceeding 40 wt %, a mechanical factor is too strong, which may cause grinding flaws, etc., and result in no remarkable enhancement in grinding speed being expected. The abrasive grain content of an abrasive solution of the invention is preferably 0.5 wt % or more and 5 wt % or less, more preferably 0.7 or more and 2 wt % or less when the total amount of the abrasive solution containing the medium is 100 wt %. In the case of less than 0.5 wt %, no abrasive grain effects are exhibited, which results in a reduction of grinding speed and a deterioration of wafer shape. In the case of exceeding 5 wt %, the surface is rough, which results in flaws, haze, etc. The abrasive concentration of the medium is preferably 0.5 or more and 50 wt % or less, more preferably 1 or more and 20 wt % or less. In the case of less than 1 wt %, no abrasive grain effects are exhibited, which results in a reduction of grinding speed and a deterioration of wafer shape. In the case of exceeding 20 wt %, the surface is rough, which results in flaws, haze, etc. <Dispersion Time> The dispersion time (ultrasonic irradiation and agitation time) is preferably 5 min or more and 15 min or less. In the case of the dispersion time (ultrasonic irradiation and agitation time) exceeding 15 min, the temperature of the abrasive solution rises up, which may increase the decomposition speed of an oxidizer, and result in a problem in grinding characteristics. In the case of less than 5 min, the dispersiveness of abrasive grains may be not sufficient. <Grinding Method> Also, the invention provides a method for grinding the surface of an object to be ground using the above abrasive solution. In this grinding method of the invention, for aggregated grains to be easily dissociated, the grinding pressure (pressure applied between the abrasive pad and the object to be ground during grinding) is preferably 2-10 kPa, more preferably 3-7 kPa. Lower grinding pressures than 2 kPa may result in insufficient dissociation of aggregated grains, and a reduction of grinding capability due to too low grinding pressure applied to the wafer. On the other hand, in the case of a compound semiconductor wafer with strong cleavage to be ground, higher grinding pressures than 10 kPa results in the wafer tending to crack due to too high grinding pressure. The grinding method of the invention can be applied to semiconductor wafers such as compound semiconductor wafers, silicon wafers, etc., and the object to be ground is not limited to a particular semiconductor wafer, but is suitable particularly for grinding wafers comprising group III-V compound semiconductors such as GaAs, GaP, GaSb, AlAs, InAs, GaAlAs, GaAsP, etc. <Semiconductor Device Fabrication Method> The invention provides a semiconductor device fabrication method comprising the step of grinding a semiconductor wafer surface or group III-V compound semiconductor wafer surface, using the above grinding method of the invention. The steps other than the grinding step of the semiconductor device fabrication method of the invention are not limited. The semiconductor device fabrication method of the invention may comprise the steps of: (1) grinding the surface of a substrate by an abrasive solution of the invention; (2) etching a grinding damage layer of the substrate surface; sequentially forming semiconductor layers and forming ohmic contact; (4) dispersing impurities and implanting ions; (5) forming a surface protection film; and (6) cutting the substrate. EXAMPLE 1 This Example examined grinding characteristics of an abrasive dissolved and dispersed in pure water, as shown in Table 1, using silica Nos. 1 - 7 as abrasive grains. TABLE 1 Composition Abrasive content [wt %] Concentration Silica (abrasive grains) 20 11 [g/l] Sodium dichloroisocyanurate 35 0.0082 [mol/l] Sodium tripolyphosphate 22 0.03 [mol/l] Sodium sulfate 18 0.06 [mol/l] Sodium carbonate 5 0.025 [mol/l] First, silica Nos. 1 and 2 use fumed silica with an average grain size of 50 nm measured by the BET method, and aggregated silica grains are formed in the conditions of Table 2. In forming each aggregated silica, fumed silica as an ingredient and a predetermined amount of pure water are mixed uniformly by a Heichel mixer. Subsequently, aggregated silica No. 1 is hot-air dried for 24 hr at 120° C. in a constant-temperature bath, while aggregated silica No. 2 is heat-dried for 2 hr being uniformly mixed at 100° C. by a Heichel mixer. Nos. 1 and 2 are then ground at 25° C. by a pin mill. Aggregated silica Nos. 3 - 7 are commercial synthetics prepared by the wet method. TABLE 2 Conditions No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 No. 7 Pure water 47.7 55 Commercial Commercial Commercial Commercial Commercial added [%] silica silica silica silica silica Dry Const. temp. Heichel mixer: bath: 120° 100° C. × C. × 24 hr 24 hr Dispersion & none Pin mill: grinding 25° C. Volatile 0 0 10 9.5 6.7 7 7 cont. [wt %] This Example prepares abrasives having composition shown in Table 1 using seven abrasive grains shown in Table 2, and then dilutes these abrasives about 20 times with pure water, and irradiates them with frequency 40 W ultrasound to prepare abrasive solutions. These abrasive solutions are taken as a reference point (0 min), and are dispersed and ground by applying a homogenizer 200 μA power (Nihon Seiki Co. Ltd.) continuously for 1, 3 and 5 minutes. Respective changes over time of their average grain size, grain-size distribution and roundness are observed. Average grain size and grain-size distribution are measured by a commercial laser-type grain-size analyzer, and roundness are measured by a commercial grain image analyzer, diluting the abrasive solutions 15 times after 0, 3 and 5 minutes. Average grain size and roundness of abrasive solutions Nos. 1 - 7 are shown in Table 3. Also, each change over time of grain-size distribution is shown in FIGS. 1-7 , and each change over time of roundness is shown in FIG. 13 . Further, this change of grain-size distribution is considered to provide an indication of cohesion. It is determined that, with grain-size distribution curves changing over time, the cohesion of abrasive grains changing to the small grain-size side tended to be weaker, while the cohesion of abrasive grains whose grain-size distribution curve change was not remarkable tends to be stronger. TABLE 3 Silica (abrasive Average grain size [μm] Roundness grains) 0[min](*1) 5[min](*1) 0[min](*1) 5[min](*1) No. 1 3.74 1.46 0.59 0.56 No. 2 14.44 5.24 0.45 0.66 No. 3 7.72 6.20 0.65 0.67 No. 4 3.26 3.03 0.70 0.68 No. 5 4.88 4.9 0.60 0.59 No. 6 12.42 12.32 0.58 0.56 No. 7 14.82 14.70 0.54 0.54 (*1)Dispersion time by the homogenizer Next, using the abrasive solutions obtained, an about 100 mm (4 inches)-size GaAs wafer is ground in the conditions shown in Table 4. The results are shown in Table 5. Further, grinding speed is measured in a central portion of wafer thickness before and after grinding by a contact laser displacement gauge, and is calculated from wafer thickness difference and grinding time. Wafer shape (TTV: Total Thickness Variation) is the measured difference between the highest and lowest points of wafer thickness, taking the back side of the wafer as the reference point of the wafer shape (TTV), and TTV shows thickness variation, i.e., flatness of the wafer surface. Also, surface roughness (Pv) is the measured difference between the highest and lowest points of the uneven surface. Also, appearance is denoted by “very good” (very few grinding flaws and marks seen), “good” (few grinding flaws and marks seen), and “poor” (many grinding flaws and marks seen). TABLE 4 Items Conditions Sample 100 mm-size GaAs wafer Grinding pressure 3.5 kPa [35 gf/cm 2 ] No. of revolutions of the plate 74 [rpm] Abrasive supply 15 [ml/min] Grinding time 60 [min] TABLE 5 Silica Grinding Wafer Surface (abrasive speed shape roughness grains) [μm/min] (TTV) [μm] (Pv)[nm] Appearance No. 1 0.6 or more 1.5 3-5 Very good No. 2 0.6 or more 1.3 3-5 Very good No. 3 0.6 or more 1.4 3-5 Very good No. 4 0.6 or more 1.4 3-5 Very good No. 5 0.53 1.6 3-5 Very good No. 6 0.52 1.8 4-7 Very good No. 7 0.55 2.0  5-10 Good COMPARATIVE EXAMPLE 1 This Comparative Example uses silica Nos. 8 - 12 as abrasive grains to examine grinding characteristics of an abrasive diluted with pure water to be dispersed therein and ground, in the same manner as Example 1. Silica Nos. 8 - 12 uses the same fumed silica as that of Example 1, and aggregated silica grains are formed in the conditions of Table 6. Each aggregated silica is mixed in the same manner as that of Example 1. Subsequently, aggregated silica Nos. 8 - 12 are heat-dried at 100° C. for 2 hr being rolled by a Heichel mixer, while aggregated silica No. 11 is heat-dried and then ground by further increasing the shear force of the Heichel mixer. Further, to weaken the cohesion between aggregated grains, heating aggregated silica No. 10 is stopped when the moisture content reaches 30 wt %. Also, aggregated silica No. 12 is commercial synthetic spherical silica by the spray method, which is dispersed in the abrasive solution as primary grains. TABLE 6 Conditions No. 8 No. 9 No. 10 No. 11 No. 12 Pure water 49 46.5 46.5 55 Commer- added [%] cial silica Dry Heichel Heichel Heichel Heichel mixer: mixer: mixer: mixer: 100° C. × 100° C. × 100° C. × 100° C. × 2 hr 2 hr 2 hr 2 hr Dispersion none none none Heichel & grinding mixer: 25° C. Volatile 0 0 30 0 0 cont. [wt %] This Comparative Example prepares five abrasives using silica Nos. 8 - 12 shown in Table 6 as abrasive grains, and then prepares abrasive solutions, in the same manner as Example 1. These abrasive solutions are taken as a reference point (0 min), and respective changes over time of their average grain size, grain-size distribution and roundness are observed in the same manner as Example 1. Average grain size and roundness of abrasive solutions of silica Nos. 8 - 12 are shown in Table 7. Also, each change over time of grain-size distribution is shown in FIGS. 8-12 , and each change over time of roundness is shown in FIG. 13 . Also, using the abrasive solutions obtained, the results of grinding in the same manner as Example 1 are shown in Table 8. TABLE 7 Silica (abrasive Average grain size[μm] Roundness grains) 0[min](*1) 5[min](*1) 0[min](*1) 5[min](*1) No. 8 12.3 3.81 0.58 0.86 No. 9 4.7 1.6 0.74 0.80 No. 10 4.14 0.27 0.75 0.79 No. 11 14.61 4.23 0.46 0.93 No. 12 5.79 5.79 0.98 0.98 TABLE 8 Silica Grinding Surface (abrasive speed Wafer shape roughness grains) [μm/min] (TTV) [μm] (Pv)[nm] Appearance No. 8 0.56 1.0 (peripheral 3-5 Very good dripping) No. 9 0.60 0.8 (peripheral 3-5 Very good dripping) No. 10 0.53 1.1 (peripheral 3-5 Very good dripping) No. 11 0.51 0.5 (peripheral 3-5 Very good dripping) No. 12 0.43 1.2 (peripheral  6-12 Poor dripping) The results of abrasive grain assessment and grinding experiments of Example 1 and Comparative Example 1 are explained below. From FIG. 13 showing change of roundness against dispersion time (dispersion and grinding time), the roundness of abrasive grains Nos. 1 - 7 of Example 1 when dispersed and ground by applying the homogenizer for 5 min is all less than 0.75, and as a result of grinding by the abrasive solutions using abrasive grains Nos. 1 - 7 , the wafer shape is good as shown in Table 5. On the other hand, the roundness of abrasive grains Nos. 8 - 12 of Comparative Example 1 when dispersed and ground by applying the homogenizer for 5 min is all more than 0.75, and as a result of grinding by the abrasive solutions using abrasive grains Nos. 8 - 12 , peripheral dripping occurred on a wall of a wafer peripheral portion as shown in Table 8. It is found from this result that, in the case of a roundness of 0.75 or less, preferably less than 0.72 or less, good-flatness wafer shape can be ensured without peripheral dripping. In other words, by using abrasive grains with a roundness of 0.55 or more and 0.72 or less, deterioration of wafer shape due to change over time of the abrasive pad can be controlled. In comparison, from the result of Comparative Example 1 showing a roundness of 0.75 or more, as abrasive grain roundness increases and abrasive grain shape approaches a sphere, wafer shape tends to be poorer and peripheral dripping is more remarkable. Abrasive grains No. 12 are silica extremely close to a sphere, which are dispersed into the medium as primary grains, and grinding by use of abrasive grains No. 12 causes flaws and chips in the wafer surface and periphery, which results in a remarkable deterioration of wafer shape and a remarkable reduction of grinding speed. Effects of grinding characteristics on abrasive grain shape are explained below. First, the relationship between abrasive grain shape and wafer shape is explained. In the case of a roundness of 0.75 or more, when abrasive grains 3 of silica close to a sphere collide with a side surface of a wafer 1 during grinding, since silica is harder than GaAs, the side surface of the wafer 1 is ground to cause broken wafer pieces 5 , as shown in FIG. 14 . Also, since silica close to a sphere has no holding force and tends to roll on an abrasive pad, silica is pushed to a peripheral portion of the abrasive pad by rotation of the plate. For this reason, the periphery of the wafer 1 is ground to cause peripheral dripping. As aggregated grain cohesion is stronger, this phenomenon is more remarkable and more flaws, chips, etc. occur. This is easily understood by analogy with the result of grinding silica No. 12 . On the other hand, more amorphous silica with a lower roundness being more different from a perfect circle is ground with the periphery of the wafer caused to rise. This makes a corner of abrasive grains 7 fragile by an impact, as shown in FIG. 15 . For this reason, when abrasive grains 7 collide with a side surface of the wafer 1 , a corner of abrasive grains 7 is ground to cause ground abrasive grains 9 , but the side surface of the wafer 1 is thereby not ground. Also, since amorphous abrasive grains 7 , unlike spherical abrasive grains 3 , are held on the abrasive pad without rolling and being pushed to a peripheral portion of the wafer. For this reason, as the roundness of abrasive grains becomes lower and more amorphous, less peripheral dripping of the wafer occurs. Second, the relationship between abrasive grain shape and grinding speed is explained. Grinding speed is largely affected by abrasive grain shape as well as being affected by a contact area between abrasive grains and the wafer, and by holding force on the abrasive pad of abrasive grains. FIG. 16 shows the relationship between roundness and grinding speed. The graph of FIG. 16 has a maximum extreme. As the roundness exceeding 0.7 approaches a perfect circle (roundness goes up), the grinding speed decreases. Also, at 0.7 or less, as the roundness is more different from a perfect circle and more amorphous, the grinding speed decreases. In the case of a roundness at 0.65 or less, a corner of abrasive grains bites into a surface of the abrasive pad so that the abrasive grains are held on the abrasive pad, but because of the contact of the point and surface, sufficient contact area cannot be ensured, which results in no high grinding speed being obtained. Also, In the case of a roundness at 0.75 or more, especially at 0.85 or more, since abrasive grain shape is close to a sphere, the abrasive grains tend to roll on the abrasive pad without being held thereon, which results in no sufficient grinding speed being obtained. The roundness for obtaining sufficient grinding speed is in the range of 0.65 or more and 0.75 or less, which is considered to be a shape of the abrasive grains for being easily held on the abrasive pad, and for obtaining sufficient contact area. In this manner, of abrasive grain characteristics (roundness, cohesion, average grain size, grain-size distribution), the most correlated characteristics with grinding characteristics (wafer shape, grinding speed) is roundness. Abrasive grain roundness and grinding characteristics, especially wafer shape and grinding speed largely affects each other. Next, examples that a shape of abrasive grain affects the wafer shape and grinding speed most are shown. As the first example, there is shown an example that cohesion, average grain size, and grain-size distribution are the same, but roundness is different. In comparison of abrasive grains No. 2 of Example 1 with No. 11 of Comparative Example 11, looking at the change of grain-size distribution against dispersion time by the homogenizer shown in FIGS. 2 and 11 , the cohesion and grain-size distribution are the same, and the average grain size is the same, as shown in Tables 3 and 7. However, by comparison of the roundness when the homogenizer is applied for 5 min, the roundness of abrasive grains No. 2 is 0.66, which was significantly different from the roundness of abrasive grains No. 11, 0.93. When ground by using an abrasive with abrasive grains No. 2 , the wafer shape and grinding speed are good, as shown in Table 5, whereas, when ground by using abrasive grains No. 11, the wafer shape deteriorates and the grinding speed decreases. As the second example, there is shown an example that roundness is the same, but cohesion, average grain size, and grain-size distribution are different. In comparison of abrasive grains Nos. 1 and 2 of Example 1, the roundness of abrasive grains Nos. 1 and 2 is the same, as shown in Table 3, but in view of Table 3, FIGS. 1 and 2 , the cohesion, average grain size, and grain-size distribution of abrasive grains Nos. 1 and 2 are significantly different. In contrast, the grinding characteristics when ground by using abrasives with abrasive grains Nos. 1 and 2 both are good, as shown in Table 5. Also, as mentioned above, since grinding characteristics vary according to roundness, the roundness can be used dependent on grinding characteristics required most in a manufacturing line. From the point of view of grinding characteristics, roundness is divided into the first range of 0.5 or more and less than 0.65, the second range of 0.65 or more and less than 0.75, the third range of 0.75 or more and less than 0.87, and the fourth range of 0.87 or more and less than 1.0. In the third range, peripheral dripping due to a subtle shape difference of abrasive grains occurs, but sufficient grinding speed may be obtained. From the above reason, however, abrasive grains exhibiting the roundness of the third and fourth ranges, the wafer shape tends to deteriorate and the grinding speed tends to decrease, which results in difficulty of use as the abrasive. The range of roundness that can be used as the abrasive is the first and second ranges. A wafer when ground by using abrasive grains exhibiting the roundness of the first range can provide a stable shape without causing peripheral dripping. Also, as secondary effects, deterioration of wafer shape accompanied by change over time of the abrasive pad is controlled, so that the life of the abrasive pad becomes longer. As described above, however, abrasive grains Nos. 5 - 7 of Example 1 exhibiting the roundness of the first range cannot provide a sufficient contact area with the wafer, and in addition, since the cohesion between primary grains is strong so that they are not easily ground during grinding, no contact area with the wafer is obtained, so that the abrasive grains exhibiting the roundness of the first range cannot ensure sufficient grinding speed. For this reason, chemical concentration adjustment is required. By adjusting a chemical concentration of sodium tripolyphosphate of the abrasive as shown in Table 1, sufficient grinding speed can be obtained. As an exception, an abrasive using abrasive grains No. 1 of Example 1 with the roundness of the first range provides a good wafer shape, and a sufficient grinding speed of more than 0.6 μm/min despite the low roundness 0.56. In this case, from the change of grain-size distribution against dispersion time of the homogenizer shown in FIG. 1 , the cohesion of abrasive grains No. 1 is weak, and when the homogenizer is applied for 5 min, the average grain size is ground from 3.74 μm to 1.46 μm. For this reason, the abrasive grains being made fine make the contact area with the wafer larger, which is considered to result in sufficient grinding speed. As described above, the average grain size is also considered to be a factor which affects grinding characteristics, but because the factors of grain size and roundness cannot be separated, it cannot be clear. Grinding characteristics when ground by using an abrasive using abrasive grains exhibiting the roundness of the second range can provide both good wafer shape and sufficient grinding speed. Abrasive grains exhibiting the roundness of the second range are most versatile. They are widely applied with less variation of grinding characteristics regardless of differences in grinding apparatus characteristics, abrasive pads, wafer shape before grinding, and so on. The wafer shape of an abrasive using abrasive grains exhibiting the roundness of the second range has a gentle inclination from a wafer peripheral portion to the center, compared with that of abrasive grains exhibiting the roundness of the first range, so that the wafer tends to cause peripheral dripping little by little with change over time of the abrasive pad. In this case, dependent on change over time of the abrasive pad, abrasive grains exhibiting the roundness of the first and second ranges are used appropriately, thereby allowing wafer shape to be maintained, which results in no loss of grinding speed, ensured stable wafer shape, and longer life of the abrasive pad. In Example 1, grinding characteristics using abrasive grains No. 6 exhibiting the roundness of the first range provide good wafer shape, but grinding speed decreases by 10%, compared with abrasive grains exhibiting the roundness of the second range. Accordingly, using abrasive grains No. 3 exhibiting the roundness of the second range, the correlation of grinding speed and a concentration of sodium tripolyphosphate which has the effect of enhancing grinding speed most is examined. Five abrasives are prepared by changing the concentration of sodium tripolyphosphate, and then abrasive solution preparation and grinding are performed. Consequently, as shown in FIG. 17 , it is found that, as the concentration of sodium tripolyphosphate becomes higher, the grinding speed becomes higher, and the effect is obtained up to an amount added about twice the concentration of sodium tripolyphosphate of Table 1. After preparing the abrasive of Table 1, when an abrasive solution is prepared, the concentration of sodium tripolyphosphate is 0.03 mol/l. The amount added of sodium tripolyphosphate which has the effect is 0.014 mol/l or more and 0.07 mol/l and less. In the case of less than 0.014 mol/l, almost no effect is obtained, which results in no sufficient grinding speed. Also, in the case of exceeding 0.07 mol/l, haze occurred in a wafer surface, which could not be removed enough in the cleaning step. The amount added of sodium tripolyphosphate is preferably 0.025 mol/l or more and 0.05 mol/l or less, which can enhance grinding speed without being affected by the wafer even when the other chemical concentrations are made higher. Using abrasive grains No. 6 , abrasives are prepared in the four concentrations of sodium tripolyphosphate shown in Table 9, and then abrasive solution preparation and grinding are performed (The results are shown in Table 10). TABLE 9 sodium tripolyphosphate [mol/l] 1 0.03 2 0.05 3 0.07 4 0.085 TABLE 10 Surface Grinding speed Wafer shape roughness [μm/min] (TTV) [μm] (Pv)[nm] Appearance 1 0.55 or more 1.3 3-5 Very good 2 0.60 or more 1.4 3-5 Very good 3 0.63 or more 1.4 3-5 Very good 4 0.67 or more 1.3 3-5 good The similar result to those using the above abrasive grains No. 3 is exhibited. By adding 0.05 mol/l of sodium tripolyphosphate, sufficient grinding speed is obtained. Also, for this reason, when abrasive grains exhibiting the roundness of the first range are used, by increasing the concentration of sodium tripolyphosphate within the above-described range, sufficient grinding speed and good wafer shape are obtained. EXAMPLE 3 In order to grasp a life of abrasive pads, after an abrasive is prepared using abrasive grains No. 3 of Example 1, an abrasive solution is prepared, and grinding is performed in the same conditions as those of Example 1 (The results are shown in Table 11). TABLE 11 Wafer Surface Silica Grinding shape roughness (abrasive No. of speed (TTV) (Pv) grains) cycles [μm/min] [nm] [nm] Appearance No. 3 1 0.60 or more 1.4 3-5 Very good 45 0.60 or more 0.85 3-5 Very good (peripheral dripping) No. 6 46 0.58 or more 1.3 4-6 Very good 95 0.57 or more 1.1 4-6 Good The result shows that the wafer shape varies little by little from 20 cycles, and at 45 cycles, peripheral dripping in the wafer is remarkable, while the measured value of TTV is 0.85. For this reason, after an abrasive is prepared using abrasive grains No. 6 so that the concentration of sodium tripolyphosphate is 0.05 mol/l in the same manner as Example 2, an abrasive solution is prepared, and grinding is performed in the same conditions as those of Example 1. The result shows that peripheral dripping in the wafer can be controlled. The grinding speed during it is the same as that using abrasive grains No. 3 . Further grinding is performed continuously until 95 cycles, which then causes slight flaws and therefore is finished. Consequently, a life of the abrasive pad can be extended from 45 cycles to 95 cycles. Also, the grinding characteristics shows that slight flaws occurred at 95 cycles, but wafer shape and surface roughness both maintain 46-cycle grinding characteristics, and the grinding speed is also the same as first 46 cycles. In this manner, by using the abrasive grains appropriately, the grinding characteristics can be maintained, while a life of the abrasive pad can be extended twice. EXAMPLE 4 This Example fabricates a semiconductor laser device with MQW (multi-quantum well) structure provided on a GaAs substrate as one example of a semiconductor device. Further, the form of a semiconductor device fabricated with the invention is not limited to the structure of this Example. First, using the abrasive solution of Example 1 shown in Table 3, a surface of the (100)-plane GaAs substrate is ground and flatted. The grinding conditions are almost the same as those shown in Table 4: the grinding pressure is 3.5 kPa; the number of revolutions of the plate is about 74 rpm; the abrasive solution supply is 15 ml/min; and the grinding time is about 60 min. Subsequently, grinding marks in the surface of the GaAs substrate are removed using a H 3 PO 4 :H 2 O etching solution according to needs. Thereafter, using MBE (molecular beam epitaxy), MOCVD (metal organic chemical vapor deposition), or the like, there are sequentially formed a first GaAlAs cladding layer (film thickness: about 0.5 μm), an MQW (multi-quantum well) active layer (film thickness: about 50 nm), a second GaAlAs cladding layer (film thickness: about 0.2 μm), and a GaAs current-limiting layer (film thickness: 3-5 μm). Further, the MQW active layer has GaAs (film thickness: 3 nm) and GaAlAs (film thickness: about 5 nm) layers formed alternately and sequentially therein. Subsequently, the GaAs current-limiting layer has an opening with a specified width (3-5 μm) provided in the (110)-plane so as to reach the second GaAlAs cladding layer. Subsequently, an electrode layer is formed in the opposite surface to the first GaAlAs cladding layer-side surface in the GaAs substrate. Subsequently, an electrode layer is formed in the opposite surface to the active layer-side surface in the second GaAlAs cladding layer and the GaAs current-limiting layer so as to fill in the above opening. And finally dicing is performed to obtain a semiconductor laser device. As a result of examining characteristics of the semiconductor laser device, it is found that the linearity of current-light characteristics after oscillation is improved, and variations of important characteristics of the semiconductor laser device, such as oscillation threshold current, is improved, in comparison with the case where no flattening grinding of the GaAs substrate is performed. Further, although the thickness of the first cladding layer is 0.5 μm in the above example, even when it is on the order of 0.1-0.2 μm, a similar result to the above example is exhibited. This is considered to be because, by flattening the GaAs substrate surface using the abrasive of the invention, effects on the extremely important MQW active layer of the laser device due to uneven surface of the GaAs substrate are reduced. Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.

Abrasive grains have mainly grains with a roundness of 0.50 or more and 0.75 or less, where the roundness is defined as the ratio of the circumference of a circle having the same area as that of a grain to the perimeter of that grain. An abrasive has the abrasive grains and at least one of an oxidizer, an oxide solution, an abrasive grain dispersion agent and a basic compound. An abrasive solution has the abrasive grains and water or hydrophilic substance.

CROSS-REFERENCE TO RELATED APPLICATONS This application is a division of U.S. patent application Ser. No. 10/832,894 filed Apr. 27, 2004, now U.S. Pat. No. 7,141,853 which in turn, is a division of U.S. patent application Ser. No. 09/879,530 filed Jun. 12, 2001 now U.S. Pat. No. 6,759,282. The disclosures of said applications are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention involves fabrication of semiconductor devices using Silicon-on-Insulator (SOI) technology. More specifically the invention is directed to the use of the SOI Buried Oxide (BOX) layer as an integral component of electronic devices and circuits. 2. Description of the Related Art Silicon-On-Insulator (SOI) technology has emerged as an electronic fabrication technique that improves characteristics such as latch-up and speed, although typically at higher manufacturing cost. The term SOI typically describes structures where devices are fabricated in single-crystal Si layers formed over an insulating film or substrate. FIGS. 11A and 11B show a typical conventional SOI structure, where a thin silicon device layer 110 formed on an insulator 111 is supported over substrate 112 . For current technology the substrate is most commonly silicon and the insulator is most commonly silicon dioxide. Devices 113 are formed in device layer 110 and interconnected by surface conductors 114 . The conventional SOI structure is predominantly created by one of two techniques. The first process, known as SIMOX (Separation by IMplanted OXygen), consists of implantation of oxygen into an Si substrate at a prescribed depth and heating it to form a continuous layer of SiO 2 . The SIMOX process requires only a single wafer. The alternate process, shown in greater detail later, is commonly referred to as “Bonded SOI” and starts with two wafers, preferably with at least one having an oxide surface. The first wafer is the carrier wafer which is joined together with the second wafer, and the second wafer is “thinned” to leave a layer of silicon bonded onto the carrier wafer, separated by an insulator layer. Both of the techniques have experienced many variations and enhancements over the years for improvement of yield and lower cost and to achieve desirable device layer quality for uniformity and defects. An important characteristic of conventional SOI that is obvious from FIG. 11B is that the insulator layer 111 is used primarily for isolating the silicon device layer 110 with its active devices 113 from the silicon substrate 112 . Thus, the conventional wisdom forms devices on the device layer 110 on only one side of the insulator layer 111 . The problem with this approach is that, although devices and interconnects are formed similar to conventional substrates, SOI techniques introduce newer problems such as floating body effects. Additionally, conventional SOI structure takes up considerably more chip “real estate” than required in corresponding non-SOI structure, since floating body effects which not an issue with conventional substrates require additional connections to the channel regions. There are also added process steps to provide ground interconnections to the substrate. More important, the conventional approach fails to recognize that the insulator layer could provide more functionality than merely separating predetermined groups of devices from the substrate. SUMMARY OF THE INVENTION The inventors have recognized that the SOI insulator layer, or BOX (Buried OXide), can be an integral part of a specific device, and further, even circuits can be advantageously built around this innovative approach. That is to say, the BOX can be considered more than a mere passive isolation mechanism separating layers of devices. It can become an integral component even of an entire circuit. As will be demonstrated, by adopting this innovative approach, a whole new possibility opens up for SOI technology that provides improved device density and speed and fewer conductor interconnects between devices. According to an aspect of the invention a method is provided for fabricating a complementary metal oxide semiconductor (CMOS) circuit on a semiconductor-on-insulator (SOI) substrate, where the SOI substrate includes a single-crystal semiconductor layer separated from a bulk semiconductor region by a buried oxide layer. In such method, a plurality of field effect transistors (FETs) are formed including a first FET and a second FET. Each of the plurality of FETs has a channel region disposed in a common device layer within the single-crystal semiconductor layer. A gate of the first FET overlies an upper surface of the common device layer, and a gate of the second FET underlies a lower surface of the common device layer remote from the upper surface. In addition, the first and second FETs share a common diffusion region disposed in the common device layer and are conductively interconnected by the common diffusion region. The common diffusion region is operable as at least one of a source region or a drain region of the first FET and is simultaneously operable as at least one of a source region or a drain region of the second FET. According to a second aspect of the invention, a method is disclosed of fabricating an electronic circuit using an SOI technique, said SOI technique resulting in formation of at least one buried oxide layer, the electronic circuit comprising a plurality of interconnected electronic devices, each electronic device comprising a respective plurality of components. The method includes fabricating a predetermined first set of respective plurality of components to be on a first side of the buried oxide layer and fabricating a predetermined second set of respective plurality of components to be on a second side of the buried oxide layer, where the second side is the opposite side of the first side, and where the buried oxide layer performs a function integral to the functioning of at least one of the electronic devices. According to a third aspect of the invention, a method is disclosed of SOI fabrication in which a buried oxide layer is formed, where the method includes forming a first set of device components to be on a first side of the buried oxide layer and forming a second set of device components to be on the side opposite the first side, where the buried oxide layer performs a function integral to the functioning of at least one device comprised of components from the first set of components and components from the second set of components. According to a fourth aspect of the invention, a method and structure are disclosed of fabricating a DRAM cell using an SOI technique on a substrate, where the SOI technique results in formation of at least one buried oxide layer. The method includes forming a buried capacitor beneath the buried oxide layer, subsequently forming an FET source and drain regions on top of the buried oxide layer, and interconnecting the capacitor to one of the source region or drain region with a via penetrating the buried oxide layer, where the via is a conductive material. According to a fifth aspect of the invention, a method and structure are disclosed of fabricating a DRAM cell using an SOI technique, where the SOI technique results in formation of at least one buried oxide (BOX) layer, whereby a capacitor for the DRAM cell is formed by a process including forming a buried electrode in a substrate, wherein the buried electrode serves as a lower capacitor charge plate and forming a diffusion link between the diffusion region of a transistor located on the upper side of the BOX and a region to comprise an upper charge plate of the capacitor, where the upper charged plate of the capacitor is formed on the upper side of the BOX when impressing a bias voltage on the buried electrode. According to a sixth aspect of the invention, a method and structure are disclosed of fabricating an electronic circuit having a plurality of electronic devices using an SOI technique, the SOI technique resulting in formation of at least one buried oxide layer. The method includes forming an interconnector of conductive material to interconnect at least two of said plurality of electronic devices, the interconnector at least partially enclosed by said buried oxide. According to a seventh aspect of the invention, a method and structure are disclosed of fabricating a dynamic two-phase shift register. The method includes forming a buried oxide layer using an SOI technique, forming a plurality of FET transistors to be in a device layer above the buried oxide layer, forming a first clock signal conductor on top of the device layer, and forming a second clock signal conductor below the device layer, the second clock signal conductor at least partially enclosed by the buried layer. According to an eighth aspect of the invention, a method and structure are disclosed of fabricating a CMOS circuit. The method includes forming a buried oxide layer using an SOI technique and forming a plurality of FET transistors to be in a device layer above the buried oxide layer, wherein at least two of the FET transistors share a common diffusion region, thereby electrically interconnecting the two FET transistors without using a separate interconnecting conductive material. According to a ninth aspect of the invention, a method and structure are disclosed of fabricating a FET using an SOI technique, the SOI technique resulting in formation of at least one buried oxide layer. The method includes forming a first gate beneath the buried oxide layer and forming a second gate on top of the buried oxide layer. According to a tenth aspect of the invention, a structure is disclosed of an electronic device including at least one SOI buried oxide layer, where the at least one buried oxide layer performs a function integral to the device. According to an eleventh aspect of the invention, a structure is disclosed of an electronic device comprising at least one SOI buried oxide layer, where the at least one SOI buried oxide layer becomes a structural element integral to the device. According to a twelfth aspect of the invention, a structure is disclosed of an electronic circuit comprising a plurality of interconnected devices, the circuit mounted on a wafer having at least one SOI buried oxide layer, wherein the at least one SOI buried oxide layer is a functional element integral to at least one of the devices. According to a thirteenth aspect of the invention, a structure is disclosed of an electronic circuit comprising a plurality of interconnected devices, the circuit mounted on a wafer having at least one SOI buried oxide layer, where the at least one SOI buried oxide layer comprises a structural element integral to at least one of the devices. According to a fourteenth aspect of the invention, a structure is disclosed of an electronic circuit comprising a plurality of interconnected devices, the circuit mounted on a wafer having at least one SOI buried oxide layer, where the two adjacent devices share at least one device component, thereby electrically interconnecting the two devices without an interconnecting conductor, and where the SOI buried oxide layer serves to isolate components of the two interconnected devices other than the shared component. According to a fifteenth aspect of the invention, a method is disclosed of SOI fabrication wherein a buried oxide layer is formed. The method includes forming a first set of device components to be on a first side of the buried oxide layer and forming a second set of device components to be on the side opposite, where the buried oxide layer is used for an active functioning of at least one buried device. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which: FIGS. 1A-1C show three exemplary kinds of structure formed in the supporting silicon body which illustrate how the BOX can be advantageously used; FIG. 2 shows exemplary device structures using the techniques taught in the invention; FIGS. 2A-2E show exemplary structures formed in the lower section silicon body prior to forming SOI substrate; FIGS. 3A-3D illustrate the bonded SOI process for completing the process of FIGS. 2A-2E to form the device illustrated by FIG. 2 ; FIGS. 4A-4E show an exemplary set of steps using the SIMOX process for forming a device illustrated by FIG. 2 ; FIGS. 5A-5D illustrate examples of different device elements formed using the invention that illustrate advantages of the invention; FIGS. 6A-6C illustrate an advantage of the invention of using the BOX to interconnect components without having to use connectors; FIGS. 7A-7B illustrate another example of the invention, as used to implement DRAM cells; FIGS. 8A-8C illustrate a second implementation of DRAM cells using the invention; FIGS. 9A-9C illustrate an example of the invention for a dynamic two phase shift register circuit, which example demonstrates the BOX as a circuit element; FIGS. 10A-10B illustrate the invention used for a NOR circuit; and FIGS. 11 a, 11 b show conventional SOI structures. Note that the drawings are drawn more to illustrate the inventive processes and structures and are not drawn to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Going back to FIGS. 11A-11B illustrating the conventional SOI device, wherein oxide layer 111 separates device layer 110 from substrate 112 . FET devices 113 are built into device layer 110 . One conventional technique forms FET transistors with the following steps: a gate oxide is formed by a surface oxidation of layer 110 , a gate electrode is formed by deposition and patterning of polysilicon, and source and drain regions are formed by implantation of a dopant. These source/drain regions, gate electrodes can then be surface wired 114 by common interconnection processes. Turning now to the invention, FIGS. 1A-1C illustrate respectively a buried gate 13 , a buried wire 14 , and a buried capacitor 15 which are exemplary structures resulting from the present invention to use the BOX 12 as an integral part of devices and even entire circuits. Either the SIMOX technique or the bonded technique can be used. Substrate 10 receives device components which are then complemented with components 16 in the device layer 11 above BOX 12 . Similar to conventional SOI structures of FIGS. 11A-11B , surface conductors 17 could still be used to interconnect devices if desired, although the invention permits interconnections in a different manner. Details of forming these structures and the advantages of the invention will become obvious to one skilled in the art after an understanding of the following sections FIG. 2 shows an exemplary SOI structure 20 in which two FETs 20 A, 20 B are constructed with the BOX 24 as an integral part at the device level. Buried elements 21 , 22 have been formed in the lower section 23 . In this discussion element 21 is a body contact and element 22 is a buried gate. BOX 24 separates lower section 23 from upper section 25 containing additional source and drain regions 26 , 27 . FIGS. 2A through 3D show an exemplary formation using the bonded SOI techniques to result in the structure 20 shown in FIG. 2 . An exemplary formation using SIMOX is illustrated in FIGS. 4A-4E . The buried elements 13 , 14 , 15 shown in FIGS. 1A-1C demonstrate that the buried elements 21 , 22 in FIG. 2 could be variously a gate, capacitor, or wire, depending on the process/material used in forming the elements. Therefore, it should be obvious that a great variety of devices can be constructed using the concepts taught by this invention. Concerning the bonded technique, FIG. 2A shows a method of constructing lower section 23 whereby a silicon dioxide layer 200 having thickness of 250-2500 A is formed on a silicon carrier substrate 201 . This layer 200 and its thickness is not critical since it is used as a selective mask in etching trenches 202 . It is quite likely that the insulator etch and later on polysilicon polish process will remove some of the oxide layer. In a preferred process, the BOX layer will be reformed after removing any residual mask layer at the same step as forming trench sidewall insulator. If needed, a silicon nitride layer 203 (not shown) of thickness in the range of 500-2500 A is used in addition to silicon dioxide 200 . Silicon nitride, although not intended as part of the BOX layer, can provide good selectivity for etching and chemical mechanical polishing and will protect the underlying oxide or the substrate. When nitride is used on top of an oxide layer, any remaining nitride layer after completion of buried structures in substrate 23 will be removed prior to bonding it to the device wafer. The final insulator stack for the mask layer preferably comprises oxide/nitride/oxide layers, although not all layers are essential. The thicknesses of the insulators are chosen depending on the depth of the trench 202 which in turn depends upon the specific component to be placed in the trench, but typically the combined thickness of the insulator stack is less than 5000 A. For forming a buried gate 13 (see FIG. 1A ), the trench depth 204 is typically about 2000-5000 A, similar to the typical thickness of gate electrodes. For forming a buried wiring layer 14 ( FIG. 1B ), the depth of the trench is typically in the range of 5000 Angstroms to 2 micron. For forming a trench capacitor 15 ( FIG. 1C ), a larger depth of the order of 2-6 microns is chosen. The process of etching vertical trenches in silicon substrate is well known. For example, for the exemplary buried gate process a standard lithography can be used to create the pattern in a resist mask, followed by a directional etching using a Cl 2 /Ar plasma such as described in U.S. Pat. No. 4,139,442, assigned to the assignee and incorporated herein by reference. Other commercially available etch processes are also satisfactory for the trench etch. After removing the resist mask, the substrate is similar to that shown in FIG. 2B . Subsequently, as shown in FIG. 2C , to further develop the buried gate structure, an insulation layer 205 , 206 will be incorporated on the sides/bottom of the trenches 202 . This insulator layer 205 , 206 typically would be an oxide or nitride layer or a combination thereof and is formed by depostion, in situ conversion of silicon, or a combination of processes. If thermal oxidation is chosen, it can use conventional steam or dry oxygen in a furnace, a rapid thermal heating in an oxidizing ambient, or any equivalent methods. Deposited oxides providing good conformality can also be used. For buried gates or buried wires, it is desired to have these conductors (yet to be formed) fully encased on the sides and bottom 207 with insulator. For other applications such as body contacts, the insulator in the bottom of the trench is not desirable 208 , and for removing the bottom insulator section, a directional etching using fluorine-containing gases such CF 4 or SF 6 can be used in a directional mode to selectively etch the newly formed insulator (oxide) 205 from the horizontal bottom surface 208 , leaving only the insulator along the trench vertical side walls. FIG. 2D shows that the trenches are then overfilled and planarized back to result in a selected conductor 209 , 210 embedded in the trench. The conductor 210 can be selected from polysilicon, tungsten or molybdenum and alike for close thermal matching with silicon and stability at the follow-on high process temperatures. An epitaxial Si 209 process can also be used. In one preferred process polysilicon 210 is formed by depositing in an LPCVD reactor at about 600-700 C, using dichlorosilane and a dopant precursor such as phosphine. The width of the gate pattern for the buried gates is restricted by the specific design ground rule. The polysilicon conductor 210 when deposited typically will fill and provide approximately a planar top surface. The polysilicon is then preferably polished by chemical-mechanical polishing (“CMP”) using, for example CABOT SC-I, a colloidal silica in an aqueous KOH solution with pH i10. Other polishing slurries commercially available and known in the field for polishing polysilicon with good selectivity to silicon nitride or silicon dioxide can also be used. At the end of polishing, the polysilicon 210 in the trench may be slightly recessed with respect to the insulator 206 but has a high degree of smoothness, typically a few nanometers. Specifically, the polishing process described in the publication “Characterization of Polysilicon Oxides Thermally Grown and Deposited on the Polished Polysilicon Films”, by Tan Fu Lei et al., IEEE Transactions on Electron Devices, vol. 45, No.4, April 1998, pages 912-917 is extremely attractive for producing a highly smooth polysilicon surface. The polish stop layer silicon nitride 203 , if it was used, is now removed from the top horizontal surfaces by wet etching selective to silicon and silicon dioxide, as is well known in the art. FIG. 2D represents approximately the appearance in cross section of the substrate after the polishing, with thermal oxide 200 on the top horizontal surfaces and polysilicon 210 . All surfaces are then subjected to post CMP clean using a dilute 50:1 ammonia in a megasonic cleaner. An additional RCA clean process could be used. At this point the height differences between the polysilicon and the silicon substrate is typically less than 500 A Next, as shown in FIG. 2E , an oxide layer 211 of about 500-1000 A is formed over the polysilicon and remnants of thermal oxide layer 200 . When 211 is formed by thermal oxidation, the thickness of oxide over doped polysilicon is expected to be somewhat thicker than the oxide growth in the surrounding Si areas. If thermal oxidation is used, 1000 A of oxide will consume about 400 A of polysilicon, whereas a slightly thinner oxide layer is formed over the silicon. The surface of the oxide is polished by CMP using a stiff pad and suitable oxide slurry such as Cabot SC-1 so as to form a continuous and smooth oxide layer. If needed, other thinning processes such as etching can be used to compliment the polishing to achieve the desired oxide thickness over the polysilicon gate electrode. The process is typically designed to leave about 100-250 A of silicon dioxide 211 over the polysilicon gate. Alternatively, a high quality CVD silicon dioxide of about 200-1000 A is deposited and polished back to leave a desired thinner oxide layer over the polysilicon gate region. Because of the method described above for the formation of the polysilicon in the trenches, the resulting structure shown in 2 E will have a thinner oxide over the polysilicon gate region 212 and a thicker oxide 213 over the silicon substrate regions. As a possible alternative, if CVD tungsten is used as the buried gate electrode. Instead of depositing polysilicon, a seed layer of TiN or Ti/TiN or TiW is deposited and followed by CVD W deposition using well established techniques with silane, hydrogen and WF 6 gases in a thermal reactor. The blanket metal film will appear similar to the polysilicon planar structure after deposition, which can be treated by CMP or plasma etched back to remove the W and the seed layers from the top surfaces. In one preferred process, the W layer will be recessed by using a plasma etch followed by forming a cap of silicide or silicon. The purpose of forming a tungsten silicide or polysilicon cap is again to form a thin oxide surface over the electrode. If a buried body contact is being formed, then there is no need to form the additional oxide on the surface of the encased conductor. Any oxide formed on the encased conductor is selectively removed. Other known variations of processes can be used to achieve essentially the structure shown in FIG. 2E with a variety of materials to form the components. Continuing with the bonded technique, FIG. 3A shows the development of the upper section 25 . Substrate 30 is prepared to become a temporary carrier. First, as an optional but one preferred technique to facilitate the removal of excess wafer material after the lower section 23 and upper section 25 have been joined (reference FIG. 2 ), hydrogen is implanted 31 into the silicon substrate 30 . Epitaxial layers 32 of silicon with different dopants from substrate or silicon-germanium may be deposited over the silicon substrate. Optionally, in the absence of a deposited epitaxial layer, the top surface region of the device substrate will become the device layer. The “Smart-Cut” process utilizing the epitaxially deposited layer is described in greater detail in U.S. Pat. No. 5,882,987, hereby incorporated by reference. The process of hydrogen implantation forms a silicon hydride layer 31 on suitable annealing, that becomes the basis of the Smart-Cut technique to allow separation of the unwanted layers of carrier wafer 30 after the top section 25 is bonded to the bottom section 23 . Although Smart-Cut is the exemplary process for transferring the device layer 32 , alternate processes of combining etching and polishing, such as those described in U.S. Pat. Nos. 4,601,779 and 4,735,679, can also be used. Device layer 32 is deposited epitaxially using, for example, SiGe, but the specific material depends upon the device to be fabricated. An etch stop layer is optionally added on top of the device layer, which could be simply a highly doped silicon layer or a silicon-germanium layer, as per the teaching of the above mentioned U.S. Pat. No. '987. A thin thermal oxide 33 of thickness 50-200 A is optionally grown on the monocrystalline surface. When the end device will include body contact, a bare silicon without oxide layer 33 is used. Hydrogen 31 is implanted under conditions taught in '987, preferably at a depth below the deposited device layer. As shown in FIGS. 3B and 3C , the device wafer 25 is then flipped and attached to the carrier substrate 23 prepared in FIGS. 2A-2E . By way of exemplary technique, the oxide surfaces are joined using surface treatments to make oxide surfaces 33 , 211 hydrophilic. Such attached wafers have sufficient bonding to withstand most handling. The wafers are now heated at about 300-600 C to complete the Smart-Cut process as shown in FIG. 3D , in which the excess wafer section 34 is then removed. In one variation of the Smart-Cut process, the wafer is heated to a temperature range 250-400 C to segregate hydrogen to the device layer interface (in the case of SiGe deposited layer), followed by cleaving the substrate 34 along the hydrogen implanted surface using water jets. The transferred device layer surface 35 is now finished to a smooth surface by polishing or etching or along the teaching of U.S. Pat. No. '987 using an optional etch-stop layer Thus, an SOI wafer 20 (see also FIG. 2 ) with buried body contact 21 and buried gate electrode 22 has now been formed. The gate oxide 36 on the buried gate electrode is roughly equal to the thickness of oxide 33 or to the sum of the two surface oxides 33 , 211 , and can be between 100-500 A, depending upon the selection of thickness of individual oxide layers. As discussed earlier, one of the oxide layers 33 can also be conveniently not formed since bare Si surface can also be effectively bonded to silicon dioxide. As discussed in the IEEE publication mentioned above, the polyoxide formed over polished polysilicon, either thermally formed or deposited, is very high quality, approaching that required for gate oxide applications. Referring now back to FIG. 2 showing the completed SOI structure, top gate electrodes 214 , 215 are formed on top of a gate oxide layer 216 . To achieve this, typically a polysilicon layer deposited on top of the top gate insulator is patterned to create top gate electrodes 214 , 215 . The device layer 25 is now the channel or body layer for both the top gates 214 , 215 and bottom gate structures 21 , 22 . The top gate electrodes 214 , 215 could be a polycide layer if the application would require a lower resistance. FIGS. 4A-4E illustrate an alternate formation using the SIMOX process of a corresponding buried contact and buried gate electrode structure. The process steps to create the buried structures 209 , 210 is same as used in FIGS. 2A-2D . Thus, FIG. 4A starts as being the same structure shown in FIG. 2D with trench/sidewall/conductor 209 and trench/sidewall/bottom/conductor 210 structures filled with doped polysilicon or other suitable refractory conductor material. Polysilicon will arbitrarily be assumed here as the conductor. FIG. 4B shows surface insulator 200 having been removed and gate insulator 401 having thickness of 50-200 angstroms being formed over the electrode 210 to be used a buried gate. In a preferred process, this gate insulator 401 is formed by oxidizing the polysilicon with the oxide insulator 200 still in place and then the insulator 200 is removed by a polish or etch process. In one preferred embodiment of this polysilicon oxidation process, the insulator 200 has an additional SiN layer to allow only the polysilicon to be exposed and thereby oxidized in a controlled manner. Thereafter, oxide layer 200 is removed and any insulating layer 402 over the buried contact 209 is selectively removed by means of a block-out mask ( FIG. 4B ). A device layer 403 is deposited under epitaxial condition, which forms a single crystal over the all silicon surface ( FIG. 4C ), except that small regions of polycrystalline Si 404 , 405 are formed over polysilicon and oxide surfaces. The regions 404 and 405 can be formed single crystalline if epitaxial conditions for lateral growth can be used, such as taught in U.S. Pat. No. 5,646,958, the contents of which are incorporated herein by reference. In FIG. 4D an implantation mask 406 is formed over the buried regions and oxygen ions 407 are implanted into substrate 201 , using typical SIMOX conditions such as taught in U.S. Pat. No. 6,043,166, the contents of which are incorporated herein by reference. The energetics of the implantation controls the depth of the implanted ions 407 . For a buried gate 210 or body contact 209 , the implant depth is chosen to be slightly beneath the device layer. For buried wires and capacitors, since the structures are fully encased in insulator, this implantation location is less critical but preferably the implant depth is chosen to be near the device layer and substrate interface so that at least part of the BOX layer formed can cover the top of the wire and capacitor elements. Using anneal conditions and timing such as taught in U.S. Pat. No. 6,043,166, the implanted oxygen is converted into a buried oxide layer 408 as shown in FIG. 4E . Transistors are formed with gate oxide 409 and gate electrodes 410 using standard masking and deposition techniques to result in the structure similar to that shown in FIG. 2 . Even though the SIMOX process has been described using a set of preferred process steps with a view to forming buried gate electrode and buried body contact elements, it should be obvious to one skilled in the art, the above described process steps can be used as well to form other elements such as buried wiring layer or capacitor elements by small variations to the above process. FIGS. 5A-5D show a magnified view of three exemplary SOI structures, buried gate electrode 50 A ( FIG. 5A ), body contact 50 C ( FIG. 5C ), and buried wire 50 D ( 5 D), for of demonstrating additional advantages of the invention. FIG. 5A shows the resultant structure 50 A when the lower section 53 and upper section 54 are formed so as to result in a buried gate electrode 58 A. Of particular interest in this structure 50 A, and which differs from the prior art, is that the buried oxide (BOX) layer 55 A is now an integral part of the second gate device 58 A. Specifically, the SOI buried oxide layer 55 A acts as the second gate insulator for the buried FET and also as isolation of the device layer 54 from the substrate 53 . Also of interest in the FIG. 5A structure 50 A is that the buried oxide layer 55 A forming the second gate insulator will generally be a different thickness than the upper oxide layer 59 forming the upper gate insulator structure. This different thickness can be a useful technique for controlling the dual gated device characteristics. FIG. 5B shows an example of a top view of the dual gates layout. The effective shapes 501 , 502 of the two gates 56 and 58 A can have different length, width or shapes to facilitate easier contact to respective gates or to obtain a device of different channel lengths so that a dual gate and single gate channel regions can be combined in parallel to achieve different gains. The top and bottom gates 56 , 58 A can be positioned to small variations such as different angles (bent gates) to facilitate for example, better lay out of wiring tracks on the top or easier contact to bottom. FIGS. 5A and 5B also show the technique of connecting the upper and lower gates 501 , 502 by vias 503 , 504 so that when the gate voltage is impressed on the top, it acts on both top and bottom, improving the device performance. In the inventive process, this connection can be achieved using a simple process of using two layers of polysilicon for the top gate electrode, such as described in U.S. Pat. No. 4,341,009, which is incorporated herein by reference. Using this referenced process, formation of the via 503 and 504 is straightforward. '009 describes a process using dual polysilicon to form buried contacts. First a thin layer of polysilicon or polycide is deposited on the gate oxide, followed by etching a contact hole through the thin electrode, gate oxide and body channel layer, and buried gate oxide to the buried gate electrode. A second gate electrode layer is now deposited and patterned to make the first and second electrode contact. During this process, it is also possible to make other connections such as body contact, as additional contact can be made to the carrier substrate. This technique is used here where the gate electrode is formed in two steps. In step 1 , a first polysilicon layer is blanket deposited over the gate oxide in forming the top device, followed by etching the via. A second polysilicon layer now is deposited on the first polysilicon which makes the contact to the body layer or bottom electrode while providing additional thickness to the top gate electrode. This stack is now patterned to include top gate electrode and the via connection. A more traditional process step can be used whereby the top electrode is formed, via 403 or 404 is etched in a separate step and a local interconnect or a contact stud metallization used to connect the top and bottom electrodes. In SOI devices, there is a strong need to connect the body silicon region to a common ground or substrate potential to stabilize the threshold voltage. FIG. 5C shows one such structure 50 C having device layer 54 , BOX layer 55 C, and substrate 53 . Region 58 C which is a polysilicon electrode that contacts directly the device layer 54 at the body region of the gate 56 . Forming such a polysilicon electrode has been discussed already relative to FIGS. 2-4 . This preferred embodiment provides a required body contact with no additional space needs, without any need for additional photo process, layer depositions, etc. This embodiment therefore represents an attractive process for forming an SOI buried contact. FIG. 5D shows a buried wire 52 , which can be used for making local interconnect between a contact of a transistor to an adjacent transistor or to a resistor or capacitor. For schematic simplicity one via contact is shown extending a via from a buried wire to the top surface above the device layer. In typical applications multiple vias are provided from the same buried wire which can be used to connect devices at the top surface. Since the buried wire layer 52 is at a different plane than the devices, wireability is easily achieved, without concerning of crossing over other devices or other connections on the top surface. One of the important features of this invention is the ability to use the SOI buried layer to form separate devices while still retaining a commonality between the devices. This feature allows devices to be interconnected without having to provide interconnection conductors, thereby improving device density. This feature is exemplarily illustrated in FIG. 6A and FIG. 6B for the case of forming separate FETs 61 , 62 sharing a common body layer 64 . Additional specific examples will be discussed later and many more should be obvious to one of ordinary skill in the art, but the examples in FIGS. 6A , 6 B will demonstrate the important concept that entire circuits can be more effectively fabricated by considering the BOX as an important component at not only the device level but also at the circuit level, as will be discussed in more detail shortly. In FIG. 6A is shown the general case of two devices 61 and 62 isolated by SOI buried layer 63 and sharing a common body layer 64 . This feature enables formation of many more FETs, with each layer of FET design being optimized by separate layout restraints. As discussed earlier, buried electrodes and body contacts can be advantageously used to interconnect these devices to form circuits. When the buried gate 62 is laterally separated from the top gate, the source/drain regions for the buried gate can be formed by patterning dummy gates over the buried gate as a masking layer and implanting selective regions to complete the buried FET device. For many applications, the source/drain of adjacent devices can be advantageously shared, as shown in FIG. 6B , to provide specific circuit interconnections. This technique increases the density of device layout since this configuration becomes a series connection at node 68 between FETs 65 , 66 without having to use additional interconnectors. It should be obvious that parallel connections are similarly possible. FIG. 6C illustrates the degree of freedom in the layout of the top electrodes 61 , 66 and bottom electrodes 62 , 65 resulting from this invention. For example, one or both of the gates can have bends in order to meet other requirements or provide other advantages such as ease of wireability. FIG. 7A illustrates a schematic of a conventional DRAM cell using a single FET 75 and a single capacitor 70 . One electrode of the capacitor is connected to the drain region of the FET 75 and the other electrode is grounded. FIG. 7B shows the SOI device embodying two of these DRAM cells and taking advantage of the invention, the first using a top gate FET 75 A and the second a buried gate FET 75 B. Buried capacitors 70 A, 70 B are formed in the substrate 78 and top gate for 75 A and buried gate for 75 B are connected to the capacitors using vias 74 A, 74 B. The structure of FIG. 7 b is formed by the combination of substrate 78 with a device layer 77 through an intermediate BOX layer 79 . Various possible processes that can be used to form these structures have been described already with the aid of FIGS. 2-4 . The formation of capacitors 70 A, 70 B in a substrate, for example, has been specifically discussed with the aid of FIGS. 2A-2D . The buried conductor 73 A, 73 B with the right choice of trench dimensions and capacitor node dielectric 71 A, 71 B (oxide or oxide/nitride formed on the trench walls) will determine the capacitance value of the buried capacitors. The capacitor ground electrodes can be formed either by use of a highly doped substrate 78 , or by diffusion drive-in of dopants to form a highly doped external regions 72 A, 72 B in the substrate along the perimeter of the capacitors 70 A, and 70 B prior to forming the node insulator. This step and additional process steps for forming such a structure is known and described in U.S. Pat. No. 5,770,484, which contents are herein incorporated. In contrast to processes where the buried capacitor is formed subsequent to the SOI substrate, the process described here, where the buried capacitor was formed prior to the SOI structure, offers process simplicity in comparison with other SOI trench capacitor processes and can provide better yields and lower cost. FIGS. 8A-8C show a variation of the DRAM cells discussed in FIGS. 7A-7B . FIG. 8A is a well known prior art schematic diagram of a single device storage capacitor circuit which uses a single transistor Q 1 and a storage capacitor C 1 . Use of depletion capacitors are well known in the art (see for example U.S. Pat. Nos. 4,163,243 and 4,259,729). The gate of Q 1 is activated by a high voltage to turn Q 1 on, thus allowing the data signal level on bit-line BL 0 to be transferred to the capacitor C 1 . The schematic shown in FIG. 8A is similar to the schematic in FIG. 7A , except that the capacitor node labeled VDD was at ground potential. FIG. 8B illustrates one embodiment of using a single depleted capacitor 80 utilizing a positive bias voltage impressed on the buried electrode to create an accumulation region 81 (counter electrode) in the device layer 82 . An important novelty of this circuit application is in the physical arrangement of the transistor Q 1 ( 83 ) located on the top of the common shared semiconductor region 82 and the capacitor C 1 ( 80 ) located on the bottom side of that same shared region. This structure is made possible by the semiconductor teaching of this invention. FIG. 8B will be further described in the following paragraph but it should be explained that a multiple variations on this scheme are easily visualized. In the embodiment of FIG. 8B the data bit to be stored is presented to the cell on bit line BL 0 . Transistor 83 (Q 1 ) is activated, as previously stated, by a high signal applied to its gate 84 , thus allowing the voltage level of BL 0 to be transferred to capacitor 80 (C 1 ). As is well known in the art, the DRAM cell is read out by preconditioning BL 0 to a predetermined voltage level that is between a logical 1 high and a logical 0 low voltage level. Bit line BL 0 is connected to a sense amplifier (not shown) which will differentially sense the voltage between BL 0 and a reference voltage. A high voltage is applied to WL 1 the gate of transistor Q 1 . This turns Q 1 on and the signal stored on capacitor C 1 will be transferred to BL 0 . This signal will be very small compared to the signal that was originally written into the cell using BL 0 . The sense bit line BL 0 will be disturbed electrically in either the positive voltage direction or negative voltage direction from its predetermined intermediate level depending on the state stored in capacitor C 1 . The sense amplifier attached to BL 0 will sense and amplify this small voltage disturbance. FIG. 8B shows that one side of capacitor Cl is connected via a diffusion 85 to transistor Q 1 . The other electrode of C 1 is a plate formed with polysilicon electrode of capacitor 80 . The insulator 86 overlying the electrode of capacitor 80 (C 1 ) is the capacitor dielectric. This dielectric could be the same or similar material SiO 2 as in BOX layer 87 . It could also be a different material such as a high dielectric material allowing a larger value of capacitance for C 1 using the same plate area as this material can be formed during the formation of the buried capacitor electrode by deposition. The arrangement of electrodes of capacitor becomes clear by comparing FIGS. 8A and 8B . The diffusion region 85 connects the top electrode of the capacitor C 1 to a plate-like region formed by inducing charge on the top surface of the thin dielectric 86 (oxide or high dielectric material) by applying a positive potential to the lower plate of C 1 . The positive potential causes negative carriers to be attracted to the top side of C 1 making it conductive and forming the top plate. The bottom plate of the capacitor is simply the buried electrode of capacitor 80 . One aspect of novelty in this structure is the location of C 1 horizontally relative to Q 1 . C 1 may be located substantially under Q 1 which produces a minimum total cell area, allowing maximum DRAM memory density on a unit area of silicon wafer. It may, however, be located substantially outside the region covered by the gate of Q 1 for a minimum density result and still operate. The point is that the location of C 1 relative to Q 1 is non critical, so long as C 1 does not come closer to bit line BL 0 than some minimum dimension established by a leakage current/storage cell retention time criteria. FIG. 8C is an extension of FIG. 8B , wherein the capacitor is provided by forming the structures 80 B and 80 T, where 80 T is now formed on top of the device layer 82 . The advantage of this is that the area of capacitor 80 can be cut in half allowing for greater overall packing density. In addition to using high dielectric constant insulators for the capacitors, one can also use roughened surface electrodes to increase the capacitor electrode area. Both these techniques are well known in the art. Additional variations of structure and materials are possible within the general concepts of forming buried structures taught in here. FIGS. 9A-9C illustrate an application of building and operation of a dynamic two phase shift register using the invented structure. FIG. 9A shows a conceptual vertical structure utilizing the semiconductor processing teaching of this invention to construct four N-type transistors that is connected as per the Figure C schematic to provide a two phase dynamic shift register with the FIG. 9B timing diagram. These dynamic shift registers have been a classical circuit technique to store data. FIG. 9A shows the cross section of one possible SOI structure created by a substrate 91 , a device layer 92 , and an oxide layer 90 separating the two. Further, along the teachings of this invention, two buried gate transistors 941 and 943 are formed in the substrate region 91 . Two top surface FETs 942 , 944 are formed using additional process steps on the device layer. All the FETs are N-type, as determined by the choice of dopants in the device layer and Source/Drain regions, and all sharing the same body layer 92 . By use of overlapping source and drain regions 95 between adjacent FETs, the series connection of the transistors as in FIG. 9C is achieved without a need for any external wiring. In a two phase dynamic shift register two transistors are used to store one bit of data. In the case of FIG. 9C , transistor 941 and 942 together store bit 1 and transistors 943 and 944 store bit 2 . Referring to FIG. 9B , clock C 1 signal 96 is applied to the gate of transistors 941 , 943 , and clock C 2 signal 97 is applied to wire connected to gates of transistors 942 , 944 . The data bit is actually stored on the parasitic capacitance of the circuit, such as the diffusion capacitance. Two clock signals 96 , 97 are used to control the shifting of the data from one bit location to the next. One bit is shifted one position by applying clock signal C 1 (a high) followed by clock signal C 2 (a high). The clocks are non-overlapping meaning that C 1 and C 2 are never both high at the same time. Eventually the data entered into the shift register is attenuated and lost after some number of shift positions unless it is restored in amplitude by a gain stage. Variations of the two phase shift registers can be constructed with more transistors than shown in FIG. 9A so as to restore or amplify the data at each bit position in the serial string. The circuits for shift registering and amplification are known in the art and the novel aspect of the present invention is the two phase shift register structure shown in FIG. 9A , which provide space saving and greater density. The two phase shift register structure of this invention register is based upon the very important semiconductor processing teaching of this invention that allows transistors to be isolated by BOX layer 90 to be formed on top and in bottom of a shared region 92 of semiconducting material. In the structure shown in FIG. 9A the transistors do not lie one above another but are staggered such that the source of one transistor is shared with the drain of a second transistor, an embodiment earlier discussed with FIG. 6B . As can be readily seen, one of the novelties in FIG. 9A is that the two transistors of this invention 941 and 942 , unlike prior art, do not reside on the same vertical level, typically both on top. In this invention, one of the transistor 941 (Q 1 ) is in the bottom, and the next transistor 942 (Q 2 ) is on the top. The wiring of the clock signal C 1 to the gate of Q 1 takes place below the common layer 92 structure, at least in part, where it is necessary to connect to gate region, i.e., via polysilicon. Similarly, the corresponding wiring to Q 2 takes place above the common layer 92 structure providing a means to connect clock signal C 2 to the gate region of transistor Q 2 . In this manner the necessary wiring to gates on either the top side or the bottom side is substantially reduced in utilization of available real-estate on any one side. Further, if geometries of the transistors, diffusions, and gate wiring were such that a conflict for available real-estate existed when attempting to wire the gate regions of two sequential transistors in the shift register chain, such conflict would be substantially reduced or eliminated by constructing the shift register in an alternating fashion of top/bottom transistor location as shown in FIG. 9A . The circuit chosen to demonstrate this concept is the two phase dynamic shift register because it is a well known application of classical MOSFET function. However other circuit applications would obviously benefit equally well with reduced gate wireability congestion thus allowing for improved device/circuit density. FIGS. 10A and 10B show the application of the subject disclosure to a CMOS NOR logic circuit. The FIG. 10A schematic shows a two-way logical NOR circuit. Input signals A & B are connected to the gates of transistors Q 2 & Q 4 and Q 1 & Q 3 , respectively. Transistors Q 1 and Q 2 are P-type transistors and transistors Q 3 and Q 4 are N-type. This schematic is well known and one of the most widely used logic circuits. The other widely used CMOS circuits are the NAND and the simple inverter circuit, and the implementation of the invention into these well known circuits would be obvious to one of ordinary skill in the art. The structure of the NOR circuit in FIG. 10B represents a vertical cross-section of a semiconductor chip utilizing the subject invention. A substrate 101 and a device layer 103 are separated by a BOX layer 102 . The transistor Q 4 is formed within the substrate (buried) using the process steps taught in the preferred embodiments. The transistors Q 1 , Q 2 and Q 3 are formed on the device layer using conventional processes of oxidation, gate electrode deposition, patterning etc. The scale of the semiconductor geometry is simplified here to assist the understanding of how the NOR circuit of FIG. 10A is realized. The most dramatic benefit and novel benefit apparent in FIG. 10B is seen in the location of transistor Q 3 directly above transistor Q 4 . It should be noted that transistors Q 1 and Q 2 are constructed on the same horizontal axis. Since the transistors Q 1 , Q 2 are P-type and Q 3 and Q 4 are N-type, the device layer has isolation regions to separate the different dopants in the device layer corresponding N-type and P-type regions. The current industry practice is to have the placement or physical location of all transistors on the same horizontal plane. However, this invention allows a unique means to fabricate transistor Q 3 , Q 4 , one above the other, thus allowing for a significant reduction in chip size for a given logical function. It should be noted that this is the technique discussed earlier in which components are connected in parallel without requiring separate interconnection conductors. Additional benefit will be apparent in this structure in the area required for the commonly shared source drain diffusions shared by transistors Q 3 , Q 4 . In particular the area of the common drain diffusion of Q 3 and Q 4 shared with the source diffusion of Q 2 is reduced in area such that the switching time on the NOR circuit is significantly reduced. This common node or diffusion also serves as the output node of the circuit. Since any capacitance reduction results in a reduced circuit delay (switching time), the speed is additionally increased. The concept here is shown for a NOR circuit but is also readily applied to the popular NAND logic circuit and many other circuit types found in the current CMOS logic technology industry that produces today's microprocessor chips and ASIC chips. These are but some examples of circuits that can be formed utilizing buried devices in conjunction with traditional FETs and other devices. Many ASIC applications can benefit with the additional design ground rules allowed by the inventive devices being available in the buried substrate. The examples discussed also demonstrate that with these techniques the buried oxide can be used for more than simple isolation. The BOX has been shown to be available for other functions such as the gate oxide for a buried transistor and the pass-through for a body contact. While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.

A method is provided in which for fabricating a complementary metal oxide semiconductor (CMOS) circuit on a semiconductor-on-insulator (SOI) substrate. A plurality of field effect transistors (FETs) are formed, each having a channel region disposed in a common device layer within a single-crystal semiconductor layer of an SOI substrate. A gate of the first FET overlies an upper surface of the common device layer, and a gate of the second FET underlies a lower surface of the common device layer remote from the upper surface. The first and second FETs share a common diffusion region disposed in the common device layer and are conductively interconnected by the common diffusion region. The common diffusion region is operable as at least one of a source region or a drain region of the first FET and is simultaneously operable as at least one of a source region or a drain region of the second FET.

GOVERNMENTAL CONTRACT CLAUSE The invention herein disclosed was made in the course of or under a contract or subcontract thereunder with the Department of Energy bearing No. EY-67-14-C-2170. CROSS-REFERENCE TO RELATED APPLICATIONS This application relates to and incorporates by reference: 1. Application Ser. No. 136,122, field Mar. 31, 1980, to Robert S. Wilks, Robert H. Sturges, and Alexander Taleff for "Pellet Inspection Apparatus" and assigned to Westinghouse Electric Corporation (herein called Wilks I). 2. Application Ser. No. 171,606, filed July 22, 1980 to Robert S. Wilks, Gerald D. Breaky, Eli Sternheim, Alexander Taleff, Robert H. Sturges, and Raymond A. Castner for "Apparatus and Method for Classifying Fuel Pellets for Nuclear Reactor" and assigned to Westinghouse Electric Corporation (herein called Wilks II). Wilks I relates to the mechanical handling and gauging system for depositing pellets one-by-one in inspection stations and inspecting each pellet for diameter, flaws, length and weight. Wilks II relates to the control for the mechanical handling and gauging system for controlling the depositing of the pellets in the inspection station and their inspection and the processing of the data derived from the inspection. This application relates to the quantification of the flaws, the high-precision derivation of the resulting flaw data and its evaluation. BACKGROUND OF THE INVENTION This application relates to the art of inspection and sorting of fuel pellets for a nuclear reactor and has particular relationship to the inspection of such pellets for surface flaws and to the evaluation of the flaws on the surfaces of the pellets for the purpose of classifying the pellets. While this application, including its claims, is confined to the processing of fuel pellets for a nuclear reactor, it is to be understood that to the extent that this invention is applicable to the processing of other articles than fuel pellets, such processing is within the scope of this invention. The pellets whose inspection and classification are the subject of this invention are relatively small cylinders, typically 0.1945±0.002 in diameter, 0.2425±0.020 in length and having a weight of 1.204±0.250 grams and a specific gravity of 10.22. For use in a nuclear reactor a number of these pellets are stacked in a tube of stainless steel or ZIRCALOY alloy to form a fuel rod. The tube is referred to as cladding. For efficient operation of a nuclear reactor and the precluding of hot spots in the reactor, particularly at the start of operation, it is essential that the heat generated in the pellets flow directly and uniformly to the cladding. It is also essential that the fracture or pulverization of the pellets be avoided during loading of the pellets into the cladding tubes. Surface flaws, depending on their shape, tend to cause non-uniform and indirect flow of heat to the cladding and fracture or pulverization of the pellets. Flaws may be classified as chips and cracks or fissures. A chip is a flaw for which distances between different sets of opposite points of the perimeter are appreciable compared to the dimensions of the pellet and are of reasonably comparable magnitude. A fissure is an elongated flaw whose length is substantially greater than its width. The distinction between a chip and a fissure is subjective. A narrow chip may be regarded as a fissure and a wide fissure as a chip. However, there are surface flaws which are clearly chips and surface flaws which are clearly fissures. Where a pellet is chipped, the air or space gap between the surfaces of the chip and the cladding is longer than the gap between the surrounding unflawed surface of the pellet and the cladding. Heat which normally flows from the pellet surface to the cladding now encounters a higher thermal resistance path between the surface of the chip and the cladding and seeks an alternate path around the chip. The path which this flow takes around the chip is shared with the heat from the adjacent unflawed portions of the pellet. A hot ring is developed on the pellet surface around the chip and also on the adjacent cladding wall. The average reactor core operating temperature must be decreased to prevent the hot ring which is developed from rising to a temperature which exceeds the safe design temperature for the cladding and can lead to puncture of the cladding. Reduced average core temperature results in reduced thermal efficiency and power generation capacity. Pellets with severe deep or long fissures may fracture and jam while being loaded in the cladding tubes. This may also occur in the case of chips. To eliminate or at least reduce the number of flawed pellets in an operating reactor and the problems which they raise, the practice in accordance with the teachings of the prior art has been to inspect the pellets manually. In accordance with common prior art practice, a pellet passed inspection if it met all of the following criteria: 1. The maximum dimension across a chip does not exceed a specified magnitude. 2. The summation of those maximum dimensions across all chips on a pellet which are greater than an inappreciable predetermined magnitude does not exceed another specified magnitude. 3. Fissures do not exceed a specified length. The inspection task is formidable. A commercial power reactor having an output of 1200 megawatts thermal energy requires about 10 million pellets. To make available this many pellets in a reasonable time demands a large number of inspectors who must inspect the pellets at a high rate. Typically 100 to 200 pellets are deposited on their sides in a grooved tray and examined by the inspector. After mentally noting the degree of fissuring and chipping on each of 100 to 200 pellets, the inspector places a second tray upside down on the first tray and inverts both trays thus turning the pellets over. He now examines the reverse side of the pellets. The inspector then mentally totalizes the damage on each pellet and sorts the pellets into categories according to the observed surface damage. This task is taxing on the memory and judgement capability of the inspector and is nerve-wracking. Another disadvantage of this manual process is that it is applicable only to pellets of weak radiation emitting material such as uranium. It is not applicable to plutonium pellets which cannot safely be handled manually. For limited use, for example for test reactors, plutonium pellets are inspected in a glove box one-by-one. Two persons are required, one picks up each pellet with tweezers and examines it; the other records the data. A further disadvantage of the prior art is that the above-listed criteria are not satisfactorially correlated to the pellet performance. For example, a circular chip of maximum passable diameter will produce a more severe hot spot than a chip of the same area which is longer but narrower. If the circular flaw were the only flaw on a pellet, criterion 2 above would pass the pellet containing this chip but would reject a more acceptable pellet having the longer narrower chip. It is an object of this invention to overcome the drawbacks, disadvantages and difficulties of the prior art and to provide apparatus for reliably inspecting for surface flaws fuel pellets for a nuclear reactor at a high time rate such that the large number of pellets required for a typical commercial reactor can be made available within a reasonable time interval. It is also an object of this invention to provide a method for carrying out such inspection in whose practice the surface quality of each pellet shall be quantitatively evaluated in such manner that it is accurately correlated to pellet performance. SUMMARY OF THE INVENTION Wilks I and II disclose apparatus including a plurality of stations in which individual pellets are subject to inspection for diameter, flaws, length and weight at a high time rate. Each pellet is advanced automaticaly from station to station during successive cycles and during each cycle all pellets in the stations are inspected. This apparatus operates in a containment so that the inspection and sorting of plutonium pellets presents no safety problem. For flaws the inspection is effected by scanning successive elemental areas of each pellet with a light beam and determining the surface quality from the transitions in the resulting light reflected from the elemental areas as the incident light passes from unflawed surface areas to flawed surface areas and vice versa (Wilks II--FIGS. 28, 29, 30, 31). In accordance with this invention, a unique optical system is provided for impinging on the pellet a sharp scanning beam of small dimensions. The scanning is produced by a prism which is rotated at a high speed about a vertical axis. A cylindrical lens interposed in a light beam on the incident side of the prism produces a fine-line vertical image just beyond the prism. As the beam passes through the successive faces of the prism, this image is swept horizontally. A second cylindrical lens interposed between the prism and the pellet focuses the fine-line image on the surface of the pellet. Since the distance between this second lens and the pellet surface is relatively short the image on the pellet is very fine and sharp. A third cylindrical lens, whose optic axis is at right angles to the axes of the first and second lenses converges the line image near the scanning prism vertically to produce an image of very small dimensions horizontally and vertically on the pellet. This image scans the pellet and the resulting reflected light serves to indicate the surface quality of the pellet at each elemental area. Typically, each elemental area is about 0.006 inch in width and height. The pellet is rotated as it is scanned. The pellet drive is synchronized with the drive for the scanning prism in accordance with this invention. The pellet drive is energized from a 60 Hertz commercial supply. The drive for the scanning prism is of higher frequency and it is energized from a voltage-controlled oscillator (VCO). The synchronization of the drives is effected by controlling the voltage of the VCO in accordance with the phase relationships of the supplies for the drives. The optical system also includes a ruled grating coordinating each resulting light value with the address on the pellet of the elemental area from which it is required. Light is impinged on the grating by a beam splitter interposed in the beam between the scanning prism and the pellet surface. This light is focused on the grating and as it sweeps across the grating during each scan, it produces a train of pulses. Specifically, the beam splitter is interposed between the pellet and the nearest to the pellet of the second and third cylindrical lenses and the optical distance between the beam splitter and the grating is equal to the optical distance between the beam splitter and the pellet surface. There is then a one-to-one relationship between the positions of the scanning image on the pellet surface and the position of the scanning image on the grating. The data derived from the scanning of each pellet is fed into and processed by a computer. The memory of the computer is programmed so as to quantize and evaluate the effect on the performance of the pellet, of each flaw. The evaluation takes into consideration the individual shape of the flaw. To each flaw, a flaw quality index FQI is assigned. This is essentially a number depending on the dimensions of the flaw and on its shape. The dimensions and shape are expressed as a shape factor S, F is a function of S. The surface quality of a pellet is expressed as a number, referred to as surface quality index, SQI. SQI is the sum of all flaw quality indexes F for the pellet. In setting up this summation each flaw quality index is weighted based on its shape and on its location, whether it is at an end of a pellet or on the surface between the ends, so that its contribution in the summation is proportional to its contribution to the degree of performance of the pellet in the reactor. In other words F is included in the summation to derive SQI in such a way as to distinguish effectively between the effects on performance of circular flaws, long-narrow flaws and flaws which in varying degrees have shapes intermediate between circular and long-narrow and also in the location of the flaw. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this invention, both as to its organization and as to its method of operation, together with additional objects and advantages thereof, reference is made to the following description taken in connection with the accompanying drawing, in which: FIG. 1 is a block diagram showing the components of the flaw detection apparatus in accordance with this invention and their relationship; FIG. 2 is an end view of the flaw station in which a pellet is subjected to inspection for flaws; FIG. 3 is a copy of a photograph of the flaw detection optical system of the mechanical handling and gauging system which has been found to be fully operative; FIG. 3A is a fragmental view in section showing the lens assembly through which the beam from the pellet enters; FIG. 4 is a diagrammatic view in side elevation of this optical system and also showing in block diagram the drives for the scanning prism and for spinning the rollers on which the pellets are seated and rotated and the synchronization of these drives. FIG. 5 is a schematic showing the manner in which a pellet spin rate on the roller stand is synchronized with the rotational speed of the scanning prism in flaw inspection; FIG. 6 is a graph showing how the position of the scanning line along the pellet in flaw detection is determined; FIG. 7 is a graph which serves to explain how the surface quality index is determined; FIG. 7A is a diagram showing the significance of the data in FIG. 7; and FIG. 8 is a block diagram which shows the algorithm for evaluating fuel pellets with respect to their surface flaws. FIG. 1 is derived from FIG. 1 of Wilks II and constitutes the portion of FIG. 1 of Wilks II which involves detection and evaluation of surface flaws. FIG. 2 is similar to FIG. 47 of Wilks I. FIG. 3 is similar to FIG. 11 of Wilks I. FIG. 4 is derived from FIG. 63 of Wilks I. FIG. 5 is identical to FIG. 13A of Wilks I. FIG. 6 is identical to FIG. 66 of Wilks. FIG. 8 is identical to FIG. 32 of Wilks II except that an error in the latter is corrected. In FIGS. 1, 2, 3, 4, 5 and 7 the numbering of the corresponding Wilks applications is retained. DETAILED DESCRIPTION OF THE INVENTION The apparatus shown in FIG. 1 includes a flaw station 129 (FIGS. 2, 3) and the flaw optics and photo cells 141. The block 141 represents the optical system (FIGS. 3 and 4) and the photo-responsive means or photo-cell which produces the counts which evaluate the flawed areas of each pellet. The apparatus shown in FIG. 1 also includes the data acquisition and process 1005. This includes the logic which acquires the data from the photo responsive means and processes this data (Wilks II--FIGS. 28, 29). The data derived from the photo responsive means is entered into a FIFO buffer 1019 (Wilks II, FIG. 2, FIG. 29) and during the MEASEN, the measurement enable interval, is transmitted through multiplexer 1019 (Wilks II--FIG. 37) and through the direct-memory access (DMA) 106 into the dedicated computer 105. The dedicated computer 105 produces a digital image of the pellet surface with its flaws and it determines the dimensions, specifically the area and perimeter, of each flaw. The computer can also produce an actual image of a pellet surface on a cathode-ray screen. The computer 105 also computes the FQI for each flaw and assigns to each flaw a weight to the FQI which is correlated to the degree of performance reduction of the pellet which each flaw, by reason of its particular shape and position, contributes. The computer 105 derives the SQI from the weighted FQI's for each pellet. The computer 105 is in communication with timing and control logic 1009 through its interface board I/O, 108 (Wilks II, FIGS. 42, 43). The board 108, through the timing and control logic 1009, coordinates the flow of data between the data acquisition and process 1005 and the computer 105 through the DMA. It also actuates the timing and control logic 1009 to actuate solenoids 471 or 473 appropriately so that the spring gates are operated in accordance with the evaluation of the flaws (or of the other parameters) of each pellet. The intelligence as to the setting of the sorting gates (through PC4, PC5--Wilks II, FIG. 5, 499-503, 501-505--Wilks I--FIG. 31) is supplied for processing to the timing and control logic 1009. It is to be borne in mind that the blocks of FIG. 1 predominantly define functions and not structure. Structurally, the components of these blocks may be intermingled. Each pellet P is subjected to inspection in the flaw station 129 on rotating rollers 267 and 269 (FIGS. 2, 3) in a box 251 which is described in more detail in Wilks I (FIGS. 45-47). The box 251 has a groove 319. A bracket or mounting 253 having a cooperative tongue member is supported in the groove 319 and secured therein. In the lower part of its head 323, the bracket 319 has an adjustable mounting 235 for a plane mirror 327. This mirror is secured in the mounting 325 by tape. The mounting 325 is in the form of a disc and can be adjusted to set the angle of the mirror 327 to the horizontal. In the upper part of this head there is a slot 329. Within this slot a bracket 331 is slidable. At its top the bracket 331 carries an adjustable mounting 333 in the form of a disc. This mounting carries a plane mirror 335 secured therein by tape. The bracket 331 is secured in slot 329 by screws 337 which pass through slots 339 in the head 323. The mirror 335 is adjustable vertically by adjusting the position of the screws 337 in the slots 339. The angle of the mirror 335 to the horizontal is adjustable by mounting 333. The mirror 327 is so set that this mirror reflects a horizontal scanning beam 341 (FIGS. 3, 4) having the contour of a sharp spot tracing a horizontal line from the source and optical system 141 to the surface of a pellet P on the seat formed between rollers 267 and 269 at the flaw station. The reflected beam scans the surface of the pellet P. Specular or unflawed surface elements of the pellet P reflect the beam to the reflector 335. This reflector is so set that it reflects the scanning beam 343 (FIGS. 3, 4) horizontally to the source and optical system 141. The box 251 at the flaw station 129 is provided with a plate 345 (FIG. 3). The plate 345 is secured to the rear wall of the box and extends completely across the deep opening of the box. The purpose of the plate 345 is to shield persons facing the apparatus from the laser beam projected towards the flaw station 129. The flaw inspection optical system (FIGS. 3 and 4) except for mirrors 327 and 329 is mounted in a container 791f. This container is similar to the containers for diameter and length inspection which are described in Wilks I. The container 791f is generally like a suitcase having a handle 793. A locating plate 795 extends from the handle 793 on one side. The function of this handle 795 in positioning the container 791f vertically is described in Wilks I. A laser beam 845 derived from a laser in the top of tube 843 is collimated and polarized and is projected through a telescope including lenses 895 and 897. Interposed between lenses 895 and 897 is a pin-hole filter 899 having a pin-hole about 35 microns in diameter. Lens 895 focuses the light on the pin-hole; lens 897 collimates the light. The beam 901 which emerges is magnified by six diameters with reference to the beam 845. This beam is reflected by plane mirror 903 so that a horizontal beam 904 is produced. Beam 904 is incident on cylindrical lens 905 which converges the beam horizontally into a thin vertical line real image. The converging beam from lens 905 is incident on scanning prism 907 which is rotated at a high speed, typically 7000 RPM, by motor 909. The beam which emerges from cylindrical lens 905 is focused as a line image a short distance in front of scanner 907, i.e., beyond the scanner 907 along the path of propagation of the beam. Scanner 907 produces a scanning beam 911 whose cross-section is a thin vertical line. Beam 911 sweeps horizontally while remaining parallel to the optic axis of lens 905. Beam 911 passes through cylindrical lens 913 whose axis of curvature is horizontal. Lens 913 converges beam 911 vertically to a sharp point. This point, i.e., the conjugate focal point of lens 913 is on the surface of pellet P. The beam from lens 913 is incident on cylindrical lenses 915 and 917 which operate as a single lens. The beam which emerges from lenses 915 and 917 is converged horizontally and also focused on the surface of pellet P. Lenses 915 and 917 cooperate to produce a sharper line on pellet P than would be produced by lens 905 or a plurality of lenses in this area. Essentially lenses 913, 915, 917 produce an image of the real image beyond scanner 907 at the surface of the pellet P. The minimum spot area (or line width for a cylindrical lens) producible from a collimated beam by a lens is diffraction limited; the larger the angle of convergence, the smaller this spot area. The focal length of lens 905 could have been selected to focus the beam directly on the pellet. But under such circumstances the spot line width would have been greater than desired. The cooperation of lenses 905, 915 and 917 makes it possible to maintain the angles of convergence and divergence to and from the lenses large enough to insure a small width as desired at the pellet surface. By providing convergence in the vertical optical axis after prism 907 by means of lens 913 the system is rendered immune to precession errors introduced in the mounting of prism 907. The beam emerging from lenses 915 and 917 is incident on a beam splitter 919 disposed at an angle of about 45° to the axis of the beam. Part of the incident beam passes through the beam splitter and emerges as beam 341. The other part of the beam is reflected vertically (actually downwardly--FIG. 3) as beam 921. Beam 341 passes through a window 922 in container 791f, is reflected by mirror 327 on the roller stand 251 at the flaw inspection station 129 and is focused as a fine sharp point on the pellet P. As the scanner 907 rotates, this line scans the pellet P. Mirror 335 reflects the light from the spot as horizontal beam 343 through another lens 925 adjustably secured in a barrel 926 (FIG. 3A) in container 791f axially aligned and penetrated by the beam 343. The beam 343 enters barrel 926 through a slot 928 in a baffle 930 (FIG. 3A). Lens 925 focuses the spot from the pellet on a baffle 927 having a narrow horizontal slit. The light passing through the slit is incident on a photocell or photo responsive device 929. The slit in baffle 927 and photocell 929 are so set with reference to beam 343, that light undergoing reflection at the surface of the pellet P passes through the slit onto the photocell 929. Light derived from a flaw in the surface of pellet P is focused as an image away from the slit and is intercepted by the wall of the baffle 927. In addition the surface of the flaw being less mirror-like than the unflawed surface diffuses the light. In either event there is for a flaw a substantial decrease in the photon energy impinging on the photocell which is an indication that the surface under the spot at the pellet surface is not unflawed. The rollers 267 and 269 on which the pellet is seated is driven by the synchronous motor 285 at a substantially lower speed than the scanner 907. Typically the pellet rotates at about 629 RPM. The pellet length is then scanned anew for each small incremental movement of the pellet circumference. The scanning traces a screen of imaginary rectangles on the pellet surface which envelops the pellet surface. The imaginary rectangles of the imaginary screen which envelops the pellet are of small area, typically 0.006 inch square. The scanning motor 909 is driven from a voltage-controlled oscillator (VCO) 931 (FIG. 5). Typically the VCO 931 has a center frequency of 12,840 Hertz. The motor 909 is supplied from VCO 931 through a divider 933 which typically divides by 32 and a low-pass filtering power amplifier 934 to preclude frequencies appreciably higher than 401.25 Hz. The motor 901 operates at a speed typically at 8025 RPM. The roll motor 285 in the flaw detection stand 251 at station 129 which is synchronous is supplied from a commercial 60 Hertz source. The 60 Hertz source is also connected to a phase-difference detector. The output of VCO 931 is also supplied through the second divider 935 to a phase-difference detector 937. The dividing factor of divider 935 is such that the signal flowing to the phase detector 937 is a 60 Hertz signal. The output of the phase detector 937 supplies synchronizing voltage to VC0931 through a low-pass filter 939. Thus prism motor 909 and roller motor 285 are synchronized since both are supplied basically from the same commercial 60 Hertz service and are maintained in synchronous by the phase-difference detector 937. The vertical beam 921 (FIGS. 3, 4) serves to provide information of the relative position on the imaginary grid of the light spot on the pellet P. Since the beams 341 and 921 are derived from a common beam focused by lenses 913, 915, 917, the conjugate focal point of beam 921 as it sweeps is at each instant the same distance from the optical center of the beam splitter 919 as the light spot on the surface of the pellet as it sweeps across the surface; i.e., the optical path distances from the reflective surface of the beam splitter to the spot in the surface of the pellet and to the conjugate focal spot of the split-off beam of 921 are equal. There is then a one-to-one correspondence between the relative positions of the two spots. A Ronchi ruling 941 is placed at the conjugate focal point of beam 921. Ruling 941 is a grating on which lines are ruled. A photocell 943 is mounted behind the Ronchi ruling 941. The light emerging from the ruling 941 causes the photocell 943 to produce successive trains T of current pulses U as shown in FIG. 6. The dimension of the Ronchi ruling 941 perpendicular to the lines is larger than the longest pellet to be subject to inspection to allow for scanning over the ends of the pellet (as well as for pellet positioning tolerances). This dimension is shorter than the length of the scan so that there is a short period of darkness between scans. This darkness interval is identified by D in FIG. 6. Each train T corresponds to a scan of the length of pellet P and each pulse U in a train corresponds to a position along the length of the imaginary screen which is being scanned. With the pulses derived from photodiode 943 the position of each elemental region of the pellet P scanned can be determined electronically. Electronic circuitry (FIGS. 28, 29--Wilks II) can determine the position of the beam within a scan by counting the light pulses U since the last pause D. The circuitry detects the end of a scan by detecting that the period of darkness D between trains T is prolonged beyond that corresponding to the duration DP between pulses. Every light pulse corresponds to a discrete address in the imaginary cylindrical grid which envelops a pellet P and rotates with it. At the peak of every pulse U the electronic circuitry examines the output from photocell 929 (FIG. 4) to evaluate the reflection from the spot at the corresponding address. The absence or presence locally of a sound surface is thus determined. It is essential that the flaw optical system shall be properly aligned. At the outset, it is assured that the drive rollers 267 and 269 are properly aligned with the related components of the mechanical handling and gauging system (101, FIG. 1--Wilks I). It is also assured that the mounting pins, pockets and grooves (FIGS. 13, 14, 15--Wilks I) for mounting the rollers and the suitcase 279f are clean and in proper condition for mounting of these parts. The laser mount 843, the mount for lens 905, the mount for the scanning prism 907, and the mount for cylindrical lenses 913, 915, 917, and their attached parts are removed from the suitcase 279f. The suitcase 791f is positioned on the inspection system table. The locating buttons (809, FIG. 15--Wilks I) should be set so that the optical mounting racks, the racks such as 902 (FIG. 3) for mounting lenses and other optical components, in suitcase 791f are parallel to the table top and the centerline of the window 922 in the suitcase 791f is a proper distance, typically 1.00 inch below the center line of a nominal pellet P resting on rolls 267 and 269. The suitcase face to which cover 910 bolts should be square with the top and back edge of the table (817, FIG. 4--Wilks I). The buttons or pins (809, FIG. 15--Wilks I) should be secured by Loctite (TM) cement and the plates 803 and 805 should be secured tightly to the suitcase 791f. The outer tube 912 and forward lens 897 of the telescope 895-897 is unscrewed from its spatial filter holder (not shown in detail; it is mounted in the bottom of the laser mount). The power to the laser is turned on and its mechanical shutter (not shown) is opened. This shutter is accessible through an access hole (not shown) in the laser mount 843. The spatial filter is aligned in accordance with the instructions of Metrologics Instruments, Inc., the manufacturer of the collimating telescope, which is used in this apparatus (Wilks I, page 40). The room should be darkened for this alignment. The outer sleeve 912 of the expanding telescope 895-897 should now be remounted. The sleeve 912 should be seated firmly against the laser mount 843. The forward lens should now be focused so that the beam 901 is collimated. The diameter of the beam 901 should be the same several feet (for example, 3 feet) as it is directly in front of the lens. The laser assembly and the other parts are remounted in the suitcase 279f. The beam 904 (FIG. 3) reflected from mirror 903 should be parallel to the optical mounting tracks 902. Typically, the beam 904 should be a distance of 1.625 inches horizontally from the tracks and a distance of 1.125 inches above the lower edge of the lower track. The appropriate setting is achieved by adjusting the laser mount 843 laterally (within the play of its mounting screws) and by adjusting the mirror 903 backward or forward or angularly. If rotation of the mirror 903 about the vertical axis is required, it will be necessary to shim the base (not shown) of the mirror at the forward or backward end. If the parts are properly adjusted, the beam 904 emerges from suitcase 791f through the center of the window 922. The mounts for lenses 905, 913, and 915-917 and their lenses and associated parts are replaced. If the parts are properly replaced, the beam, now 341 (FIGS. 3, 4), emerges through the center of window 922. If the beam 341 is high or low it is set by shimming the mount for lens 905. If the beam 341 is shifted horizontally, it is set by shimming either or both lenses 913 and/or 915, 917. The scanning prism 907 is replaced. The prism is spun slowly to assure that the sweeping beam 911 scans equal distances either side of the optical center line. The prism 907 may be shimmed as necessary. Now the seat 267-269 for the pellet P in box 251 is adjusted so that the pellet is properly positioned for flaw inspection. The beam shield 345 is removed and the mount 253 (FIG. 2) is adjusted so that the center line of the mount 325 for the lower mirror is 327 at the same level as the center of window 922; i.e., typically 1.00 inch below the center line of a nominal pellet P on rollers 267 and 269. The slide 331 is adjusted so that the center-to-center distance between mirror mounts 325 and 333 is such that the center of mount 333 is aligned with the center of window 906. (FIG. 3). Typically, the distance between the centers of mirror mounts 325 and 333 should be 2.375 inches. The scanning prism 907 is adjusted so that the center of the scan of beam 341, projected from the suitcase 791f is in line with the normal position of a nominal pellet on the rolls 267-269. The lower mirror 327 is adjusted angularly so that the beam 341 is incident on the pellet P at the elevation of its axis. The vertical spot size is adjusted by moving the mount for lens 905 or the mount for lens 915-917 forward or backward on the optical mounting track. This spot size can be checked with a 100-line per inch Ronchi ruling (grating). The open spaces between the lines of such a grating is 0.005 inch. The ruling is placed where the scanned spot normally is incident on the pellet P and with its lines horizontal. A piece of paper is held between the grating and the observer. As the grating is moved slowly upwardly while being held in its plane, the light on the paper flickers. The position of the ruling should be positioned where the light has the minimum intensity on the paper. When the spot is of the proper dimensions, there should be substantially no light on the paper. Ronchi rulings of 80 or 133 lines per inch (gap widths of 0.0062 inch and 0.0038 inch) may be used to develop skill and confidence in this practice. The horizontal spot width can be adjusted by moving lens 913 backward and foward using the same technique but with the rulings vertical. A piece of lens tissue is taped over the baffle 930 (FIG. 3A) in front of the imaging spherical lens 925; i.e., in front the suitcase 71f. The tissue acts as a viewing screen. The room is darkened and then the upper mirror 335 (FIG. 2) is adjusted angularly to a position at which the light reflected from the pellet is vertically centered on the baffle opening 928. The lower mirror 327 is adjusted to maximize the image brightness. The tissue is then removed from the baffle. The mounting plate for photocell 929 is adjusted so that the photocell is at its mid position. The slide for the grating 941 and photocell 943 and the slide for the photocell 929 and slot 927 are adjusted until these components are in their mid positions. Lens tissue is taped over the slot 927. The spherical lens 925 is adjusted to sharply focus the reflection from pellet P on the slit 927. Fine focusing can be achieved with an axially oriented slide (not shown). The tissue is removed. The scanning prism 907 is spun to check that the scanned image is parallel to the slit 927. Adjustment is effected by the slide which holds the slit 927 and photocell 929. The slit 927, which is formed of razor blades, is adjusted to narrow the slit until the light spot nearby is incident on the blades. The vertical slide which holds the grating and photocell is adjusted so that the scanned line image is very near the lower blade. It is desirable at this point to discuss briefly the difficulties which the aspect of this invention involving the optical system overcomes. The task which gave rise to this invention was the provision of condensing a collimated beam to a sharp scanning spot on a pellet. A way to accomplish this object is to place a convex spherical lens before the scanning prism 907; i.e., between the source and the scanning prism. This lens would produce a light-spot image on the pellet. But this expedient involves at least two drawbacks. First, the scanning prism cannot be perfectly mounted and it wobbles as it spins. This causes the scanned line upon the pellet surface to be cast at different elevations for successive prism face scans. If the lens were positioned after the prism 907 (instead of before it) the light paths emerging from the prism would still be parallel to the path of the entering light and would therefore converge to the same elevation. The rays would, however, all converge to the same spot and there would be no scan. The second difficulty has to do with the problem of obtaining a small spot size at the pellet surface. On the one hand, the minimum sized spot to which a lens can converge a collimated beam is inversely proportional to the effective f-number of the lens; in other words, to the diameter of the beam divided by the focal length of the lens. This constraint is imposed by natural laws. On the other hand, the position most appropriate for the spot converging lens is before the scanning prism, but between there and the pellet are the scanning prism and its mount, an instrument case wall, a containment wall, a beam-splitter, a mirror, and the bulk of the stand on which the pellet rests. Space taken up by this gear decidedly limits how close to the pellet the converging lens can be positioned. That in turn limits the minimum spot size to a value which is too great for this application. This invention overcomes the above drawbacks with lens 905 and the interposition of lenses 913 and 915-917. The computer 105 is programmed to evaluate each pellet in dependance upon the shape and extent of its surface flaws. The quantification of the shapes of flaws in the practice of this invention will now be described. The significant characteristics of a flaw are its area A and its perimeter P. As a basis for quantifying each flaw a dimensionless flaw shape factor, which is a function of A and P, is adopted. The factor S is defined by the equation: ##EQU1## The value of K is an arbitrary choice. It is selected here so that S is 1 when A/P 2 is maximum. A/P 2 is a maximum when the defect is circular. Hence A o =πr 2 and P o =2πr. The subscript 0 indicates that the parameter is for a circle. ##EQU2## Solving (2) we get K=4π. Therefore; ##EQU3## A criterion which appears in Paragraph 3.7 of the specifications of Hanford Engineering Development Laboratory called for rejection of all pellets containing fissures or cracks extending greater than 180° around a pellet surface or extending greater than 0.100 inch in the axial direction. If such a fissure is to be detectable by a scanning light spot as in this case, it should be about as wide as the spot. A fissure of half that width could absorb only about half the incident light energy. If this were the threshold established to differentiate an acceptable pellet surface from an unacceptable surface, such a flaw would have a 50% probability of detection. By the same argument a fissure having a width equal to the scanned element would have a 100% probability of detection. Since the light intensity distribution of the cross-section of the beam is Gaussian, the detection probability is greater than stated for any fissure except a fissure parallel to the scan. Suppose there is a fissure which is 0.100 long (shortest rejectable length) and 0.006 wide (the typical diameter for the scanning spot). Its area, perimeter, and S would be as follows: ##EQU4## Experience suggests that fissures and chips are easily discernible to the eye, probably because of the marked difference in their shapes. The inventors cannot recall ever seeing a fissure as wide as a 0.012" nor a chip which was 0.100 long and only 0.012" wide (S for such a chip would be 0.301). Since neither chips nor rejectable fissures appear to occur near S=0.3, a fissure is defined as a flaw with S equal to or less than 0.3. Conversely, any flaw with S>0.3 will be defined as a chip. This should offer a reasonable margin of safety on either side. The software for flaw detection of this invention does not analyze flaw orientation. To be safe, any fissure longer than 0.100 is a cause for pellet rejection. As a practical matter fissure length can be estimated in either of two ways--by area or by perimeter. A 0.100 inch long fissure with a 0.012 inch width (marginally rejectable) has an area of 0.0012 square inches and a perimeter of 0.224 inch. A fissure with either an area or a perimeter greater than this would be rejected. It is to be kept in mind that the apparatus according to this invention arbitrarily assigns a 0.006 inch width to any detectable fissure narrower than 0.006 inch. Chips are of concern because heat generated beneath a chip must flow out to the surface regions beyond the chip boundaries before it can be conducted to the cladding. For a small circular chip, it is assumed that the diverted energy is proportional to the flaw area and the pellet surface through which it dissipates if proportional to the chip circumference. The local temperature increase at the flaw circumference would be roughly proportional to the increased heat flux attributed to the flaw; in other words, in ratios of area to circumference (A÷P). For a circular flaw A÷P=πr 2 ÷2πr=r/ 2 . Now, r and P are proportional, therefore, the quality index for quantifying the dimensions of a circular chip should be weighted in direct proportion to its perimeter. If a chip were infinitely long compared with its width than the heat flux would be two-dimensional rather than three. Using the same reasoning as above the heat flux would increase in direct proportion to the chip width (as would the chip edge temperature). For flaws of infinite (but constant) length the chip width is linearly related to the chip area. It follows that the flaw quality index for quantifying a long narrow flaw should be weighted in proportion to the dimensions of its area. The flaw quality index of circular flaws should then be based on perimeter, and that of very long flaws should be based on area. For flaws intermediate the long and circular flaws, it would appear reasonable to base the flaw quality index partly on each. How to ration the allocation will now be considered. For determining the allocation, a function α is defined which is called the allocation function. The function has values ranging from unity when S=1 to zero when S=0. If a flaw has an α=1, the flaw quality index, is based 100% on perimeter; if α=0, it is based 100% on area. If α is 0.75, the flaw quality index is based 75% on perimeter and 25% on area. As a practical matter, it is reasonable to assume that when the ratio of length to width of a chip becomes larger than about five to one, the heat flux pattern would become essentially two-dimensional. The allocation function α must yield a result close to zero for this flaw. Furthermore, it must be assymptotic with zero at S=0. S, the shape factor, for a rectangle is very near to what is required for α in accordance with the above analysis. The following Table I presents the data involved in the quantification of rectangular flaws of various dimensions. TABLE I______________________________________y x A P A/P.sup.2 S = 4π A/P.sup.2______________________________________1 0 0 2 0. 0.1 1 1 4 .0625 .7851 2 2 6 .0556 .6991 5 5 12 .0347 .4361 10 10 22 .0207 .2601 20 20 42 .0113 .1421 50 50 102 .0048 .0601 100 100 202 .0025 .03081 ∞ ∞ ∞ 0. 0.______________________________________ The first and second columns from the left tabulate the width of y and the length x of the rectangle of FIG. 7A which represents a flaw. The third and fourth columns present the corresponding areas A and perimeters P, the fifth column A/P 2 and 6th column, the shape factor S=4πA/P 2 . FIG. 7 is a graph based on Table I. The shape factor S is plotted vertically as a function of the length x divided by the width y. This quotient is plotted horizontally. It is seen that S increases as x/y decreases but drops to a low value for magnitudes of x/y above about 16. It is desirable for proper quantification of flaws that S approach the x/y axis more sharply. To achieve this purpose α is equated to S q , where q is greater than 1. A value of q=3 would yield α=0.08 for a rectangle with a length to width ratio of 5. The value of q can be fine-tuned as more is learned about in-core performance of flawed pellets. Based on the above analysis the flaw quality index F may be derived as follows: F=αP.sup.2 +(1-α)A (8) F=S.sup.q P.sup.2 +(1-S.sup.q)A ref. (7) and (8) (9) ##EQU5## The surface quality index, SQI, for an entire pellet is the summation of flaw quality indices for all flaws (including fissures) for a pellet. A criterion adopted by Hanford Engineering Development Laboratory called for rejection of all pellets having two or more flaws each having a major width greater than 0.050 inch. Two circular chips of 0.050 diameter are rejectable under this criterion. This criterion may be established for the maximum acceptable magnitude for SQI by substituting appropriate magnitudes in equation (10) above. The Hanford Engineering Development Laboratory criterion weighted chips which contacted the ends of a pellet more severely in favor of rejection than chips between the ends. This weighting is achieved in the practice of this invention by multiplying F for an end chip by a factor γ where γ>1. Very small but evenly distributed flaws are likely to have little effect on pellet performance so long as the total flawed area is small with respect to the total pellet surface area. But when the ratio becomes large the average temperature of the remaining surface must climb. This requires that a maximum allowable flawed area criterion should be applied. A max is established at 10% of the nominal pellet surface area. For a typical pellet this is ##EQU6## Flaws which are so small that they constitute surface roughness have no appreciable effect on heat transfer and are of no interest in evaluation of pellets for flaws. The threshold area below which flaws are of no consequence is defined as factor T, for example 0.000324 square inch. The algorithm shown in FIG. 8 presents the analysis carried out by computer 105 pursuant to its program based on the above discussion. It is assumed that a pellet has been scanned and the crude or raw data entered in the memory of the computer. The computer computes the flaw quality index, FQI, of each flaw and sums the FQI's to derive a pellet surface quality index which is evaluated. For the first flaw the answer to "Is last flaw analyzed?" is "No.". The area A of the flaw is computed. If A<T, T being the maximum ignorable flaw area, further analysis of that flaw is aborted. If A>T, the process continues. For the first flaw, the area of the first flaw is the total. The perimeter P is computed and S=4πA/P 2 is computed. If S>0.3, and A>0.0006 in 2 , the pellet is rejected for an unacceptable fissure. If not, the flaw quality index F=S.sup.q P.sup.2 =(1-S.sup.q)A is computed. In the equation for F, q is an empirically determined magnitude, P is the perimeter and A the area of a flaw. If the current flaw touches the end of a pellet the value of F is modified by multiplying F by γ. γ is an empirically determined factor usually greater than 1. SQI is the quality factor which was determined by adding Fs for flaws which were analyzed earlier. For the first flaw the F is adopted as SQI. If at this point SQI>SQI LIMIT, the acceptable limit, the pellet is rejected. If SQI<SQI LIMIT the above described process is repeated with F reset to 0. The F for the second flaw is detected and the new F is added to the first SQI. If now SQI<SQI LIMIT, the above process is repeated. All flaws for the pellet are analyzed in this way. The following are causes for pellet rejection: 1. The sum of the flaw areas which exceed T are greater than AMAX; 2. A flaw having a shape factor less than or equal to 0.3 and an area greater than T and also 0.0006 square inch; 3. A surface quality index greater than SQI LIMIT. Otherwise, the pellet is acceptable. While a preferred embodiment of this invention has been disclosed herein, many modifications thereof are feasible. For example, instead of being scanned by a light beam, the pellets could be scanned by a sonar beam or by a magnetic field or a photograph of the pellet could be analyzed by a densitometer. This invention should not be restricted except insofar as is necessitated by the spirit of the prior art.

The invention provides a method of and apparatus for optically inspecting nuclear fuel pellets for surface flaws. The inspection system includes a prism and lens arrangement for scanning the surface of each pellet as the same is rotated. The resulting scan produces data indicative of the extent and shape of each flaw which is employed to generate a flaw quality index for each detected flaw. The flaw quality indexes from all flaws are summed and compared with an acceptable surface quality index. The result of the comparison is utilized to control the acceptance or rejection of the pellet.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to the field of security systems. More particularly, the present invention relates to a system and method for the remote monitoring of a premises from a location other than the premises. [0003] 2. Description of Related Art [0004] Conventional security systems typically protect a building using make/break contacts strategically placed at doors, windows, and other potential entry points and motion sensors in strategic areas inside the building. Other devices include glass breakage detectors, panic or medical alert buttons, temperature and flood sensors, smoke detectors, and P.I.R. (passive infra red) sensors, a type of motion sensor that senses heat differences caused by animate objects such as humans or animals. Also used are vibration sensors which, when placed upon a window for example, detect when the window is broken, and radio frequency (rf), radar, and microwave sensors, as well as laser sensing. When the system is on and a sensor is tripped, a signal is sent through a wire, or using radio frequencies (on wireless systems), to a main controller which sounds a siren and dials out via telephone, an IP connection, or cellular service to the monitoring station whenever an alarm condition occurs. [0005] One technological approach to determining whether or not an alarm condition exists is through the use of separate audio monitors operating in concert with separate alarm sensors. U.S. Pat. Nos. 4,591,834 and 4,918,717 are directed to such systems. For example, U.S. Pat. No. 4,591,834 refers to the use of miniature, low-frequency dynamic microphones. Alarm activities noted at the microphones are verified via a separate network of discriminator sensors which comprise geophones. Signal processing techniques are utilized to distinguish alarm activity. Intrusion and discriminator sensors are arranged in known patterns comprised of multiple sensors of each type. U.S. Pat. No. 4,918,717 refers to a system wherein a number of microphones are distributed about a secured premises in relation to other intrusion sensors. Upon detection of an intrusion alarm, the microphones can be manually enabled one at a time from the central station to allow an operator to listen to audio activity in proximity to the sensor alarm. [0006] Another approach is the use of video images to monitor a location. In many prior art devices, however, the video images may not be received by the monitoring party until several moments have passed after the recorded event has actually taken place, likely causing any response to be late and less effective. [0007] Another disadvantage with existing security systems is that after a person has left the premises, he or she may not be certain that he or she remembered to activate or arm the security system. In prior art systems, it has been necessary to return to the premises to arm the security system or ask someone else to check on the premises and report back to the person. Returning to the premises is time-consuming and inconvenient, and may not be possible if the person is traveling or is otherwise unable to return to the premises. [0008] In addition, the owner of a premises may desire to monitor the premises or communicate with an occupant of the premises, whether or not an alarm has been triggered. One approach for remote monitoring or remote communication involves the use of web cams. A disadvantage to using web cams is that they fail to address privacy concerns by failing to inform or notify the occupant of the premises that remote surveillance is occurring. Instead, the attraction of web cams to consumers is the ability to spy on a location without individuals knowing the web cam is transmitting images of the premises. [0009] Furthermore, the owner of the premises may desire to modify aspects of the security system while he or she is away from the premises. In many prior art systems, the owner is unable to modify certain aspects of the security system. Instead, the security system must be reconfigured by a representative of the security system manufacturer or a complex process using the keypad with limited user interface. It is therefore desirable for a user at a remote location to be capable of arming and disarming the security system, changing aspects of the security system, and generally having access to control the monitoring of the premises from the remote location. [0010] Prior art systems generally do not provide for two-way audio communication. Two-way audio capabilities enable owners of the premises and monitoring personnel to communicate with individuals present at the premises, providing an extra means for determining the status of the premises (such as determining if an alarm event is actually occurring) and, in the case of a remote user communicating with the premises, the opportunity to maintain a sense of control of the premises such as communicating with a child at the premises). [0011] Prior art systems generally do not provide for hands-free communication by occupants of the premises with a remote user. In cases in which the occurrence of an alarm event has resulted in an occupant being injured or otherwise unable to operate the security system, the only option was to wait for someone to check on the premises and notify the proper authorities. Furthermore, prior art systems generally do not transmit images or sound during non-alarm periods. It is therefore desirable to provide a security system capable of transmitting images and sound during non-alarm time periods, and to further provide a way for individuals at a monitored location to communicate with users accessing the security system from a remote location, and without the need for acknowledging the remote user in order to communicate. [0012] There is a desire to balance security, privacy, and convenience concerns, particularly with residential security systems. Many prior art security systems sacrifice security and lack convenience for the sake of privacy. It is therefore desirable to provide a security system that provides security of the premises, is configurable to address privacy concerns of the occupants, and is convenient for the users of the security system to access the system remotely. SUMMARY OF THE INVENTION [0013] From the foregoing, it can be appreciated that a need has arisen for a security system and method that overcomes the limitations of the prior art. It is desirable that such a security system provide the convenience of remote monitoring of a premises by a remote user, while simultaneously addressing privacy concerns by providing a notification signal to alert occupants of the premises that remote monitoring is occurring. It is further desirable that such a system use available infrastructure and protocols and overcome the limitations of conventional methods. [0014] Accordingly, the present invention provides a method for remote monitoring of a premises, comprising the steps of operatively coupling a geographically remote client to a security system server which is capable of authenticating a user of the remote client, operatively coupling the remote client to a security gateway which is capable of managing the monitoring of the premises, activating a signal at the premises for notifying an occupant at the premises that remote monitoring is occurring, and transferring information between the security gateway and the remote client. The transfer of information between the security gateway and the remote client is controlled by the user of the remote client. The security gateway may be operably coupled to at least one camera and to at least one audio station. [0015] The notification signal may comprise an audible signal or a visible signal or both. An audible notification signal may comprise a sound uniquely associated with the remote user, and can comprise speech, which may identify the remote user. A visible notification signal may comprise a depiction of the remote user, or a graphical image, or an alphanumeric message, which may identify the remote user, and which may be transmitted to a keypad at the premises. The visible notification signal may be transmitted to a display device, such as a television. The visible notification signal may further comprise an activation signal for a light source at the premises, such as a light emitting diode (LED). The LED may be located on a camera or on a keypad, for example. [0016] In accordance with one embodiment, the inventive method may further comprise steps for verifying the identification of the remote user, transmitting an access token from the security system server to the remote client, providing the security gateway with information about the remote user and the access token and disabling communication between the security system server and the remote client. The access token may be adapted to allow the remote client to access the security gateway based on the user's permission profile, which is created by a General Administrator of the security gateway. The access token may expire at a designated time and date, or after a designated length of time has elapsed, or after a designated number of accesses has occurred, or upon access being removed by a General Administrator. The access token may allow access to specific features of the security gateway in accordance with the user's permission profile. [0017] In another embodiment, the inventive method may further provide a controller capable of performing one or more building automation control functions, which may include without limitation controlling air conditioning systems at the premises, doors at the premises, lighting devices at the premises, irrigation systems at the premises, or electrical appliances at the premises. [0018] In yet another embodiment, the inventive method may provide for streaming data in substantially real-time from the security gateway to the remote client. In still another embodiment, the inventive method may provide for substantially real-time audio communication or video communication, or both, between the remote client and the security gateway. [0019] The inventive method may also provide for continuously caching audio and video data. Furthermore, the method of the present invention may provide for recording audio and video data during a particular time period. The particular time period may comprise intervals according to a pre-determined schedule, or may be determined upon demand of an administrator of said security gateway. The particular time period may begin prior to triggering of an alarm, or prior to triggering of a sensor. [0020] The present invention further provides a system for remote monitoring of a premises by a geographically remote user, comprising a security system server capable of authenticating the user, a security gateway capable of managing the monitoring of the premises, one or more cameras, and one or more audio stations, wherein the security gateway provides an audiovisual signal at the premises for notifying an occupant at the premises that remote monitoring is occurring. The inventive system may further comprise a controller capable of performing building automation control functions. The system may also provide for streaming data in substantially real-time from said security gateway to said remote client. The system may further provide for substantially real-time synchronized audio and video communication between said remote client and said security gateway. [0021] The present invention can be also used in many different vertical segments within the security industry. In this present invention, the audio and video digitization and processing including compression is centralized at the security gateway. As processors become less expensive and more efficient, these functions can be done at the individual camera or at the audio station. The security gateway may then act as a central communications and controller for the cameras, audio stations and various other sensors. [0022] The present invention provides the advantage of using the security system as a platform for two-way audio and video communication. By making communication between a remote user and the premises very convenient, the present invention allows the owner of the premises to be proactive in monitoring the premises by allowing remote viewing as well as communicating with individuals at the premises. BRIEF DESCRIPTION OF THE DRAWINGS [0023] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein. [0024] It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. In addition, although the figures may depict embodiments wherein each of the components represent different devices or locations, they can be combined into a single device or location. In addition, a single component may be comprised of a combination of components. [0025] [0025]FIG. 1 is a block diagram of a security system according to one embodiment of the disclosed system and method. [0026] [0026]FIG. 2 is a block diagram of a security system according to an alternative embodiment of the disclosed system and method. [0027] [0027]FIG. 3 is a block diagram of a security gateway according to one embodiment of the disclosed system and method. [0028] [0028]FIG. 4 is a more detailed block diagram of a security system according to one embodiment of the disclosed system and method. [0029] [0029]FIG. 5 is a process flow diagram depicting the process flow for a remote user at a remote location accessing a security system according to one embodiment of the disclosed system and method. DETAILED DESCRIPTION OF THE INVENTION [0030] The present invention addresses several shortcomings of the prior art by providing a security system and framework that is configured to deliver real-time information, including audiovisual information about alarm conditions and/or personal conditions to remote users. As a further advantage, the framework may be easily adapted for use in other applications that incorporate real-time information and video delivery. [0031] The term “security system” is used in this document to mean a system for monitoring a premises, e.g., for the purpose of discouraging and responding to burglaries, fires, and other emergency situations. Such a security system is well-suited for residential homes, but may also find use with schools, nursing homes, hospitals, businesses or any other location in which real-time information may be useful in obtaining adequate response upon the occurrence of alarm conditions. By integrating broadband features, including audiovisual capabilities, web access and wireless capabilities, and video and voice over IP protocols, embodiments of the present invention provide audiovisual alarm verification, 24-hour monitoring capabilities, and a secure web site with remote access features and security-focused content. [0032] The term “lifestyle monitoring” is used in this document to mean audiovisual monitoring and communicating on demand during non-alarm situations. The term “audiovisual” is used in this document to mean audio or video or both. An example of a non-alarm situation is when a parent checks on latch-key children or a caregiver checks on an elderly person. Embodiments of the present invention may be used to give peace of mind to the owner of the premises while he or she is away from the premises. Embodiments of the present invention may also be used to proactively respond to situations before they become emergencies. [0033] The term “remote user” is used in this document to mean any individual located at any location other than the premises or the central monitoring station. A remote user may include the owner of the premises, when the owner is not physically located at the premises. A remote user may also include a guest user, such as an individual whom the owner has given permission to access certain aspects of the security system. Because monitoring personnel at a central monitoring station do not have access to the security system except during alarm events, they are not considered remote users as they are described in this document. [0034] For purposes of the present invention, the term “premises” refers to real property, including one or more structures thereupon and their surroundings. For the purposes of the present invention, a premises preferably comprises a residential housing, but it will be appreciated by one skilled in the art that a premises may also comprise commercial facilities, educational facilities, and the like. [0035] Further, the term “a” is generally used in the present disclosure to mean one or more. Still further, the terms “coupled” and “operatively coupled” mean connected in such a way that data may be transmitted or received. It is understood that “coupled” and “operatively coupled” do not require a direct connection, a wired connection, or even a permanent connection. It is sufficient for purposes of the present invention that the connection(s) be established for transmitting and receiving information. [0036] In the present disclosure, the term “high-speed” or “high-bandwidth” generally means capable of providing sufficient bandwidth for data to be transmitted in real-time, i.e., with substantially no latency. In one embodiment, high-speed connections are those capable of transmitting at speeds of at least 128 Kbps. High-speed connections include but are not limited to cable modem connections, xDSL connections, and high-speed wireless connection. [0037] The term “non-alarm event” is used in this document to describe an event that occurs at the premises which does not constitute an alarm event. A non-alarm event is designated by the triggering of a sensor. For example, a motion sensor located near the front door may detect the presence of a person approaching the front door. This person may be, for example, a delivery person dropping off a package for the resident and would not constitute an alarm event. This non-alarm event, however, may be used by the owner of the premises to analyze the security system effectiveness (such as determining the capability of the front door camera to capture images in case of an alarm event), for lifestyle purposes (such as how often people approach the front door), or to provide monitoring personnel with a general time frame associated with an alarm event. [0038] The term “remote client” is used in this document to mean any processor-based device capable of connecting to a network. For example, a remote client may comprise a personal computer, a PDA, or a mobile phone. [0039] Referring now to the drawings, FIG. 1 depicts a block diagram of an exemplary security system 100 according to one embodiment of the present invention. Security system 100 comprises a security gateway 115 , which is typically located, but is not required to be located, at premises 110 . Security system 100 further comprises a monitoring client 133 operatively coupled to security gateway 115 through a network 120 . Security system 100 further comprises a security system server 131 operatively coupled to security gateway 115 through network 120 . [0040] In general, network 120 may be a public network or private network, a single network or a combination of several networks. In most embodiments, network 120 may be, but is not required to be, an IP-based network. In some embodiments it may be desirable for all or a portion of network 120 to include publicly available networks, such as the Internet, to avoid the need for installing, purchasing, or leasing additional infrastructure. However, in some systems, e.g., those that use high-bandwidth transmissions, it may be desirable to include dedicated high-bandwidth connections including, without limitation, leased lines, frame relay networks, and ATM networks, within network 120 . Further, in some systems it may be desirable to use a network 120 with quality of service guarantees given the real-time nature of the information that is transmitted. [0041] Generally, security gateway 115 is a processor-based device operable to monitor premises 110 by capturing and recording audiovisual information relating to the premises during pre-alarm, and post-alarm-periods, as well as during non-alarm events. Security gateway 115 also detects and relays alarm conditions at premises 110 and captures information relating to such alarm conditions. Upon triggering of an alarm, security gateway 115 sends cached, stored, and live information from pre-event, pre-alarm, and post-alarm segments to security system server 131 for verification and response. [0042] Security gateway 115 may, but is not required to be, located at premises 110 . Some or all components of security gateway 115 may be located remotely, but remain operatively coupled to security sensors 105 , audio stations 107 , and video cameras 112 which are located at premises 110 . In accordance with a preferred embodiment of the present invention, premises 110 comprises a building such as a residential home. Advantageously, the present invention provides for sensors 105 , audio stations 107 and video cameras 112 to be located indoors as well as outdoors. For example, sensors 105 , audio stations 107 and video cameras 112 may be located in certain rooms or zones within the building on premises 110 , as well as outside the doors of the building. [0043] Monitoring client 133 generally comprises a software program that may be used to display some or all of the information provided by security gateway 115 . Monitoring client 133 may be a stand-alone program or integrated into one or more existing software programs. One or more operators may then use this information to evaluate whether the alarm condition corresponds to an actual alarm condition and then take additional action, if desired, such as alerting the appropriate authorities. [0044] Security system 100 generally includes one or more sensors 105 coupled to security gateway 115 for the purpose of detecting certain events. One skilled in the art will appreciate that security system 100 is not limited to any specific type or model of sensor 105 . A variety of need for installing, purchasing, or leasing additional infrastructure. However, in some systems, e.g., those that use high-bandwidth transmissions, it may be desirable to include dedicated high-bandwidth connections including, without limitation, leased lines, frame relay networks, and ATM networks, within network 120 . Further, in some systems it may be desirable to use a network 120 with quality of service guarantees given the real-time nature of the information that is transmitted. [0045] Generally, security gateway 115 is a processor-based device operable to monitor premises 110 by capturing and recording audiovisual information relating to the premises during pre-alarm, and post-alarm periods, as well as during non-alarm events. Security gateway 115 also detects and relays alarm conditions at premises 110 and captures information relating to such alarm conditions. Upon triggering of an alarm, security gateway 115 sends cached, stored, and live information from pre-event, pre-alarm, and post-alarm segments to security system server 131 for verification and response. [0046] Security gateway 115 may, but is not required to be, located at premises 110 . Some or all components of security gateway 115 may be located remotely, but remain operatively coupled to security sensors 105 , audio stations 107 , and video cameras 112 which are located at premises 110 . In accordance with a preferred embodiment of the present invention, premises 110 comprises a building such as a residential home. Advantageously, the present invention provides for sensors 105 , audio stations 107 and video cameras 112 to be located indoors as well as outdoors. For example, sensors 105 , audio stations 107 and video cameras 112 may be located in certain rooms or zones within the building on premises 110 , as well as outside the doors of the building. [0047] Monitoring client 133 generally comprises a software program that may be used to display some or all of the information provided by security gateway 115 . Monitoring client 133 may be a stand-alone program or integrated into one or more existing software programs. One or more operators may then use this information to evaluate whether the alarm condition corresponds to an actual alarm condition and then take additional action, if desired, such as alerting the appropriate authorities. [0048] Security system 100 generally includes one or more sensors 105 coupled to security gateway 115 for the purpose of detecting certain events. One skilled in the art will appreciate that security system 100 is not limited to any specific type or model of sensor 105 . A variety of sensors 105 may be used, depending on the desired type and level of protection. Examples include, without limitation, magnetic contact switches, audio sensors, infrared sensors, motion detectors, fire alarms, panic buttons, and carbon monoxide sensors. Sensors 105 may be wired directly into an alarm control panel built into security gateway 115 , or they may be wirelessly connected. The type of sensors 105 to be used depends on the specific application for which security system 100 is designed. In some embodiments, multiple sensors 105 may be used. In such embodiments, security gateway 115 may consider data from all, some, or one of sensors 105 in the detection of alarm conditions. Additionally, security system 100 can store multiple video events triggered by sensors 105 , or at scheduled times. [0049] Security system 100 also includes one or more cameras 112 and audio stations 107 operable to capture video data and audio data, respectively, from premises 110 . Cameras 112 may be, but are not required to be, 360-degree cameras or panoramic cameras. Audio stations 107 may include microphones and speakers and are capable of providing two-way communication as well as emitting a signal for alerting occupants of the premises that communication is occurring. [0050] In addition, security gateway 115 may be configured to create an association between one or more sensors 105 and an associated camera 112 or audio station 107 . Whether or not separate sensors 105 are present, security gateway 115 may capture video or audio or both from cameras 112 and audio stations 107 to assist in the determination of whether an alarm condition exists and thereby whether to generate and send an alarm signal to the security system server 131 . Cameras 112 and audio stations 107 continuously transmit audiovisual data to security gateway 115 for caching (i.e., temporarily storing), recording (i.e., storing for a long term), or streaming to a remote user 152 or security system server 131 . In some embodiments, sensors 105 , such as motion detectors, infra-red sensors and audio sensors, may be replaced by an intelligent alarm module that is able to detect motion or intrusion by analyzing the video data or audio data or both generated from cameras 112 and audio stations 107 . [0051] In some embodiments, the segment of audiovisual data may be compressed using one or more of any number compression techniques known by one of skill in the art. For example, this may involve the use of video compression algorithms such as Motion Pictures Expert Group (MPEG). Further, the resolution or color depth of the video may be reduced to lessen the amount of bandwidth required for transmission. In one embodiment, alarm video can be transmitted at least 3 frames per second. In addition, the alarm video may have an end resolution (i.e., after interpolation and/or image enhancement, etc.) of 320 pixels by 240 pixels or higher, and optionally may be transmitted in color. It is noted that the present invention is not limited to any particular audio, video, or communications standards. The present invention may incorporate any such standards, including, without limitation: H.323, Adaptive Differential Pulse-Code Modulation (ADPCM), H.263, MPEG, User Datagram Protocol (UDP), and Transmission Control Protocol/Internet Protocol (TCP/IP). [0052] A disadvantage with intrusion systems in the prior art, including video surveillance systems, is that they provide very little or no information leading up to the alarm event. Prior art systems are typically configured to record audiovisual information only after an alarm is triggered. The only information that a monitoring agent typically receives is specific to that information about how an alarm event was defined which usually includes the time, type and location of sensor that was triggered. This limited information does not adequately help the monitoring agent verify the event. Even in video surveillance systems, the monitoring agent typically only views live camera(s) associated with that alarm sensor, which may not be adequate. A typical prior art intrusion system protects the perimeter of a residence or facility, and alarm events are only declared when the perimeter sensors, such as window or door contact switches, or internal sensors, such as motion sensors, are triggered. [0053] The present invention, however, provides for continuous caching of audiovisual data while the security system 100 is armed. Furthermore, if the security system 100 is armed and one of the sensors 105 is triggered, the segment of cached audiovisual data immediately prior to, during, and immediately following the triggering of the sensor 105 is stored in memory, preferably located in the security gateway 115 for privacy reasons, or in another storage device that is operatively coupled to the security gateway 115 via a network. For example, when a particular sensor 105 is triggered, cached audiovisual data from the camera 112 and audio station 107 associated with that sensor 105 , beginning several seconds prior to the triggering of the sensor 105 and ending several seconds after the triggering of the sensor 105 , may be stored in the memory. In addition, audiovisual data may be also be stored in memory at scheduled times. The General Administrator may view the stored data and may archive it if desired. If the system alarm is triggered, then the monitoring client 133 may access the stored data. The length and number of stored segments can be adjusted depending upon the capacity of the memory. [0054] Furthermore, information from cameras 112 that are placed outside the facility of premises 110 is used in the verification of alarms. For example, in one implementation, a front door camera records “events” for a fixed duration of time, such as ten seconds. The events are defined by a motion sensor being triggered. In one implementation, the security gateway stores approximately twenty of these non-alarm events. However, this event is not an alarm event but a non-alarm event. If the alarm system is triggered, the monitoring agent can in substantially real time access the various non-alarm audiovisual events. The non-alarm information is used by the monitoring agent to provide contextual information surrounding an actual alarm event. [0055] An advantage of continuously caching audiovisual data and storing the cached data before and after a particular sensor 105 is triggered, even though an alarm has not been triggered, is allowing the ability to capture important information leading up to an intrusion or other alarm event. The stored data can provide context to audiovisual data surrounding the triggering of an alarm and can thus be used to verify whether an alarm is an actual emergency situation or a false alarm. For example, a potential intruder may walk around the premises 110 prior to breaking in, in order to look for a point of entry. The cached data surrounding the triggering of the sensors 105 provide the monitoring client 133 , and ultimately law enforcement, with more information about the intruder than may be available if the camera 112 only began recording after the alarm was triggered. A monitoring agent reviewing this information, within minutes of the alarm triggering, will be able to review the stored non-alarm audiovisual events and make a verification decision. For example, if the non-alarm information includes several events illustrating strange behavior by someone that does not look like the owner or occupant or authorized guest of premises 110 , this is likely to be an actual alarm event. Non-alarm information is recorded even when the intruder is leaving the premises 110 . For example, a front door camera may record the intruder leaving the premises 110 and getting into his getaway car, further providing evidence for verification and possibly prosecution. In all recorded events, both non-alarm and alarm, the security gateway 115 records a segment of audiovisual information prior to a sensor 105 being triggered. In one implementation, the length of this pre-event recording is five seconds. It will be appreciated by those of skill in the art that the length of recording may be customized in accordance with the requirements and specifications of the particular security gateway 115 and the preferences of the owner of the premises 110 . This function is enabled by the continuous caching of pre-event information in the security gateway 115 . [0056] A further advantage to continuously caching audiovisual data and storing the cached data before and after a particular sensor 105 is triggered is the added convenience and peace of mind of the owner of the premises. For example, the owner of the premises 110 may view the stored data remotely in order to verify whether a false alarm has occurred, or to check to see if the owner's child has come home from school safely. [0057] The present invention provides for access to security gateway 115 and security system server 131 by remote user 152 using a remote client 155 which is located at a remote location 150 . Remote user 152 may be the General Administrator, i.e., a person (typically the owner of premises 110 ) having full access to security gateway 115 , including without limitation having the following capabilities: accessing all zones; arming and disarming security system 100 ; reviewing logs of alarm events and non-alarm events; accessing account information such as the billing address, phone number, and contact persons; renaming a sensor; performing maintenance on the system such as checking battery levels; creating guest accounts for other remote users 152 , including defining access permissions for the guest user and creating a username and password for the guest user; and adjusting controls on the security system 100 , such as the gain control for the microphones, the volume controls for the speakers, and the time limit for caching information. Alternatively, remote user 152 may be a guest user, i.e., a user whose permissions and access are controlled by the General Administrator. The features of the security system that a guest user may access are defined and modified according to the General Administrator's preferences. Additional information regarding general system administrative functions and user permissions can be found in U.S. Pat. Nos. 5,689,708; 5,694,595; and 5,696,898, the contents of which are incorporated by reference herein. [0058] Remote client 155 is operatively coupled to security gateway 115 and security system server 131 . Remote user 152 is authenticated by security system server 131 . In a preferred embodiment, remote users 152 are identified by a user name and password. It will be appreciated by those skilled in the art, however, that the present invention contemplates the use of many authentication techniques, including without limitation, physical possession of a key, user name and password, smartcards, and biometrics. For example, the system could recognize the remote user's 152 facial features, signature, voice or fingerprint and disarm the system without a Personal Identification Number (PIN) code. Additional information regarding the use of biometrics may be found in U.S. Pat. No. 5,526,428, the contents of which are incorporated herein by reference. [0059] Remote client 155 may connect to security system server 131 and security gateway 115 (after authentication) via network 120 . In one particular embodiment, remote client 155 includes a web-browser-based video client for accessing audio and video data. Typically, the web-based video client is a web browser or a plug-in for a web browser. After authentication, security system server 131 may be configured to create a data connection between remote client 155 and security gateway 115 such that communications between remote client 155 and security gateway 115 bypass security system server 131 . Advantageously, this avoids network bottlenecks at the security system server 131 , particularly when transmitting large amounts of data such as during the transmission of streaming audiovisual data [0060] In one embodiment, once authenticated, remote user 152 may perform lifestyle monitoring from remote location 150 through security gateway 115 . The remote monitoring feature allows remote user 152 at remote location 150 to view all or only selected portions of the video images from video cameras 112 , and to hear all or only selected portions of audio data from audio stations 107 . Depending on the access permissions assigned to remote user 152 , remote user 152 may further have the capability to accomplish the following: arm and disarm the system 100 ; configure the security system 100 to monitor different zones; review and change account information; and participate in lifestyle communications with occupants at premises 110 . In addition, remote user 152 may be able to configure the quality of the audiovisual data for remote monitoring. Depending on the bandwidth of the connection, the information transmitted to remote client 155 may be of a lower quality than that transmitted to security system server 131 for verification of alarm signals. For example, in one embodiment, the video transmitted to remote client 155 may have a lower frame rate, lower resolution, and/or lower color depth. [0061] Security gateway 115 may be configured to limit the transmission of all data (heartbeat, control, video, and audio) to a configurable ceiling relating to the remote client 155 access. Advantageously, this may provide the necessary amount of bandwidth to deliver the requested services, but prevents one user from creating a network bottleneck by requesting too much data at once. In one embodiment, a 128 kbps transmission ceiling is imposed. Access by web based client 155 to security gateway 115 may be preempted whenever an alarm condition occurs so that monitoring personnel have full control over cameras 112 and audio stations 107 to respond to the alarm condition. [0062] The present invention also provides for lifestyle monitoring by a guest user. Access permission for each remote user 152 is defined by the General Administrator. Access may be limited to certain time intervals (such as only at certain times during the day), a certain interval of time (such as beginning Friday and ending Sunday), or for a certain number of times (such as three times a day or three times with no expiration date). Access may also be limited to certain cameras 112 or audio stations 107 , etc. [0063] When a guest user performs lifestyle monitoring, the guest user will have limited access to security system 100 . Thus, guest users may not have full access to all cameras 112 and all audio stations 107 at all times. For example, remote user 152 may be able to access video from a camera 112 in a kitchen twenty-four hours a day, but may never be able to monitor audio or video from a bedroom. As another example, remote user 152 may be given permission to view video from several cameras 112 on a particular day, but only on that particular day. Remote user 152 may also be given permission to only access certain audio stations 107 . [0064] Although remote users 152 may be given unlimited access to a part or all of the security system 100 , such access does not necessarily give the remote users 152 the capability or authorization to change the security settings. Therefore, remote user 152 can access at least a portion of security system 100 without accidentally or intentionally disarming parts or all of the system. Furthermore, remote user's 152 access privileges to security system 100 may be withdrawn or rescinded at any time by the General Administrator. [0065] An advantage to allowing remote user 152 to access certain cameras 112 and audio stations 107 is that a lifestyle communication between the remote user 152 and one or more occupants of premises 110 can take place without requiring the occupants to do anything to acknowledge remote user 152 and start a communication session. Unlike prior art video telephony systems, the system in accordance with the present invention is particularly advantageous in situations in which an occupant at premises 110 is unable to physically respond, for example, a person with certain disabilities. Such a system is further advantageous in other settings in which a person at premises 110 is unwilling to participate in lifestyle communication, such as an unruly child. Thus, the present invention provides for lifestyle communication without requiring an occupant of the premises 110 to walk to a keypad or other device to acknowledge remote user 152 and start a communication session. [0066] In one embodiment of the present invention, security gateway 115 may comprise a controller capable of performing one or more building automation control functions. Such functions may include without limitation controlling air conditioning systems, doors, lighting devices, irrigation systems, and electrical appliances at the premises. Building and home automation is described in more detail in U.S. Pat. Nos. 5,510,975; 5,572,438; 5,621,662; and 5,706,191, the contents of which are incorporated herein by reference. [0067] Reference is now made to FIG. 2, which depicts a block diagram of the system 100 of FIG. 1, according to an alternative embodiment of the present invention. As shown, security gateway 115 is operatively coupled to data center 132 through network 120 , which is, in turn, operatively coupled to a monitoring client 133 through network 134 . [0068] Data center 132 stores customer information including billing information and security system settings, and is generally configured to automate certain aspects of security system 100 . Data center 132 receives audio and video from security gateway 115 and sends it in real-time to monitoring client 133 . Data center 132 authenticates remote user 152 of remote client 155 , recognizes multiple alarm notifications, and monitors the various components of security gateway 115 . Technology-intensive equipment including the security system server 131 may be kept in the data center 132 where physical access may be strictly controlled. Advantageously, in this configuration, non-technical personnel may be kept away from the sophisticated and expensive equipment in the data center 132 , and the non-security-related personnel would not have direct access to view sensitive alarm notifications and videos. Any alarm notification and audiovisual information sent by security gateway 115 is transmitted to the security system server 131 at the data center 132 . The security system server 131 logs the alarm notification and retrieves information about the customer, which may include, without limitation, any prior alarm notifications or events. The security system server 131 also transmits the alarm notification and audiovisual information, along with any additional information, to one or more monitoring clients 133 , where such information and video may be displayed for a monitoring operator to determine if an alarm condition exists. [0069] In the illustrative embodiment, communications among security gateway 115 , data center 132 , and monitoring client 133 may occur through public and/or private networks. In particular, security gateway 115 is coupled to data center 132 , which is coupled to monitoring clients 133 through network 134 . Although network 134 is logically depicted as a single network, it will be appreciated by one skilled in the art that network 134 may comprise a plurality of data networks that may or may not be homogeneous. In one embodiment, at least some of the monitoring clients 133 may be coupled to the security system server 131 through the Internet. In other embodiments, monitoring clients 133 may be coupled to the security system server 131 through dedicated connections such as a frame relay connection or ATM connection. Advantageously, maintaining dedicated lines between security gateway 115 and security system server 131 and between security system server 131 and monitoring client 133 provides a secure connection from security gateway 115 to monitoring client 133 that may have dedicated bandwidth and/or low latency. Network 134 includes all such networks and connections. In another embodiment, not shown, data center 132 may be coupled to monitoring clients 133 through network 120 . [0070] Reference is now made to FIG. 3, which illustrates an exemplary embodiment of the security gateway 115 of FIG. 1 for use in monitoring the premises 110 . As shown in FIG. 3, security gateway 115 may include an alarm control panel 310 , a video module 320 , a user interface 350 , a communications interface 340 , and an audio module 330 . As shown in FIG. 3, the components of security gateway 115 are configured to communicate with one another through system bus 305 . In other embodiments, some or all of the components may be directly connected or otherwise operatively coupled to one another. [0071] Alarm control panel 310 interfaces with one or more sensors 105 , which may be wired or wireless. In some embodiments, it may include an interface to the Public Switched Telephone Network (PSTN) or a cellular network. However, as shown, the interface to the PSTN may be contained in the communications interface 340 instead of the alarm control panel 310 . The alarm control panel 310 is preferably capable of operation in isolation as per UL requirements for residential fire applications and residential burglary operations. Alarm control panel 310 is further capable of continuing to operate in the traditional manner regardless of the state of the video subsystem. [0072] Alarm control panel 310 may be configured to communicate with the other components of the security system to monitor their operational state. Information that the alarm control panel 310 may receive includes, but is not limited to, whether security gateway 115 can communicate with the security system server through the communications interface 340 , information about AC power failure, trouble by zone, fire trouble, telephone line trouble, low battery, bell output trouble, loss of internal clock, tamper by zone, fail to communicate, module fault, camera trouble, and intercom trouble. The detected operational failure of any component in security gateway 115 may be indicated by a communications loss between components and a concurrent alarm condition reported by alarm control panel 310 and displayed for the user on user interface 350 or announced through audio module 330 . In addition, any detected operation failures may be communicated to the security system server 131 through communications interface 340 . Alarm control panel 310 may also be configured to record alarm conditions and associated data in memory. The security system server 131 may also be configured to record alarm conditions and associated data in addition to or in lieu of alarm control panel 310 doing so. In some embodiments, alarm control panel 310 supports dialup access by authorized users to remotely configure the system. However, the preferred mode of configuration is through an Internet web site. In other embodiments, other components of security gateway 115 may be configured to perform this function. For example, in one embodiment, video module 320 records alarm conditions and the associated data. [0073] Video module 320 may perform many functions including but not limited to analyzing data from one or more of the sensors 105 or cameras 112 to determine whether an alarm condition exists; accessing data stored in memory; generating alarm video to transmit to security system server 131 in response to detection of an alarm condition; and communicating with security system server 131 and remote client 155 through communications interface 340 . In addition, video module 320 may buffer video from cameras 112 in memory. Then, based on predefined criteria, older video that is not considered essential to any alarm signals may be discarded. Video module 320 may also be configured to record video, or portions thereof, on a predetermined basis, which may correspond, for example, to the requirements of the customer. Non-alarm video may be stored for later retrieval by the customer. In one embodiment, the customer or remote user at remote location 150 may able to adjust said predetermined basis including, without limitation, adjusting the recording times, duration, and total length of recordings. In some embodiments, non-alarm video may also be sent to the security system server 131 for storage. Video module 320 is also capable of streaming live audio and video from the residence during alarm conditions, pre-alarm events, post-alarm events, and non-alarm events, as well as for lifestyle monitoring. If a camera 112 is analog, video module 320 may digitize the video before transmitting it. When security system 100 is armed, audio and video data are constantly being stored in the video module's memory for potential use as pre-event media. In one particular embodiment, video module 320 contains sufficient memory to store sixty seconds of pre-alarm video and audio from each camera 112 and microphone 334 at audio station 107 in RAM and up to several hours of audio/video content (per camera 112 and audio station 107 ) on disk. When an alarm condition occurs, this cached data may be stored more permanently. The General Administrator of a security system 100 may delete recorded information, archive non-alarm information, and adjust the cache length. A guest user may only make such changes if the General Administrator has assigned such permissions and access to the guest user. [0074] Audio module 330 controls audio stations 107 , which typically include an audio transmitter, such as one or more speakers 338 , and an audio receiver, such as one or more microphones 334 . In a typical configuration, several microphones 334 and speakers 338 would be located throughout premises 110 . The audio signals detected by microphone(s) 334 are recorded through audio module 330 . Audio module 330 may record the audio or it may transmit the audio to video module 320 for storage. Audio module 330 may be capable of selecting an individual audio input 334 or any combination of audio inputs 334 . Further, audio module 330 may play back audio signals through speaker(s) 338 . Audio module 330 may provide gain control for microphones 334 and volume control for speakers 338 in audio station 332 . [0075] Communications interface 340 may serve as the gateway between security gateway 115 and one or more communications networks such as a Hybrid Fiber Coaxial Network (HFC) plant, PSTN 145 , WAN, LAN, and wireless networks. Communications interface 340 may comprise software and hardware including, but not limited to a network interface card. In some embodiments, communications interface 340 may be physically separate from the other components of security gateway 115 . Regardless of its form, communications interface 340 assists in the communication of data to and from security gateway 115 and security system server 131 . [0076] In addition, security gateway 115 may include a web-enabled user interface 350 . User interface 350 may further include a display device, such as a computer screen, television or keypad, for displaying information to the user. Such information may include, without limitation, the current system status, whether an alarm condition has been detected, and whether any components have failed. In addition, other non-system-related information such as the time, date, weather forecasts, and news bulletins may be displayed. In the illustrative embodiment, user interface 350 is operatively coupled to a keypad 357 . A user could thereby activate or deactivate the security system by entering a predetermined code on keypad 357 . It will be understood with the benefit of this disclosure by those of skill in the art that other types of user interfaces 350 may be used with this invention. For example, security gateway 115 may be activated or deactivated with a remote portable transmitter 355 . Wireless remote 355 communicates with user interface 350 via wireless receiver 352 . Additional receivers may be used with the present invention to pick up weak signals. Security gateway 115 is further capable of responding to wireless remotes 355 for changing alarm states of the security system. Each wireless remote 355 may comprise, for example, a key fob, which may be identified to security gateway 115 as a unique user. [0077] In some embodiments of the present invention, two-way audio communications may be initiated between a remote user 152 and the premises 110 through audio module 330 . The monitoring station personnel cannot initiate lifestyle functions. To address privacy concerns, monitoring personnel have access to the security system components only during alarm events. Advantageously, the two-way audio communication allows the remote user 152 to interact with a person at the premises without the need for the person at the premises to acknowledge communications channels. [0078] In order to address privacy concerns, in accordance with a preferred embodiment of the present invention, an audio or visual indicator may be included to notify occupants at the premises that they are under remote surveillance. While streaming live media for lifestyle monitoring or any other remote connection is made with the security system 100 , security gateway 115 activates a notification signal such as an audible or visible “splash tone” on a frequent basis. For purposes of the present invention, the term “splash tone” is used broadly to mean an audio cue or visual cue, or both, to indicate to one or more persons at the premises that remote surveillance and monitoring of the premises 110 is occurring. [0079] The notification signal may include a unique tone, bell, or other manufactured sound. The notification signal may be a unique tone which repeats periodically. The notification signal may also include audible signals such as speech and other messages that announce the identity of the remote user 152 . The notification signal may further comprise a unique message when remote monitoring begins, such as “[Grannie] has established a connection.” The notification signal may further comprise a signal to indicate when remote surveillance has ended, such as “[Grannie] has disconnected.” [0080] The notification signal may also include a visual cue, such as an LED located a keypad or on the appropriate camera(s) 112 . The notification signal may also include visual data for indicating the identity of the remote user 152 . For example, a graphical image, a depiction of the user, or an alphanumeric message may be used to identify the remote user 152 . Therefore, the notification signal may be unique depending on the identity of the remote user 152 . [0081] In one embodiment, the security system may include one or more “smart cameras” that have much of the functionality of the Video Module 320 built in. Specifically, these smart cameras may be operable to perform video capture, compression and storage and to communicate with the security gateway using a home area network, e.g., a wireless standard such as the home networking standard 802.11b, or power-line. In essence, the smart camera would function as a network appliance that is able to receive instructions from the security gateway to control the session, FPS (frames per second), quality, bandwidth, support other supervised communication from the gateway, and to transmit video and other information to the security gateway. Preferably, transmission between the camera and security gateway 115 should be secure and reliable, even taking into account the relatively noisy household environment. Optionally, the smart camera is operable to detect motion in the recorded image and send an event signal to the security gateway. The camera may integrate other sensor functionality such as audio discrimination and analysis and motion detection. [0082] Reference is now made to FIG. 4, which depicts a more detailed illustration of the various components of the security system server 131 of FIG. 1 and a central monitoring station 136 , according to one embodiment of the present invention. These components may be software programs executable on processor-based devices operable to communicate with one another through LAN 405 and LAN 445 , respectively. In one particular embodiment, these components are processor-based devices operating under the Microsoft® Windows NT™ operating system. However, it is understood that the present invention is not limited to the illustrated configuration. For example, the components may be implemented as software running on one or more computing devices. Alternatively, the components may be implemented in several devices that may be directly connected via communications interfaces (e.g., serial, parallel, IEEE 1394, IR, RF or USB). [0083] Central monitoring station (CMS) 136 is a facility operatively coupled to data center 132 and security gateway 115 . Any alarm notification and audiovisual information sent by the security gateway 115 is transmitted to central monitoring station to determine if an alarm condition exists. If an alarm condition exists, CMS 136 personnel can contact the appropriate authorities, etc. In this configuration, a concentration of trained personnel handle systems located throughput the country. In most embodiments, the communication channel between the data center 132 and central monitoring station 136 is secure, and accordingly, an unencrypted protocol may be used. In one particular embodiment, an unencrypted ASCII protocol over a TCP/IP connection may be used. In configurations where the connection between the security system server 131 and monitoring client(s) 133 is not secure, it may be desirable to use an encrypted protocol. [0084] Monitoring client 133 resides in central monitoring station 136 and is operable to display video and images transmitted from security gateway 115 in real-time, as well as provide two-way communication between monitoring client 133 and security gateway 115 . In the present disclosure, the term “real-time” is intended to generally mean that no substantive time period elapses between the captured audiovisual data and the receipt of audiovisual data corresponding to the event by monitoring client 133 . [0085] As shown, security system server 131 may comprise alarm receiver 410 , media handler 415 , automation system server 420 , web interface 432 , application server 434 , database server 436 , and messaging interface 438 . [0086] Alarm receiver 410 receives the alarm notification and associated information from security gateway 115 . The alarm event is then logged and recorded by automation system server 420 . Alarm events can also be reported by security gateway 115 to alarm receiver 440 via a Communications network such as PSTN 145 . Alarm receiver 440 posts the alarm condition to automation system server 420 . Monitoring client 133 retrieves audio and video data from media handler 415 . In one particular embodiment, the monitoring client 133 retrieves the audio and video data from media handler 415 using Microsoft® ActiveX. In other embodiments, other media handling/communications protocols may be used, including, without limitation, custom protocols. The communications protocol is used to transmit audio and video content from media handler 415 , submit control messages (for selecting cameras, microphones, and speakers during live feeds), and support Voice Over IP (VoIP), streaming audio, and video services between the residence and monitoring client 133 during an alarm condition. [0087] Automation system server 420 is generally configured to store customer data, for example contact information, billing information, passwords, as well as alarm history. Alternatively, some or all of this information may be stored in monitoring client 133 or at another remote site. Since this data is usually low bandwidth, dedicated bandwidth may not be necessary. However, it may be desirable for security purposes for it to remain in data center 132 . Automation system server 420 may also serve as a workflow system for operators responding to alarm conditions, as well as a log of all monitoring activity. In an exemplary embodiment, automation system server 420 is a database application based on, for example Microsoft SQL Server 7 , running under Windows NT. CMS personnel may interface with automation system server 420 over the network via a client application, which may be built into monitoring client 133 . [0088] Media handler 415 is generally operable to provide several functions. For example, media handler 415 receives and stores video and audio data associated with alarm conditions from security gateway 115 and relays alarm condition data, for example audio and video, to monitoring client 133 . Media handler 415 may also be responsible for keeping track of the network addresses for all the security gateways 115 that are attached. For example, media handler 415 relays alarm conditions reported via TCP/IP from security gateway 115 to automation system server 420 . Media handler 415 may also provide access to audio and video associated with alarm conditions to authorized personnel for a predetermined time period after an alarm condition is detected. Additionally, media handler 415 may relay control and configuration data destined for security gateways 115 . This data may originate either from an operator (located at central monitoring station 136 ) through monitoring client 133 or from remote user 152 at remote location 150 . [0089] The communications protocol between monitoring client 133 and media handler 415 may be proprietary and/or may use standard protocols. The communications protocol between security gateway 115 and media handler 415 may provide secondary pathways for transmitting alarm notifications, relays configuration information to security gateway 115 (including control messages for arming and disarming partitions, bypassing zones, and selecting cameras 112 and audio stations 107 for live feeds), uploading pre-event and relevant non-alarm audio and video to media handler 415 during an alarm condition, transmitting live video and audio during an alarm condition, supporting voice over IP (VoIP) services between the residence and monitoring client 133 during an alarm condition, and performing software updates. [0090] Web interface 432 provides authorized remote users 152 with the ability to view and edit account information, arm and disarm security system 100 , and view and hear live and recorded media from premises 110 , all through a network-based interface. In many embodiments, this network-based interface is an Internet web site, or a portion of a web site. After the remote user 152 is authenticated, application server 434 provides and/or facilitates the features available to remote client 155 through web interface 432 . The particular features that are made available are a design decision that may vary based upon several factors, which may include, without limitation, the permissions of the remote user 152 and the type of premises that is monitored. [0091] Messaging interface 438 may also provide for transmission of a message to remote client 155 by page, phone, e-mail, interactive voice response, short message service, or other messaging tool. Such a message will serve to notify multiple contacts on the alarm contact list when an alarm event has taken place or is taking place. [0092] In one embodiment, a three-tier architecture may be used to provide such an interface. [0093] The first tier may consist of web servers running Internet Information Server (IIS) on Windows NT™, which is responsible for static web content such as images. Requests for dynamic content may be forwarded to application server 434 . Application server 434 generally provides or facilitates all of the functionality that is accessible to remote clients 155 . The third tier is a database tier that may be provided by automation system server 420 . Data storage may be, for example, a billing database. Authorized users may receive information from the database regarding their account by accessing database server 436 . Application server 434 may access automation system server 420 to obtain account information and issue commands ultimately destined for security gateway 115 . [0094] After remote client 152 is authenticated, application server 434 may be configured to allow remote client 152 to view audiovisual content from security gateway 115 , communicate with automation system server 420 to access customer data, and access features of the security system 100 . In one embodiment, such features may include, without limitation, arming or disarming security system 100 ; adjusting sensitivities of sensors 105 (if present); adjusting alarm condition detection sensitivity; remote monitoring; adjusting camera 112 settings and audio station 107 settings; adjusting settings for lights, HVAC (heating, ventilation, and air conditioning) systems, irrigation systems and other environmental controls; and reviewing alarms and recordings. In particular, application server 434 may allow remote user 152 to access media directly from security gateway 115 . In one embodiment, a live feed from the premises is available with the ability to select among cameras 112 and microphones 334 . In some embodiments, only video from certain specified cameras is accessible for remote clients. In some embodiments, application server 434 may be configured to allow remote user 152 to initiate a two-way audio connection with the security gateway 115 so that the remote user 152 can communicate through the audio stations 332 via speaker(s) 338 and microphone(s) 334 attached to security gateway 115 . Communication between application server 434 and automation system server 420 may take the form of calls to stored procedures defined in the master database maintained by automation system server 420 . [0095] Access to web interface 432 requires successful authentication using any technique discussed above, such as entering a username and password. Preferably, all account-specific web content, including the login request, employs the secure HTTP protocol. In one embodiment, each customer may be assigned a General Administrator (GA) account. GA accounts have full access to their respective associated security gateway 115 . The GA account can also create a number of guest user (“remote user” 152 ) accounts that have limited access (as discussed above) to their respective associated security gateway 115 . Typically, all account information is stored through automation system server 420 , including usernames and passwords. Web interface 432 retrieves account data from automation system server 420 for display via the Web, by means of one or more stored procedures. The GA can modify a subset of this account data and update the corresponding entries in automation system server 420 . [0096] Referring now to FIG. 5, a process flow diagram is shown illustrating the process for remote monitoring of a premises by a remote user using a remote client located at a remote location using a security system such as the security system 100 of FIGS. 1 - 2 . In particular, remote users may access features of a security gateway such as the security gateway 110 of FIG. 3. These features include without limitation viewing and editing account information, arming and disarming the security system, and accessing live and recorded audiovisual data from the premises. [0097] In step 500 , the remote user connects to a security system server. In an exemplary embodiment, the remote user may connect to the security system server using a web browser such as Netscape Navigator or Microsoft® Internet Explorer. In other embodiments, the remote user may connect to the security system server via an interactive television platform having a friendly and easy-to-navigate user interface. [0098] In step 510 , the remote user provides the security system server with information for authentication. The type of information used for authentication may take many forms. For example, in one embodiment, a media handler associated with the security system server may require some sort of a username and password combination. Further, it is to be understood by the disclosure of one of skill in the art that any other procedure suitable for authenticating the identity of the remote user may be used, such as by validating the remote user's biometric data. [0099] The security system server verifies the authentication information in step 520 . If the information is not authenticated, then the remote user is denied access to the features of the security gateway, and process flow ends in step 590 . Precautions against unauthorized access may be implemented, including, but not limited to, logging incidents of access attempts, with emphasis on denied access. [0100] In step 530 , the security system server determines if the remote user has the necessary permissions to access the security gateway. Necessary permissions may include access to a particular camera or a particular audio station located at the premises, access during a particular time period, access to audio and or video information, and access to change passwords, settings and/or activate and deactivate the security system. If the remote user does not have the necessary permissions, the remote user is denied access to the security system, and process flow ends in step 590 . [0101] If the remote user has the necessary permissions, in step 540 , the security system server provides the remote client and the security gateway with an access token. The access token will typically comprise the identity of the remote user, the identity of security gateway to be accessed, the access permissions to be granted for the access token, and the desired lifespan of the token, as well as a digital signature of the security system server. It is noted that in accordance with the present invention, the remote user is only allowed access to those features corresponding to the permissions associated with the remote user's permissions profile. For instance, the remote user may only have permission to access a camera in a baby's nursery, and may lack access to the other cameras in the premises. Alternatively, if the remote user is the General Administrator of the security gateway, then he or she has full access to the security gateway features. [0102] The remote client then connects directly to the security gateway and provides the security gateway with the access token in step 550 . It is noted that the term “connects directly” means that communications between the remote client and security gateway do not pass through security system server. The security gateway inspects the access token received from the remote client and compares it to the access token received by the security gateway in step 560 . If the access tokens do not match, then the remote user at the remote client is denied access to the security gateway, and process flow ends in step 590 . [0103] If the access tokens match in step 565 , then the remote user may access features of the security gateway in step 570 in accordance with the user's permissions profile. During access by the remote user of the security system cameras or audio stations at the premises, the security gateway activates a notification signal comprising an audiovisual cue at the premises in step 575 , indicating to occupants of the premises that remote monitoring is occurring. For example, an LED on a camera at the premises may be activated while the remote user is accessing that camera. In another example, an audible tone may be activated while the remote user is accessing an audio station at the premises. The remote user will continue to be able to access designated security gateway features until the remote user logs out according to step 580 or the access token expires according to step 585 . [0104] In some embodiments, the security system server may assign a lifespan to the access token. In such cases, after a pre-specified time or event, the access token expires and the remote user may not access the security gateway after the expiration of the access token. In order to access to the features of the security gateway after expiration of the access token, the remote user must reconnect to the security system server and provide valid authentication information. [0105] Accordingly, the remote user may then connect directly to security gateway to perform remote monitoring through security gateway, check the system status, initiate a two-way audio conference, and/or any other features made available by security gateway and falling within the remote user's permissions. In some embodiments, only remote monitoring and two-way audio conferencing is made available through security gateway. In these embodiments, all non-media features are provided through security system server. [0106] The remote monitoring feature allows remote user to view all or portions of the video signal from video cameras and to hear all or portions audio information from audio stations. Depending on the bandwidth of the connection, the video may be of a lower quality than that transmitted to central monitoring station for verification of alarm signals in order to save bandwidth. For example, in one embodiment, the video transmitted to remote user may have a lower frame rate, lower resolution, and/or lower color depth. Depending on the remote user's permissions and the remote client's capabilities, the remote user may be able to configure the quality of the video for remote monitoring. [0107] In addition, depending on the remote user's level of permissions, the remote user may access remote features of the security gateway directly to reconfigure the security system. Once authenticated, the remote user may reconfigure some or all of the features of the security gateway. These features may include, without limitation, arming or disarming the security system; adjusting sensitivities of sensors (if present); adjusting alarm condition detection sensitivity; remote monitoring; adjusting camera and audio station settings; and reviewing alarms and recordings. Camera settings may include without limitation pan, tilt, focus, brightness, contrast and zoom. [0108] The present invention also overcomes similar problems with personal emergency response systems (PERS) and telemedicine, including telehealth. The monitoring clients in these applications can now use the video and alarm to better diagnose the problem. In many ways, alarms from health sensors, emergency panic buttons and the like are similar to alarm sensors in terms of generating false and unwanted alarms. This system also enables health care givers and concerned family members to use the remote client feature for increased peace of mind. [0109] The foregoing examples are included to demonstrate embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

A method is disclosed for remote monitoring of a premises, comprising the steps of operatively coupling a geographically remote client to a security system server which is capable of authenticating a user of the remote client, operatively coupling the remote client to a security gateway which is capable of managing the monitoring of the premises, activating a signal at the premises for notifying an occupant at the premises that remote monitoring is occurring, and transferring information between the security gateway and the remote client. The transfer of information between the security gateway and the remote client is controlled by the user of the remote client. The security gateway may be operably coupled to at least one camera at the premises and to at least one audio station at the premises. The notification signal may comprise an audible signal or a visible signal or both. An audible notification signal may comprise a sound uniquely associated with the remote user, and can comprise speech, which may identify the remote user. A visible notification signal may comprise a depiction of the remote user, or a graphical image, or an alphanumeric message, which may identify the remote user, and which may be transmitted to a keypad at the premises. The visible notification signal may be transmitted to a display device, such as a television. The visible notification signal may further comprise an activation signal for a light source at the premises, such as a light emitting diode (LED). The LED may be located on a camera or on a keypad, for example.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application contains subject matter, which is related to the subject matter of the following co-pending applications, each of which is assigned to the same assignee as this application, International Business Machines Corporation of Armonk, N.Y. Each of the below listed applications is hereby incorporated herein by reference in its entirety: [0002] entitled ‘Hierarchical Six-Transistor SRAM’, docket number YOR920060639US1; [0003] entitled ‘Hierarchical 2T-DRAM with Self-Timed Sensing’, docket number YOR920060640US1; [0004] entitled ‘eDRAM Hierarchical Differential Sense AMP’, docket number YOR920060637US1; and [0005] entitled ‘DRAM Hierarchical Data Path’, docket number YOR920040364US1. TRADEMARKS [0006] IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies. BACKGROUND OF THE INVENTION [0007] 1. Field of the Invention [0008] This invention relates to an SRAM memory array comprising memory cells with each cell containing seven devices, and in particular to a memory array wherein the basic storage nodes, which store the true and complement of the data, are constructed from six devices, forming a cross-coupled flip-flop cell. One internal storage node of this cell being connected to a separate read-pass device which passes the state of this node to a local bit line (LBL) for single-ended sensing, with the gate of this separate read-pass device connected to a separate read-word line. [0009] 2. Description of Background [0010] Before our invention current six device SRAM cells were encountering significant stability problems as we scale below 0.1 micron. The main reason for this is that the device tolerances, particularly the threshold voltage variations from device to device, do not scale appropriately as the technology scales to smaller dimensions. When an SRAM cell is read, the bit lines are precharged ‘HIGH’ which places a ‘disturb’ signal on the ‘0’ node of the cross-coupled flip-flop. For the nominal design case, this ‘disturb’ signal is quite tolerable. However, if the threshold variations between devices is sufficiently large, this ‘disturb’ signal can cause some cells to flip state, i.e. a stored ‘0’ becomes a ‘1’ and vice versa. Current SRAM cell designs employ two techniques to circumvent this, 1) reduce threshold variations by making the devices, and hence cell, larger than the smallest size normal scaling rules would allow, and 2) use eight devices per cell, with the extra devices eliminating the ‘disturb’ signal during reading. Both techniques significantly increase the size of the SRAM cell and hence reduce the density, a very undesirable result. [0011] A typical, 6T SRAM cell has two internal nodes, ‘A’ and ‘B’ one example of which is illustrated in prior art FIG. 1A which store ‘0’/‘1’ respectively on the two nodes for a stored ‘0’, and the reverse of ‘1’/‘0’ respectively on the nodes for a stored ‘1’. These two nodes are coupled to a pair of balanced bit/sense lines, which are used for both reading and writing. For reading the state of the cell, both bit lines are precharged ‘HIGH’ through a pass access device on each node (not shown). Subsequently, the word line of the selected row goes ‘HIGH’ and connects nodes ‘A’ and ‘B’ of this cell to the precharged bit lines through devices N 2 and N 3 . As a result, within the cell, the internal storage node, which happens to currently be latched at ‘0’, will thus see a large voltage applied to it, which is the ‘disturb’ signal. If the difference in threshold voltages of the cross-coupled devices N 1 and N 2 is sufficiently large, this ‘disturb’ can cause the voltage on this ‘0’ node to rise sufficiently such that the cross-coupled arrangement will pull the previously ‘1’ node to ‘0’, thus reversing the stored state, a significant error. [0012] One current method used to eliminate this read ‘disturb’ sensitivity is the use of an eight device SRAM cell one example of which is illustrated in prior art FIG. 1B . This adds two nFET devices, plus one read bit line and one read word line to each cell as illustrated by the encircled area 102 . One of the storage nodes, for example node ‘B’ as illustrated, is connected to the gate of the pull down nFET device. This device has its source grounded and its drain in series with the read-select nFET. This read-select device has its drain tied to a separate read-bit line, while a separate read word line activates its gate. Thus each cell has the addition of two FET devices, plus one read bit line and one read word line. [0013] For a given technology, the threshold variations between adjacent devices become larger as the devices approach minimum dimensions. Thus one method for improving stability is by making the device channel length and width larger, which results in lower density, an undesirable effect. If we wish to increase cell stability without increasing the cell device sizes, the bit line capacitance must be reduced without significantly increasing the effective, average cell size. SUMMARY OF THE INVENTION [0014] The shortcomings of the prior art are overcome and additional advantages are provided through the provision of an SRAM memory array comprising a plurality of memory cells, each of the plurality of memory cells further comprising a device, each of the plurality of memory cells having seven of the device; a first storage node; a second storage node; and a first local bit line; the first storage node and the second storage node store true and complement of data and are constructed with six of the devices forming a cross-coupled flip-flop cell, one of the devices being configured as a first read-pass device, the second storage node is connected to the first read-pass device, the first read-pass device passes the state of the second storage node to the first local bit line effectuating single ended sensing, the first read-pass device gate is connected to a first read word line. [0015] System and computer program products corresponding to the above-summarized methods are also described and claimed herein. [0016] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings. TECHNICAL EFFECTS [0017] As a result of the summarized invention, technically we have achieved a solution which is an SRAM memory array comprising memory cells with each cell containing seven devices coupled with a hierarchical bit/sense line structure (7 Transistor/Hierarchical cell, 7T/H) to significantly reduce the read ‘disturb’ sensitivity associated with a smaller cell size. BRIEF DESCRIPTION OF THE DRAWINGS [0018] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: [0019] FIG. 1A illustrates one example of a prior art six device (6T) SRAM cell having two internal nodes, ‘A’ and ‘B’; [0020] FIG. 1B illustrates one example of a prior art eight device (8T) SRAM cell which uses two additional devices for the reading of the cross-coupled six device SRAM cell; [0021] FIG. 1C illustrates one example of a prior art read ‘disturb’ voltage on node ‘B’ of 6T cell due to the discharging of a very large, precharged bit line capacitance through device N 0 ; [0022] FIG. 2 illustrates one example of a modified SRAM cell showing addition of one read-pass n-device per cell, connected to local read bit line LRBL for isolating the read ‘disturb’. Single-ended sensing is used via a hierarchical bit line pair, LRBL and global read bit line GRBL, interconnected by one read-head for every 8 or more (a design parameter) cells per LRBL; [0023] FIG. 3 illustrates one example of a cell showing multiple cells, connected to one complete local read bit line, LRBL for isolating the read ‘disturb’ issue. Single-ended sensing is used via a hierarchical bit line pair, LRBL and global read bit line GRBL, interconnected by one read-head for every, typically, 8 or more (a design parameter) cells per LRBL. (16 chosen for simplicity); [0024] FIG. 4 illustrates one example of a multiple local read bit lines LRBLs connected to multiple global read bit line, GRBL with column read-sense amp at end of the GRBL; [0025] FIG. 5 illustrates one example of a modified, symmetrical 7T/H SRAM cell, providing three separate ports, one separate port for writing and two separate ports for two simultaneous reads of different cells. All three ports can reference same or different cells simultaneously; [0026] FIG. 6 illustrates one example of simulation results for 7T/H SRAM of FIG. 2 write-bit line all have 256 cells; [0027] FIG. 7 illustrates one example of simulation results for 8T SRAM of prior art FIG. 1B write-bit line and read-bit line have same number of cells; and [0028] FIG. 8A-8B illustrates one example of Vt-Tolerance—stability of 7T/H SRAM of FIG. 2 to device Vt differences. Write-bit lines all have 256 cells. [0029] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. DETAILED DESCRIPTION OF THE INVENTION [0030] Turning now to the drawings in greater detail, in an exemplary embodiment of the present invention, this invention makes use of a seven device SRAM cell coupled with a hierarchical bit/sense line structure (7 Transistor/Hierarchical cell, 7T/H) to significantly reduce the read ‘disturb’ sensitivity with a smaller cell size and hence minimal impact on density. It also provides a faster read access for comparable loads on the read bit line. Write time may also be slightly reduced due to the smaller cell size, depending on the technology layout restrictions. [0031] In an exemplary embodiment of the present invention, the ‘disturb’ signal on the internal node is significantly reduced by the use of only one additional pass gate tied to one of the internal node (either ‘A’ or ‘B’) and the pass gate is connected to a local read bit line, LRBL, which is one section of a hierarchical bit line structure one example of which is illustrated in FIG. 2 . The circuit 106 encircled is added to each 6T cell. Several cells, such as 8 to 64, depending on the desired speed and other specs, share the local read bit line, LRBL. In the following, 16 bits per LRBL are assumed, to simplify the figures. The local read bit line, LRBL, connected to 16 pass gates from 16 cells, has one read-head device with its source tied to ground, drain tied to a global read bit line, GRBL, and gate connected to the LRBL as illustrated, (for an nFET read-head—a pFET device can also be used for a read-head but is not as effective). Multiple local read bit lines, LRBLs, each with a separate read-head, are connected to a global read bit line as discussed latter. [0032] In addition to the read-head, each LRBL has a separate nFET for discharging and holding LRBL to ground after sensing as indicated by device “LRBL Precharge 0” in FIG. 3 . This is required since once an LRBL is charged high, by reading a stored ‘1’ for instance, the read-head will be turned ‘ON’ and remain ‘ON’. If the LRBL is not discharged, subsequent attempts to read other cells which have a stored ‘0’ on the same LRBL will encounter a large voltage already on the LRBL and will possibly give an incorrect sense signal. [0033] Thus one advantage of the present invention is that the SRAM read ‘disturb’ can be significantly reduced by the addition of only one read-pass nFET per cell plus one read-head and one LRBL Precharge-‘0’ device per every 8 to 64 cells (depending of design parameters) as illustrated by the encircled circuit 104 . The two additional bit lines per cell, namely LRBL and GRBL, run parallel to each other and can be placed on different metal levels to minimize the impact on cell area. This is a substantial area saving and allows a faster read cycle; the amount depending on how much of a density improvement is desired. [0034] One of the issues that can give rise to the read ‘disturb’ can best be understood in terms of the capacitance loading connected to an SRAM cell during reading. An equivalent circuit for the reading of the cross-coupled six device SRAM cell, is illustrated in prior art FIG. 1C . It is assumed that the storage node ‘B’ is at ‘0’ volts initially (node ‘A’ necessarily at Vdd volts). In the state of the art, balanced sensing, a pair of (nearly) identical capacitors, C(BL) (capacitance of the bit lines) are precharged to Vdd and then suddenly connected to nodes ‘A’ and ‘B’. Node ‘A’, being already at Vdd, is not affected. However, node ‘B’, initially at ‘0’, now has a large capacitor, C(BL) the bit line capacitance at voltage Vdd connected to it. The FET pull-down device, N 0 , must sink the charge on C(BL) to ground in order to discharge it to some low value. However, device N 0 , even in the ‘ON’ state has a significant resistance, so the voltage from node ‘B’ to ground will increase above ‘0’. In the meantime, device N 1 has its gate voltage supposedly at ‘0’ (at voltage of node ‘B’) so it is ‘OFF’, and P 1 is ‘ON’, which allows node ‘A’ to remain ‘HIGH’. However, if the threshold voltage, Vt, of device N 1 just happens to be sufficiently lower than that of device N 0 , and if node ‘B’ happens to rise sufficiently ‘HIGH’, device N 1 will start to turn ‘ON’. The feedback effect of the cross-coupled arrangement will reinforce this and can cause the node voltages at ‘A’ and ‘B’ to reverse states, an error. [0035] The culprit in this scenario is the very large bit line capacitance which makes it difficult to hold node ‘B’ at ‘0’, plus the large tolerance variation between devices N 0 and N 1 (note, tolerance variations on P 1 and P 0 contribute in a somewhat analogous manner). [0036] Since the tolerance variations on the FET devices are fixed by the technology, these cannot be changed, except by making the devices and thus cell larger than minimum size. The tolerance difference between adjacent devices varies as k/(SqRt(Width*Length)) where ‘k’ is a technology constant. Thus, if the length and/or width are made larger, the tolerance variation is reduced, but the density decreases significantly, if this is to be avoided, then the alternative solution is to control the capacitance load connected to the internal nodes, for reading the cell state. This is exactly what differentiates the 7T/H from the 8T cell. In the 8T cell (prior art FIG. 1B ) the large bit line capacitance C(BL) of the 6T cell is replaced by a very small capacitor, namely the gate capacitance of the pull-down FET which is directly connected to node ‘B’. Also, this gate capacitance is not precharged into any state, but rather takes on the voltage of node ‘B’ during writing of the cell. There are some other capacitance components, and displacement currents when the read-select device is turned ‘ON’ for reading that cell, but these are small. Thus we expect this arrangement to have a minimum ‘disturb’ effect on the cell. However, it requires two additional devices per cell, giving a significant reduction in density. [0037] Compared to the 6T cell, the 7T/H cell of this invention significantly reduces the capacitance load, C(BL) placed on the cell during reading by the use of a hierarchical bit line. Thus the 7T/H cell will tolerate larger ‘disturb’ conditions than the 6T cell, for equivalent number of cells per bit line. The 7T/H cell will be slightly less stable than the 8T cell. Nevertheless there is a very wide range of stable cell operation for the 7T/H cell and it gives significantly faster read-access time and smaller cell size than the 8T cell. [0038] The writing of the 7T/H cell is identical to that of the 6T or 8T cell. The writing speed will be comparable or slightly faster than the 8T cell due to the density improvement, (shorter word line and/or bit line, depending on layout). [0039] Multiple cells connected to one global read bit line referred to as a column are connected by means of a hierarchy of local read bit lines, LRBLs, and read-heads, RH, as indicated in FIG. 3 . Multiple cells are connected to any one LRBL, through multiple read-pass nFETs, one for each cell as shown. Multiple such LRBLs are connected to a GRBL via a read-head, one read-head per LRBL. The number of LRBLs with read-head, per GRBL is a design parameter. A typical number might be 16, with a range from 1 to 64 or more. This column arrangement gives one bit per word line. To achieve multiple bits per word line, identical columns are added to the word lines as one example is illustrated in FIG. 4 . [0040] It can be seen that for both the 8T and 7T cells, an additional word line is required. Furthermore, for the 8T cell, one additional bit line is required and the 7T cell requires two additional bit lines, namely the LRBL (short segments) and GRBL. However, these two bits lines run parallel to each other and can be placed on separate metal wiring levels, requiring only one wiring pitch per cell, similar to the 8T cell. [0041] For reading, the 7T/H cell makes use of a hierarchical bit line structure to achieve speed and density. A global read bit line, GRBL, is initially precharged high (e.g. to Vdd) and subsequently is either pulled to ‘0’ or remains ‘HIGH’ for sensing the two binary states of the cell. Whether the GRBL is pulled to ‘0’ for a stored ‘1’ or stored ‘0’ is purely arbitrary, depending on the definition of internal cell nodes, ‘A’ and ‘B’ illustrated in FIG. 2 , for ‘1’ and ‘0’, as well as which of these two node is used for reading, as will be seen. [0042] In an exemplary embodiment for example and not a limitation, the fundamental idea for reading is that one of the cell nodes, ‘A’ or ‘B’, (assume node ‘B’ in the following) is initially connected to a very lightly loaded (small capacitance) local read bit line, LRBL, through a read select pass gate as illustrated in FIG. 2 . This pass device transfers the voltage at node ‘B’ to the gate of a read-head, RH, which is connected to the global read bit line as illustrated. GRBL has previously been precharged ‘HIGH’, to Vdd. If node ‘B’ is at Vdd (node ‘A’ thus is at ‘0’), the read-head device will be turned ‘ON’ and will discharge GRBL to ‘0’. If node ‘B’ is at ‘0’ (node ‘A’ high), then the RH device is ‘OFF’ and the GRBL remains ‘HIGH’. [0043] Before reading commences the local read bit line, LRBL, is discharged and held at ground. At the beginning of the read cycle, the LRBL is released from ground (floating) by turning ‘OFF’ the nFET LRBL precharge ‘0’. This is necessary since an array of cells will have multiple LRBL and multiple read-heads connected to one global read bit line, and all these other LRBL must be deactivated (at ‘0’) so their respective read-heads are ‘OFF’, except the one chosen to be read. By so doing, the selected LRBL can take on the voltage state of node ‘B’ of the selected cell when the read-pass device is turned ‘ON’ by a +voltage signal on a separate word line used for reading, namely word-line-read, WLR. [0044] Simulations have shown that for typical cell device sizes, and lengths of bit lines crossing 256 word lines per column (row any value) the 7T/H sensing structure gives a read time from word line ‘HIGH’ (50% pt) to GRBL ‘LOW’ (50% Pt) which is more than twice as fast as the 8T structure. Presently, SRAM arrays for high speed L 2 cache applications are using very short bit lines, i.e. column covering only 8 to 16 bits, in order to limit the ‘C’ loading, thus giving higher speed and better stability. However, this requires significantly more peripheral devices (sense amps, drivers, selectors etc), which can be avoided by the use of the 7T/H cell. [0045] On example of simulations of the 7T/H and 8Tcells for various configurations and conditions are illustrated in FIGS. 6 and 7 . Referring to FIGS. 6 and 7 there is illustrated one example of tables that present the nominal read access delay for the 7T/H and 8T cell respectively and show very significant speed improvement of the 7T/H over the 8T cell, as follows for three different column heights covering 64, 128 and 256 word lines (64, 128, 256 cells per bit line) the array delay (50% points) from word line rising to bit line falling for the 7T/H vs. 8T cell using a nominal design with near minimum devices three cases of which are summarized as follows: [0046] Case 1 : [0047] 64 bits per global bit line [0048] Delay 7T/H=68 ps [0049] Delay 8T=122 ps [0050] Case 2 : [0051] 128 bits per global bit line [0052] Delay 7T/H=96 ps [0053] Delay 8T=234 ps [0054] Case 3 : [0055] 256 bits per global bit line [0056] Delay 7T/H=168 ps [0057] Delay 8T=444 ps [0058] In each case, the 7T/H cell is a factor of almost 2 to 2.6 times faster than the 8T cell. The complete set of devices and conditions for these simulations are illustrated in FIG. 6 , and 7 . It can be seen that increasing the sizes of some selected devices can improve the speed of these cells, but this compromises density. Thus various density speed tradeoffs are possible. [0059] One of the fundamental design issues can be when a read cycle commences and the capacitance load of the selected LRBL and associated devices is ‘dumped’ on node ‘B’ of the SRAM cell ( FIG. 2 ). The current drawn out of node ‘B’ to charge this LRBL is proportional to ‘C’ dV/dt where ‘C’ is the total capacitance connected to node ‘B’ by the read-pass device, and ‘V’ is the voltage across the LRBL capacitance. The faster this occurs (i.e. shorter time constant on the RC read circuit), the more current drawn from node ‘B’, and the larger the ‘disturb’ on node ‘B’. The cell may or may not be able to supply this charging current in a stable manner, depending on the actual, and relative sizes of the various devices. For increased speed, a fast charging time (small time constant) is desired which reduces the ‘disturb’ margins on the SRAM cell Vt tolerances (i.e. more sensitive to ‘disturbs’). The read stability can be improved by making the time constant larger—one way to do this is by decreasing the width of the read-pass device. This will make the cell smaller, which is desirable, but slower, usually not desirable, but depends on the application. [0060] In a similar manner, the cell stability for reading can be adjusted by changing (very slightly) the widths of devices in the cell itself. For instance, if the number of cells connected to one LRBL is increased, the ‘C’ load on node ‘B’ increases and may cause instability. This can be improved by a slight increase in the width of the cell P 0 device as illustrated in FIG. 2 . The tradeoffs are very dependent on exact array and cell parameters, but many such tradeoffs are possible and give this cell a wide design range of density/speed. [0061] The 7T/H cell and array is quite stable over a wide range of Vt variations. For the devices sizes used in the cell, a typical maximum spread in Vt (in current technologies) for near-adjacent devices is a delta of about 50 mV. Assuming this is divided as plus and minus 25 mV for adjacent n devices and likewise for adjacent p devices, and picking the worst case arrangement of the Vt variations in the cross-coupled flip-flop, the stability for the 7T/H cell in various configurations (number of cells on Local Bit Line, LBL, and number of LBL on a global read bit line, GRBL) one example of which is illustrated in FIGS. 8A-8B (Vt-Tolerances). It can be seen that the cell, in a minimum configuration, is stable for up to 4 times (+ and −100 mV) the allowed Vt spread on the cell devices. The cell is also very tolerant of Vt variations in the read-head, an important issue. [0062] The 7T/H cell may possibly even offer advantages over the 6T cell. As the device tolerances become more severe, the 6T cell must use device sizes, which are larger than, normal scaling would allow. In such cases, the 7T/H cell can use smaller devices, and even though an additional device is required per cell, the total area, even including the additional read and write lines, may give a better density. The design point where this would happen is highly technology dependent, but could possibly be significant. [0063] There are many tradeoffs, which can be made for speed vs. cell size which give this 7T/H cell considerable flexibility and potential application. [0064] By making the 7T/H SRAM cell symmetrical, one example of which is illustrated in FIG. 5 , several additional and important features are achieved. If the additional global read bit line, GRBL 2 and read word line 2 are keep separate from GRBL 1 and read word line 1 , then the cell becomes a true 3-port cell capable of simultaneously writing to one cell while reading data from two other cells. These simultaneous three accesses can be directed all to the same cell, to two cells or three cells with no interference. [0065] Alternatively, if the read word line 2 is electrically tied to read word line 1 , then only one cell can be read on one cycle (another can be simultaneously written, of course). But now the bit read lines, GRBL 1 and GRBL 2 act as a balance sense pair which gives a signal transition and hence clock for reading both a stored ‘1’ and ‘0’, unlike the previous, single ended sensing. This has some advantages in overall clocking and timing of full arrays. [0066] The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof. [0067] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately. [0068] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided. [0069] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention. [0070] While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.

An embodiment of the present invention is an SRAM memory array comprising memory cells with each cell containing seven devices, wherein the basic storage nodes, which store the true and complement of the data, are constructed from six devices, forming a cross-coupled flip-flop cell. One internal storage node of this cell being connected to a separate read-pass device which passes the state of this node to a local bit line (LBL) for single-ended sensing, with the gate of this separate read-pass device connected to a separate read-word line.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the priority benefit of pending U.S. Provisional Patent Application No. 61/095,980 titled “Method to Perform PET Image Reconstruction Using Both Scattered and Unscattered Photons,” filed Sep. 11, 2008 (the “Provisional Application”). The complete disclosure of the Provisional Application is hereby incorporated herein by reference in its entirety. BACKGROUND [0002] In Positron Emission Tomography (PET) an annihilation event is identified by time coincidence between the detection of two 511 keV, annihilation photons in two different detectors located around the patient. If two detectors A and B are hit coincidentally by full-energy photons, the detectors estimate a Line-of-Response (LOR) along which an annihilation has occurred. The position of the annihilation (and therefore the position of the radioactive source) along this line is not known, but existing technology reconstructs the image of the original radioactivity distribution from the large set of LORs identified by detector pairs in coincidence. [0003] A large fraction of the 511 keV photons emitted during the decay and annihilation process undergo scatter before exiting the patient's body, mainly Compton scatter, during which they lose energy. 511 keV energy photons that reach the detectors are called “true” or “unscattered” photons. Photons with energy lower than 511 keV at the detectors are called “scattered” photons. A time coincidence of two detected photons is called a “coincidence event.” A true coincidence event is an event in which both detected photons have 511 keV energy. A scatter coincidence event is an event in which one or both detected photons are scattered photons. DESCRIPTION OF THE DRAWINGS [0004] FIG. 1 illustrates a cross section of a patient in a PET scanner with a source of unscattered photons and a pair of detectors A and B. Unscattered photons allow estimation of a line passing through the source. [0005] FIG. 2 illustrates a cross section of a patient in a PET scanner with a source of two photons, one of which undergoes Compton scatter. In this case, a straight line joining detector pairs A and B does not provide correct information about the position of the source. [0006] FIG. 3 illustrates a cross section of a patient in a PET scanner with a source of two photons, one of which undergoes Compton scatter. The scatter angle and the energy of the scattered photon are related through eq. (1), the trajectory of the two photons can be identified if the energy E B2 is known. But the position of the source is the trajectory cannot be identified. [0007] FIG. 4 illustrates a cross section of a patient in a PET scanner with a source of two photons, one of which undergoes a Compton scatter. The scatter angle and the energy of the scattered photon are related through eq. (1) and therefore the trajectory of the two photons can be identified if the energy E B2 is known. The difference of time-of-flight (also determinable as the difference in time-of-arrival) provides the additional information needed to identify the position of the source in the trajectory. DETAILED DESCRIPTION [0008] Reference will now be made in detail to embodiments of the technology. Each example is provided by way of explanation of the technology only, not as a limitation of the technology. It will be apparent to those skilled in the art that various modifications and variations can be made in the present technology without departing from the scope or spirit of the technology. For instance, features described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present technology cover such modifications and variations that come within the scope of the technology. [0009] The technology can recover positional information from photons scattered in the patient during positron emission tomography (PET), and use scattered photons in PET image reconstruction in addition to unscattered photons. The technology uses energy and time-of-flight combined information to locate a radioactive (PET) source in the case at least one of the emitted photons undergoes Compton scatter before being detected. [0010] The technology enables scatter events, presently rejected in PET scanners, to be used for reconstruction, increasing PET scanner sensitivity as measured by effective number of coincidence events per unit dosage. The technology can allow increased PET sensitivity for a given dose by, and can allow for lower doses for a given sensitivity. [0011] A scattered photon has lost its original direction, and the LOR connecting two detectors in coincidence does not contain the source if one or both the detected photons are scattered, and cannot be used by present conventional PET reconstruction algorithms. For this reason, scattered events are not used in PET image reconstruction. They are usually rejected using one or both of two methods: discriminating on the energy of the detected photon, and subtracting estimated scatter events from the total events. [0012] The energy discrimination is performed by rejecting detected photons with energy below a threshold, for example 400 keV, Not all scatter events are rejected by energy discrimination. Scatter estimation is usually based on a simulation that estimates the amount of scattered events still accepted by the energy discrimination process. As a consequence of this process, only a small fraction of the events are accepted and used for image reconstruction, only the events considered “unscattered.” The overall result is the rejection of the large majority of the coincidence events, reducing the scanner sensitivity. [0013] The technology disclosed herein aims to recover some of the loss of sensitivity due to this process by accepting scattered events to be used for image reconstruction. [0014] FIG. 1 illustrates a cross section 110 of a patient in a PET scanner with a source 120 of unscattered photons and a pair of detectors, A 130 and B 140 . If two unscattered photons (paths indicated by 150 a and 150 b , energy upon arrival at each detector about 511 keV) are detected in time coincidence at detector A 130 and detector B 140 , then the straight line drawn between detector A 130 and B 150 estimates a line passing through the source 120 . [0015] FIG. 2 , illustrates an example of a photon pair (paths indicated by 250 a , 250 aa , and 250 b ) emitted from a source 120 in which one photon (path indicated by 250 a and 250 aa ) undergoes a Compton scatter. In this case the straight line 270 joining the detector A 130 and B 2 240 does not provide correct information about the position of the source 120 . The scatter angle θ (deviation from the original direction) and the energy of the scattered photon are related as [0000] E scat = E 0 1 + E 0 m 0  c 2  ( 1 - cos   θ ) ( 1 ) [0016] Where E 0 is the initial energy of the emitted photon, m 0 is mass of the electron the photon scatters off, e is the speed of light, and E scat , is the energy of the photon after the scatter event at S 280 . This relation can be inverted and the scattering angle can be calculated as a function of the energy of the scattering photon θ=ƒ(E scat ). [0017] Knowing the position of detector A 130 and detector B 2 240 , and the energy E 0 and E B2 of the photons detected in A and B 2 , equation (1) defines the trajectory of the two photons in the plane shown in FIGS. 2 and 3 . The scattering point S 280 is localized, but there is not enough information to determine (within accuracy of the variables) where the source O is located in the segment SA, the line between the scatter point and detector A. ( FIG. 3 ). [0018] Time-of-flight difference between the two photons can be used to determine the position of the source even if one of both the two photons has undergone a Compton scatter. In particular, the difference of time-of-flight (or arrival time) of the two photons provides the additional information needed to identify the position of the source in the trajectory, as illustrated in FIG. 4 . [0019] Referring to FIG. 4 , T A is the flight time of the unscattered photon at detector A; T B is the flight time of the scattered photon in detector B; y B is the length of the segment BS joining detector B 2 240 and the scattering point S 280 ; x B is the length of the segment SO joining the scattering point S 280 and the unknown source positions O; x A the length of the segment OA joining the source position O and detector A 130 ; SA is the segment joining S and A of length x B +x A ; and c the speed of light. T A and T B are related to x A , x B , and y B : [0000] T A = x A c ( 2 ) and T B = x B + y B c ( 3 ) [0020] The time of flight difference can be expressed as: [0000] T B - T A = x B + y B - x A c = ( SA - x A ) + y B - x A c = SA + y B - 2   x A c ( 4 ) [0021] From equation (4) the unknown position x A can be computed as: [0000] x A = SA + y B 2 - ( T B - T A ) · c 2 ( 5 ) [0022] In equation (5) SA and y B are determined given the knowledge of the positions of the detectors A 130 and B 2 240 , and of the photon energy E A and E B . The time-of-flight difference T B −T A is also known in a TOF PET scanner. [0023] The uncertainty of the location of the source O is determined by the uncertainty of the measurement of energy ΔE and the uncertainty of the measurement of time-of-flight ΔT. Embodiments of the present technology use Equations (1) and (5) as the equations to be included in a projector used in PET reconstruction. [0024] In order to locate the position of the source, the technology can estimate the scatter angle θ to identify the trajectory, and then estimate the position along the trajectory. The technology can use equation (1) to obtain θ from E scat , and equation (5) to obtain x A from the time of flight difference T B −T A . Since the quantities E scat and T B −T A are measured with instrumental uncertainties ΔE (energy resolution) and ΔT (time resolution), consequently the derived quantities θ and x are known with uncertainties Δθ and Δx, that can be derived using from equations (1) and (5). Therefore, in the reconstruction algorithm, forward and back projectors can use a probability function (for example a Gaussian) for the trajectory identification which has as a mean value θ and a width Δθ and a probability function (for example a Gaussian) for the position identification in the trajectory which has as a mean value x and a width Δx. [0025] The above description of the technology above is based on a two-dimensional (2D) model, in which all trajectories are in a plane. Alternative embodiments include those employing a 3D geometry. In 3D applications, a set of trajectories on a cone of opening θ are defined for a detected energy E B . The cone can be used in the projector as described above. [0026] Other embodiments can use a combined technique of rejecting photons below an energy threshold, estimating and subtracting part of scattered events, and accepting part of the scattered events using the method described herein. [0027] In some embodiments, the technology can use additional information on the location of the patient in the FOV of the PET scanner to apply further constraints of the acceptable trajectories. For example, MRI, ultrasound or CT images can be available in multimodality PET scanners. Those images can define the boundary of the volume where the sources can be located. [0028] In some embodiments, the technology can use the additional information to create a pseudo-LOR by identifying the detector a photon likely would have hit had it not been scattered. Pseudo-LORs can supplement true coincidence event LORs in forming the PET image. [0029] PET systems can take the form of hardware and software elements. In some embodiments, the technology is implemented in a PET system in software, which includes but is not limited to firmware, resident software, microcode, etc. Furthermore, the technology can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium (though propagation mediums in and of themselves as signal carriers are not included in the definition of physical computer-readable medium). Examples of a physical computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD. Both processors and program code for implementing each as aspect of the technology can be centralized or distributed (or a combination thereof) as known to those skilled in the art. [0030] A PET data processing system suitable for storing program code and for executing program code will include at least one processor coupled directly or indirectly to memory elements (e.g., computer-readable media) through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories that provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers, Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Moderns, cable modem and Ethernet cards are just a few of the currently available types of network adapters.

Determining the position of a radioactive source in a PET system. Detecting a scatter coincidence event characterized by a full-energy photon detected at a first detector and partial-energy photon at a second detector. Measuring the arrival time difference between the partial energy photon and the full energy photon. Measuring the energy of the partial-energy photon. Determining a scattering point as a function of the position of the first detector, the position of the second detector, the energy of the partial-energy photon, the energy of an unscattered photon, the mass of a scattering electron, and the speed of light. Determining the position of a radioactive PET source along a line between the scatter point and the first detector as a function of the distance between scatter point and the first detector, the distance between scatter point and the second detector, and the measured time difference.

TECHNICAL FIELD The present disclosure generally relates to aircraft display systems and methods for operating aircraft display systems. More particularly, the present disclosure relates to aircraft synthetic vision systems that utilize data from local area augmentation systems, and methods for operating such aircraft synthetic vision systems. BACKGROUND Many aircraft are equipped with one or more vision enhancing systems. Such vision enhancing systems are designed and configured to assist a pilot when flying in conditions that diminish the view from the cockpit. One example of a vision enhancing system is known as a synthetic vision system (hereinafter, “SVS”). A typical SVS is configured to work in conjunction with a position determining unit associated with the aircraft as well as dynamic sensors that sense aircraft altitude, heading, and orientation. The SVS includes or accesses a database containing information relating to the topography along the aircraft's flight path, such as information relating to the terrain and known man-made and natural obstacles proximate the aircraft flight path. The SVS receives inputs from the position determining unit indicative of the aircraft location and also receives inputs from the dynamic sensors. The SVS is configured to utilize the position, heading, altitude, and orientation information and the topographical information contained in the database, and generate a three-dimensional image that shows the topographical environment through which the aircraft is flying from the perspective of a person sitting in the cockpit of the aircraft. The three-dimensional image (also referred to herein as an “SVS image”) may be displayed to the pilot on any suitable display unit accessible to the pilot. The SVS image includes features that are graphically rendered including, without limitation, a synthetic perspective view of terrain and obstacles located proximate the aircraft's flight path. Using a SVS, the pilot can look at a display screen of the display unit to gain an understanding of the three-dimensional topographical environment through which the aircraft is flying and can also see what lies ahead. The pilot can also look at the display screen to determine aircraft proximity to one or more obstacles proximate the flight path. The approach to landing and touch down on the runway of an aircraft is probably the most challenging task a pilot undertakes during normal operation. To perform the landing properly, the aircraft approaches the runway within an envelope of attitude, course, speed, and rate of descent limits. The course limits include, for example, both lateral limits and glide slope limits. In some instances visibility may be poor during approach and landing operations, resulting in what is known as instrument flight conditions. During instrument flight conditions, pilots rely on instruments, rather than visual references, to navigate the aircraft. Even during good weather conditions, pilots typically rely on instruments to some extent during the approach. Some SVS systems known in the art have been developed to supplement the pilot's reliance on instruments. For example, these systems allow pilots to descend to a low altitude, e.g., to 150 feet above the runway, using a combination of databases, advanced symbology, altimetry error detection, and high precision augmented coordinates. These systems utilize a wide area augmentation system (WAAS) GPS navigation aid, a flight management system, and an inertial navigation system to dynamically calibrate and determine a precise approach course to a runway and display the approach course relative to the runway centerline direction to pilots using the SVS. The usefulness of these SVS systems for approach and landing is limited, however, by the accuracy of the topographical database, particularly in the terminal area of the airport. It has been discovered, for example, that in some instances, published terminal area topographical data may include unintended errors or biases in relation to the geographic position of certain features, such as runways, obstacles, etc. If these errors or biases are then introduced into the SVS topographical databases, then the 3-D rendered images presented to the pilot on the SVS may not match the aircraft's actual environment, which is problematic in the context of flying a precision approach to the airport supplemented by the SVS. Accordingly, it is desirable to provide SVS systems and methods that are able to validate topographical information contained in a topographical database, in particular the geographical location of runways and obstacles in the terminal area of an airport. It is also desirable to provide such SVS systems and methods that are capable of correcting any errors or biases in the topographical database that may be determined by the validation. Furthermore, other desirable features and characteristics of exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. BRIEF SUMMARY Provided are aircraft synthetic vision systems that utilize data from local area augmentation systems, and methods for operating such aircraft synthetic vision systems. In one exemplary embodiment, an aircraft synthetic vision display system (SVS) includes a topographical database including topographical information relating to an airport, a global positioning system receiver that receives a satellite signal from a global positioning satellite to determine a geographical position of the aircraft, and a ground-based augmentation system receiver that receives a ground-based signal from a ground-based transmitter associated with the airport, wherein the ground-based signal includes geographical information associated with the airport. The SVS further includes a computer processor that retrieves the topographical information from the topographical database based on the geographical position of the aircraft, that retrieves the geographical information associated with the airport, that validates the topographical information using the geographical information associated with the airport, and that corrects the topographical information using the geographical information associated with the airport to generate corrected topographical information. Still further, the SVS includes a display device that renders three-dimensional synthetic imagery of environs of the aircraft based on the corrected topographical information. In another exemplary embodiment, a method of operating a synthetic vision system of an aircraft includes the steps of receiving a satellite signal from a global positioning satellite to determine a geographical position of the aircraft and receiving a ground-based signal from a ground-based transmitter associated with the airport, wherein the ground-based signal includes geographical information associated with the airport. The method further includes, using a computer processor, retrieving topographical information based on the geographical position of the aircraft, retrieving the geographical information associated with the airport, validating the topographical information using the geographical information associated with the airport, and correcting the topographical information using the geographical information associated with the airport to generate corrected topographical information. The method further includes rendering three-dimensional synthetic imagery of environs of the aircraft based on the corrected topographical information. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: FIG. 1 is a functional block diagram of a synthetic vision system according to an exemplary embodiment of the present disclosure; FIG. 2 is an exemplary image that may be rendered on the synthetic vision system of FIG. 1 ; and FIG. 3 is a flow chart illustrating a method of operation for the synthetic vision system of FIG. 1 in accordance with exemplary embodiment of the present disclosure. DETAILED DESCRIPTION The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description. Embodiments of the present disclosure utilize ground-based data sources located at an airport, such as a local area augmentation system (LAAS), to validate the data from the topographical databases (particularly navigational database 108 , runway database 110 , and obstacle database 112 ). If the topographical database information does not match the information from the ground-based data source, then there is determined to be an error or bias in the data from the topographical databases. The error or bias is then corrected utilizing the information from the ground-based data source. The corrected topographical information is then utilized by the processor 104 to provide an accurate display on the display device 116 of the SVS 100 . The accurate display includes an accurate runway position, accurate obstacle positions, and accurate terrain renderings. With this verified and corrected display, the SVS 100 can be used as a supplement to the aircraft's instrument approach systems (e.g., ILS, VOR, GPS) until about 150 feet height above threshold (HAT). As used herein, the term “synthetic vision system” refers to a system that provides computer-generated images of the external scene topography from the perspective of the flight deck, derived from aircraft attitude, high-precision navigation solution, and database of terrain, obstacles, and relevant cultural features. A synthetic vision system is an electronic means to display a synthetic vision depiction of the external scene topography to the flight crew. Synthetic vision creates an image relative to terrain and airport within the limits of the navigation source capabilities (position, altitude, heading, track, and the database limitations). The application of synthetic vision systems is through a primary flight display from the perspective of the flight deck or through a secondary flight display. Referring to FIG. 1 , an exemplary synthetic vision system is depicted and will be described in accordance with various embodiments of the present disclosure. The system 100 includes a user interface 102 , a processor 104 , one or more terrain databases 106 , one or more navigation databases 108 , one or more runway databases 110 , one or more obstacle databases 112 , various sensors 113 , a multi-mode receiver (MMR) 114 , and a display device 116 . The user interface 102 is in operable communication with the processor 104 and is configured to receive input from a user 109 (e.g., a pilot) and, in response to the user input, supply command signals to the processor 104 . The user interface 102 may be any one, or combination, of various known user interface devices including, but not limited to, a cursor control device (CCD) 107 , such as a mouse, a trackball, or joystick, and/or a keyboard, one or more buttons, switches, or knobs. In the depicted embodiment, the user interface 102 includes a CCD 107 and a keyboard 111 . The user 109 uses the CCD 107 to, among other things, move a cursor symbol on the display screen (see FIG. 2 ), and may use the keyboard 111 to, among other things, input textual data. The processor 104 may be any one of numerous known general-purpose microprocessors or an application specific processor that operates in response to program instructions. In the depicted embodiment, the processor 104 includes on-board RAM (random access memory) 103 , and on-board ROM (read only memory) 105 . The program instructions that control the processor 104 may be stored in either or both of the RAM 103 and the ROM 105 . For example, the operating system software may be stored in the ROM 105 , whereas various operating mode software routines and various operational parameters may be stored in the RAM 103 . It will be appreciated that this is merely exemplary of one scheme for storing operating system software and software routines, and that various other storage schemes may be implemented. It will also be appreciated that the processor 104 may be implemented using various other circuits, not just a programmable processor. For example, digital logic circuits and analog signal processing circuits could also be used. No matter how the processor 104 is specifically implemented, it is in operable communication with the terrain databases 106 , the navigation databases 108 , the runway databases 110 , the obstacle databases 112 , and the display device 116 , and is coupled to receive various types of external data from the various sensors 113 (such as airspeed, altitude, air temperature, heading, etc.), and various aircraft position-related data from the MMR 114 , which receives signals from various external position-related data sources such as VOR, GPS, WAAS, LAAS, ILS, MLS, NDB, etc. The processor 104 is configured, in response to the position-related data, to selectively retrieve terrain data from one or more of the terrain databases 106 , navigation data from one or more of the navigation databases 108 , runway data from one or more of the runway databases 110 , and obstacle data from one or more of the obstacle databases 112 , and to supply appropriate display commands to the display device 116 . The display device 116 , in response to the display commands, selectively renders various types of textual, graphic, and/or iconic information. A brief description of the databases 106 , 108 , 110 , and 112 , the sensors 113 , and the MMR 114 , at least in the depicted embodiment, will be provided. The terrain databases 106 include various types of data representative of the terrain over which the aircraft is flying, and the navigation databases 108 include various types of navigation-related data. These navigation-related data include various flight plan related data such as, for example, waypoints, distances between waypoints, headings between waypoints, data related to different airports, navigational aids, obstructions, special use airspace, political boundaries, communication frequencies, and aircraft approach information. It will be appreciated that, although the terrain databases 106 , the navigation databases 108 , the runway databases 110 , and the obstacle databases 112 are, for clarity and convenience, shown as being stored separate from the processor 104 , all or portions of either or both of these databases 106 , 108 , 110 , 112 could be loaded into the RAM 103 , or integrally formed as part of the processor 104 , and/or RAM 103 , and/or ROM 105 . The databases 106 , 108 , 110 , 112 could also be part of a device or system that is physically separate from the system 100 . In one exemplary embodiment, the processor 104 is adapted to receive terrain data from the terrain database 106 and navigation data from the navigation database 108 , operable, in response thereto, to supply one or more image rendering display commands. The display device 116 is coupled to receive the image rendering display commands and is operable, in response thereto, to simultaneously render (i) a perspective view image representative of the terrain data and navigation data and (ii) one or more terrain-tracing lines. The perspective view image includes terrain having a profile determined by elevations of the terrain. Each terrain-tracing line (i) extends at least partially across the terrain, (ii) represents at least one of a ground-referenced range to a fixed location on the terrain and a aircraft-referenced range from the aircraft to a fixed range away from the aircraft, and (iii) conforms to the terrain profile. Notably, the visibility of the terrain information displayed on the screen of visual display 116 may be enhanced responsive to one or more suitable algorithms (e.g., implemented in software) executed by the processor 104 , which functions to determine an aircraft's current position, heading and speed, and initially loads a patch of terrain data for a region that is suitably sized to provide a rapid initialization of the data. The processor 104 monitors the aircraft's position, heading, and speed (also attitude when pertinent) from sensors 113 and MMR 114 , and continuously predicts the potential boundaries of a three-dimensional region (volume) of terrain in the flight path based on the aircraft's then-current position, heading and speed (and attitude when pertinent). The processor 104 compares the predicted boundaries with the boundaries of the initially loaded terrain data, and if the distance from the aircraft to a predicted boundary is determined to be less than a predetermined value (e.g., distance value associated with the boundaries of the initially loaded data), then the processor 104 initiates an operation to load a new patch of terrain data that is optimally sized given the aircraft's current position, heading and speed (and attitude when pertinent). Notably, for this example embodiment, the processor 104 can execute the data loading operations separately from the operations that determine the aircraft's current position, heading and speed, in order to maintain a constant refresh rate and not interfere with the continuity of the current display of terrain. One important aspect of situational awareness is to be aware of obstacles which pose a threat to the craft. This is particularly true for aircraft during take-off and landing or other low altitude operations and even more so in low visibility conditions. Some displays depict information on obstacles in or near the aircraft's travel path. Obstacle data should be presented in such a way that it will provide timely awareness of the height, location, and distance of possible threats without distracting from the other primary information on the display. The processor 104 generates data for display on the display 116 based on the position of the aircraft and obstacle data. Obstacles can be sought and displayed for different locations along one or more flight paths, thereby assisting an operator choose the safest path to follow. The obstacle database 112 may contain data regarding obstacles, wherein the processor 104 sends a signal to the display 116 to render a simulated graphical representation of the obstacle based on that data, or the obstacle database may contain actual images of the obstacles, wherein the processor 104 sends a signal to display the actual image based on the positional data. The processor 104 analyzes the data received from the obstacle database 112 and determines if the obstacles are within a selected distance from the aircraft. Obstacles that are not within a selected distance are not displayed. This procedure saves processor load and reduces display clutter by only displaying obstacles that are of interest to the aircraft. Size, speed, and altitude of the aircraft and size of the obstacle may be considered along with distance in determining whether to display the obstacle. The runway database 110 may store data related to, for example, runway lighting, identification numbers, position, and length, width, and hardness. As an aircraft approaches an airport, the processor 104 receives the aircraft's current position from, for example, the MMR 114 and compares the current position data with the distance and/or usage limitation data stored in the database for the landing system being used by that airport. The sensors 113 may be implemented using various types of sensors, systems, and or subsystems, now known or developed in the future, for supplying various types of aircraft data. The aircraft data may also vary, but preferably include data representative of the state of the aircraft such as, for example, aircraft speed, heading, altitude, and attitude. The number and type of data sources received into MMR 114 may also vary. However, for ease of description and illustration, only a VHF data broadcast (VDB) receiver 118 functionality and a global position system (GPS) receiver 122 functionality are depicted in FIG. 1 , as these receivers are particularly relevant to the discussion of the present disclosure. As noted above, though, modern MMRs include the ability to receive many more signals beyond the illustrated GPS and VDB receiver functionalities. The GPS receiver 122 functionality is a multi-channel receiver, with each channel tuned to receive one or more of the GPS broadcast signals transmitted by the constellation of GPS satellites (not illustrated) orbiting the earth. Each GPS satellite encircles the earth two times each day, and the orbits are arranged so that at least four satellites are always within line of sight from almost anywhere on the earth. The GPS receiver 122 , upon receipt of the GPS broadcast signals from at least three, and preferably four, or more of the GPS satellites, determines the distance between the GPS receiver 122 and the GPS satellites and the position of the GPS satellites. Based on these determinations, the GPS receiver 122 , using a technique known as trilateration, determines, for example, aircraft position, groundspeed, and ground track angle. These data may be supplied to the processor 104 , which may determine aircraft glide slope deviation therefrom. Preferably, however, the GPS receiver 122 is configured to determine, and supply data representative of, aircraft glide slope deviation to the processor 104 . The VDB receiver 118 functionality is a multi-channel receiver configured to received VHF signals in the 108.0 to 117.975 MHz band from a ground station that is associated with a particular airport. The VHF data signals include corrections for GPS satellite signals. The VHF data signals also include broadcast information that is used to define a reference path typically leading to the runway intercept point. This data can include information for as many as 49 different reference paths using a single radio frequency. (Even more reference paths could be supported by using additional radio frequencies.) The VDB signal employs a differential 8-phase shift key (D8PSK) waveform. This waveform was chosen because of the relatively good spectral efficiency in terms of the number of bits per second that can be supported within a 25 kHz frequency assignment. Four message types are currently defined for VDB signals. Message Type 1 includes differential correction and integrity related data for the GPS satellites. Message Type 4 includes final approach segment definitions for each runway end or approach at the airport. The display device 116 , as noted above, in response to display commands supplied from the processor 104 , selectively renders various textual, graphic, and/or iconic information, and thereby supply visual feedback to the user 109 . It will be appreciated that the display device 116 may be implemented using any one of numerous known display devices suitable for rendering textual, graphic, and/or iconic information in a format viewable by the user 109 . Non-limiting examples of such display devices include various cathode ray tube (CRT) displays, and various flat panel displays such as various types of LCD (liquid crystal display) and TFT (thin film transistor) displays. The display device 116 may additionally be implemented as a panel mounted display, a HUD (head-up display) projection, or any one of numerous known technologies. It is additionally noted that the display device 116 may be configured as any one of numerous types of aircraft flight deck displays. For example, it may be configured as a multi-function display, a horizontal situation indicator, or a vertical situation indicator, just to name a few. In the depicted embodiment, however, the display device 116 is configured as a primary flight display (PFD). Referring to FIG. 2 , exemplary textual, graphical, and/or iconic information rendered by the display device 116 , in response to appropriate display commands from the processor 104 is depicted. It is seen that the display device 116 renders a view of the terrain 202 ahead of the aircraft, preferably as a three-dimensional perspective view, an altitude indicator 204 , an airspeed indicator 206 , an attitude indicator 208 , a compass 212 , an extended runway centerline 214 , a flight path vector indicator 216 , and an acceleration cue 217 . The heading indicator 212 includes an aircraft icon 218 , and a heading marker 220 identifying the current heading (a heading of 174 degrees as shown). An additional current heading symbol 228 is disposed on the zero pitch reference line 230 to represent the current aircraft heading when the center of the forward looking display 116 is operating in a current track centered mode. The center of the forward looking display 116 represents where the aircraft is moving and the heading symbol 228 on the zero-pitch reference line 230 represent the current heading direction. The compass 212 can be shown either in heading up, or track up mode with airplane symbol 218 representing the present lateral position. Additional information (not shown) is typically provided in either graphic or numerical format representative, for example, of glide slope, altimeter setting, and navigation receiver frequencies. An aircraft icon 222 is representative of the current heading direction, referenced to the current ground track 224 , with the desired track as 214 for the specific runway 226 on which the aircraft is to land. A distance remaining marker 227 may be shown on the display 116 , in a position ahead of the aircraft, to indicate the available runway length ahead, and the distance remaining marker 227 may change color if the distance remaining becomes critical. Lateral deviation marks 223 and vertical deviation marks 225 on perspective conformal deviation symbology represent a fixed ground distance from the intended flight path. The desired aircraft direction is determined, for example, by the processor 104 using data from the navigation database 108 , the sensors 113 , and the external data sources 114 . It will be appreciated, however, that the desired aircraft direction may be determined by one or more other systems or subsystems, and from data or signals supplied from any one of numerous other systems or subsystems within, or external to, the aircraft. Regardless of the particular manner in which the desired aircraft direction is determined, the processor 104 supplies appropriate display commands to cause the display device 116 to render the aircraft icon 222 and ground track icon 224 . As noted previously, the usefulness of the SVS system 100 for approach and landing is limited by the accuracy of the topographical databases 106 , 108 , 110 , and 112 , particularly in the terminal area of the airport. It has been discovered, for example, that in some instances, published terminal area topographical data may include unintended errors or biases in relation to the geographic position of certain features, such as runways (database 110 ), obstacles (database 112 ), etc. If these errors or biases are then introduced into the SVS topographical databases, then the 3-D rendered images presented to the pilot on the SVS may not match the aircraft's actual environment, which is problematic in the context of flying a precision approach to the airport supplemented by the SVS. Embodiments of the present disclosure utilize ground-based data sources located at an airport, such as a local area augmentation system, to validate the data from the topographical databases (particularly runway database 110 ). If the topographical database information does not match the information from the ground-based data source, then there is determined to be an error or bias in the data from the topographical databases. The error or bias is then corrected utilizing the information from the ground-based data source. The corrected topographical information is then utilized by the processor 104 to provide an accurate display on the display device 116 of the SVS 100 . The accurate display includes an accurate runway position, accurate obstacle positions, and accurate terrain renderings. With this verified and corrected display, the SVS 100 can be used as a supplement to the aircraft's instrument approach systems (e.g., ILS, VOR, GPS) until about 150 feet height above threshold. A LAAS at an airport generally includes local reference receivers located around the airport that send data to a central location at the airport. This data is used to formulate a correction message (Type 1), which is then transmitted to users via VDB. The VDB receiver 118 functionality on the aircraft uses this information to correct GPS signals, which then provides a standard ILS-style display to use while flying a precision approach. The LAAS VDB transmitters also transmit broadcast information that is used to define a reference path typically leading to the runway intercept point (message Type 4), which includes final approach segment definitions for each runway end or approach at the airport. An aircraft on approach to the airport will begin receiving LAAS VDB signals once the aircraft enters within the usable range of the LAAS system, which is usually about a 25 nm radius from the airport. Prior to entering the usable range, the SVS 100 is receiving GPS data (receiver functionality 122 of the MMR 114 ). SVS 100 relies on the GPS data, and the topographical databases 106 , 108 , 110 , and 112 to display the image on display 116 . Upon entering the LAAS usable range, the aircraft begins to receive the VDB signal from the LAAS via the VDB receiver 118 functionality of the MMR 114 . Message Type 4 of the VDB signal includes final approach segment definitions, for example in terms of geographic reference coordinates. The topographical database information, particularly that of databases 108 , 110 and 112 , may then be validated using the message Type 4 information from the VDB signal. If the topographical database information does not match the message Type 4 information, then there may be determined to be an error or bias in the topographical database information. The message Type 4 information from the VDB signal is then used to correct the topographical information. The corrected topographical information is then used to render the SVS display on display device 116 , providing the flight crew with a high-fidelity SVS display that may be used as a supplement for use during an instrument approach, down to a HAT of about 150 feet. The use of LAAS message Type 4 information as validation should not be understood to exclude the use of other validation data source. For example, in addition to the foregoing described validation, message Type 1 information may be used to validate and correct the GPS signal, which may then be used by the SVS 100 as part of its display/validation scheme. Moreover, satellite-based correction signals from a wide area augmentation system (WAAS) may be used for the same purpose. Still further, onboard validation means, such as inertial navigation systems (INS), may be used to validate and cross-check the received GPS signal for purposes of providing an accurate SVS display that is usable as a supplement with instrument approaches. In some embodiments, it is proposed that that the VDB is modified to carry more information, e. g., runway closure NOTAM, runway occupancy status, hold short traffic information, etc., to facilitate a timely and improved visual situational awareness. This runway closure NOTAM, runway occupancy status, or hold short traffic information may be displayed to the flight crew as an appropriate graphical or textual indication on the display 116 of SVS 100 . For example, runway closure NOTAMs may be provided in text, runway occupancy status may be indicated by an aircraft symbol on the runway, and hold short traffic information may be indicated as an appropriate line or bar at the hold short point of the runway. In further embodiments, the SVS 100 may include a “level of service” monitor to indicate the health of the SVS 100 . Various monitors may validate the information and allow the synthetic scene to be used for navigation and lower minimums. The level of service monitor may be provided on display device 116 , and may include green text that lists the type of approach, the unique identifier for the approach, and a label that indicates the health of the SVS 100 . When the label is written in green text, it means that the approach is usable, and that all of the validation scheme are operating properly (and that if any error or bias has been detected, it has been appropriately corrected using the VDB information). An audible signal or its accompanying text in an amber box in the level of service monitor means the approach must either be abandoned or flown as a normal ILS or other instrument approach. Below the normal ILS or other approach minimums, the box turns red and pilots must fly the missed-approach procedure. FIG. 3 provides an exemplary flowchart of a method of operation 300 of the SVS 100 in accordance with an exemplary embodiment of the present disclosure. At step 301 , the SVS receives a GPS signal indicating a position of the aircraft. At step 303 , the SVS receives a VDB signal including final approach segment information from a ground-based augmentation system (i.e., a LAAS) at an airport. At step 305 , the SVS accesses one or more topographical databases (i.e., terrain, navigation, runway, and/or obstacle) and retrieved topographical information pertaining to the position of the aircraft. At step 307 , the SVS uses the VDB signal to validate the topographical information. Step 309 is a determining step wherein the SVS determines whether the topographical information has been validated, i.e., whether the topographical information matches the VDB signal information. At step 311 , if the topographical information has been validated, the SVS displays a synthetic vision image to the flight crew of the aircraft on a flight display based on the topographical information. At step 313 , if the information does not match, then the topographical information is corrected using the VDB information, namely the final approach segment information. Then, at step 315 , the SVS displays a synthetic image to the flight crew of the aircraft on the flight display based on the correct topographical information. In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Numerical ordinals such as “first,” “second,” “third,” etc. simply denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language. The sequence of the text in any of the claims does not imply that process steps must be performed in a temporal or logical order according to such sequence unless it is specifically defined by the language of the claim. The process steps may be interchanged in any order without departing from the scope of the invention as long as such an interchange does not contradict the claim language and is not logically nonsensical. Furthermore, depending on the context, words such as “connect” or “coupled to” used in describing a relationship between different elements do not imply that a direct physical connection must be made between these elements. For example, two elements may be connected to each other physically, electronically, logically, or in any other manner, through one or more additional elements. While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.

An aircraft synthetic vision display system (SVS) includes a topographical database including topographical information relating to an airport, a global positioning system receiver that receives a satellite signal from a global positioning satellite to determine a geographical position of the aircraft, and a ground-based augmentation system receiver that receives a ground-based signal from a ground-based transmitter associated with the airport, wherein the ground-based signal includes geographical information associated with the airport. The SVS further includes a computer processor that retrieves the topographical information from the topographical database based on the geographical position of the aircraft, that retrieves the geographical information associated with the airport, and that corrects the topographical information using the geographical information associated with the airport to generate corrected topographical information. Still further, the SVS includes a display device that renders three-dimensional synthetic imagery of environs of the aircraft based on the corrected topographical information.

TECHNICAL FIELD [0001] The present invention relates to a tool for opening an extruded profiled body of a power cord assembly device. It also relates to such an extruded profiled body and a method of introducing a fibre optical cable into a power cable assembly device. BACKGROUND OF THE INVENTION [0002] When putting a fibre optic cable inside a power cord assembly device with the prior art tools, it has proven complicated to perform the operation, and is thus time consuming. [0003] A tool for opening an extruded profiled body of a power cord assembly device is known from SE-C-530 277. It is cumbersome to use, since the tool must be introduced into the same a slit of the power cord assembly where the fibre optic cable is to be introduced. OBJECT OF THE INVENTION [0004] The object of the present invention is to improve the accessibility to a chamber of the profiled body, where the fibre optic cable is to be introduced. SUMMARY OF THE INVENTION [0005] This has been solved by a tool for opening an extruded profiled body of a power cord assembly device as initially defined, which further comprises at least one pair of guide means and at least one support means, said pair of guide means and said support means being arranged in a frame, [0000] wherein a first guide means of said pair of guide means is arranged and shaped to releasably connect to the an interconnection area of the profiled body, and wherein a second guide means of said guide means is arranged and shaped to releasably connect to a second interconnection area of the profiled body, said support means being provided with a support member adapted to bear against a portion of the first wall opposite to the slit, the distance of the guide means relative to the support means being such that the slit is widened in the area of the elongation of the profiled body where the tool is applied, hereby allowing a fibre optic cable to be introduced into the chamber. [0006] Hereby, damages on the fibre optic cable are avoided. Furthermore, the introduction is made easier and faster and is thus less expensive. [0007] It has also been achieved by a power cable assembly of the initially defined kind, furthermore comprising a profiled body made of a polymer material and adapted to the cross-sectional shape and elongation of the power cable, said profiled body ( 4 ) comprising a chamber and a slit to said chamber, said chamber being adapted to receive a fibre optic cable via said slit. [0008] Hereby is achieved a profiled body suitable to be used in said tool [0009] It has furthermore been achieved by the method of the initially defined kind, including the steps of [0000] applying a pressure on the first wall substantially between the first and second end portions in a direction towards the slit; applying a pressure on at least one of said second and third wall in a direction towards the first wall until the slit is wider than the diameter of the fibre optic cable; introducing the fibre optic cable through the slit into the chamber; placing a guide means along the longitudinal extension of the slit, the guide means having an elongated guide member with two elongated sides, the lateral dimension of the elongated guide member being less that the diameter of the fibre optic cable; controlling and guiding the fibre optic cable into the chamber via said slit by means of the guide member; moving the profiled body in relation to the guide means together with the fibre optic cable; moving the guide member out of the slit, the fibre optic cable ( 30 ) remaining inside said chamber. [0010] Hereby, as safe method is defined for readily and easily introducing a fibre optic cable into the chamber of the profiled body. [0011] Suitably, said support means is rigidly connected to the frame, said guide means being movably connected to the frame by means of a helical joint, a gear rack joint or a sliding joint. [0012] Preferably, the first and second guide means are provided with friction reducing means adapted bear against and slide along the profiled body in the vicinity of the first interconnection area and the second interconnection area, respectively, for facilitating movement in the longitudinal extension of the profiled body. Suitably, the friction reducing means is a movable member. In particular the movable member is a ball, a roll or a wheel. [0013] Suitably, said support member of is provided with friction reducing means adapted bear against and slide along the outer surface of the first wall of the profiled body, for facilitating movement in the elongation of the profiled body. Preferably, the friction reducing means is a movable member. In particular, the movable member is a ball, a roll or a wheel. [0014] Preferably, the number of pairs of guide means is at least two, and the number of support members is at least two. In particular, the number of pairs of guide means is four, and the number of support members is at least four. Hereby, a controlled introduction of the fibre optic cable into the chamber is achieved. [0015] Suitably, a guide bar is provided for guiding the fibre optic cable into the slit, wherein the guide bar is provided with a guide member the transversal dimension of which being less than the width of the slit. Hereby, a controlled guiding of the optic fibre to remain in the chamber is achieved. [0016] Preferably, the guide bar is provided with a U-shaped guide member for controlling the introduction of the fibre optic cable into the slit, said U-shaped guide member being aligned with the elongated guide member, the guide bar being connected to the frame in front of and facing the guide members, the open part of the U-shaped guide member being turned towards at least one of the support members in such a way that the U-shaped guide member and the elongated guide member are facing the slit of a profiled body introduced between the support members and the guide means, the guide bar being positioned in the frame such that the U-shaped guide member is upstream the elongated guide bar in relation to the direction of movement of the profiled body. [0017] Hereby, a controlled introduction of the optic fibre cable into the chamber is achieved. DRAWING SUMMARY [0018] In the following, the invention will be described in more detail by reference to the enclosed drawings, in which [0019] FIG. 1 is a cross-section of a power cable assembly device; [0020] FIG. 2 is a cross-section of a power cable provided with the power cable assembly device shown in FIG. 1 ; [0021] FIG. 3 is a cross-section of an alternative power cable assembly device; [0022] FIGS. 4 a - 4 d illustrate schematically a tool for enabling introduction of a fibre optic cable inside the power cable assembly device shown in FIGS. 1-3 ; and [0023] FIGS. 5-8 illustrate schematically alternative tools for enabling introduction of a fibre optic cable inside the power cable assembly device shown in FIGS. 1-3 ; [0024] FIG. 9 a - 9 b illustrates an alternative tool and a combined such tool; [0025] FIGS. 10 a - 10 d illustrate an alternative combined tool; and [0026] FIG. 11 illustrates a set up of tools in the assembly of a power cable. DETAILED DESCRIPTION [0027] FIG. 1 shows a power cable assembly device 2 in the form of an extruded profiled body 4 with a first wall 6 , a second wall 8 , a third wall 10 . The first wall 6 is convex while the second and third walls 8 , 10 are concave, the reason for which will be discussed farther below. The cross-section of the profiled body has first and second end portions 5 a , 5 b , opposite to one another. [0028] The cross-section of the first wall 6 of has a first end 6 a and a second end 6 b . Likewise, the second wall 8 has a first end 8 a and a second end 8 b , and the third wall 10 has a first end 10 a and a second end 10 b . The first end 6 a of the first wall 6 is connected to the first end 8 a of the second wall at the first end 5 a of the profiled body, while the second end 6 b of the first wall 6 is connected to the first end 10 a of the third wall 10 at the second end 5 b of the profiled body. [0029] The second end 8 b of the second wall 8 continues to a first angled transition 12 a and further to a first radial transition 14 a . Likewise, the second end 10 b of the third wall 10 continues to a second angled transition 12 b and further to a second radial transition 14 b. [0030] The first and second angled transitions 12 a , 12 b are converging towards the first and second radial transitions 14 a , 14 b , the latter being substantially parallel to one another and thus substantially radial to the convex first wall 6 . The first and second radial transitions 14 a , 14 b are arranged at a distance from one another, defining an open slit 15 . [0031] Inside the profiled body 4 , a chamber 16 defined by a substantially annular wall 18 is arranged. The annular wall 18 extends from the first radial transition 14 a to the second radial transition 14 b . A pair of reinforcement members 20 a , 20 b are arranged between the annular wall 18 and the first wall 6 . [0032] The assembly device 2 is made by extrusion of a polymer material, such as PE (e.g. MDPE or HDPE) or PVC and may have a length of several kilometres. [0033] At least the second and third walls 8 , 10 have a thickness in the range 2-6 mm, more preferably 2.5-4 mm, most preferably 3 mm, and thin layer 21 of the semi-conductive material is in the range 0.01-0.5 mm, more preferably 0.05-0.35 mm, even more preferably 0.1-0.3 mm, even more preferably 0.15-0.25 mm, most preferably 0.2 mm. [0034] FIG. 2 shows the interior of a power cable 22 provided with three neighbouring first, second and third power cores 24 a , 24 b , 24 c , each provided—from the centre to the periphery—with a conductor 25 a , a first second semi-conductive layer 25 b , insulation 25 c , a second semi-conductive layer 25 d , a layer of swelling material 25 e , a metal screen 25 f made of led and a third semi-conductive mantle 25 g. [0035] The first and second semi-conductive layers 25 b , 25 d form a smooth surface which controls the electric field strength. The swelling material 25 e tightens against water in case the led screen 25 f would start leaking. [0036] Each power core 24 a , 24 b , 24 c has a peripheral point 26 a , 26 b , 26 c in relation to the diametrical centre 19 of the power cable 22 , i.e. in the central space 27 d . The three peripheral points 26 a , 26 b , 26 c form together in relation to the centre point 19 an imaginary circle 26 d. [0037] The first and second power cores 24 a , 24 b touch one another at a contact point 23 a and define a peripheral space 27 a together with the imaginary circle 26 d . Likewise, the second and third power cores 24 b , 24 c have a contact point 23 b and define a second peripheral space 27 b together with the imaginary circle 26 d and the third and first power cores 24 c and 24 a have a contact point 23 c and define a third peripheral space 27 c together with the imaginary circle 26 d . The first, second and third power cores 24 a , 24 b , 24 c define between the contact points 23 a , 23 b , 23 c a central space 27 d. [0038] In the peripheral space 27 a , a first assembly device 2 a is provided. Likewise, a second assembly device 2 b is arranged in the second peripheral space 27 b , and a third assembly device 2 c is arranged in the third peripheral space 27 c. [0039] The power cable is provided with a jacket 28 to keep the power cores 24 a , 24 b , 24 c and the assembly devices 2 a , 2 b , 2 c together as one unit and to keep the circular cylindrical shape and mechanical protection. The jacket 28 comprises—from the periphery towards the centre point 19 —two layers 29 a of yarn made of polypropylene (PP), a first steel wire armour layer 29 b , a first soft layer 29 c of laying bands, a second steel wire armour layer 29 d , a second soft layer 29 e of laying bands. [0040] As can be understood from FIG. 2 , the concavity of the outer surface of the second and third walls 8 , 10 of each assembly device 2 a , 2 b , 2 c depends on the diameter of the power cores 24 a , 24 b , 24 c . In the same manner, the convexity of the outer surface of the first wall 6 of each assembly device 2 a , 2 b , 2 c depends on the radius of curvature of the imaginary circle 26 d. [0041] An elongated a fibre optic cable 30 comprises a fibre optic wave conductor 31 , i.e. a bundle of optical fibres inside a metal tubing 32 a together with a mass 32 b , such as a gel. The metal tubing 32 a is covered with a layer of semi-conductive layer 33 . [0042] FIG. 3 shows another assembly device 2 made by extrusion of a polymer material, such as PE (e.g. MDPE or HDPE) or PVC. [0043] Also in this embodiment, the first wall 6 of the profiled body 4 is convex and has first and second ends 6 a , 6 b ; the second wall 8 is concave and has first and second ends 8 a , 8 b ; and the third wall 10 is concave and has first and second ends 10 a , 10 b . The first, second and third walls are connected to one another as described in connection with FIG. 1 above. [0044] However according to this embodiment, the second end 8 b of the second wall 8 continues to a first curved transition 13 a and further to a first radial transition 14 a . Likewise, the second end 10 b of the third wall 10 continues to a second curved transition 13 b and further to a second radial transition 14 b . Also in this embodiment the first and second radial transitions 14 a , 14 b are substantially parallel to one another and are thus substantially radial to the convex first wall 6 . [0045] However, according to this embodiment, the first and second radial transitions 14 a , 14 b are arranged without distance from one another, i.e. the slit 15 is closed, even though the slit for clarity reasons have been shown to be somewhat open. [0046] Also in this embodiment, the annular wall 18 defining the chamber 16 extends from the first radial transition 14 a to the second radial transition 14 b . However, no further reinforcement members are needed. Instead, the annual wall 18 is partly constituted by the first wall 6 . [0047] FIG. 4 a shows a tool 39 and a profiled body 4 of the kind shown in FIG. 1 . The tool 39 has a pair of arms 40 , 42 connected at one end 40 a , 42 a by means of a hinge 43 , respectively, to an interconnection means 44 . The opposite ends 40 b , 42 b of the arms 40 , 42 are provided with guide means 41 in the form of hook members shaped to grasp about the edges 5 a , 5 b of the profile 4 of the power cable assembly device 2 . [0048] Centrally between the hinges 43 , the interconnection means 44 is provided with a support means 46 via a helical joint 47 . The support means 46 is at one end provided with a support portion or member 48 and at the other end with a nut or turning handle 49 for manual operation of the support means 46 . [0049] The support means 46 may instead be actuated by e.g. an electric step motor. [0050] The withdrawal tool 39 is now ready to be moved along the longitudinal extension of the profiled body 4 , in order to open the slit 15 for introduction of the fibre optic cable 30 into the chamber 16 via the slit. [0051] In order to allow such movement, the material of the whole of or part of the tool 39 is preferably, but not necessarily, made of a low friction material. [0052] As shown in FIG. 4 b , support portion 48 of the support means 46 and the guide means 41 are provided with a friction reducing means 50 , in the form of a ball bearing 52 comprising a single ball, in order to allow the withdrawal tool 39 to be moved along the profiled body 4 . [0053] Of course, the ball bearing 52 may comprise more than one ball. [0054] Even though FIG. 4 b shows the tool 39 together with a profiled body 4 of the kind shown in FIG. 3 , it is to be understood that the profiled body 4 of the kind shown in FIG. 1 could be used. Likewise, the profiled body 4 of the kind shown in FIG. 3 could be used together with the tool of FIG. 4 a. [0055] FIG. 4 c shows an alternative friction reducing means 50 in the form of a roller bearing 54 , having a single roll or wheel. [0056] Of course, the roller bearing 52 may instead comprise more than one roller or wheel. [0057] The profiled body 4 indicated with broken lines may be of the kind shown in FIG. 1 or 3 or of any other kind, having substantially the same shape. [0058] FIG. 4 d shows an alternative friction reducing means 50 in the form of a low friction material 56 , such as PTFE. [0059] It should be noted that the guide means 41 may be provided with one kind of friction reducing means 50 , as shown in FIGS. 4 b - 4 d , or no friction reducing means shown in FIG. 4 a , while the support means 46 is provided with none or another kind of friction reducing means shown in FIGS. 4 a - 4 d. [0060] FIG. 5 shows a variant of the tool 39 , according to which the support means 46 is connected to the interconnection means 44 via a gear rack joint 58 , while the pair of arms 40 , 42 are connected to the interconnection means 44 by means of hinges 43 . [0061] The first and second arms 40 , 42 are each provided with guide means 41 in the form of a guide wheel 41 a , 41 b connected via an axle 76 . The support means 46 is provided with a support member 48 in the form of a double encapsulated ball-bearing 54 connected via an axle 72 to a U-shaped bearing support 73 . [0062] The support means 46 is actuated by a power source 60 , e.g. an electric step motor, a solenoid or a hydraulic or pneumatic cylinder, such that the support means is allowed to move in its longitudinal direction. [0063] Of course, the support means 46 may instead be manually actuated. [0064] In this variant, the guide wheels 41 a , 41 b of the arms 40 , 42 are positioned under the first and second ends 5 a , 5 b of the profiled body 4 by turning one or two of the arms 40 , 42 about the respective hinge 43 . [0065] FIG. 6 shows a variant of the tool 39 , according to which the first and second arms 40 , 42 are connected to the interconnection means 44 via helical joints 62 , while the support means 46 is rigidly connected to the interconnection means 44 . [0066] The first and second arms 40 , 42 are each provided with a guide wheel 41 a , 41 b via an axle 76 , and the support means 46 in the form of a U-shaped bearing support 73 provided with an encapsulated ball-bearing 54 via an axle 72 . [0067] The support means 46 is actuated by a power source 60 , e.g. an electric step motor, such that the arms 40 a , 40 b is allowed to move in their longitudinal direction. Of course, the arms could instead be turned manually. [0068] In this variant, the guide wheels 41 a , 41 b of the arms 40 , 42 are positioned under the first and second ends 5 a , 5 b of the profiled body 4 by turning one or two of the arms 40 , 42 . [0069] FIG. 7 shows a further variant of the tool 39 , according to which the support means 46 as well as the arms 40 , 42 are rigidly connected to the interconnection means 44 , while the guide means 41 in the form of hooks are pivotably connected to the arms 40 , 42 about hinges 68 and further provided with a locking means 70 for facilitating grasping of the guide means 41 behind the edges 5 a , 5 b of the profiled body 4 . [0070] Of course, the guide means 41 and the support means 46 may be provided with no friction reducing means 50 as shown in FIG. 4 a , or with any other kind, e.g. as shown in FIGS. 4 b and 4 c , or a combination thereof, as explained above in connection with FIGS. 4 a - 4 d. [0071] FIG. 8 shows a further variant of the tool 39 , according to which the arms 40 , 42 are rigidly connected to the interconnection means 44 , while the support means 46 is helically movable in relation to the interconnection means 44 . In this case, the edges 5 a , 5 b of the profiled body 4 are manually positioned against the support member 48 and behind the guide means 41 , or by means of a separate tool. [0072] The different friction reducing means 50 shown in FIGS. 4 b - 4 d or any combination thereof, are applicable also in this case. [0073] FIG. 9 a illustrates yet another variant of the withdrawing tool 39 , according to which the support means 46 as well as the arms 40 , 42 are rigidly connected to the interconnection means 44 . Also in this case, the edges 5 a , 5 b of the profiled body 4 are manually positioned against the support member 48 and behind the support members, or by means of a separate tool. [0074] FIG. 9 b shows a tool 39 comprising a combination of three tools of the kind shown in FIG. 9 a . By means of a frame 74 , the three tools are interconnected to one combined tool. In this variant, the support members 46 a , 46 b , 46 c having different the lengths, i.e. l 1 <l 2 <l 3 . [0075] When introducing the profiled body from the left to the right in tool 39 of FIG. 9 b , the slit 15 will be gradually opened by the support members, and will thus allow a fibre optic cable 30 to be introduced into the chamber 16 without difficulty. The fibre optic cable (not shown in FIG. 9 b ) could be introduced to the right in the figure, either by hand or by means of a tool. It should be noted that the tool 30 could be turned upside down. In that case, gravity could be used for introducing the fibre optic cable into the rightmost tool. [0076] It should be noted that the different tools 39 and friction reducing means 50 shown in FIGS. 4 b - 4 d , 5 and 6 or any combination thereof, are applicable in the tool of FIG. 9 b [0077] FIG. 10 a shows a further variant of the tool 39 provided with support means 46 comprising four support members 48 in the form of double encapsulated ball-bearings 54 . Each ball-bearing 54 is rotatably connected via an axle 72 to a U-shaped bearing support 73 across an axis through the aligned ball-bearings 54 . The tool 39 is furthermore provided with guide means in the form of four pairs of guide wheels 41 a , 41 b of encapsulated needle bearings 55 a , 55 b , each rotatable about an axle 76 , said axle 76 being parallel to the axles 72 of the ball-bearings 54 . [0078] In order to position the four ball-bearings 54 in relation to one another and in relation to the guide wheels, the tool 39 comprises a grid of parallel plates 75 of a first frame part 74 a of an interconnection means 44 in the form of a frame 74 , together forming a grid. Of course, the grid of parallel plates 75 could instead be constituted by a single plate. [0079] The frame further comprises a pair of side walls 74 b , 74 c , connected perpendicularly to the first frame part 74 a by screws 90 . The side walls 74 b , 74 c are furthermore adjustably connected to a frame support 74 f by screws 94 in a row of holes 96 . In this manner, the first frame part 74 a can be moved in a direction across the row of holes 96 . Thus, the position of a plane through the axles 72 of the ball-bearings 54 can be adjusted in relation to the guide wheels 41 a , 41 b , depending on the thickness of the profiled body 4 . [0080] The frame support 74 f is provided with an entrance opening 92 for introduction of the profiled body 4 into the tool 39 . An access slot 93 in the frame support 74 e allows for taking the tool 39 apart even if the profiled body 4 is still inside the tool 39 . [0081] The frame 74 further comprises a pair of plates 74 d , 74 e each connected to extension plates 74 g , 74 h . The plates 74 d , 74 e are each provided with a slot 97 a , 97 b in their opposing ends (the rear ends being hidden) for adjustable connection with screws 98 a , 98 b to a pair of rows of holes 99 in the frame support 74 f . Hereby, the frame 74 is adjusted for the lateral dimension of the profiled body 4 . [0082] A pair of reinforcement members 74 i , 74 k are each provided with four sets of screws 80 a . Each guide wheel 41 a , 41 b is independently movable in a slot 78 in the plates 74 d , 74 e towards a plane through the axles 72 of the ball-bearings 54 , and is adjustable in the slot 78 by means of a corresponding set screw 80 a . After performed adjustment, the position of the guide wheel 41 a or 41 b is fixed by means of a lock nut 80 b. [0083] The set of screws 80 a and lock nuts 80 b are adjusted in such a way that each guide wheel 41 a , 41 b is positioned at a predetermined distance relative to the support member 48 . In this way, it is possible to adjust each pairs of guide wheels 41 a , 41 b relative to the other pairs of guide wheels 41 a , 41 b to bear against the edges of 5 a , 5 b of the profiled body 4 . By said adjustment, the slit 15 will be widened and thus opened at a predetermined position between the first pair of wheels and the fourth pair of wheels. [0084] In FIG. 10 b is shown an elongated guide beam 82 having lateral sides 82 a , 82 b , a guide side 82 c and a connection side 82 d (hidden). The guide beam 82 is to be arranged opposite to and facing the support members 48 . The guide beam 82 is provided with an elongated guide member 84 to be positioned parallel to a plane through the axles 72 of the ball-bearings 54 , by screws 83 a in elongated slits 83 b , 83 c in two pairs of arms 83 d , 83 e connected to the side walls 74 b , 74 c of the frame 74 . [0085] In FIG. 10 c is shown the guide beam 82 from the opposite direction. At a first end 82 e of the guide beam, an elongated U-shaped guide member 85 is provided, while at a second end 82 f , and on the same longitudinal side 82 c , an elongated guide member 84 is provided. Between the elongated guide, the U-shaped member 85 and the elongated guide member 84 , a transition section 86 a is provided between first and second sections 86 b , 86 c . In the transition section 86 a , the lateral extension of the elongated U-shaped member 85 , measured from the connection side 82 d is reduced in a longitudinal direction from the first section 86 b towards the elongated guide member 84 . Furthermore, in the transition section 86 a the lateral extension of the elongated member 84 , measured from the connection side 82 d is reduced in a longitudinal direction from the second section 86 c towards the U-shaped member 85 . [0086] In FIG. 10 d is shown that the fibre optic cable 30 is controlled to keep a longitudinal orientation relative to the slit 15 of the profiled body by the U-shaped guide member 85 at the first section 86 b extending from the first end 82 e to the transition section 86 a . It also shows that the fibre optic cable is introduced into the profiled body 4 via slit 15 by the transition section 86 a of the diminishing elongated U-shaped guide member 85 and the raising elongated guide member 84 , and that the fibre optic cable 30 is guided to stay inside the chamber by the elongated guide member 84 in the section 86 c extending from the transition section 86 a towards the second end 82 f. [0087] FIG. 11 shows the first step of assembly of the power cable. [0088] First, the power cores 24 a , 24 b , 24 c are held 120° in relation to one another by means of not shown equipment in the periphery of an imaginary circle 100 . [0089] Then, between the power cores 24 a , 24 b , 24 c three tools 39 a , 39 b , 39 c of the kind shown in FIGS. 10 a - c , are arranged 120° in relation to one another in the periphery of the imaginary circle 100 in relation to and between the power cores 24 a , 24 b , 24 c. [0090] As explained above in connection with FIG. 10 a , the frame 74 is adjusted for the power cable assembly device 2 to be used, i.e. first frame part 74 a is mounted in predetermined holes of the frame support 74 f , and the pair of plates 74 d , 74 e are mounted in predetermined holes 99 . [0091] In each tool 39 a , 39 b , 39 c , a profiled body 4 is positioned between the four pairs of guide wheels 41 a , 41 b , starting from the level of frame support 74 f (i.e. seen from the lower part in FIG. 10 a ) and the four support members 48 . [0092] The screws 80 a of the first, second and third pairs of wheels 41 a , 41 b , counted from the frame support 74 f , are adjusted such that the slit 15 of the profiled body 4 of FIG. 1 or FIG. 3 is opened somewhat more than the diameter of the fibre optic cable 30 , while the fourth pair of wheels 41 a , 41 b are adjusted to allow the slit 15 to be smaller, such that the width of the slit is less than the diameter of the fibre optic cable 30 , but wider than the transversal dimension of the guide member 84 . [0093] A fibre optic cable 30 is now introduced via the entrance opening 92 of the frame 74 (cf. FIG. 10 a ) in each profiled body 30 mounted in the tools 39 a , 39 b , 39 c , and is introduced into the chamber 16 and through the end of the profiled body 4 and temporarily fixed inside the profiled body upon start. [0094] A guide beam 82 of the kind described above is then mounted. [0095] Each profiled body 4 is collected together with the power cores 24 a , 24 b , 24 c at a distance from the tools 39 a , 39 b , 39 c (above the tools as seen in FIG. 10 a and FIG. 11 ) and are assembled while pulling the profiled bodies 4 and power cores 24 a , 24 b , 24 c away from the tools 39 a , 39 b , 39 c. [0096] During this movement, the slit 15 is opened by the support members 48 and the guide members 41 , while fibre optic cables 30 are guided into the chamber by the guide beam 82 . [0097] It should also be noted that the tools 39 a , 39 b , 39 c may be mounted for introduction of the fibre optic cable 30 through the entrance opening 92 of the frame 74 horizontally or vertically. [0098] In case of high torsional stiffness of the profiled body 4 , a higher pressure may have to be applied on one side 8 than the other 10 by the guide wheels 41 a , 41 b , or a pressure may even only be applied on one side 8 by one or more guide wheels 41 a , while a lower or even no pressure may be applied on the other side 10 by one or more guide wheels 41 b. [0099] In FIG. 11 , the simultaneous introduction of a fibre optic cable 30 into three power cable assembly devices 2 of a power cable 22 . However, in case only one or two fibre optic cables 30 are to be introduced into the power cable, the tools 39 a , 39 b , 39 c will still be used as guide tools for the assembly of the cores 24 a , 24 b , 24 c and the power cable assembly devices. The support members 48 and guide wheels 41 a , 41 b of the tool or tools used only as guide tools will then preferably be adjusted in such a way that the slit of such profiled bodies 4 will not be opened. [0100] It should be noted that the guide beam 82 could instead be divided into three different items, corresponding to the sections 86 a , 86 b and 86 c . Alternatively, the first and second sections 86 b , 86 c could instead be a pair of wheels with a peripheral shape corresponding to the cross-section of the first and second sections 86 b , 86 c , respectively. [0101] It should be noted that the encapsulated ball-bearing 54 could be exchanged to an encapsulated roller bearing, having circular cylindrical rollers, or to plain bearings. Likewise, the encapsulated needle-bearings could be exchanged to small ball-bearings or plain bearings. Of course the bearings could also be non-encapsulated.

A tool for opening an extruded profiled body of a power cord assembly device includes at least one pair of guides and at least one support, the pair of guides and the support being arranged in a frame, wherein a first guide of the pair of guides is arranged and shaped to releasably connect to the an interconnection area of the profiled body, and wherein a second guide of the pair of guides is arranged and shaped to releasably connect to a second interconnection area of the profiled body, said support being provided with a support member adapted to bear against a portion of the first wall opposite to a slit in the profiled body, the distance of the pair of guides relative to the support being such that the slit is widened in the area of the elongation of the profiled body where the tool is applied, thereby allowing a fibre optic cable to be introduced into the chamber.

FIELD OF THE INVENTION [0001] The present invention relates to an automatic control system. DESCRIPTION OF THE RELATED ART [0002] With an appliance for performing automatic control of transportation means such as an automobile, a train, an airplane, a ship, a spaceship or the like, a robot, a manufacturing device, a management device, or the like, the state of an appliance which is a control target is monitored by a control unit by connecting the control target and the control unit by an electrical wire (a wire), and the operation of the control target is controlled. As many electrical wires as the number of states (contact point information) to be controlled and monitored between the control unit and the control target are required, and the structure is complicated to the extent, thereby increasing the manufacturing cost. [0003] Accordingly, a method of performing data communication by using a fewer number of electrical wires as the signal lines by serial communication or the like, and performing various kinds of control has been invented and put to practical use. Particularly, with a control system for vehicle control, machine control or the like, such as a relay connection unit or an electronic control unit described in JP 2008-5290 A, signals indicating the contact point information are multiplexed by using a communication control IC for vehicle LAN for performing transmission and reception of messages that is compliant with communication standards such as CAN (Controller Area Network) or FlexRay (a registered trademark of Daimler Chrysler AG) to thereby control a large number of control targets by a small number of signal lines. [0004] In addition, the vehicle LAN is hierarchically divided into groups, and a gateway is arranged at a connection portion of an upper vehicle LAN and a lower vehicle LAN. Furthermore, with respect to the vehicle LAN, error check is performed by communicating, at the same time, information of a redundant item for determining whether a message to be communicated is accurate, for example, and a message for which communication failure has occurred is discarded. Accordingly, occurrence of control failure due to a message which has been changed by communication failure may be prevented in advance. [0005] FIG. 7 is a diagram showing an example of a conventional automatic control system 90 . In FIG. 7 , the reference numeral 91 denotes a control target, the reference numeral 92 denotes a slave station to which the control target 91 is to be connected, the reference numeral 93 denotes a master station provided with a control unit 94 for controlling the control target 91 , the reference numeral 95 denotes a relay station, existing between the master station 93 and the slave station 92 , for relaying contact point information about the control target 91 , the reference numeral 96 denotes a first communication line, the reference numeral 97 denotes a second communication line, the reference numerals 93 a and 95 a denote communication units for transmitting and receiving the contact point information via the first communication line 96 , the reference numerals 95 b and 92 a denote communication units for transmitting and receiving the contact point information via the second communication line 97 , the reference numeral 92 b denotes an input/output port for storing the contact point information transmitted and received by the communication unit 92 a and inputting/outputting the contact point information to/from the control target 91 , the reference numeral 93 b denotes a dual port memory (hereinafter referred to as DPM) for storing the contact point information transmitted and received by the communication unit 93 a, and the reference numeral 95 c denotes a DPM for storing the contact point information transmitted and received by the communication units 95 a and 95 b. [0006] Additionally, the control target 91 includes a motor 91 a, a rotary encoder 91 b provided to the motor 91 a, and a switch 91 c, for example. [0007] According to the automatic control system 90 configured in the above manner, the contact point information transmitted from the control unit 94 to the motor 91 a is written to the DPM 93 b, and then, the contact point information stored in the DPM 93 b is transmitted by the communication unit 93 a to the communication unit 95 a of the relay station 95 via the first communication line 96 and is written to the DPM 95 c. Also, the contact point information written to the DPM 95 c is transmitted by the communication unit 95 b to the communication unit 92 a of the slave station 92 via the second communication line 97 and is written to the input/output port 92 b to be output to the motor 91 a. [0008] Similarly, the contact point information to be input to the input/output port 92 b from the rotary encoder 91 b or the switch 91 c is transferred to the DPM 93 b by communication using the second communication line 97 and the first communication line 96 and is input to the control unit 94 , and the control unit 94 is thereby enabled to control the motor 91 a according to the state of each of units 91 b and 91 c. [0009] However, according to the conventional automatic control system 90 , the update cycle (the communication cycle) of the contact point information transmitted and received by the communication units 95 b, 92 a, 93 a and 95 a is slower than the cycle of control by the control unit 94 , and thus, the control unit 94 is not able to sufficiently fulfill its capacity. That is, the control unit 94 is able to detect the state of the control target 91 only at least after a time longer than the slowest communication cycle of the communication units 95 b, 92 a, 93 a and 95 a has elapsed, and there is a long wait time for the control unit 94 , and thus, the control unit 94 performs unnecessary calculation process to that extent and unnecessarily increases the power consumption. [0010] In addition, the cycle by which the control unit 94 is able to obtain the updated contact point information is affected by the number of relay stations 95 or the timing of the control unit 94 accessing the DPM 93 b, and there is an issue that, since the length of delay time by which the contact point information of the control target 91 may be detected is not constant, temporally accurate control cannot be performed. [0011] Furthermore, in the case an automatic control logic for counting the pulse of the rotary encoder 91 b as the contact point information is built, for example, it is conceivable that unnecessary pulses are counted or that there are uncounted pulses due to occurrence of a communication error. To cope with such a communication error, it is conceivable to perform error check for each communication using each of communication lines 96 and 97 , but then, the influence of communication delay due to the error check may become significant. [0012] On the other hand, as one effective error check method, error check by so-called double collation of checking, at the time of the contact point information changing, whether the information is changed to the latest information two times in a row is performed. However, as in the example shown in FIG. 7 , in the case communication at different speeds is being relayed, contact point information with an error may be communicated two times in a row depending on the timing of the relayed communication, and communication failure may not be removed even if the double collation is performed. [0013] Accordingly, conventionally, the communication speeds of the communication units 95 b, 92 a, 93 a and 95 a are increased as much as possible to secure synchrony of control by the control unit 94 . That is, to transmit and receive a contact point signal that changes at a speed of about several tens to several hundreds kHz, a LAN capable of high-speed communication at a sufficient speed of several Mbps to 1 Gbps, for example, may be introduced, and pseudo-simultaneity may be achieved. However, it is inevitable that if the communication speed by LAN is increased, the cost for introducing the LAN is increased to that extent. [0014] In addition, these days, many microcomputers used as the control unit include a port that is compliant with SPI (Serial Peripheral Interface: a communication standard proposed by Motorola) or I2C (I-squared-C: a communication standard proposed by Philips), a UART (Universal Asynchronous Receiver Transmitter) port, and an isochronous serial bus interface, and simplification using these is desired. SUMMARY OF THE INVENTION [0015] The present invention has been made in view of the circumstances described above, and its object is to provide an automatic control system, a contact point information collection and distribution device, and a slave station of the automatic control system that are capable of synchronizing and controlling a control target while preventing unnecessary signal processing. [0016] To solve the problem described above, a first invention provides an automatic control system including a slave station that is connected to a control target, a master station that is connected to a control unit for controlling the control target, a contact point information collection and distribution device, existing between the master station and the slave station, that collects and distributes a series of contact point information communicated at a predetermined communication cycle, and a plurality of communication lines that connect between the master station and the slave station via at least one contact point information collection and distribution device, wherein the contact point information collection and distribution device performs collection and distribution of the series of contact point information in synchronization with all the communication lines under the control of the control unit, and wherein the control unit makes the contact point information collection and distribution device perform collection and distribution of the series of contact information in synchronization and compares contact point information collected via the contact point information collection and distribution device with past contact point information collected in a previous communication cycle and assumes as true in a case of matching, and performs control by true contact point information. [0017] According to the automatic control system, the master station transmits and receives the contact point information to/from the contact point information collection and distribution device, and also, transmits and receives a series of contact point information to the slave station at a predetermined communication cycle by communication via the contact point information collection and distribution device, and thus, update of a series of contact point information is completed at both the master station and the slave station at every predetermined communication cycle. [0018] Additionally, the contact point information in the present invention means bit information indicating, for example, a contact point for performing on/off control of an actuator of the control target, and a bit signal indicating the on/off state of a sensor or a switch of the control target, and means a signal having two values, high and low, or a signal having three values, high, low and open. This contact point information is optimally bit information for controlling each control target installed on a mobile body such as a vehicle, but it is needless to say that, even if the contact point information is any of various types of bit information used in an automatic control system of other FA devices and the like, application to any communication system that performs collection and distribution of a series of bit information in a predetermined communication cycle is possible. [0019] Since the control unit compares contact point information collected by communication with past contact point information collected in a previous communication cycle and assumes the contact point information to be true in the case of matching, and thereby performs control by the contact point information, the control target may be controlled after the accuracy of the communicated contact point information is checked, and the operation is reliable. That is, comparison of pieces of contact point information is performed across communication cycles, and this is a method of checking that the same contact point information is received two times in a row (hereinafter referred to as double collation). Communication failure occurring due to an external disturbance such as noise rarely, or realistically never, exerts the same influence on the same contact point information across communication cycles. Accordingly, erroneous control based on communication failure may be practically eliminated by the double collation. [0020] Also, the contact point information used in the automatic control by the control unit is updated being delayed by the amount of a known delay time that can be calculated based on a predetermined communication cycle, and thus, the control unit is capable of performing synchronous control, and the reliability of control is improved to that extent. In addition, according to the double collation, the contact point information communicated over a plurality of communication lines may be checked by the control unit performing the comparison just once, and thus, the signal processing load on the control unit may be suppressed to the minimum. [0021] The control unit is an arithmetic processing unit of a one-chip microcomputer, for example, and communication using the communication lines is performed by a serial communication port that is generally embedded in the one-chip microcomputer, for example. This serial communication port is a contact point information transmitting and receiving unit that performs serial communication by any of the serial bus interface such as SPI or I2C, the isochronous serial interface, UART compliant with the RS-232C standard, or by a token passing method. Moreover, in this case, the master station is the one-chip microcomputer itself, and the master station includes the contact point information transmitting and receiving unit (the serial communication port) that is connected to the control unit configured from the arithmetic processing unit inside the master station. [0022] Also, the control unit is configured so as to be capable of executing a sequence control program and the like, for example, for automatically controlling the control target. Furthermore, the control unit preferably performs transmission and reception of a series of contact point information by serial communication, and the number of signal lines may thereby be reduced, and miniaturization of the package as one-chip and simplification of wiring may be achieved. [0023] With the serial communication that is performed between the control unit and the contact point information collection and distribution device of the master station, it is conceivable to achieve synchrony with respect to all the communication lines by the contact point information collection and distribution device transmitting a transfer preparation completion signal indicating transfer preparation completion of the contact point information that is to be relayed to the master station, and starting transmission and reception of the contact point information when the transfer preparation completion signal is received by the master station. However, the synchrony may also be achieved by the master station intermittently transmitting transfer start timing signals to the contact point information collection and distribution device, and the contact point information collection and distribution device starting transmission and reception of the contact point information according to reception of the transfer start timing signal. Alternatively, it is also possible to omit the signal mentioned above, and when the master station starts transmission of a serial signal of the contact point information to the contact point information collection and distribution device, the contact point information collection and distribution device may start transmission and reception of the contact point information to/from the slave station in synchronization with the start of reception of the serial signal. [0024] Furthermore, the communication to be performed between the contact point information collection and distribution device and the slave station may be serial communication by the serial bus interface such as SPI or I2C, the isochronous serial interface, or UART compliant with the RS-232C standard, but in the case of performing collection and distribution of the contact point information of a mobile body, wire saving is preferably achieved by performing voltage superimposition (PLC: Power Line Communications) and using the communication line as the power line (common use). [0025] Normally, the speed of the arithmetic processing for performing automatic control by the control unit is sufficiently higher than the communication cycle using the communication line, and the control unit does not require the capacity to perform high-speed processing, and can thus be manufactured at a cost lower to the extent. Or, the control unit may perform automatic control of the control target and other arithmetic processing in parallel so that its arithmetic processing capacity is effectively used. In any case, by performing automatic control in synchronization with the communication cycle of the contact point information collection and distribution device, necessary and sufficient automatic control processing may be performed. [0026] The control unit includes a first buffer for storing the contact point information received in the previous communication cycle, and a second buffer for updating and storing the contact point information when the contact point information that is received in the current communication cycle is compared with the previous contact point information stored in the first buffer and is assumed to be true in the case of matching, wherein in a case the control target is to be controlled based on the contact point information stored in the second buffer, since the contact point information received in the previous communication cycle is recorded in the first buffer, the contact point information recorded in the first buffer and the contact point information currently received may be compared, and that the same latest contact point information is received two times in a row may be easily determined in the case of matching, and the value of the contact point information may be relied upon as being the true value. [0027] Furthermore, since the contact point information which is confirmed to be the accurate value by the matching is stored in the second buffer, highly reliable automatic control may be easily performed by performing control based on the contact point information stored in the second buffer. Checking of the matching is signal processing that may be easily performed, and by performing the process by software by the arithmetic processing unit, the hardware structure maybe simplified, and the time spent by the control unit waiting for update of the contact point information by communication may be effectively used. However, the process may also be performed by hardware by using a comparator, and the arithmetic processing load on the arithmetic processing unit may be reduced as much as possible. In either way, the control unit is to control a plurality of serial communication tasks, but a great processing load is not applied on the arithmetic processing unit. [0028] In this invention, the contact point information collection and distribution device may include contact point information transmitting and receiving units existing between the slave station and the master station and connected to the communication lines and being for transmitting and receiving a series of contact point information in a predetermined communication cycle, a relay buffer for storing contact point information which has been transmitted or received, and a communication cycle adjustment unit for synchronizing a communication cycle of each communication line with control by the control unit. [0029] With the contact point information collection and distribution device described above, each contact point information transmitting and receiving unit transmits and receives a series of contact point information in a predetermined communication cycle, and thus, the contact point information stored in the relay buffer may be updated to the latest information in the predetermined communication cycle. In addition, the communication cycle adjustment unit synchronizes the communication cycle of each communication line with the control by the control unit, and thus, the contents of the relay buffer is updated to the latest contact point information at every communication cycle. [0030] The contact point information transmitting and receiving unit is any of serial communication ports including the serial bus interface such as SPI or I2C, the isochronous serial interface, and UART compliant with the RS-232C standard, and a serial communication port that performs communication by the token passing method. [0031] Moreover, the communication cycle adjustment unit may adopt various methods to control transmission and reception of the contact point information by the contact point information transmitting and receiving unit and achieve synchronization of the communication cycle, but the synchronization is preferably achieved by transmission and reception, with the master station, of a transfer permission signal permitting transfer, a transfer preparation completion signal indicating that data on the slave station side to be transferred is ready, a transfer completion signal indicating that transfer of data on the master station side to be transferred is completed, and the like. [0032] That is, for example, the communication cycle adjustment unit causes the contact point information transmitting and receiving unit on the slave station side to receive the contact point information from the slave station when the transfer permission signal is received from the master station and causes the contact point information to be stored in the relay buffer, and then, outputs the transfer preparation completion signal to the master station side, and then, causes the contact point information transmitting and receiving unit on the master station side to perform transmission and reception of the contact point information with the master station and causes the relay buffer to store the contact point information, and causes the contact point information transmitting and receiving unit on the slave station side to transmit the contact point information from the master station after the transfer completion signal from the master station side is received. [0033] Accordingly, the contact point information that is to be received by the master station is first received via the communication line on the slave station side, and then, transmission and reception of the contact point information is performed by performing communication with the master station, and when reception of the contact point information from the master station side is completed, the contact point information is transmitted via the communication line on the slave station side, and thus, synchronization may be achieved between the master station and the slave station with respect to the contact point information by the communication in one communication cycle. [0034] However, the communication cycle adjustment unit may also simultaneously start communication by the contact point information transmitting and receiving units on the master station side and the slave station side using the contact point information stored in the relay buffer at the time of start of the communication cycle, and may update the contact point information in the relay buffer at the time of end of the communication cycle. In this case, the contact point information is updated with a delay of one communication cycle with every intervening contact point information collection and distribution device, but since the delay time is known, automatic control taking the delay time into account may be appropriately performed. [0035] In any case, the contact point information collection and distribution device transmits and receives a series of contact point information in a predetermined communication cycle, and thus, the contact point information that is transmitted and received may be updated in synchronization in each predetermined communication cycle. [0036] In this invention, the slave station may include an input unit, connected to a control target, for inputting contact point information obtained from the control target, a contact point information transmitting and receiving unit for transmitting and receiving a series of contact point information in a predetermined cycle by transmitting the contact point information input from the input unit to a communication line and receiving, from a communication line, contact point information from a master station connected to a control unit for controlling the control target, and an output unit for outputting the contact point information to the control target when the contact point information received in the communication cycle is compared with a series of contact point information received in a previous communication cycle and is assumed to be true in a case of matching. [0037] The control unit may obtain the contact point information of the control target by the contact point information input from the input unit being transmitted to the master station side via the contact point information transmitting and receiving unit, and the control target may be operated according to the contact point information from the control unit by the contact point information from the control unit being received via the contact point information transmitting and receiving unit and being output by the output unit to the control target. Also, since the contact point information that is transmitted and received by the contact point information transmitting and receiving unit is updated at every predetermined communication cycle, the control unit may perform synchronization control on the control target, and may control accurate response time, and thus, the reliability of automatic control is improved to that extent. [0038] Furthermore, since the output unit assumes the contact point information to be true when the contact point information received in the communication cycle is compared with a series of contact point information received in a previous communication cycle and is found to match, correct contact point information is output to the control target after the accuracy of the received contact point information is confirmed, and thus, operation failure due to communication failure may be prevented. [0039] The contact point information transmitting and receiving unit is any of serial communication ports including the serial bus interface such as SPI or I2C, the isochronous serial interface, and UART compliant with the RS-232C standard, and a serial communication port that performs communication by the token passing method. [0040] As described above, according to the present invention, the control target may be controlled while being synchronized with the same cycle as the communication cycle, and thus, unnecessary arithmetic processing is not performed. That is, increase in the power consumption due to unnecessary arithmetic processing is prevented, and the arithmetic processing load on the control unit may be reduced. [0041] Also, since the delay time of the contact point information transmitted and received between the control target and the control unit is known by the synchronization control, temporally accurate control may be performed to improve the reliability of the control. [0042] In addition, even if contact point information is altered due to occurrence of a communication error or the like, this contact point information may be reliably removed, and the reliability is improved to that extent. BRIEF DESCRIPTION OF THE DRAWINGS [0043] FIG. 1 is a diagram showing an entire structure of an automatic control system, a contact point information collection and distribution device, and a slave station of the automatic control system of a first embodiment of the present invention; [0044] FIG. 2 is a diagram showing a connection state of main units of the automatic control system shown in FIG. 1 ; [0045] FIG. 3 is a diagram showing an example of communication by the automatic control system; [0046] FIG. 4 is a diagram showing an entire structure of an automatic control system of a second embodiment; [0047] FIG. 5 is a diagram showing an example of a connection state of main units of the automatic control system shown in FIG. 4 ; [0048] FIG. 6 is a diagram showing an example of communication by the automatic control system; and [0049] FIG. 7 is a diagram showing an example of a conventional automatic control system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0050] Hereinafter, an automatic control system, a contact point information collection and distribution device, and a slave station of the automatic control system of a first embodiment of the present invention will be described with reference to FIGS. 1 to 3 . FIG. 1 shows an entire structure of an automatic control system 1 of a vehicle of the present invention, FIG. 2 shows a connection state, and FIG. 3 is a diagram for describing an operation of the automatic control system. [0051] The automatic control system 1 shown in FIG. 1 is for performing vehicle window opening/closing control, for example, and the reference numeral 2 denotes a control target. Also, the control target 2 at least includes a motor 2 a, a rotary encoder 2 b provided to the motor 2 a, and a switch 2 c for performing window operation input and the like. [0052] The reference numeral 3 denotes a slave station connected to the control target 2 , the reference numeral 4 denotes a control unit for controlling the control target 2 , the reference numeral 5 denotes a master station connected to the control unit 4 (in the present embodiment, it is configured from a one-chip microcomputer in which the control unit 4 is embedded as an arithmetic processing unit and which is connected therein), the reference numeral 6 denotes a contact point information collection and distribution device, the reference numeral 7 denotes a communication line connecting the contact point information collection and distribution device 6 and the master station 5 by SPI, the reference numeral 8 denotes a communication line connecting the contact point information collection and distribution device 6 and the slave station 3 by performing communication according to the token passing method by voltage superimposition communication (PLC) (in the present embodiment, this is a power line, but is referred to as the communication line 8 in the following description), and the reference numeral 9 denotes a control unit (hereinafter “ECU”) of the automatic control system 1 including the master station 5 and the contact point information collection and distribution device 6 . [0053] The slave station 3 includes a contact point information transmitting and receiving unit 10 , connected to the communication line 8 , for performing transmission and reception of contact point information by performing communication according to the token passing method by PLC, an output unit 11 for outputting contact point information received via the contact point information transmitting and receiving unit 10 to the control target 2 , and an input unit 12 for inputting contact point information obtained from the control target 2 so as to enable transmission thereof via the contact point information transmitting and receiving unit 10 . Also, the output unit 11 includes a first buffer 11 a for storing a series of contact point information received via the contact point information transmitting and receiving unit 10 , a second buffer 11 b for storing the contact point information when the contact point information received from the contact point information transmitting and receiving unit 10 is compared with previous contact point information stored in the first buffer 11 a and is found to match, and an output port 11 c configured from a drive circuit for amplifying, and outputting to the motor 2 a, the contact point information stored in the second buffer 11 b. On the other hand, the input unit 12 includes an input port 12 a for inputting contact point information from the control targets 2 b and 2 c, and an input buffer 12 b for storing the contact point information input via the input port 12 a. [0054] In the present embodiment, an example is shown where two buffers 11 a and 11 b are provided to the output unit 11 as hardware, and contact point information that is received is compared with a series of contact point information received in the previous communication cycle and is output when it is assumed to be true in the case of matching, but the buffers 11 a and 11 b may of course be provided to the contact point information transmitting and receiving unit 10 . Additionally, in the present embodiment, only the structure of the slave station 3 provided on the driver's seat side of a vehicle is described in detail, but the contact point information transmitting and receiving unit 10 , the output unit 11 , the input unit 12 and the control target 2 are also provided, although not shown, to the slave stations 3 for the passenger seat and the back seat. [0055] Furthermore, the one-chip microcomputer configuring the master station 5 includes a contact point information transmitting and receiving unit 13 for performing bidirectional serial communication by SPI, a transmission buffer 14 for recording contact point information that is to be transmitted via the contact point information transmitting and receiving unit 13 , a first buffer 15 for storing a series of contact point information that is received via the contact point information transmitting and receiving unit 13 , and a second buffer 16 for updating and storing the contact point information when the contact point information received in the current communication cycle is compared with a series of previous contact point information stored in the first buffer 15 and is assumed to be true in the case of matching. [0056] Moreover, in the present embodiment, the main unit of the master station 5 is the contact point information transmitting and receiving unit 13 , and this contact point information transmitting and receiving unit 13 is connected to the control unit 4 via the buffers 14 to 16 . Accordingly, the control unit 4 is connected to the master station 5 while being formed inside the one-chip microcomputer configuring the master station 5 . Also, the buffers 14 to 16 are all memories that can be accessed by the arithmetic processing unit of the one-chip microcomputer, and are storage areas managed by programs that can be executed by the control unit 4 , and these buffers 14 to 16 may be configured from registers in the control unit 4 , or may be configured by hardware such as memory elements. [0057] The contact point information collection and distribution device 6 includes contact point information transmitting and receiving units 17 and 18 that are connected to the communication lines 7 and 8 , respectively and transmit and receive a series of contact point information in a predetermined communication cycle, a relay buffer 18 , configured from a dual port memory or the like, for storing the contact point information which has been transmitted and received, and a communication cycle adjustment unit 20 for synchronizing the communication cycle of each of the communication lines 7 and 8 with control by the control unit. Additionally, in the present embodiment, the contact point information transmitting and receiving unit 17 performs bidirectional communication by SPI via the communication line 7 , and the contact point information transmitting and receiving unit 18 performs communication according to the token passing method by PLC via the communication line 8 . The relay buffer 19 includes separate areas for storing the contact point information from the master station 5 and the contact point information from the slave station 3 , and the sizes of the areas are preferably settable according to the contents of the series of contact point information to be handled so as to increase the versatility. [0058] As shown in FIG. 2 , to perform bidirectional serial communication by SPI at the connection portion of the master station 5 and the contact point information collection and distribution device 6 , the communication line 7 includes an operation clock signal SCLK, a transfer permission signal PLCEN for permitting voltage superimposition on the communication line 8 , a transfer start timing signal SS of the contact point information collection and distribution device 6 and a transfer completion signal DATAEN indicating completion of transmission and reception of a series of contact point information by the master station 5 that are output from the side of the master station 5 , and an operation enabled signal WREQ indicating an operation enabled state and a transfer preparation completion signal RDY that are output from the side of the contact point information collection and distribution device 6 , and SPI bus lines MOSI and MISO for transmitting and receiving bidirectional serial data in the form of a bit stream. [0059] In the following, a method of maintaining synchrony of pieces of contact point information transmitted and received among the master station 5 , the contact point information collection and distribution device 6 , and the slave station 3 will be described with reference to FIG. 3 . [0060] When the master station 5 outputs a transfer permission signal PLCEN indicating permission of data transfer by PLC using the communication line 8 to the contact point information collection and distribution device 6 at time t 0 , the communication cycle adjustment unit 20 of the contact point information collection and distribution device 6 outputs an operation enabled signal WREQ to the master station 5 and, at the same time, causes the contact point information transmitting and receiving unit 18 to start issuing of a token signal by PLC to thereby collect contact point information of each slave station 3 , and to receive the contact point information input to the input unit of each slave station 3 by PLC, and causes the buffer 19 to store the latest contact point information collected from each slave station 3 . At this time, the latest contact point information that is input may be made stable by providing the buffer 12 b to the input unit 12 . Then, at time t 1 , a transfer preparation completion signal RDY is output. [0061] Next, the master station 5 checks that the transfer preparation completion signal RDY is output, and outputs a transfer start timing signal SS to the contact point information collection and distribution device 6 and, at the same time, performs bidirectional serial communication by SPI with the contact point information collection and distribution device 6 to thereby perform transmission and reception of a series of contact point information in a bidirectional manner. At this time, a series of contact point information from each slave station 3 received by the contact point information transmitting and receiving unit 13 is compared with the previous contact point information recorded in the first buffer 15 and only the contact point information that matches is written to the second buffer 16 , and thus, information in which an error is included due to an external disturbance such as a noise does not enter the second buffer 16 . On the other hand, since the contact point information to be distributed by the master station 5 to each slave station 3 is also transmitted via the buffer 14 , the latest contact point information may be made stable. Then, the master station 5 outputs a transfer completion signal DATAEN at time t 2 when transmission and reception of all of a series of contact point information to be collected and distributed has been completed. [0062] The communication cycle adjustment unit 20 of the contact point information collection and distribution device 6 checks that the latest contact point information from the master station 5 is recorded in the relay buffer 19 by checking that the transfer completion signal DATAEN is output from the master station 5 , and causes the contact point information transmitting and receiving unit 18 to start issuing of a token signal by PLC to transmit a series of contact point information received from the master station 5 to the slave station 3 by PLC. [0063] Furthermore, from time t 3 when the latest contact point information from the master station 5 is distributed to each slave station 3 by using the contact point information transmitting and receiving unit 18 , the communication cycle adjustment unit 20 causes the contact point information of each slave station 3 to be collected, receives the contact point information input to the input unit of each slave station 3 by PLC, and causes the latest contact point information collected to be stored in the buffer 19 . Then, at time t 4 , a transfer preparation completion signal RDY is output to the side of the master station 5 . Then, exchange of signals from time t 1 to time t 4 is repeated, and collection and distribution of a series of contact point information may be performed in one communication cycle T with all the units on the automatic control system 1 being in synchronization with the transfer preparation completion signal RDY. [0064] Also, the control unit 4 of the master station 5 may execute automatic control programs such as a sequence program according to the communication cycle T, and may perform automatic control according to the state of each control target 2 . Since the communication lines 7 and 8 both perform transmission and reception of a series of contact point information in a predetermined communication cycle, the communication cycle T may reliably be made to have a constant length and the automatic control by the control unit 4 may be completely synchronized with this communication cycle T. [0065] Accordingly, even in the case of performing communication according to a plurality of protocols and over a plurality of communication lines 7 and 8 , since the contact point information of the control target 2 is input to the control unit 4 being delayed by multiples of the known communication cycle T and the contact point information output from the control unit 4 is output to each control target 2 being delayed by multiples of the known communication cycle T, the control unit 4 may accurately control the control target 2 while taking these delay times into account. [0066] The control unit 4 performs automatic control by performing collection and distribution of the contact point information in the communication cycle T that is generally slower than the operation speed of the control unit 4 , and thus, a high-speed operation is not necessary, and execution by an inexpensive one-chip microcomputer is enabled. Also, since the control unit 4 performs automatic control that is synchronous with the communication cycle T, other types of signal processing may be performed using the time when the automatic control processing is not performed. [0067] FIG. 4 is a diagram showing a structure of an automatic control system 21 of a second embodiment, FIG. 5 is a diagram showing a connection state of main units, and FIG. 6 is a diagram showing an example of communication. In FIGS. 4 to 6 , portions denoted with the same reference numerals as in FIGS. 1 to 3 are the same or equivalent portions, and detailed description thereof is omitted. [0068] In FIG. 4 , the reference numerals 22 and 23 denote upper and lower contact point information collection and distribution devices, and the reference numeral 24 denotes a communication line connecting the upper and lower contact point information collection and distribution devices 22 and 23 . In the present embodiment, serial communication by a plurality of communication lines 7 , 24 and 8 is performed in three hierarchical stages, and in the intermediate stage where the communication line 24 is used, serial communication by I2C is performed, for example. Thus, a plurality of contact point information collection and distribution devices 23 may be provided, and the amount of data of the contact point information handled by the lower contact point information collection and distribution device 23 may thereby be reduced, but this is omitted in the drawing for the sake of simplicity of the description. [0069] As shown in FIG. 5 , the communication line 7 connecting the master station 4 and the upper contact point information collection and distribution device 22 includes an operation clock signal SCLK, a transfer permission signal PLCEN, a transfer start timing signal SS of the contact point information collection and distribution device 22 , and a transfer completion signal DATAEN 1 , and an operation enabled signal WREQ 1 indicating an operation enabled state and a transfer preparation completion signal RDY 1 that are output from the side of the contact point information collection and distribution device 22 , and SPI bus lines MOSI and MISO for transmitting and receiving bidirectional serial data. [0070] On the other hand, the communication line 24 connecting the upper and lower contact point information collection and distribution devices 22 and 23 includes an operation clock signal SCLK, a transfer permission signal PLCEN, and a transfer completion signal DATAEN 2 indicating completion of transfer of a series of contact point information to be transferred from the contact point information collection and distribution device 22 to the contact point information collection and distribution device 23 , and an operation enabled signal WREQ 2 indicating an operation enabled state and a transfer preparation completion signal RDY 2 indicating completion of preparation of contact point information that is to be transmitted from the contact point information collection and distribution device 23 to the contact point information collection and distribution device 22 that are output from the contact point information collection and distribution device 23 , and an I2C bus line SDA for transmitting and receiving bidirectional serial data. [0071] In the following, an operation of the second embodiment will be described with reference to FIG. 6 . When the master station 5 outputs, at time t 5 , a transfer permission signal PLCEN to the contact point information collection and distribution devices 22 and 23 , the contact point information collection and distribution devices 22 and 23 output operation enabled signals WREQ 1 and WREQ 2 , and at the same time, the contact point information collection and distribution device 23 performs collection of the contact point information of each slave station 3 by performing communication by PLC using the communication line 8 , and then, outputs a transfer preparation completion signal RDY 2 at time t 6 . The upper contact point information collection and distribution device 22 checks the transfer preparation completion signal RDY 2 , performs collection of the contact point information from the contact point information collection and distribution device 23 by performing communication by I2C using the communication line 24 , and outputs a transfer preparation completion signal RDY 1 at time t 7 . [0072] Next, the master station 5 checks that the transfer preparation completion signal RDY 1 is output, and performs bidirectional transmission and reception of a series of contact point information by performing bidirectional serial communication by SPI with the upper contact point information collection and distribution device 22 . Then, the master station 5 outputs a transfer completion signal DATAEN 1 at time t 8 when transmission and reception of all of a series of contact point information that is to be collected and distributed has been completed. [0073] Also, the upper contact point information collection and distribution device 22 checks that reception of the latest contact point information from the master station 5 has been completed by checking that the transfer completion signal DATAEN 1 is output by the master station 5 , transmits a series of contact point information from the master station 5 to the lower contact point information collection and distribution device 23 by performing communication by I2C using the communication line 24 , and at time t 9 when all of a series of contact point information from the master station 5 has been transferred, outputs a transfer completion signal DATAEN 2 to the contact point information collection and distribution device 23 . [0074] Furthermore, the lower contact point information collection and distribution device 23 distributes the latest contact point information from the master station 5 to each slave station 3 by using the communication line 8 from time t 9 when output of the transfer completion signal DATAEN 1 from the contact point information collection and distribution device 22 is confirmed, performs collection of the contact point information of each slave station 3 and receives the contact point information input to the input unit of each slave station 3 by PLC from time t 10 when the process mentioned above is completed, and outputs a transfer preparation completion signal RDY 2 at time t 11 . Then, exchange of signals from time t 6 to time t 11 is repeated, and collection and distribution of a series of contact point information may be performed in one communication cycle T′ with all the units on the automatic control system 21 being in synchronization with the transfer preparation completion signals RDY 1 and 2 . [0075] As in the present embodiment, by performing collection and distribution of the contact point information in several hierarchical stages by using a plurality of communication lines 8 and 24 , even in the case a series of contact point information with a large amount of data is to be collected and distributed, since the amount of data of the contact point information to be collected and distributed by using the lower communication line 8 may be divided and reduced, the communication cycle T′ may be made shorter as a result of reducing the amount of data of the contact point information that is to be handled, even if the communication speed of the communication line 8 is relatively low. [0076] Even when the structure of the communication lines 7 , 8 and 24 configuring the automatic control system 21 is complicated as in the present embodiment, error check may be performed at once at the stations on both ends (the master station 5 and the slave station 3 ) by double collation, and an error due to communication failure may be reliably removed, and simple and highly reliable collection and distribution of the contact point information across a plurality of communication lines may be performed.

An automatic control system synchronizes and controls a control target while preventing unnecessary signal processing. The system includes a slave station that is connected to the control target, a master station that is connected to a control unit for controlling the control target, a contact point information collection and distribution device that collects and distributes a series of contact point information communicated at a predetermined communication cycle, and communication lines connecting between the master and slave stations via the contact point information collection and distribution device. The contact point information collection and distribution device collects and distributes the series of contact point information in synchronization with all the communication lines under the control of the control unit. The control unit compares the collected contact point information with past contact point information and assumes as true in a case of matching, and controls by true contact point information.

RELATED APPLICATIONS The present application claims priority to Japanese Patent Application Serial No. 2011-141259, filed Jun. 24, 2011, and having an international PCT Application Serial No. JP2012-060139 and international tiling date of Apr. 13, 2012, which are herein incorporated by reference. The present invention relates to data storage, and more specifically, the present invention relates to a linear recording tape storage device which executes optimum writing upon receipt of a series of commands including mixed read and write commands (Read and Write), and to a method and a program for executing the same. BACKGROUND A tape recording device (a tape drive) is a sequential access device. Drive operations include mount/load and unmount/unload of a tape cartridge. Tape operations include operations on a tape medium which are position movement (a Position command), writing (a Write command), reading (a Read command) and synchronization (a Sync command: Synchronize). Data to be written in the tape includes user data and a file marker (FM) representing a user data delimiter. A write operation is performed either in a write-append method in which data is written in the tape from a position past the end of data after the tape is moved, or in an overwriting method in which old data is overwritten with new data. Normally, the tape drive is able to perform read and write operations in a mixed manner, and these operations involve a moving operation and a synchronization operation (flush). The synchronization and moving operations cause the tape to move in a longitudinal direction thereof, thereby lowering the Read and Write performance of the tape drive. Note that the synchronization operation is an operation of ensuring that data temporarily stored in a buffer is written in a tape medium. A hierarchical storage management (HSM) system allows the mixed read and write operations to be performed on tape drives. The tape drive is also included in a tape library which is at a lower layer of the HSM system. A single tape drive, however, is not required to perform read and write operations in a mixed manner in order to prevent the lowering of the overall performance of the entire read and write processing. Instead, the single tape drive performs either the write operation or the read operation for each mount of a tape cartridge. Alternatively, a plurality of tape drives may each be used for either of write and read operations. These techniques require more tape drives, increase time-consuming (effort-taking) mount operations, and thus lower the processing performance. There are some environments in which a tape cartridge is used exclusively for a read or write operation. Large-scaled scientific and technical calculations, in particular, cannot achieve higher performance, if a single tape cartridge is used for both mixed read and write operations. This also holds true for a hierarchical storage system which includes general tape storage devices. Japanese Patent Application No. 2009-294309 provides a mechanism for causing a tape drive to perform read/write operations in a mixed manner in a single cartridge. Here, the writing method is an append writing method (Append Write). In the append writing method, the end of data (EOD) of write data in a tape is sequentially brought back by using a sequential moving method of the tape drive. The writing method of a tape drive, however, includes Over Write in addition to the append write. The Over Write command is used to overwrite data (for example, a data set) having been written on a tape with new data by using the append write. Accordingly, it is necessary to consider a case where the Over Write is received in mixed read/write operations in a single tape drive and tape cartridge. BRIEF SUMMARY According to one embodiment, a tape recording device includes a buffer configured for storing data related to reading and writing, a read/write head for reading data from a tape into the buffer and writing data from the buffer onto the tape, the tape being provided in a tape cartridge, a non-volatile memory configured for storing data stored in the buffer in response to a write command, and a controller configured for: receiving a series of commands from a higher-level device (each command moving to a tape position specified by a moving command), the series of commands including mixed read, overwrite, and append write commands, wherein the read commands include first, second, . . . , m-th, n-th . . . , read commands in this order, and wherein n=m+1, reading data from a specified position of the tape and storing data in the buffer in response to a read command, and writing data stored in the buffer from an appended data end position of the tape (EOD) in response to an append write command. According to another embodiment, an append writing method for writing into a tape recording device includes receiving a series of commands from a higher-level device (each command moving a tape to a tape position specified by a moving command), the series of commands including mixed read, overwrite, and append write commands, wherein the read commands include first, second, . . . , m-th, n-th . . . , read commands in this order, and wherein n=m+1, reading data from a specified position of the tape using a read/write head and storing data in a buffer in response to a read command, and writing data stored in the buffer from an appended data end position of the tape (EOD) in response to an append write command. In yet another embodiment, a computer program for writing into a tape recording device causes a computer to perform the steps of: (a) upon receipt of an append write command, storing data stored in the buffer in an appended data end position in a non-volatile memory (EOD in the non-volatile memory), (b) sending back a completion notification of the append write command to a higher-level device when data in the buffer is written in the non-volatile memory, (c) moving the data temporarily stored in the non-volatile memory and then moving to a tape writing position (EOD) where the data temporarily stored in the non-volatile memory is to be written to perform append writing on a basis of a predetermined criterion so as to minimize a moving distance by which a tape travels relative to a head, when moving from an end position on the tape of read data for a m-th read command to a reading start position for a subsequent n-th read command, wherein n=m+1, and (d) when receiving an overwrite command of data in a predetermined position on the tape between mixed commands in a series of commands, updating an overwrite data end position as an appended data end position (EOD) when the tape position for overwriting the data is encountered earlier than an appended data end position of the tape (EOD), and updating the overwrite data end position as an appended data end position in the non-volatile memory (EOD in the non-volatile memory) when the tape position for overwriting the data is encountered later than the appended data end position of the tape (EOD). Other aspects and embodiments of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention. It is preferable to provide a (linear recording) tape storage device having an optimum method of writing upon receipt of overwrite in the midst of performing read/write operations in a mixed manner, and a method and a program for executing the same. In one general embodiment, a tape recording device which performs operations of position movement, reading, and writing on a tape medium back and forth in a longitudinal direction of the tape medium and which receives a series of commands from a higher-level device is presented. The series of commands includes mixed read (Read), overwrite, and append write (Write) commands and the plurality of read commands includes first, second, . . . m-th, n-th . . . (m, n=m+1) read commands in this order. The tape recording device includes: a buffer for storing data related to the reading and writing; a tape for recording the data stored in the buffer; a read/write head for reading the data from the tape into the buffer and writing the data from the buffer onto the tape, a controller configured for reading data from the specified position of the tape and storing the data in the buffer in response to a read command and for writing the data stored in the buffer from an appended data end position for data writing of the tape, e.g., end of data (EOD), in response to an append write command; and a non-volatile memory for storing the data stored in the buffer in response to a write command. Furthermore, in this embodiment, the controller may be configured to: (a) upon receipt of the append write command, store the data stored in the buffer from an appended data end position in the non-volatile memory (EOD in the non-volatile memory); (b) send back a completion notification of the append write command to the higher-level device when the data in the buffer is written in the non-volatile memory; (c) move the data temporarily stored in the non-volatile memory and then moving to a tape writing position (EOD) where the data temporarily stored in the non-volatile memory is to be written to perform writing on the basis of a predetermined criterion so as to minimize a moving distance by which the tape travels relative to the head, when moving from an end position on the tape of read data for the m-th read command to a reading start position for the n-th read command after receipt of the append write command; and (d) when receiving an overwrite command (Over Write) of data in a predetermined position on the tape between the mixed commands in the series of commands, wherein the overwrite command causes the end of written data to be in a data end position (EOD), update the overwrite data position as an appended data end position (EOD) when the tape position for overwriting the data is earlier (a value smaller) than the appended data end position of the tape (EOD), and update the overwrite data position as an appended data end position in the non-volatile memory (EOD in the non-volatile memory) when the tape position for overwriting the data is later (a value greater) than the appended data end position of the tape (EOD). The device is characterized in that the criterion is satisfied when the data end position of the tape (EOD) at which the data is to be written exists within the moving distance (between the end position and the start position) according to one embodiment. The device is further characterized in that the controller stores the updated data end position (EOD) into the non-volatile memory. The device is also characterized in some approaches in that the controller stores the updated data end position (EOD) into the non-volatile memory of the tape cartridge which includes the tape. In another general embodiment, a method for writing into a tape recording device includes the steps of: (a) upon receipt of the append write command, storing the data stored in the buffer in an appended data end position in the non-volatile memory (EOD in the non-volatile memory); (b) sending back a completion notification of the append write (synchronization) command to the higher-level device when the data in the buffer is written in the non-volatile memory; (c) moving the data, temporarily stored in the non-volatile memory and then moving to a tape writing position (EOD) where the data temporarily stored in the non-volatile memory is to be written to perform writing on the basis of a predetermined criterion so as to minimize a moving distance by which the tape travels relative to the head, when moving from an end position on the tape of read data for the m-th read command to a reading start position for the subsequent n-th read command; and (d) when receiving an overwrite (Over Write) command of data in a predetermined position on the tape between the mixed commands in the series of commands wherein the overwrite command causes the end of the written data to be in a data end position (EOD), updating the overwrite data position as an appended data end position (EOD) if the tape position for overwriting the data is earlier (a value smaller) than the appended data end position of the tape (EOD), and updating the overwrite data position as an appended data end position in the non-volatile memory (EOD in the non-volatile memory) if the tape position for overwriting the data is later (a value greater) than the appended data end position of the tape (EOD). In this embodiment, the tape recording device includes a buffer for temporarily storing data related to reading and append writing, a tape for recording the data stored in the buffer, a read/write head for reading the data from the tape into the buffer and writing the data from the buffer onto the tape, and controller for reading data from a specified position of the tape and storing the data in the buffer in response to a read command and for writing the data stored in the buffer from the tape in response to an append write command and which performs operations of position movement, reading, and writing on the tape medium back and forth in a longitudinal direction of the tape medium, when a single tape cartridge having the tape medium is loaded in the tape recording device and the tape recording device receives a series of commands including mixed read (Read), overwrite, and append write (Write) commands from a higher-level device (each moving to a tape position specified by a moving command, i.e., Position) where the plurality of read commands includes first, second, . . . m-th, n-th . . . (m, n=m+1) read commands in this order. In this method, the tape recording device and/or the tape cartridge is provided with a non-volatile memory for storing the data stored in the buffer in response to a write command. In yet another general embodiment, a computer program product for writing into a tape recording device causes a computer to perform the steps of: (a) upon receipt of the append write command, storing the data stored in the buffer in an appended data end position in the non-volatile memory (EOD in the non-volatile memory); (b) sending back a completion notification of the append write (synchronization) command to the higher-level device when the data in the buffer is written in the non-volatile memory; (c) moving the data temporarily stored in the non-volatile memory and then moving to a tape writing position (EOD) where the data temporarily stored in the non-volatile memory is to be written to perform writing on the basis of a predetermined criterion so as to minimize a moving distance by which the tape travels relative to the head, when moving from an end position on the tape of read data for the m-th read command to a reading start position for the subsequent n-th read command; and (d) when receiving an overwrite (Over Write) command of data in a predetermined position on the tape between the mixed commands in the series of commands wherein the overwrite command causes the end of the written data to be in a data end position (EOD), updating the overwrite data position as an appended data end position (EOD) if the tape position for overwriting the data is earlier (a value smaller) than the appended data end position of the tape (EOD), and updating the overwrite data position as an appended data end position in the non-volatile memory (EOD in the non-volatile memory) if the tape position for overwriting the data is later (a value greater) than the appended data end position of the tape (EOD). In this embodiment, the tape recording device includes a buffer for temporarily storing data related to reading and append writing, a tape for recording the data stored in the buffer, a read/write head for reading the data from the tape into the buffer and writing the data from the buffer onto the tape, and controller for reading data from a specified position of the tape and storing the data in the buffer in response to a read command and for writing the data stored in the buffer from the tape in response to an append write command and which performs operations of position movement, reading, and writing on the tape medium back and forth in a longitudinal direction of the tape medium when a single tape cartridge having the tape medium is loaded in the tape recording device and the tape recording device receives a series of commands including mixed read (Read), overwrite, and append write (Write) commands from a higher-level device (each moving to a tape position specified by a moving command, i.e., Position) where the plurality of read commands includes first, second, . . . , m-th, n-th . . . , (m, n=m+1) read commands in this order. Furthermore, in this embodiment of the computer program product, the tape recording device and/or the tape cartridge is provided with a non-volatile memory for storing the data stored in the buffer in response to a write command. According to one embodiment, a tape recording device is able to increase the overall performance of the mixed operations even when a higher-level device intervenes for overwriting in a series of commands including mixed read and append write commands. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration example of a tape library including a tape drive according to one embodiment. FIG. 2 illustrates normal operations of moving, reading, and writing performed on a tape of a tape drive, according to one embodiment. FIG. 3 illustrates an example of conventional mixed read and write operations. FIG. 4 illustrates that omission of a synchronization operation results in reduction in tape moving distance. FIG. 5 illustrates reduction in moving distance resulting from omission of write and synchronization operations in one embodiment. FIG. 6 illustrates a table summarizing a relationship in moving distance increase or decrease between omission of a synchronization operation and a subsequent rewrite operation. FIG. 7 illustrates that a writing position exists in a moving operation, according to one embodiment. FIG. 8 illustrates modes in which data is written in a tape when there is no free space in a non-volatile storage area. FIG. 9 illustrates an operation flow of appended data writing. FIG. 10 illustrates a flow of receiving both of Over Write and append write commands in mixed append write and read operations. FIG. 11 illustrates an operation flow of synchronization. FIG. 12 illustrates an operation flow of moving between two points when a writing position exists therebetween. DETAILED DESCRIPTION Hereinbelow, a description is given of an embodiment (hereinafter, referred to as “example”) of a method of append writing new data when an intervention of overwriting (Over Write) in a linear recording tape drive on which a single tape cartridge is loaded and which has received a series of commands including mixed read and append write (Append Write) commands from a host. This example is illustrative only and is not intended to limit a tape recording device for append writing in any way. It is conceived that a total tape moving distance and duration with respect to a read/write head are reduced in mixed append write and read operations of a tape drive with a single tape cartridge (cartridge) loaded thereon. Accordingly, a summary of the example is given so that the following particular matters are performed. 1. When there arises a need for a synchronization operation (writing in the tape) of data written in a buffer, the data to be flushed is written in a temporary non-volatile storage area. 2. As the temporary storage area, used is an area where no movement in the tape is required or where the total tape moving distance and duration is made less than those for recording in an originally intended area. In addition, writing time is equal to or shorter than normal writing time. 3. The temporarily stored data is rewritten later in the originally intended recording position. Normally, the data is left in the buffer, and rereading from the temporary storage area is not required in the rewriting. 4. The rewrite operation is performed as a moving operation in a subsequent process. 5. If data in the buffer is lost due to accidental powering-off, the data is read from the temporary non-volatile storage area as processing of recovery from an error, and then is written in the originally intended recording position. First, a description is given of a tape drive and a tape library including the tape drive, to which this embodiment is applied. FIG. 1 is a diagram illustrating a configuration example of a tape library 100 including the tape drive, to which this embodiment is applied. As illustrated in FIG. 1 , the tape library 100 includes a tape drive 10 , a library control mechanism 30 , an accessor 40 , and a cartridge slot 50 . Among them, the tape drive 10 includes a host interface (hereinafter, referred to as “host I/F”) 11 , a buffer 12 , a channel 13 , a write head 14 a , a read head 14 b , and a motor 15 , and also includes a controller 16 , a head position control system 17 , and a motor driver 18 . Furthermore, a tape cartridge (hereinafter, simply referred to as “cartridge”) 20 is also illustrated, since the cartridge 20 is loadable in the tape drive 10 by being inserted into the tape drive 10 . The cartridge 20 includes a tape 23 wound around reels 21 and 22 . With the rotation of the reels 21 and 22 , the tape 23 is moved in a longitudinal direction thereof, from the reel 21 to the reel 22 , or from the reel 22 to the reel 21 . A magnetic tape is exemplified as the tape 23 , but a tape medium other than the magnetic tape may be used. The cartridge 20 also includes a cartridge memo 24 . The cartridge memory 24 records information of, for example, how data is written in the tape 23 . The indices of the data written in the tape 23 and a use status of the tape 23 are checked in as non-contact manner by using, for example, an RF interface, thereby enabling high-speed access to the data. In FIG. 1 , an interface, like the RF interface, for accessing the cartridge memory 24 is shown as a cartridge memory interface (hereinafter, referred to as “CMI/F”) 19 . Meanwhile, the host I/F 11 communicates with a host 200 . For example, from the host 200 , the host I/F 11 receives a command for writing data in the tape 23 , a command for moving the tape 23 to a target position, and a command for reading data from the tape 23 . Incidentally, SCSI is exemplified as a communication standard used for the host I/F 11 . In SCSI, a first command corresponds to a Write command, a second command corresponds to a Locate command or a Space command, for a tape moving operation; and a third command corresponds to a Read command. The host I/F 11 responds to the host 200 , whether or not processing in response to a corresponding one of the commands succeeds or fails. Data buffered in the buffer 12 is written in the tape 23 by a synchronization operation (Flush). The synchronization after Write is explicitly specified by a command (such as to Write Filemark command), or implicitly specified by a command (such as a Locate, Space, Rewind, or Unload command for moving, the position). Moreover, depending on an option of the Write command itself, the Write command itself might not be completed until the synchronization is completed. The buffer 12 is a memory in which data to be written into the tape 23 and data read from the tape 23 is accumulated. For example, the buffer 12 comprises Dynamic Random Access Memory (DRAM). Further, the buffer 12 is formed of a plurality of buffer segments, and each buffer segment stores a dataset which is a unit of reading from and writing in the tape 23 . The channel 13 is a communication channel used for transmitting data to be written in the tape 23 to the write head 14 a and for receiving data, which has been read from the tape 23 , from the read head 14 b . When the tape 23 moves in the longitudinal direction, the write head 14 a writes information in the tape 23 , while the read head 14 b reads information from the tape 23 . The motor 15 rotates the reels 21 and 22 . Although the motor 15 is shown by a single rectangle in FIG. 1 , it is preferable to provide one motor 15 for each of the reels 21 and 22 , namely two motors 15 in total. The controller 16 controls the entire tape drive 10 . For example, the controller 16 controls writing or reading data to or from the tape 23 in accordance with a command received by the host I/F 11 . The controller 16 also controls the head position control system 17 and the motor driver 18 . The head position control system 17 is a system which controls the write head 14 a and the read head 14 b to track on a desired wrap. The wrap is a group of a plurality of tracks on the tape 23 . When there arises a need for moving to a different wrap, electrical switching of the write head 14 a or the read head 14 b is also required. Therefore, the head position control system 17 controls such switching. The motor driver 16 drives the motor 15 . When the two motors 15 are provided as described above, two motor drivers 18 should be provided, too. Meanwhile, the library control mechanism 30 is a mechanism which controls the accessor 40 and the tape drive 10 in response to an instruction from the host 200 . Specifically, the library control mechanism 30 instructs the accessor 40 to load the cartridge 20 in the tape drive 10 so that data designated by the host 200 is able to be read or written, and instructs the tape drive 10 to read the data designated by the host 200 from or to write the data onto the cartridge 20 loaded by the accessor 40 . The accessor 40 takes the cartridge 20 out of the cartridge slot 50 to load the cartridge 20 in the tape drive 10 in accordance with the control of the library control mechanism 30 . The cartridge slot 50 is a space for storing a cartridge 20 in which no data is read or written. Here, the cartridge slot 50 is shown by a single rectangle, but, actually, there are provided a plurality of slots for storing a plurality of cartridges, respectively. Note that only one tape drive 10 is shown in FIG. 1 , but a plurality of tape drives 10 may be provided. In the latter case, the library control mechanism 30 notifies the accessor 40 of identification information of one of the tape drives 10 to which a read or write command is to be transmitted, and thereby instructs the accessor 40 to load a cartridge 20 in the tape drive 10 . FIG. 2 illustrates operations of normal position movement of data (Position command), reading (Read command), and append writing (Write command) which are performed in the tape 23 of a tape drive. The tape drive may be a linear recording enterprise tape product (TSxx series by IBM Corp.) or one in compliance with Liner Tape-Open (LTO). First, data reading and writing are performed on a wrap #0 in the right direction as shown by an arrow 201 , and then the travelling direction of the tape 23 is reversed as shown by an arrow 202 . Subsequently, data reading and writing are performed on a wrap #1 in the left direction, and then the travelling direction of the tape 23 is reversed as shown by an arrow 203 . Furthermore, data reading and writing are performed on a wrap #2 in the right direction, and then the travelling direction of the tape 23 is reversed as shown by an arrow 204 . In the last step, data reading and writing are performed on a wrap #55 in the left direction as shown by an arrow 205 . As described above, in the linear recording tape drive, the data reading and writing are performed in data storage areas called wraps defined in the tape 23 , while the read/write head reciprocates between the beginning of the tape 23 (BOT) and the end of the tape (EOT). The wrap is a set of a plurality of tracks arranged in parallel with each other and spaced away from each other in a width direction of a tape. Each of the write head 14 a and the read head 14 b may include a plurality of channels (eight or 16 read/write elements). The write head 14 a and the read head 14 b enable the operations of moving, reading, and writing to be performed on the plurality of tracks in parallel in the same wrap. In the case of serial reading/writing, the read/write head reciprocates in the wraps. Note that the beginning of the tape 23 is an example of a first end portion and the end of the tape 23 is an example of a second end portion. Meanwhile, through a HSM system, the tape library 100 located in the lowest layer receives a series of commands for mixed read/write operations from the host 200 . The following provides an example of enhancing the performance in operation processing of the entire series of commands in the case where a single tape drive receives such a series of commands for the mixed read/write operations. In this embodiment, the total tape moving distance and duration is reduced when a tape drive performs mixed operations of append writing and reading on a single tape cartridge loaded in the tape drive. Before describing the example, a description is given allow much a synchronization operation increases a moving distance in the mixed read/write operations. Then, an example is provided in which enhancement of the overall performance is exerted by substantially omitting the moving distance involved with the synchronization operation. First, as a premise of description of the example, an example below should be understood in which conventional mixed read and write operations involve an unnecessary moving distance. FIG. 3 illustrates the example of the conventional mixed read/write operations. A description is given of an example of receiving a series of commands including mixed Read and Write commands when a tape is traveled linearly relative to tracks such as from right to left or left to right. As shown in the following series of commands (1) to (9), movement is performed after a write (append write) operation (Write) to perform a read operation (Read), and further, a write operation (Write) is performed: (1) Write data9→(2) Write FM9 w/Sync (Synchronization [Flush] is performed simultaneously with writing FileMarker9)→(3) Position tape to position C (a command for moving to a position C)→(4) Read data3→(5) Position tape to position B→(6) Write data 10→(7) Write FM10 w/Sync→(8) Position tape to position F→(9) Read data7 Operations of the tape drive are performed as described below. User data is represented by data1 to data10 and FileMarkers (FM) as the delimiters of data are represented by FM1 to FM10. 1. At position A, data9 is buffered in a buffer ((1)). 2. After data9 is written from the buffer as a synchronization operation, FM9 is written ((2)). The writing of data9 and FM9 results in movement from position A to position B. 3. The tape moves from position B to position C ((3)). 4. Data3 is read ((4)). The reading of data3 results in movement of the tape from position C to position D. 5. The tape moves from position D to position B ((5)). 6. Data10 is buffered in the buffer ((6)). 7. After data10 is written as a synchronization operation, FM10 is written ((7)). The tape moves from position B to position E. 8. The tape moves from position E to position F ((8)). 9. Data7 is read. The tape moves from position F position G ((9)). As shown in FIG. 3 (in a lower part of FIG. 3 ) the total tape length is schematically shown, and the above series of operations results in a moving distance of the tape as indicated by the positions A→B→C→D→B→E→F→G. A synchronization operation (for example, Flush by a Sync command) and a moving operation (the Position command) always occur between a write operation and a read operation, in one approach. The mixed operations involve a long tape moving distance. The mixed operations in this case result in an increase by an overlapping section (B→E) resulting from the synchronization operation and subsequent halfway moving to the target position F. Specifically, in the conventional operations, there arises a problem that the moving operation requires a duration increased by this increase amount. Therefore, a study has been made on whether the synchronization operation and the subsequent overlapping section can be omitted. FIG. 4 shows that omission of a synchronization operation enables reduction in a tape moving distance. By omitting the writing into a tape medium in response to a synchronization command in the same series of commands ((1) to (9)) from the conventional operations ( FIG. 3 ), the moving distance is able to be reduced. The following is the operations of the tape drive in accordance with the same series of commands as in the previous page, in accordance with FIG. 4 : 1. At position A, data9 is buffered in a buffer ((1)). 2. After data9 is written from the buffer as a synchronization operation, FM9 is written ((2)). The tape moves from position A to position B. 3. The tape moves from position B to position C ((3)). 4. Data3 is read ((4)). The tape moves from position C to position D. 5. Moving the tape from position D to position B ((5)) is omitted. 6. Data10 is buffered in the buffer ((6)). 7. A synchronization operation on data10 and FM10 ((7)) is omitted, and data10 is maintained buffered in the buffer ((6)). 8. The tape moves from position D to position F ((8)). 9. Data7 is read ((9)). The tape moves from position F to position G. The moving distance is represented by the positions A→B→C→D→F→G. The aforementioned example including the synchronization operations has three moving operations (D→B→E→F), while this example has only one moving operation for moving the tape from position D to position F, thereby reducing the moving distance. Specifically, the moving distance is reduced in the following three operations as compared to the case shown in FIG. 3 . Moving operation from position D to position B in accordance with the fifth command; A synchronized write operation of data10 and FM10 involving movement of the tape from position B to position E, in accordance with the seventh command; and A moving operation from position E in position F in accordance with the eighth command. At the time that a completion notification is sent in response to the synchronization command, however, it is necessary that data is properly written in the medium and future access is ensured. The synchronization operation is substantially ensured for the host in one approach. In addition, the following example discloses a write-once method which suppresses an increase in a moving distance of a series of commands including mixed Read and Write commands by placing Writes strategically. The following configuration is discussed in accordance with one embodiment in order to ensure a synchronization operation for the host with respect to data stored in the buffer: 1. A tape cartridge or a tape drive is provided with a new temporary non-volatile storage area. The provision of the non-volatile storage area gives the tape cartridge or the tape drive an access characteristic that reduces the synchronization operation. Examples of the non-volatile storage area include a non-volatile memory such as a flash memory attached to the cartridge and/or the drive, a special storage area in a tape medium, and the like. 2. In the tape drive, appended data is temporarily stored in the non-volatile storage area to delay an append write operation in the tape to the originally intended end of write data, such as physical end of data (EOD) on the tape. Separately, at a convenient time, a rewrite operation is started at the originally intended end of data (EOD) on the tape. (1) The non-volatile storage area is used to ensure that data may always be read from the tape cartridge (or the tape drive) alter sending back a completion notification of processing in response to a synchronization request from the host. (2) The non-volatile storage area is hidden from the host. Specifically, when a read operation occurs after a write operation, data is read from the non-volatile storage area as if the data were written at the originally intended position. By being provided with a new non-volatile storage area, the tape drive receives a series of commands including mixed Read and Write transmitted from the host. Generally, Read is often performed after a reading position is specified. Similarly, Write for append writing is performed after a writing position is designated as the EOD. The reading position and the writing position, however, often are not related to each other. If a write operation (substantial synchronization operation) at a target position (physical EOD) on the tape can be executed in the course of moving between read operations, as append writing, an unnecessary tape moving distance is able to be reduced. If a writing position (physical EOD) on the tape for writing data stored in the non-volatile storage area exists between any two of a plurality of moving positions for subsequent Read operations, the writing in the tape during the moving increases the overall performance of the series of commands. 1. In the example, in accordance with a synchronization operation subsequent to an append write command (Write), data stored in the buffer is stored in a non-volatile storage area. 2. It is necessary to perform an operation in which the data temporarily stored in the non-volatile storage area is written at an originally intended position on a tape (end of data (EOD)). A moving distance in the rewrite operation has a converse relation with a moving distance in the writing and synchronization operations. This means that a distance reduced by the omission of the synchronization operation is equal to a moving distance increased by the rewrite operation. Data is rewritten in a case where the moving distance or duration can be made less than those in the conventional operations. For example, if a position (EOD) to be rewritten (to be append written) is to be passed through during moving operations for a plurality of Read commands, data is able to be rewritten without moving exclusively for the rewritten operation. In order to ensure data storing for the synchronization operation, it is useful to prevent a state in which there is no free space in the temporary storage area in one approach. When a synchronization command is received, a free space (unused ratio) in the non-volatile storage area might be reduced, depending on a moving distance for rewriting and temporarily stored data volume. When the non-volatile storage area is completely full, data in the non-volatile storage area is unconditionally rewritten from the EOD of the tape. After the rewrite operation, a normal write operation is subsequently performed on the tape. In addition, when the Rewind command or the Unload command for the cartridge is received, the rewrite operation is performed unconditionally, because Rewind and Unload mean that the tape cartridge is used up. FIG. 5 illustrates a moving distance at the time of an append rewrite operation which a substantial synchronization operation is ensured by using the non-volatile storage area. FIG. 5 illustrates increase and decrease of the moving distance caused by omission of the synchronization operation and the rewrite operation in the example. A distance in the longitudinal direction of the tape is considered. Rewriting is assumed to be performed during moving from the current position A to a moving target position B (C, D, E). Relationships among a rewriting start position X, a completion position Y, and the moving target position B (C, D, E) viewed from the current position A are classified. 1. The moving target position B is located in the same direction as the rewriting start position X and the completion position Y, and is farther from the current position A than the rewriting start position X and the completion position Y. 2. The moving target position C is located in the same direction as the rewriting start position X and the completion position Y, and is located between the rewriting start position X and the completion position Y. 3. The moving target position D is located in the same direction as the rewriting start position X and the completion position Y, and is closer to the current position A than the rewriting start position X and the completion position Y. 4. The moving target position E is located, in an opposite direction to the rewriting start position X and the completion position Y with respect to the current position A. In addition, a difference in the writing direction affects the moving direction from the position A to B (to C, D, E). There are two writing directions: the same writing direction (an upper figure of FIG. 5 ) as the moving direction; and an opposite writing direction (a lower figure of FIG. 5 ) to the moving direction. The following describes relationships, in the above directions, between a distance as a result of the moving operation from the position A→B (C, D, E) and a moving distance from the position A→X→Y→B (C, D, E) as a result of addition of the rewrite operation. 1. In the case of the same direction, the moving distance as a result of the rewriting does not increase (1-a). In the case of the opposite direction, the movement of the position A→B is the same as the movement of the position A→X→B, and therefore the moving distance increases by a distance of a reciprocation between the positions X and Y (1-b). 2. In the case of the same direction, the distance increases by a difference between the movement of the position X→Y→C and the movement of the position X→C (2-a). In the case of the opposite direction, the movement of the position A→C is the same as the movement of the position A→Y→C, and therefore the moving distance increases by a distance of a reciprocation between the positions Y and X (2-b). 3. In the case of the same direction, the movement of the position A→X is the same as the movement of the position A→D→X, and therefore the distance increases by a distance of a movement of the position D→X→D (3-a), in the case of the opposite direction, the movement of the position A→X is the same as the movement of the position A→D→Y→X, and therefore the moving distance increases by a distance of a movement of the position D→Y→X→V→D (3-b). 4. In each of the directions, the distance increases by a distance of a movement of the position A→X→Y→A (4-a, 4-b). By omitting the write and synchronization operations, the moving distance is made equal or reduced regardless oldie moving, target position after rewriting. The moving distance can be reduced in the rewrite operation when the moving distance has the converse relation with the moving distance in the synchronization operation. FIG. 6 illustrates a table summarizing a relationship in moving distance increase or decrease between omission of the synchronization operation and the subsequent rewrite operation (the cases 1-a to 4-b FIG. 5 ). 1. It was found that the moving distance reduced due to the omission of the synchronization operation on the tape medium has the converse relation with the moving distance as a result of the rewrite operation, as described with reference to FIG. 5 . 2. When the ratio of the omission of the synchronization operation to occurrence of the rewrite operation is 1:1, no change occurs in the total moving distance. In one embodiment, any data stored in the buffer is stored in a non-volatile storage area (non-volatile memory) in the synchronization operation. By storing data in the non-volatile memory, a rewrite operation involving tape movement can be omitted. Then, when the movement for the rewrite operation can be omitted, the total moving distance can be reduced. The case 1-a is a case where the moving distance for the rewrite operation can be fully omitted. In the case 1-a, the rewriting position (physical EOD) on the tape is located within the moving distance between two Read commands (movement from the data end position for first Read for reading the tape to the data beginning position for second Read for reading the tape). In the case 1-a, the data stored in the non-volatile memory by the synchronization operation is rewritten in the tape in the course of the subsequent movement. 3. When a plurality of synchronization operations are omitted and a rewrite operation for data stored in the non-volatile memory can be executed in the course of movement for a plurality of subsequent Read operations, the total moving distance of the series of commands including mixed Read/Write commands is always reduced In one embodiment, rewriting processing in the moving operation may be determined as follows: —Moving Pattern: Case 1-a Before starting the moving operation, the execution of the rewrite operation is determined. When the moving pattern is as in the case 1-a, there is no increase in moving distance for the rewrite operation. That is, the increase in moving distance is zero. Thus, the rewrite operation is always performed in movement for the subsequent Read operation. Referring to FIG. 5 , this is the case where the tape writing position (X→Y) is located between two tape positions (A→B). —Moving Pattern: Cases 1-b, 2-a, and 2-b The rewrite operation increases a moving distance. The increase ratio depends on an originally intended moving distance, the position A→B (C, D, E), the rewriting start position X, and the position Y depending on the volume of data to be rewritten (X→Y). Whether or not to perform the rewriting processing is determined on the basis of the relationship to be described later between the volume of temporarily stored data and the moving distance as a result of rewriting. The rewriting (X→Y) of the data stored in the non-volatile memory is able to be performed without an increase up to halfway of the writing from the position X to Y. In the case where the distance from the position X to Y, however, does not completely overlap the moving distance between two points (A→C, D, E), the rewrite operation causes an increase in the distance. If the increase is small, rewriting of most part of data can be performed within the moving distance. Since there occurs an increase due to moving for some part of tape writing, however, there is not no much advantage of writing between Read commands in this case. —Moving Pattern: Cases 3-a, 3-b, 4-a, and 4-b Since the moving operation for the rewrite operation largely increases the moving distance compared to the originally intended moving distance, the rewriting is not performed. This is obviously a case where positions of data (X→Y) to be written do not overlap in the course of moving for subsequent a plurality of Read commands, and thus there is no advantage for the entire series of commands. When the append write command and the synchronization command are received, the following two operations are conceivable. 1. A moving operation is not performed, but new user data is written in the temporary storage area. (Advantage) Since movement for the writing processing is not performed, the moving distance can be reduced. (Disadvantage) The temporary storage area might run short during the writing. 2. Writing in the temporary storage area is not performed, but a rewrite operation is performed and then writing is performed at the originally intended position. (Advantage) The temporary storage area can be saved. (Disadvantage) It is necessary to move to the rewriting start position X and then to perform rewriting. The advantage and disadvantage of each of the two operations above have to correlation with the following two points. Specifically, these two operations are determined based on the volume (use ratio of data stored in the temporary non-volatile storage area and a moving distance from the current position to the rewriting start position. For example, in the cases of the aforementioned moving pattern 1-b, 2-a, and 2-b, if movement between two points for reading involves a large increase, it is chosen in principle that the rewrite operation is not performed on the tape. In addition, even if a rewrite operation between read operations involves some increase in the moving distance, reduction in distance as a result of the writing in the temporary storage area might be larger than the increase. In this case, it is possible to make a choice of executing the rewrite operation during the movement for Read. FIG. 7 illustrates the case 1-a where an EOD which is the append writing position exists in the course of movement. The data stored in the buffer is not append written in the tape, but stored in the non-volatile storage area. In the case of moving from the position A to B for Read, the course of movement includes an append tape writing position (physical EOD) for a normal synchronization operation and a distance for writing (distance X-Y). The direction (X→Y) of writing data in the tape is the same as the moving direction for Read (A→ 13 ). As described above, in the movement subsequent to a synchronization command, the append writing position (physical EOD) and the tape writing length (the volume of data) are included in the moving distance. If the Read direction matches the rewriting direction, it is advantageous to perform, during the movement, the operation of rewriting the data stored in the non-volatile storage area. FIG. 8 illustrates modes in which data is written in the tape in the case where there is no free space in the non-volatile storage area, according to several embodiments. In the case where the temporary storage area runs short during writing therein, the rewrite operation is unconditionally performed. Unless the rewrite operation is performed on the tape, a write operation cannot be continued because there is no free space in the non-volatile storage area. After the rewrite operation, a normal tape write operation may be performed continuously. The followings show a difference in moving distance from the normal write and synchronization operations. There already exists data10 and FM10 in the temporary storage area. In the case where the temporary storage area runs short during receiving data11 anew, there is no change in moving distance if the moving direction from the current position A to the rewriting start position X is the same as the writing direction (an upper figure, case 1-a). If the moving direction from the current position A to the rewriting start position X is opposite to the writing direction (a lower figure, case 1-b), there is an increase by a distance of a reciprocation between the positions Y and X. The increase in moving distance is normally smaller than the reduction in distance as a result of writing in the temporary storage area, and therefore the append writing can be performed. When the Rewind command or the Unload command for the cartridge is received, the rewrite operation is performed unconditionally, because Rewind and Unload mean that the tape cartridge is used up. In this state, the moving target of the position B or E is the ROT of the tape. The positions C and D ( FIG. 5 ) cannot be the moving targets, i.e., the SOT. The corresponding moving patterns are 1-a, 1-b, 4-a, and 4-b. The rewrite operation might cause a considerable increase in moving distance. For example, the moving patterns 4-a and 4-b correspond to this case. A rewrite operation is required to ensure data custody and to use the cartridge as normal when the cartridge is remounted. The increase in moving distance is offset by the reduction in distance by writing in the temporary storage area, except for a ease where the moving pattern 4-a is repeated in a state where the current position A is located closer to the BOT than the rewriting start position X. Another example is provided based on the linear recording method in which position movements for Read and Write are performed back and forth in the longitudinal direction of a tape medium. Append writing in movement on the tape in the tape drive is applied to a case where data is sequentially read from or written in the tape. The example of the present invention is applied to a case of receiving a series of commands including mixed Read and Write commands from an upper-level device (host) in the case where one cartridge is loaded in the tape drive. The mixed Read and Write commands included in the series of commands issued by the host to the tape drive are executed. Hereinbelow, a description is given of a flowchart of operations for the append write command (Write), the read command (Read) and the moving command (position) assumed for Read, according to one embodiment. FIG. 9 illustrates an operation flow of appended data writing (Write) in one embodiment. 1. The tape drive receives a Write command in the tape position A ( FIG. 5 ) from the host. Data transmitted from the host, which is to be append written in the tape, is stored in the buffer. The tape position (physical EOD) in which data is to be append written in the tape is the position X ( FIG. 5 ). After the append writing, the position Y (X→Y) is the EOD. A Position command causes the moving to the position X. The EOD after the append writing is the position Y. The movement from the position Y to, for example, the position B is performed by using a moving command (Position command). In this embodiment, it is assumed that, in the case where the current position of the tape is the position A after Read, direct movement to a target position B is performed for the next Read. Although described later, the section X-Y is located within the same wrap in this movement, and therefore data is stored in the non-volatile memory in order to append write data in the tape ( FIG. 12 ). 2. Referring again to FIG. 9 , it is checked whether the data can be written into a non-volatile (NV) cache (e.g., non-volatile memory). When there is no free space in the NV cache, writing is performed as normal. 3. When there is a free space, the data is stored in the NV cache. 4. When there is no free space, perform normal writing on the data. 5. In each of the above two cases, a completion notification of the write operation is sent back to the host upon completion of the writing. The Write command has been described with respect to only append writing in the above. In the append writing method, the end of data (EOD) of write data in a tape is sequentially brought back by using a sequential moving method of the tape drive. The writing method of the tape drive, however, includes Over Write in addition to the append write. The Over Write command is used to overwrite data (for example, a data set) having been written in a tape with new data by using the append write. Upon the overwrite operation, the end of the overwrite data becomes the end of data (EOD) of the tape and the subsequent write data is treated as no data. FIG. 10 illustrates a flow of receiving both of the Over Write and append write commands in mixed append write and read operations. The following describes each of the steps 1 to 100 in FIG. 10 : 1. The tape drive receives a write command (Write) in the mixed read and write operations. Most of the write commands received during the mixed operations are likely to be append write commands. In one embodiment, it is also assumed that the tape drive receives an Over Write command in the mixed operations. 10. The tape drive checks whether the received write command is an Over Write or append write command. When the command is append write, append writing (corresponding to steps 2 to 5 in FIG. 9 ) is performed in step 7 . 2. When the tape drive receives the Over Write command, the processing proceeds to step 3 or 5 . 3. This step is provided for a case where the tape drive receives the Over Write command and data in the tape is to be overwritten. The end of data which is in the tape physical position specified for data writing by the Over Write command is updated and stored as the end of data (EOD) to be append written in the tape. At this point, data is not written in the specified tape physical position. In the subsequent step 7 , data is temporarily stored in the non-volatile memory (NV cache). Finally, at an optimum time (steps 10 → 11 → 12 in FIG. 12 ) during a subsequent moving operation, the data stored in the NV cache is written in the specified physical position of the tape. In the Over Write method, the data after the EOD in the tape is treated as invalid (in other words, empty). Furthermore, data is treated as invalid, also with respect to data which is to be used for the append write command received before the Over Write command and which is temporarily stored in the NV cache but not yet moved to the tape. The EOD is temporarily stored in a non-volatile memory such as an NV cache, a cartridge memory (CM: a non-volatile memory in the tape cartridge), or a data set (data in the tape). 5. This step is provided for a case where the tape drive receives the Over Write command and data in the NV cache is to be overwritten. In some cases, there is data which is to be used for the append write command received before the Over Write command and which is temporarily stored in the NV cache but not yet moved to the tape. The data in the NV cache is overwritten. The end of the overwrite data in the cache is considered as the end of appended data in the cache (EOD in the cache) and the end of data is updated and stored in the non-volatile memory. The data after the EOD in the NV cache is treated as invalid (in other words, empty). Finally, data up to the updated EOD in the cache is written from the end of appended data (EOD) in the tape at an optimum time (steps 10 → 11 → 12 in FIG. 12 ) during the subsequent moving operation. 6. As a result of the overwriting, the end of appended data in the tape (EOD the tape) and the end of appended data in the NV cache (EOD in the cache) are stored as logical EODs. The higher-level device (host) does not recognize whether the appended data exists in the NV cache or in the tape. 7. This step is common to both the Over Write and append write commands. As has already been described with reference to the flow of append write ( FIG. 9 ), this step corresponds to the flow of steps 2 →( 3 or 4 )→ 5 in FIG. 9 . In this embodiment, in step 3 of FIG. 9 , data for the Over Write command is temporarily stored in the NV cache. Unless the data can be stored in the NV cache, the same processing as for step 4 in FIG. 9 is performed. 100: If the overwrite data is stored in the NV cache, a completion notification of the write operation is sent back to the host. FIG. 11 illustrates an operation flow of a synchronization (Sync) command. 1. The tape drive receives a synchronization command (Sync) from the host. Alternatively, the Write command may involve a synchronization operation. Further, the tape drive may receive, a synchronization request implicitly specified by a position moving command in a state where data remains in the buffer as a result of a Write command. 2. It is checked whether data is already being written in the tape. 3. If data is being written, the normal append writing is performed on the tape through the normal synchronization processing. 4. If data is not being written, it is checked whether data can be written in the NV cache. In other words, the check is made by determining whether there is the following area. 5. If there is a free space in the NV cache, the data is stored in the NV cache, and then a completion notification of the synchronization is sent back to the host ( 8 ). 6. If there is no free space in the NV cache, the normal writing is performed ( 3 ) and then a completion notification of the synchronization is sent back to the host ( 8 ). FIG. 12 illustrates a flow of a moving operation in the case where a writing position exists in the movement, between two positions. 1. A moving command is received from the host. 2. Is it a movement to a logical EOD? A logical EOD is a position where data writing is completed as an EOD for the host and the tape drive notifies the host of the position. A physical EOD is an internal end of data of the drive. The physical EOD is a position in which the drive completes data writing on the tape in a state where data is written in the non-volatile memory, there are two physical EODs of “an EOD on the tape” and “an EOD in the non-volatile memory.” In a state where data is not written in the non-volatile memory, there is only one physical EOD of “an EOD on the tape.” The logical EOD in this case corresponds to the EOD on the tape. 3. If the current position is the EOD (the EOD on the tape or the FOE) in the NV cache), there is no need to move. A completion notification of the movement is sent back to the host ( 4 ). The Write flow ( 6 , FIG. 9 or FIG. 10 ) and then the synchronization command flow ( 7 , FIG. 11 ) are executed. 8. If the current position is not the to logical EOD ( 2 ), it is checked whether data exist: in the NV cache. 9. If data does not exist in the NV cache, a moving command (A→B) for Read transmitted from the host is executed. Then, a completion notification of the movement is sent back to the host ( 13 ). 10. If data exists in the NV cache, it is determined whether writing should be performed during movement. For example, if an EOD for data writing exists on the way during movement, the writing is determined to be executed. 11. If the data should be written, the data in the NV cache is rewritten in the tape from the EOD on the tape ( 12 ). 12. Normal movement is performed ( 9 ) is determined in step 10 that the data should not be written during movement, simply movement (A→B) is performed ( 9 ). Then, a completion notification of the movement is sent back to the host ( 13 ). The above example has been described with respect to the movement between Read commands in the series of commands including mixed Write and Read commands. The scope of the present invention is not limited to this example, and is provided on the assumption that the completion of a synchronization operation is ensured in writing in anon-volatile storage area. The scope of the present invention includes substantial tape writing of data stored in the non-volatile storage area if there is a chance of subsequently encountering a target tape position in a subsequent movement on the tape. Generally in a hierarchical storage management system, a lowest-layer tape library receives a series of commands including mixed Read and Write commands. The tape drive with one cartridge loaded thereon has many chances in which tape writing positions for the write and synchronization commands overlap in movement for subsequent Read commands. As tong as a new non-volatile storage area is provided in the tape drive or the cartridge and a predetermined capacity thereof (for example, 100 Mbytes or more) is secured, it is possible to guarantee the performance of the operation of the series of commands as a whole by deferring append writing in the tape. As described above, the library system in various embodiments exerts an advantageous effect of avoiding a replacement by unloading and loading of a cartridge exclusively for writing or reading. The system in various embodiments has an advantageous effect of achieving the speed-up as a whole even in the case where an overwrite operation is included in mixed read and write operations by minimizing the moving operation involved with data writing.

A tape drive is provided, which executes an optimum writing method even when overwrite is intervened between mixed read and write operations. When an overwrite command is received while executing the mixed operations, which writes to a predetermined tape position, when a tape position to overwrite on is encountered before the append-written data ending position of the tape (tape EOD), the overwritten tape position is regarded as the append-written data ending position of the tape (tape EOD) to update the tape EOD by the overwritten tape position. When a tape position to overwrite is encountered after the append-written data ending position of the tape (tape EOD), the overwritten tape position is updated by the append-written data ending position of a non-volatile memory (non-volatile EOD). The updating the EODs enhances the performance of the mixed read and write operations even when an overwrite command is intervening.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to casting tools and the techniques for forming an exact replica of an eroded area in an underground gasoline storage tank and repair of the eroded area. 2. Description of Prior Art A wide variety of approaches have been attempted to investigate this erosion problem. One of the approaches has been sonic graphing of eroded areas, inspection by closed circuit TV cameras. Dentists employ related techniques in producing mouth impressions of damaged or missing teeth. A known, related method for determining wear or erosion in the mechanical fields pertains to the determination of defects in a spur gear employing a casting procedure, such as U.S. Patent to Sawyer, No. 2,601,703, entitled "Method for Testing Surface Defects." SUMMARY OF THE INVENTION A common condition exists in underground gasoline storage tanks is highly eroded area in the bottom of the tank just below the filler pipe. The causes are attributed variously to repeated contact with the area by the measuring stick, promoting rusting and erosion due to electrolysis varying with the Ph of the soil. The repeated use of the measuring stick disperses sediments, tends to remove erosion and polishes the area accelerating further erosion. An object of this invention was to determine and accurately measure the extent of erosion, to ascertain the necessity for repair or replacement. Another object was to provide suitable tools for casting the eroded area compatible with casting under adverse conditions in underground tanks containing a motor fuel product. Another object was to design tools capable of casting the eroded area and determining the extent of the erosion and repair the area if required. In accomplishing the foregoing objectives a brush is used to relatively clean the area. The casting cup is placed over the exposed area and a heavy grade gear oil is injected into the cup to remove casting inhibitors such as alcohol blended with the hydrocarbons in the product. A cylindrical cup of maximum diameter to pass through the filler pipe is used. The cup is sealed to the bottom of the tank employing caulking compound such as caulking strips or other yieldable substances. The cylindrical injector comprises a drive rod, a piston, and a cylinder having a dispensing valve. The procedures employed generally comprise employing the injector to place gear oil in the molding cup positioned in the tank. The gear oil displaces casting inhibitors collecting in the fluid sediment in the tank. The gypsum casting materials in combination with a fluid is injected into the eroded area. Negative casting is formed below the surface of the product in the tank in approximately 15 minutes. The negative casting is removed and a positive casting produced reproducing the eroded area of the tank. If it is necessary to repair the tank, the tank is evacuated and thoroughly cleaned. The same injector or an injector of a larger capacity can repair the eroded area after a thorough cleaning of the area with phosphoric acid or other suitable cleaners. Epoxy or other durable plastic materials may be injected into the eroded area effecting a repair. BRIEF DESCRIPTION OF THE DRAWINGS For a detailed description of the invention reference is made to the attached drawings wherein identical reference characters refer to identical or equivalent components throughout the various views and the detailed description. FIG. 1 is a plan view partially fragmented and sectionalized of the tool in combination placed in an underground gasoline storage tank simulating injection of the casting materials. FIG. 2 is a plan view of the casting cup and the extension shaft. FIG. 3 is a plan view of the cleaning brush and the extension handle FIG. 4 is a detailed view partially fragmented illustrating the injector. FIG. 5 is a fragmented view of the dispensing valve body. FIG. 6 is a fragmented view of the dispensing nozzle. FIG. 7 is a fragmented view of the dispensing nozzle of FIG. 6 rotated 90°. FIG. 8 is an illustration of the eroded area of the bottom of the tank. FIG. 9 is a sectional view of the positive casting being produced from the negative casting. FIG. 10 is a negative casting. FIG. 11 is a positive casting. FIG. 12 is a sectional view of the negative casting taken substantially on line 12--12 of FIG. 10. FIG. 13 is a sectional view of the positive casting taken substantially on line 13--13 of FIG. 11 looking in the direction of the arrows. DESCRIPTION OF THE PREFERRED EMBODIMENT For a detailed description of the design of the tools employed in association with the method your attention is invited to FIGS. 1-7. For an illustration of the product produced by the tools and the resulting method your attention is invited to FIGS. 8-13. The tools and the method of this invention are designed for employing in a gasoline storage tank 11 embedded in the soil 12. The unusual environment impose particularly demands in the fact that the tank 11 contains a product 13. The upper part of the tank 11 usually contains a mixture of gas and air 14. Condensed water vapor 15 collects on the interior walls 16 of the tank 11. The bottom 17 of tank 11 usually contains a strata of collected fluid sediments 18 and scale and erosion 19 on the bottom 17 of tank 11 just below filler pipe 20. Filler pipe 20 normally comprises a collar 21 mounted in the top 22 of tank 11. Upper filler pipe 23 is attached to collar 21 having a cap or cover 24. Projecting into tank 11 is the lower filler pipe 25 which extends to a point closely adjacent the bottom 17 of tank 11. In this general area is located the scale and eroded area 19 which creates the problems this invention is designed to solve. This specific eroded area 26 can progress in tank 11 under certain soil 12 conditions to such an extent as to produce a perforation 27 of tank 11. This permits a leakage of the product 13 or might permit water to flow into the tank 11. The presence of water in the fluid sediment 18 is usually a collection of condensed water vapor 15 collected from the interior wall 16 of tank 11. For a description of the specific tools performing the methods of this invention attention is invited particularly to FIGs. 1-7. Tools for practicing the method and producing the desired results are illustrated in FIGS. 1-7 comprising a brush 30 for removing solid sediments 31 from the eroded area 26. The tools are constructed of various diameters of 2, 3 and 4 inches. The particular tool selected is determined by the diameter of the filler pipe 20. The largest diameter which will pass through the filler pipe 20 is preferably used. For a description of the construction of the specialized tools reference is particularly made to FIGS. 1-7. The brush 30 is used to remove the solid sediments 31 in the vicinity of the eroded area 26 prior to initiating the further procedures of this method. Brush 30 is mounted on an extension handle 32 which was constructed from a section of plastic pipe having an inside diameter of 11/4 inches. Extension handle 32 included an extension handle collar 33 at one end having a threaded inside diameter of 11/2 inches. The threaded arm 34 of brush 30 was screwably attached to extension handle collar 33. The brush 30 might be of various configurations and design; however, the preferred embodiment was constructed in the general configuration as illustrated in FIG. 3. The characteristic of the brush should be rather sturdy. In the preferred embodiment a coarse fiber bristle brush was employed. The extension handle 32 was constructed of sections of PVC pipe 4' in length. If an extension handle 32 of greater length is required sections of pipe may be screwably connected together in an integral structure. For a description of the construction of the casting cap 36 reference is particularly made to FIG. 2. An extension shaft 37 constructed of plastic PVC pipe is employed. The pipe in this instance has an inside diameter of 11/2 inches. The casting cap 36 was constructed from a block of aluminum alloy using conventional machining processes. The cup 36, however, might be constructed by casting, extrusion, or even by injection molding of metal or plastic. As previously stated the casting cups 36 are constructed with three sizes having a diameter of 2, 3 and 4 inches. The 3 inches model of the casting cup was constructed with 3 inches inside diameter and a 31/4 inches outside diameter. Cylindrical body 39 was 5 inches long having a rectangular aperture 40 in one side wall 33/4 inches by 31/2 inches. The dimensions of this rectangular aperture 40 is somewhat optional in that it is employed only to remove castings which will be hereinafter described. Casting cup 36 is constructed with a sloping collar 41 approximately 2 inches long of the general configuration illustrated in FIG. 3 including a threaded connector 42 which is screwably connected to the extension shaft collar 43. Casting cup 36 includes a casting collar 44 at the end of the cylindrical body opposite the sloping collar. The casting collar 44 has a height of 1 inch. These dimensions might vary in various designs of the casting cup. For a description of the construction of the injector 45 attention is invited to FIGS. 1, 4-7. In the preferred embodiment injector 45 included an injector cylinder 46 17 inches long having an inside diameter of 1 inch. Movably mounted internal of the injector cylinder 46 was injector cylinder piston 47 having a diameter of 1 inch and including an O-ring 48 mounted in a piston groove 49 sealing piston 47 in relation to the injector cylinder 46. Approximately in the center of injector cylinder 46 was constructed a rod stop 50 through which operating rod 51 projects. The rod stop 50 in conjunction with injector cylinder piston 47 and rod guide 52 limit the movement of injector cylinder piston 47 regulating the capacity of the injector. In the preferred embodiment the positioning of rod guide 52 relative injector cylinder piston 47 limit the movement of the rod guide 52 to the top 53 of the cylinder and injector cylinder piston 47 to the bottom 54 of the cylinder. A dispensing valve 55 was threadably secured to the bottom 54 of the cylinder. The construction of the valve is illustrated in FIGS. 4-7. The valve includes a valve body 56 having dispensing nozzle threads 57 for attaching the device to injector cylinder 46. Movably mounted in dispensing valve body 56 is the dispensing nozzle 58 constructed with dispensing nozzle throat 60 projecting along its axis approximately for its entire length. At the upper end of dispensing valve 55 was constructed a valve seat 61. Just below this valve seat 61 was constructed a multiplicity of feed apertures 62 projecting into dispensing nozzle throat 60. Mounted external of dispensing nozle 58 is a closing spring 63 placed under compression load around dispensing nozzle 58 and secured in position by securing pin 64. To facilitate the materials being discharged from the dispensing nozzle 58 release slots 65 were formed in each side of dispensing nozzle 58. The foregoing substantially describes the specialized equipment design. The materials utilized in association with the equipment will be further described in the description of the procedures of the process. DESCRIPTION OF THE METHOD AND OPERATION The first step of the casting procedure would be to place brush 30 in the tank 11 through filler pipe 20 and rotate the brush 30 to remove any solid sediments 31 from eroded area 26. The next step is to attach a rope-like segment of caulking compound 66, such as "Finger-Tite Caulking Strips" distributed by Maclanburg-Duncan Co. of Oklahoma City, Okla., around the bottom edge 67 of casting cup 36. The next step is to place the casting cup 36 in the filler pipe 20 pressing down slightly to seal the casting collar 44 against the bottom of the tank 17 over the eroded area 26. Next we fill injector 45 with 90 weight gear oil. Injector 45 is positioned through the extension shaft 37 and downward pressure on injector 45 permits the gear oil to flow into and fill the area of casting collar 44. This procedure displaces certain casting inhibitors which are present in the fluid sediments 18 in the bottom of tank 17. Gasoline or motor fuels are generally referred to in the industry as the product and include various additives. Among the additives can be alcohol which is an inhibitor to solidifying of the casting materials employed in the process of this invention. The injection of the gear oil displaces the inhibitors from the area of casting collar 44. The next step of the procedure is to fill the injector with a charge of casting materials. Among the satisfactory casting materials used in the preferred procedure was compound containing gypsum sold under the trade name of "Denstone" by Modern Materials of St. Louis, Mo. Another satisfactory material which may be acquired in most dental supply houses is "Caststone." A charge for the injector is a mixture of 50 percent and 50 percent of the powdered Denstone or Caststone. Under adverse casting conditions where the tank 11 has shifted or there is a perforation 27 of tank 11, a thicker mixture, such as one part water to 4 parts powder may be employed. After filling the injector 45 with the charge, the next step is to inject the casting materials into casting cup 36 filling the area internal of the casting collar 44. The next step is to allow the casting materials to remain in position for approximately 15 minutes to solify. Caststone and Denstone will solidify in approximately 10 minutes; however, under varying temperature conditions it has been discovered that a setting time of 15 minutes in this procedure is normally satisfactory under any conditions. Next, remove the casting cup 36 lifting the negative casting 68 from the storage tank 11. Next, remove the negative casting 68 from the casting cup 36. This may be accomplished by bumping the casting with the hand at the bottom edge 67 of the casting cup 36 and removing the casting through the rectangular aperture 40. If desired, the following procedures may be followed to produce a positive casting 69. Coat the surface of negative casting 68 with release assisting coating, such as "Liquid Foil 71" used by Dentists. Next, place a collar of masking tape 70 around negative casting 68 substantially as illustrated in FIG. 9. Next, prepare a mixture of the Denstone or Caststone 50--50 mixture with water or a more fluid mixture and pour a positive cast 69 into the void above negative casting 68. Permit the materials to set for approximately 15 minutes and remove the tape 70 separating the negative casting 68 and the positive casting 69. Next, break the positive and negative castings apart by applying pressure to the castings. This procedure results in an exact reproduction of eroded area 26 in the bottom of the tank 17. To repair the eroded area 26 in instances where there is perforation 27 in the bottom 17 of the tank 11, the tank would normally be required to be completely evacuated of any fluid and the interior of the tank particularly in the eroded area 26 thoroughly cleaned. This cleaning might be accomplished by various cleaning methods such as buffing or cleaning the area with phosphoric acid. After the area is thoroughly cleaned and dry, a method of repair would be to fill the injector 45 or an injector having a larger capacity than the one described in the foregoing description with epoxy or other suitable repair materials. Materials may be positioned through the filler pipe 20 and placed over the eroded area 26 and dispensed. When the epoxy or other durable fluid solidifying repair materials are placed in position they solidify, closing the perforation 27 and repairing the eroded area 26. Having described in detail the equipment and procedures for practicing this invention including the detailed steps of the process; what is desired to be claimed is all methods and tools not departing from the scope of this invention as defined in the appended claims.

A method and apparatus for accurately determining the depth and extent of erosion in underground gasoline storage tanks at service stations. The apparatus provides for cleaning the interior of the tank adjacent the filler pipe, casting a duplicate of the eroded area by means of a casting cup and injector depositing molding materials, and removing the negative of the eroded area. The equipment comprises a brush and extension handle, a casting cup has a cylindrical body with a rectangular opening in the wall for removing solidified casting. The injector includes an operating rod, a cylinder, a piston, and a dispensing valve. The dispenser may be used for injecting a variety of fluids into the eroded area for dispersing inhibitors, injecting molding materials, and in the repair steps after the tank has been emptied and the eroded area cleaned.

CLAIM OF PRIORITY [0001] This application claims priority to U.S. Provisional Patent Application No. 62/048,868 filed Sep. 11, 2014, and U.S. Provisional Patent Application No. 62/075,475 filed Nov. 5, 2014, the entire disclosures which are incorporated herein. FIELD OF THE INVENTION [0002] The present invention relates generally to waste water systems. More particularly, the present invention relates to an anchored multi-layer liner system for use in the rehabilitation or repair of waste water system components such as manholes, sewer pipes, lift stations, etc. BACKGROUND OF THE INVENTION [0003] Deterioration of waste water system components is a severe and growing problem. Originally built of brick, block or concrete construction, these components develop leaks, cracks and holes due to age, erosion, corrosion and ground water intrusion. Leakage from old manholes and sewer lines contaminates the environment and sometimes result in catastrophic damage with respect to clean-up and repair costs. [0004] Since the cost of repairing the components is typically much less than the cost of replacement, many techniques have been developed to repair and rehabilitate waste water system components. For example, it is known to recast manholes and the like through the use of forms and poured concrete, such as shown in U.S. Pat. No. 5,032,197 to Trimble. Because this process is very labor intensive, many techniques are directed toward spray-applied liners. For example, U.S. Pat. No. 5,002,438 to Strong teaches the use of sprayed cement to form a liner inside the deteriorating structure. Spray-applied epoxy, acrylic or polyurethane liners are also known, as is the use of resin impregnated substrates, such as felt, as taught in U.S. Pat. No. 5,017,258 to Brown et al. [0005] Note, however, it is not uncommon for current spray-applied systems to suffer from moisture, delamination, shrinkage and structural weakness problems resulting from the typical environment encountered in the repair operation. Moreover, in various instances, it is known for portions of existing liner systems to become separated from the substrate to which they are applied, especially where water intrusion can be expected, accompanied by the subsequent build up of hydrostatic pressure. The joints between pre-cast sections of various waste water components, such as manholes, are known to cause such damage to liners. [0006] The present invention recognizes and addresses considerations of prior art constructions and methods. SUMMARY OF THE INVENTION [0007] One embodiment of multi-layer liner system for application to a substrate includes a primer layer, a first moisture barrier layer, the first moisture barrier layer being impervious to moisture, a second moisture barrier layer, a foam layer, the foam layer being sandwiched between the first moisture barrier layer and the second moisture barrier layer, and an anchor assembly extending outwardly from the substrate into the multi-layer liner. [0008] Another embodiment of a multi-layered liner system is a method of applying a multi-layer liner system to a substrate, including the steps of applying a primer layer, applying a first moisture barrier layer to the primer layer, the first moisture barrier layer being impervious to moisture, applying a foam layer to the first moisture barrier layer, applying a second moisture barrier layer to the foam layer so that the foam layer is sandwiched between the first moisture barrier layer and the second moisture barrier layer, and attaching an anchor assembly to the substrate so that the anchor assembly extends outwardly from the substrate into the multi-layer liner. [0009] Yet another embodiment of a multi-layered liner system for application to a substrate includes a foam layer, the foam layer being applied to the substrate, a first moisture barrier layer, the first moisture barrier layer being impervious to moisture and disposed on an outer surface of the foam layer, and an anchor assembly including a first portion disposed within the substrate and a second portion extending outwardly from the substrate into the foam layer so that the second portion is embedded in the foam layer. [0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0011] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which: [0012] FIG. 1A is a perspective cross-sectional view of a portion of an embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0013] FIG. 1B is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0014] FIG. 1C is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0015] FIG. 1D is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0016] FIG. 2A is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0017] FIG. 2B is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0018] FIG. 2C is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0019] FIG. 3A is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0020] FIG. 3B is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0021] FIG. 3C is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0022] FIG. 4 is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0023] FIG. 5 is a perspective cross-sectional view of a portion of an alternate embodiment of an anchored multi-layer liner system, applied to a waste water system component, in accordance with the present invention; [0024] FIG. 6A is a cross-sectional view of a manhole constructed of pre-cast components; and [0025] FIG. 6B is a cross-sectional view of the manhole as shown in FIG. 6A , further including a partial application of the anchored multi-layer liner system shown in FIG. 4 . [0026] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure. DETAILED DESCRIPTION [0027] Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. [0028] As illustrated by the sectional depiction in FIG. 1A , an embodiment of the present invention comprises a multi-layer liner 10 applied to a concrete, brick, block, metal or the like substrate 20 , and further secured thereto by an anchor system 30 . Typically, the substrate 20 will be a deteriorated manhole or sewer pipe having an irregular surface with cracks or holes. The liner 10 comprises a primer layer 11 , a first moisture barrier layer 12 , a foam layer 13 , and a second moisture barrier layer 14 . Preferably, the liner 10 is applied so as to cover the entire internal surface of the substrate 20 , which is usually generally tubular in configuration, although any shape or configuration is possible and the technique is applicable without regard to the particular shape of the substrate 20 . [0029] The substrate 20 surface is initially prepared using high pressure water or abrasive sand blasting to remove all hard contaminants, any micro-organisms or living matter such as mold, mildew, etc., and any loose degraded materials of the substrate itself. This abrading step results in a clean surface with an optimized surface for adhesion of the liner 20 . Next the primer layer 11 is spray-applied using conventional compressed air spraying devices. The primer layer is a material capable of adhering to the substrate 20 even if wet, and is preferably an epoxy material. The primer layer 11 is applied to a necessary thickness to insure adhesion of the first moisture barrier 12 to the substrate 20 , and is generally applied to a dry film thickness between 2 and 10 mils, and preferably at a thickness of approximately 5 mils. The primer layer 12 is coated over the entire surface to be repaired. [0030] The next step is to spray-apply, again using conventional techniques, the first moisture barrier layer 12 onto the primer layer 11 . The first moisture barrier layer 12 is preferably composed of a polymer blend of separate components which are mixed as they exit the spray nozzle, the components reacting to form a hard material upon curing. Preferably, a blend of a polyurea component and an isocyanate component is utilized, with the two components formulated to have similar viscosities. The first moisture barrier layer 12 is applied to a dry film thickness of preferably between 40 to 80 mils, and even more preferably at a thickness of 60 mils. The material used for the first moisture barrier should have a gel time of less than a few seconds and preferably less than 3 seconds, with total cure time of less than 60 seconds and preferably less than 30 seconds, and have minimal shrinkage during curing. This rapid cure is necessary to insure integrity of the first moisture barrier 12 even when applied under non-optimum conditions. The preferred polyurea and isocyanate blend has a tensile strength of greater than 1500 psi, an elongation percentage of 125%, tear strength of 350 psi, a shore D hardness of 55 and an 100% modulus of greater than 1500. The first moisture barrier layer 12 is impermeable to water and other fluids and is a structurally rigid layer adhered to the substrate 20 so as to remain adhered under pull test conditions of greater than 300 psi. The first moisture barrier layer 12 is applied to completely cover the primer layer 11 . [0031] In the embodiment shown in FIG. 1A , the next step is to install the anchor system 30 to the substrate 20 prior to applying the foam layer 13 . In this manner, the portion of the anchor system extending outwardly from the substrate 20 will be fully embedded in the foam layer 13 , thereby providing a resistive force to any forces that may tend to cause multi-layer liner 10 to separate from the substrate 20 , such as, but not limited to, hydrostatic pressure due to water intrusion. As shown, anchor system 30 includes a plurality of elongated anchor plates 34 (only one is shown) that are each secured to the substrate 20 by one or more fasteners. In the instant case, the fasteners being used comprise a plurality of threaded bolts 31 and correspondingly threaded nuts 33 . [0032] After a suitable number of anchor plates 34 have been installed, the next step is to spray-apply, again using conventional techniques, a foam layer 13 . The foam layer 13 is preferably composed of a polyurethane blend which rapidly foams and cures upon exiting the spray nozzle of the application equipment. Preferably, the foam material is primarily closed cell and has a rise time of less than 30 seconds and preferably less than 10 seconds. The foam layer 13 is applied preferably to result in a dry thickness of at least 500 mils, although the foam layer 13 can be thicker overall or in selected areas if necessary. The foam layer 13 as applied creates a smoother inner surface, its bulk filling any holes, depressions or cracks in the substrate 20 surface. Additionally, the foam layer 13 encapsulates the exposed anchor plates 34 and associated fasteners, bolts 31 and nuts 33 , so that the anchor system 30 provides a plurality of points at which adhesion of the foam layer 13 to the substrate 20 is enhanced. The foam layer 13 preferably has a density of between 4.5 to 5.5 pounds per cubic foot, a compressive strength of between 105 to 110 psi, a closed cell content of over 90 percent, and shear strength of between 225 to 250 psi. As with the other layers, the foam layer 13 is applied over the entire previous layer. [0033] Finally, the second moisture barrier layer 14 , preferably composed of the same material as the first moisture barrier layer 12 , is spray-applied over the entire surface of foam layer 13 . Preferably, the second moisture barrier layer 14 is also applied to a dry film thickness of between 40 and 80 mils, and even more preferably to a thickness of approximately 60 mils. If necessary due to circumstances, greater thicknesses of first moisture barrier layer 12 and second moisture barrier layer 14 may be utilized. [0034] The resulting anchored multi-layer liner 10 is a water impermeable barrier strongly adhered to the substrate 20 , via its own adhesive properties as well as the anchor system 30 , which prevents liquids from leaking out of the waste water system and also prevents ground water from entering the system. More importantly in terms of longevity, the liner 10 is a structural member which strengthens the components of the waste water system no matter to what extent they have deteriorated. Previously used water impermeable liners, whether composed of epoxy, acrylic, polyurethane or resin impregnated substrates, are not strongly adhered to the substrate and tend to delaminate over time. These typical liners do not reinforce or impart any structural strength to the system components. The multi-layer liner 10 of the invention not only creates a liquid barrier, it adds to the strength of the waste water system components by providing a reinforcing member which is structurally rigid due to its multi-layer composition. The liner 10 is a stressed skin panel, comprised of a structurally rigid foam internal layer 13 bounded by two adhered surface layers, first moisture barrier layer 12 and second moisture barrier layer 14 , which are under stress due to the rapid cure rate of the material when applied. This rapid cure time does not allow internal stresses created by the small amount of shrinkage during curing to be relaxed, as occurs in sprayed films with long cure times. The principles of stressed skin panels, well known in the construction industry for walls of large buildings, provide for a structural member with increased structural strength and integrity of multiple factors beyond that of the individual components taken separately. Thus, the combination of the stressed skin panel created by the multi-layer combination of first moisture barrier layer 12 , foam internal layer 13 and second moisture barrier layer 14 adhered to the waste water system component results in a repaired component with exceptional structural characteristics due to the reinforcing properties of the liner 10 , and is a vastly improved system over those in use today. [0035] Referring now to FIG. 1B , an alternate embodiment of the anchored multi-layer liner 10 includes, similarly to the first embodiment, a plurality of anchor plates 34 that are secured to substrate 20 by way of bolts 31 and nuts 33 . Additionally, other fasteners may be used such as powder activated fasteners 40 , 42 ( FIG. 4 ). Note, however, that this embodiment differs from the first embodiment shown in FIG. 1A in that each anchor plate 34 is disposed between foam layer 13 and second moisture barrier layer 14 rather than in the foam layer 13 . As shown in FIG. 1C , anchor plate 34 is disposed on top of second moisture barrier layer 14 . As shown in FIG. 1D . anchor plate 34 is encapsulated by first moisture barrier layer 12 . [0036] The embodiment shown in FIG. 2A is similar to that of FIG. 1A . with the exception that, the anchored multi-layer liner 10 does not include first moisture barrier layer 12 , The embodiment shown in FIG. 2B is similar to that of FIG. 1B with the exception that anchored multi-layer liner 10 does not include first moisture barrier layer 12 . The embodiment shown in FIG. 2C is similar to that of FIG. 1C with the exception that anchored multi-layer liner 10 does not include first moisture barrier layer 12 . [0037] The embodiments shown in FIGS. 3A through 3C are similar to those shown in FIGS. 2A through 2C , with the exception that primer layer 11 has been replaced with a layer of cementitious material 21 that is sprayed on substrate 20 as described in U.S. Pat. No. 5,002,438 to Strong, the entire contents of which are incorporated herein by reference. [0038] As shown in FIG. 4 , in an alternate embodiment, wire mesh 36 can be used rather than anchor plates. As shown in FIG. 4 , wire mesh 36 is preferably secured to the substrate after first moisture barrier layer 12 is applied so that wire mesh 36 is embedded in foam layer 13 when it is applied. Note. various types of wire mesh, of varying gauges, such as galvanized hardware cloth, can he used in the anchor system. [0039] As shown in FIG. 5 , reinforcing bar 38 , commonly known as rebar, may also be used in alternate embodiments of the anchor system. As shown, the fasteners used to secure rebar 38 to the substrate 20 include a pair of ears 37 that are connected by a metal band which forms a loop 39 around the rebar 38 . The ears 37 are then secured to substrate 20 by a shaft 35 passing therethrough. Preferably, rebar 38 is secured to the substrate 20 after the first moisture barrier 12 is applied and prior to the application of foam layer 13 and second barrier layer 14 . In yet another embodiment, fiberglass netting, matting strips, etc., (not shown) may be secured to the substrate 20 and serve to anchor the multi-layer liner 10 thereto. [0040] Referring now to FIGS. 6A and 6B , an example use of an embodiment of the present anchored multi-layer liner system 10 is discussed. Specifically, the wire mesh 36 embodiment shown in FIG. 4 is utilized in a pre-cast waste water component, specifically a manhole 50 . As shown in FIG. 6A , the manhole 50 is constructed of a plurality of pre-cast concrete sections 52 , 54 . 56 and 58 that extend down to a sewer pipe 60 , A first section 52 and a second section 54 meet at a first joint 53 , the second section 54 and a third section 56 meet at a second joint 55 , and the third section 56 and a fourth section 58 meet at a third joint 57 , Note, however, more or fewer sections may be used. As previously discussed with regard to waste water components constructed of pre-cast sections, they are often susceptible to water intrusion, etc., at the joints between the various sections. Therefore, with prior art liner systems, the liners are often susceptible to separation from the substrate 20 at the joints due to hydrostatic pressure. [0041] Referring now to FIG. 6B , to help prevent such separation, the anchor system 30 according to the present disclosure can be applied at the joints 53 , 55 and 57 after water intrusion, etc., is detected or during original construction, As shown, the wire mesh 36 anchor system 30 is secured to the inner surface of the manhole 50 at each of the joints 53 , 55 and 57 . Alternatively, the wire mesh 36 can be secured to substantially the entire inner surface of the manhole 50 where necessary, i.e., where excessive leakage may be expected, As previously discussed, wire mesh 36 is preferably applied after a primer layer 11 and a first moisture barrier layer 12 ( FIG. 4 ), but prior to the foam layer 13 and the second moisture barrier layer 14 ( FIG. 1A ). FIG. 6B shows only a partial application of the multi-layer liner 10 so that the anchor system 30 is more readily seen. [0042] While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.

A multi-layer liner system for application to a substrate, comprising a primer layer, a first moisture barrier layer, the first moisture barrier layer being impervious to moisture, a second moisture barrier layer, a foam layer, the foam layer being sandwiched between the first moisture barrier layer and the second moisture barrier layer, and an anchor assembly extending outwardly from the substrate into the multi-layer liner.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This patent application claims the benefit of U.S. Provisional Patent Application No. 60/463,615, filed Apr. 17, 2003. FIELD OF THE INVENTION This invention pertains to surface positioning guides for rotary hand-held tools and more specifically to removable surface positioning guides that can be removably mounted to rotary hand-held tools. BACKGROUND OF THE INVENTION Rotary hand-held tools are common tools that are frequently used for a variety of work tasks around the house and workplace. There are literally hundreds of different attachable and detachable surface engaging bits for these rotary hand-held tools, including, for example bits configured for such tasks as carving, engraving, routing, grinding, sanding, sawing, sharpening, cutting, polishing, cleaning, drilling and other work tasks. The versatility of such rotary hand-held tools and interchangeability of bits has made these tools very popular in the marketplace. The small size of these tools are also advantageous and provide for easy manipulation. One of the more popular rotary hand held tools include the Dremel® brand rotary tools. These rotary hand-held tools include a housing having a size and contour that provides a gripping surface and a rotary output that is driven by a motor contained within the housing (e.g. an output shaft, chuck and/or collet). Different types of bits can be readily attached and detached to the rotary output to be driven thereby about an axis of rotation. In addition, the housings of these devices conventionally provide a screw thread for attachment of a surface positioning guide. Such positioning guides are sometimes referred to as “cutting guides”. The guides may be used in such applications as dry wall cutting to cut holes for electrical switches, outlets and the like. A surface positioning guide is disclosed in U.S. Pat. No. 6,244,796 to Schuebel et al. The '796 patent generally discloses a surface positioning guide that is angled and includes groove tabs to facilitate use of the rotary tool for such applications as grout removal. While rotary hand-held tools are very versatile, it will be readily appreciated that the large number of bits and different guides and other housing attachments can quickly run up the costs and expense for someone who wishes to have all of the available options and features for their tool. Further, the more different bits and attachments a person has, the more difficult it is to organize the attachments in an orderly and compact manner. Further, there is always a desire to increase the functions and versatility of such rotary tools. Heretofore, there have been significant drawbacks in some existing products, which will readily be appreciated once the present invention is appreciated. BRIEF SUMMARY OF THE INVENTION The present invention provides a more adjustable surface positioning guide that increases the versatility of rotary hand-held tools and that decreases the number of different surface positioning guides and/or other attachments needed for rotary hand-held tools. Several different inventive aspects are disclosed and claimed herein. According to one aspect, the surface positioning guide includes a pivot joint between a guide base and a mounting adapter adapted to be removably coupled to the screw thread of rotary hand-held tools. The guide base pivots relative to the mounting adapter about the pivot joint between operable positions. The respective openings of the mounting adapter and the guide base align with each other in the operable positions so as to communicate the driven bit of the rotary hand-held tool through the guide base. According to another aspect of the present invention, a surface positioning guide includes at least one spring supported by the mounting adapter either directly or indirectly that biases a guide base axially away from the mounting adapter. The guide base is movable toward the mounting adapter against the biasing of the at least one spring to effect a plunging movement such that the bits of rotary hand-held tools can be selectively plunged into a working surface. The surface positioning guide includes a first stop arranged to limit how far the guide base is biased away from the mounting adapter and a second stop arranged to limit how far the guide base can be moved toward the mounting adapter. According to another aspect of the present invention, the guide base of a surface positioning guide includes a reversible and/or interchangeable base flange. The base flange defines an opening which is adapted to receive the surface engaging bit therethrough. The base flange also defines first and second faces. The base flange is movable relative to a support member which is carried by the mounting adapter to selectively locate either the first face or the second face at a foremost end of the removable surface positioning guide for engaging the working surface. According to another aspect of the present invention, a removable surface positioning guide for a rotary hand-held tool comprises a mounting adapter integrally including an internally threaded sleeve portion concentric about a tool axis that is adapted to be threadably mounted to the housing of the rotary hand-held tool. The mounting adapter also includes a pair of axially extending linear guides and a first stop. The removable surface positioning guide also comprises a pivot body integrally including a pair of linear tracks sliding against the linear guides such that the pivot body is axially movable relative to the mounting adapter. The pivot body defines a pivot axis perpendicular to the tool axis and a pair of pivot support structures on the pivot axis. At least one spring that is supported by the mounting adapter biases the pivot body away from the mounting adapter. The first stop engages the pivot body to limit how far the pivot body is biased away from the mounting adapter. A pair of pillow blocks integrally provide hinge structures pivotably supported by the pivot support structures. The pillow blocks support a base flange is a position for engaging the working surface. The base flange is supported by the pillow blocks and defines an enclosed opening adapted to receive the surface engaging bit therethrough. Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a removable surface positioning guide for a rotary hand-held tool in accordance with an embodiment of the present invention. FIG. 2 is an isometric view of the removable surface positioning guide in combination with a rotary hand-held tool shown in dashed lines to illustrate how the surface positioning guide mounts to the front end of a rotary hand-held tool. FIG. 3 is an exploded isometric assembly drawing of the surface positioning guide shown in previous Figures. FIGS. 4–6 are plan, side elevation and bottom side views of the surface positioning guide shown in previous Figures. FIG. 7 is a cross section of the surface positioning guide taken about line 7 — 7 of FIG. 4 . FIG. 8 is a cross section of the surface positioning guide taken about line 8 — 8 of FIG. 5 . FIGS. 9–10 are isometric illustrations of an alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1–2 , an embodiment of the present invention is illustrated as a removable surface positioning guide 10 for a rotary hand-held tool 12 (which is illustrated as a commercially available Dremel® rotary tool). Before turning to the details of the removable surface positioning guide 10 , a brief description of the rotary hand-held tool 12 will be given to provide a better understanding of the disclosed embodiments. Referring to FIG. 2 , the rotary hand-held tool 12 includes a generally ring shaped housing 14 which can be manually grasped for manipulation. The housing 14 contains a motor (not shown) and a rotary output at its front end shown as a chuck or collet 16 that is extended by a surface engaging bit 20 when attached. The collet 16 is driven about a tool axis 18 by the motor and provides for ready attachment and detachment from the surface engaging bit 20 which is used to engage a working surface. Also at the front end, the housing 14 defines a threaded attachment tip 24 which can be used to removably attach various surface positioning guides, such as the guide 10 disclosed herein. A protective cover or cap 26 that screws on the is threaded attachment tip 24 is typically provided to protect the threaded attachment tip 24 of the rotary hand-held tool 12 when a surface positioning guide attachment is not being used. Referring now to FIGS. 1–3 , the illustrated embodiment of the surface positioning guide 10 includes a mounting adapter 30 , a pivot body 32 , and a guide base 33 , which may comprise a pair of pillow blocks 34 and a base flange 36 . In a preferred embodiment, all of these primary structural components may be molded or formed from plastic material. With this arrangement axial sliding occurs with plastic to plastic sliding contact and pivoting occurs with plastic to plastic pivoting contact. The mounting adapter 30 integrally includes an internally threaded sleeve portion 38 that is concentric about the tool's rotational axis 18 . As indicated in FIG. 2 , the threaded sleeve portion 38 screws onto to thread threaded attachment tip 24 of the housing 14 of the rotary hand-held tool 10 . The mounting adapter 30 carries and supports, either directly or indirectly, the other components of the surface positioning guide 10 when mounted to the rotary hand-held tool 10 . The mounting adapter 30 also defines a central opening 39 extending therethough is sized and arranged to communicate the rotary output communicated by the collet 16 and the surface engaging bit 20 through the middle region of the surface positioning guide 10 when mounted to the rotary hand-held tool 12 . The pivot body 32 is slidably carried by the mounting adapter 30 . The pivot body 32 defines a central opening 41 therethrough about the tool axis 18 that slidably receives the mounting adapter 30 and that also provides central clearance for communicating the surface engaging bit 20 through the surface positioning guide 10 . To facilitate and guide linear sliding motion, and referring to FIGS. 1 , 3 , and 8 , the mounting adapter 30 integrally includes and unitarily defines a pair of linear guide rails 40 that are received in linear guide tracks 42 of the pivot body 32 . The ends of at least one of the rails 40 integrally defines a stop tab 44 that engages a corresponding abutment surface 46 on the pivot body 32 to limit how far the pivot body 32 can axially slide away from the mounting adapter 30 . The stop tab 44 may also be used to axially retain the pivot body 32 on the mounting adapter 30 as indicated in the preferred embodiment. Referring to FIGS. 3 and 7 , one or more springs 48 are arranged between the pivot body 32 and the mounting adapter 30 . The springs 48 may be contained within a spring chamber 50 , with different portions of the spring chamber 50 a , 50 b being integrally formed into the pivot body 32 and the mounting adapter 30 . As shown, when multiple springs are used, the springs are preferably equally spaced angularly about the tool axis 18 to ensure balance of forces along the linear guide mechanism. The springs 48 are supported by the mounting adapter 30 and serve to bias the pivot body 32 and the guide base 33 away from the mounting adapter 30 . The mounting adapter 30 also includes another stop which may be adjustable for limiting the linear sliding movement of the pivot body 32 and guide base 33 toward the mounting adapter 30 . In the disclosed embodiment, the adjustable stop is provided by a threaded bolt 52 that is screwed into a threaded hole 54 formed into the mounting adapter 30 . The threaded bolt 54 may be rotated to adjust its axial position with an axially aligned abutment surface 56 defined by an outward extending tab 58 on the pivot body 32 . When the end of the bolt 54 strikes the abutment surface 56 , the linear sliding movement of the pivot body 32 and guide base 33 is stopped. An advantage of this arrangement is that the guide base 33 is movable toward the mounting adapter 30 against the biasing of the springs 48 to effect a plunging movement such that the bit 20 driven by the rotary hand-held tool 12 can be plunged into a working surface. The adjustable stop provided by the threaded bolt 52 can be used to control the depth of the plunging movement and therefore the depth of the bit 20 into the working surface. Since the guide base 33 can be positioned against the working surface, the guide base 33 can be utilized to hold and position the rotary tool 12 at a fixed angular orientation, such the plunging movement can be effected directly along the axis 18 . This can prevent lateral movement or shifts in orientation, thereby increasing accuracy and precision when drilling holes with drilling bits or driving into a working surface with other surface engaging bits. In addition, a lock is preferably provided to hold relative axial positions when plunging movement is not desired. The lock is provided by a thumb screw 59 (shown as a shoulder bolt) that can be used to selectively clamp the pivot body 32 to the mounting adapter 30 . Although a thumb screw 59 is illustrated, it will be appreciated that the lock may be alternatively provided by other forms of clamping mechanisms or lock mechanisms (e.g. a pin and hole device). The thumb screw 59 is screwed into a nut 61 that is supported by the pivot body 32 . The end of the thumb screw 59 fits into a axial slot 63 formed into the mounting adapter 30 . The screw 59 can be selectively tightened to axially fix the relative positions of the pivot body 32 (and thereby the guide base) at one of a number of relative axial positions or selectively loosened to allow for plunging movement. The pivot body 32 defines a pivot axis 60 perpendicular to the tool axis 18 and a pair of cylindrical pivot support structures 62 that project laterally outward along the pivot axis 60 . The pivot support structures 62 may include lateral slits 64 such that the pivot support structures 62 have some flexibility and are able to flex radially outward slightly when wedges 70 , 71 are inserted into conical openings 66 formed centrally in the pivot support structures 62 . The slits 64 may also provide for a detent mechanism that provides for clicking between discrete angular positions when the guide base 33 is pivoted about the pivot axis 60 . Referring to FIG. 3 , the pillow blocks 34 of the support base 33 comprise pivot/hinge structures shown cylindrical openings 68 that slidably received the pivot support structures 62 of the pivot body 32 . The pillow blocks 34 are fitted on the pivot support structures 62 on opposed lateral ends of the pivot body 32 for pivoting movement relative thereto about the pivot axis 60 . The wedges 70 , 71 when pressed into the conical openings 66 of the support structure are operable to flex the pivot structures 62 outwardly in a manner that laterally retains the pillow blocks 34 on the pivot body 32 , while also allowing for pivoting movement of the guide base 33 relative to the pivot body 32 . One or more screws 74 may be used to better secure the wedges 70 , 71 in place if desired. In addition, one or both of the screws 74 can serve as a locking device for selectively fixing the angular position of the pivot body 32 relative to the guide base 33 . Although a thumb screw 74 is illustrated, it will be appreciated that the locking device may be alternatively provided by other forms of clamping mechanisms or lock mechanisms (e.g. a pin and hole device). The pillow blocks 34 carry and support the base flange 36 . The base flange 36 defines a central opening 76 that is large enough such that the central opening 76 axially aligns with central opening 39 of the mounting adapter 30 in different operable axial and angular positions between the guide base 33 and the mounting adapter 30 . In this manner, a suitable surface engaging bit 20 can be communicated through the openings 39 , 76 for engaging a working surface. The base flange 36 may comprise flat outer rail surfaces 48 that can be used to laterally position or offset the surface engaging bit 20 laterally from an edge or wall perpendicular to the working surface. However, it will be appreciated that the base flange 36 can alternative take multiple shapes or forms such as circular if desired. The base flange 36 may fully enclose the opening 76 or partially enclose the central opening 76 . The base flange 36 includes tabs 80 that project laterally outward. The tabs 80 slide and/or snaps into a corresponding receiving slots 82 formed into the pillow blocks 34 . In this manner, the base flange 36 is readily removable and can be interchanged with outer flange members of different configuration if desired. Additionally, the base flange 36 can be reversed to locate either a first face 84 or a second face 86 at the foremost end of the guide 10 and tool 12 , where the face is positioned for engaging and if desired sliding against a surface. This provides the advantage of further increasing versatility of the positioning guide 10 . As shown the first face 84 (currently located at the foremost end) is planar such that it can slide easily against a planar surface (e.g. drywall). The second face 86 is generally planar but also includes projecting guide tabs 88 that can be received into grooves in a working surface (e.g. such as grout grooves) which can be useful if it is desired that the surface positioning guide 10 follow a groove in the working surface during use. The guide tabs 88 are linearly aligned perpendicular relative to the pivot axis 60 such that the surface engaging bit 20 aligns linearly with the guide tabs 88 when in use. The base flange 36 can readily be reversed by unscrewing the thumb screw 74 and removing one of the pillow blocks 34 to release the base flange 36 . The base flange 36 can be flipped and reconnected to the pillow blocks 34 to selectively locate either of the first and second faces 84 , 86 at the foremost end for engaging a working surface. In either position, the base flange 36 is generally open above to provide viewing windows 98 . The viewing windows 98 may be defined by multiple components when assembled as shown in FIGS. 1 , 4 and 5 , where it is shown to be generally between the base flange 36 , pillow blocks 34 and pivot body 32 . Users can look through the viewing windows 98 to view the surface engaging bit 20 as it acts upon the working surface. The surface positioning guide 10 may also optionally include indicating mechanisms that indicate the angle and axial depth of the surface engaging bit 20 relative to the working surface when in use. Accordingly, an axial scale 90 and point 92 may be provided between the pivot body 32 and the mounting adapter 30 for indicating axial position and depth. An angular scale 94 and pointer 96 may be provided between the pivot body 32 and one or both of the pillow blocks 34 for indicating angular position. An alternative embodiment of a removable surface positioning guide 10 a is shown in FIGS. 9–10 . This embodiment is very similar to the first embodiment and it will be understood by one of ordinary skill in the art that this embodiment has similar structures that operate in a very similar manner to the first embodiment. Therefore, only significant changes will be addressed. First it will be noted that there are some cosmetic changes in the design of the surface positioning guide 10 a. Turning to other differences, the guide base and more particularly the base flange 36 a of this embodiment includes an intermediate cavity portion 100 along the outer rail surface 48 a . This provides laterally spaced coplanar linear guide edges 102 that are connected to the intermediate cavity portion 100 by rounded corners 104 . The advantage of this arrangement is that the outer rail surface 48 a of the base flange 36 a can slide flat or square against flat surfaces for accurate position and also can be maintained at a constant or predetermined location against circular, annular or curved surfaces in which the projecting portion or the working surface enters the cavity portion 100 and the rounded corners 104 engage two spaced points along the circular, annular or curved working surface. In addition, the arrangement of the axial locking mechanism has been rotated ninety degrees. As shown in FIGS. 9 and 10 , a thumb screw 59 a extends through the pivot body 32 a to engage a rail surface of the mounting adapter 30 a . Thus, the thumb screw 59 a need not extend through the pillow blocks 34 a. Although preferred embodiments have been shown, there are several alternatives that are also encompassed by the invention. For example, the pivot body 32 could be eliminated and pivoting could take place directly between the mounting adapter and the base member. Another alternative is that linearly sliding and/or plunging movement could take place between the pillow blocks or other support members and the base flange. The base could be a unitary member with integrally formed pillow blocks and base flange members. It should be appreciated that any single aspect, whether it be axially plunging, pivoting adjustment, or interchangeability of the base member could be provided independently in alternative embodiments, not just in combination as shown. These alternatives are not exhaustive of possibilities but are included herein to provide a more comprehensive understanding of the protection that is intended to be afforded herein. All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

A removable surface positioning guide for a rotary hand-held tool provides one or more adjustable features for selective positioning of a surface engaging bit driven by the rotary hand-held tool. The surface positioning guide may include a pivot joint between a guide base and a mounting adapter. The guide base pivots relative to the mounting adapter about the pivot joint between operable positions. The surface positioning guide may include at least one spring supported by the mounting adapter either directly or indirectly that biases a guide base axially away from the mounting adapter. The guide base is movable toward the mounting adapter against the biasing of the at least one spring to effect a plunging movement. The surface positioning guide may include a reversible or interchangeable base flange with differently configured faces that are adapted to be placed against a working surface.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to energy efficient buildings and more specifically to a building insulation system, which provides better insulating properties than that of the prior art and which removes humidity typically trapped in the walls, roof and insulation of the building. 2. Discussion of the Prior Art A brochure MB304 published by the North American Insulation Manufacturers Association (NAIMA) continuously since 1991 describes the state of the art most typically used to insulate roofs and walls of pre-engineered metal buildings. This type of building currently represents over 40% of all non-residential buildings of two stories or less built in the US each year. U.S Pat. No. 4,446,664 to Harkins discloses a building insulation system. U.S. Pat. No. 4,573,298 to Harkins discloses a building insulation system. U.S. Pat. No. 5,953,875 of Harkins discloses a slide-in building insulation system. U.S. Pat. No. 6,247,288 to Harkins discloses a roof fabric dispensing device for insulation systems and air barriers over the exterior plane of the building structural members. U.S Pat. No. 5,968,311 is a device for installing a vapor retarder over the purlins or joist to support insulation. U.S. Pat. No. 6,705,059 is a rolled fabric carriage device for unrolling a vapor retarding fabric over the tops of purlins which is used to support insulation. U.S. Pat. No. 6,216,416 is a system for installing insulation over purlins. U.S. Pat. No. 5,921,057 is an apparatus for dispensing an insulation support sheet over the purlins. U.S. Pat. No. 5,653,081 is a method for paying out an insulation support sheet for insulating a building roof over the purlins. U.S. Pat. No. 4,222,212 is an insulated roof over the purlins. There are temporary buildings, which have a waterproof coverings over the tops of framing members to form a roof covering and which are commonly used for agricultural and storage purposes. One common problem with the design of current buildings having integrated thermal insulation systems is the requirement for structural fastening of the insulation support apparatus through the plane of the insulation system. The “through-fastening” creates multiple thermal bridges, which reduces the building thermal performance up to fifty percent. The most predominant methods used to insulate pre-engineered metal buildings from as early as the 1950s, until today is simply draping the insulation over the exterior of the building structural members for support, applying the exterior building sheeting directly over the insulation and then applying the exterior sheeting attachment fasteners through the exterior sheeting, through the insulation from the exterior into the underlying building roof and wall structural members. This method results in thermal bridging fasteners with a frequency of about one fastener per every ten square feet of exterior surface area or less. A second common problem is that insulation products in building roofs and walls are sandwiched between the roof or wall structural members and the overlying building exterior sheeting with compression of the insulation thickness and its inherent loss of thermal performance which results from this compression. Placing the roof and wall insulation tightly against the exterior roof and wall sheeting panels blocks the solar heat energy from being absorbed and radiated off the interior surface of the sheeting materials for any practical use. The solar energy that hits the building roof and wall surfaces is lost from any practical collection and use. At the same time, fossil fuel energy is purchased to provide heating, cooling and hot water heating for the building occupants and processes. The third common problem of achieving energy efficient buildings is that the thermal insulation has traditionally been installed during the roof and wall sheeting process. Insulation methods which require the installation of fasteners from the interior during the integrated insulation and exterior sheeting process are shunned by installers of these materials in favor of methods that simply compress the insulation between the roof and wall structural members and the roof and wall sheeting panels with only externally applied fasteners. Such methods eliminate the need for fastening from the interior side of the roof and wall structure during the insulation and sheeting process and therefore are preferred by installers. This practice severely limits the thermal performance of the buildings to much less than the desirable economic insulation levels. Due to the insulation thickness reductions and thermal bridging, building thermal performance is much less than what is required to honestly meet the minimum installed thermal performance criteria set forth by the various state energy codes. The most common building insulation methods not only compress the insulation thickness by variable percentages, but also thermally bridge the exterior conductive building sheeting surfaces to the interior exposed thermally conductive surfaces of the purlins, joists and girts. These structural configurations maximize the uncontrolled heat transfer between the two thermally bridged surfaces on the opposite sides of the thermal insulation layer and will frequently result in seasonal condensation on the interior exposed building structural members. The roof and wall structural members become very hot in the summer, when the heat is not wanted in the building interior conditioned space and are cold in the winter, when the heat is wanted in the building interior conditioned. Buildings that are thermally bridged between through the thermal insulation with exterior exposed conductive sheeting materials and interior exposed conductive roof purlins or joist and exposed conductive wall girts result in the opposite seasonal heat transfer effect that is desired and major loss of heating energy. The cold exterior surface temperatures in the winter typically float up and down crossing over the dew point temperature of the interior conditioned air and also of the dew point temperature of the air trapped within the insulation of the roof and wall assemblies of the building. Fiberglass insulation is mostly air. This condition results in condensation of the water vapor that increases conductivity and reduces the insulation thermal performance, which may result in permanent building structural damage and may also interfere with the building use. If the condensed liquid water accumulates within the building roof and wall assemblies it may also result in dripping and damage to interior building contents. Prior art like that disclosed in the Harkins U.S. Pat. No. 4,446,664 invention uses a steel strap support system, which temporarily spans across building bays with steel straps fastened at their ends and often installed in a woven mesh. A flexible sheet material is custom fabricated to fit the designated building areas, referred to as building bays, with the absolute minimum of field seams except along the building bay perimeter beams, where there is no problem sealing the edges as the workmen work on the top side of the rafter beams. The flexible sheet material is spread out and clamped in position on the platform of spanned support strapping and then fasteners are required to be installed through the steel straps and sheet material from the building interior into the inside flange of building roof purlins or joist from the interior. This method requires approximately one interior applied fastener for every 30 square feet of the building roof or wall structures. Each fastener is a thermal bridge between the steel strapping and the metal structure to which it is attached. The invention of the U.S. Pat. No. 4,446,664 creates a defined space for insulation to expand, which eliminates virtually all unwanted compression of the insulation in the roof structures. This method also completely isolates all-of-the highly conductive metal roof and wall purlins or joist surfaces from direct contact with the interior conditioned air. This system however requires the installation of the fasteners from the interior of the building during the integrated process of installing the insulation and the sheeting of the building's exterior roof surfaces. The Harkins '664 patent, while much more thermally efficient than typical methods, is often avoided in favor of much less thermally efficient insulation products and methods which do not require fasteners to be installed from the building interior during the integrated roof insulation and exterior roof sheeting process. Another problem that occurs in metal panel sheeted buildings is seasonal condensation problems in the wall and roof systems. This phenomenon becomes particularly evident with metal-sheeted buildings because the metal panel temperatures change almost instantly with a change in exterior temperatures. Typically, water vapor within the building interior conditioned space concentrates along with a natural heat gradient at the highest elevations within the building heated space. The concentration of water vapor in air is often measured and expressed as relative humidity. The warmer the air mixture is, the more the weight of water, in vapor form, it can hold. Water vapor will condense on any surface of the building structure it contacts, which is below its dew point temperature. The dew point temperature is the temperature at which the relative humidity of the air contacting the cooler surface will reach 100% relative humidity and begin depositing the excess water vapor as liquid water on that cooler surface. A similar phenomenon occurs within an air mixture itself as it cools and this condensation manifests itself as fog, dew, rain and other forms of precipitation. In buildings, water vapor will migrate through the vapor retarders, through poorly sealed joints, through staple holes, through gaps, etc. and will condense on the interior surface of the exterior sheeting panels when the exterior surface temperatures are below the dew point temperature of the air mixture within the insulation space of the roof and wall assemblies of the building. The typical preferred insulation methods fill the roof and wall assemblies to the exterior sheeting and any moisture is trapped inside of the wall and roof assemblies. The moisture may condense and may accumulate seasonally during cold temperatures. This trapped water vapor and resultant liquid water will cause premature deterioration of the building roof and wall building components and will shorten the useful life of the building if it can't escape naturally. Many older metal buildings leak air or breathe through the eave and wall flashings and the unsealed wall panel joints due to wind pressure differences. This breathing allowed much of the trapped water vapor to escape, but at the expense of thermal insulation performance. New energy code requirements for sealing all construction joints will essentially eliminate this typical water vapor escape mechanism resulting in a much greater potential for condensation and accumulation of liquid water within these building roof and wall assemblies of the future. Buildings that have the compressed thermal insulation, buildings that attempt to fill the roof and wall cavities, buildings that have thousands of staple holes along uniformly spaced insulation facing seams, buildings that have substantially thermally bridged conductive interior and exterior surfaces, buildings that trap and accumulate condensed water vapor within the insulated roof and wall assemblies, and buildings which repel the free solar heat energy hitting its exterior surfaces require significantly greater heating and cooling equipment capacities, require excessive fuel piping, require excessive electrical wiring, require excessive service capacities and cost significantly more to heat, cool and ventilate than would be required, if the above mentioned problems were solved. Accordingly, there is a clearly felt need in the art for a building insulation system, which provides the following useful advantages: That creates a defined space of sufficient air volume and distance between the roof and wall thermal insulation layer and the conductive exterior sheeting materials to achieve the economic insulation thickness and air gap space to operably manage the intrinsic air mixture, the air flows within and the collection of solar heat from the adjacent heat absorbing, conducting and radiating surfaces of the exterior building sheeting and of their thermally bridged roof purlins and wall girt structural members. That creates a continuous insulation layer without having structural thermal bridging, nor having fasteners inserted through the insulation layer to support itself. An insulation layer that is supported completely from the interior side without the need for any fasteners installed from the interior during the integrated ceiling thermal insulation and exterior sheeting process of a building. That provides for the natural collection and concentration of heat energy within defined air gap spaces created within the roof and wall assemblies, which heat can be actively collected from the defined spaces by one of several methods and used to reduce energy consumption for the building, its occupants and related processes. That provides for water vapor control within the defined roof and wall assembly spaces to concentrate the water vapor by natural means and to actively remove and collect the water from the roof and wall defined air gap spaces as required to minimize any damaging accumulation and allow the simple collection and use of the clean water for various useful purposes. That maximizes the absorption, collection and transfer of solar heat energy hitting the exterior surfaces of the building and to actively use the clean solar energy to reduce the consumption of purchased energy for the building interior space conditioning and related use processes. The colors and the emissivities of the roof and wall exterior sheeting panel surfaces can be selected to maximize solar energy absorption, transfer and use of the free solar energy, as opposed to reflecting it back into the external environment with it's value completely wasted, as is currently the predominant practice and also part of a growing trend known as “cool roofs” and highly reflective, “low emissivity” surface coating. That use an active heat collection duct and piping systems installed at optimal locations within the defined air gap layers created within the walls and roof assemblies as a source for concentrated heat to be used directly with air circulation and/or indirectly through the use of a heat exchanger system such as a water pumping and storage system with fan-coil heat transfer units, baseboard type heating radiators, or the use of electric powered, refrigerant type of compressor driven electric heat pumps that collect heat from the pre-heated, pre-concentrated air within the solar wall and solar roof air gap layers in lieu of exterior unheated ambient air as a source for the heat energy it collects and transfers. Efficiencies of over 50 Btu's per watt are expected from this new solar heat pump building invention. That would facilitate the collection, concentration and storage of the clean solar heat energy in water stored in insulated reservoirs for off peak demand use for space heating and hot water production processes. Excess heat energy collected can be used to melt snow and ice off roofs, driveways, sidewalks, etc. to eliminate typical removal costs, saving equipment costs, time and additional energy. The relatively clean water from snow and ice melting can also be collected, and recycled for many useful purposes. That interconnects the wall solar energy air gap collection system to the roof solar energy air gap layer collection system which will facilitate the transfer of concentrated heat from the wall air gap layer to the roof air gap layer on demand. This heat transfer allows the building roof to be kept free of snow and ice by using solar heat energy collected in the wall air gap layer to maintain the solar exposed roof absorptive surface area exposed to direct solar energy to absorb the maximum solar energy possible. That will use free solar heat from the solar wall collection system to eliminate ice damming on cold roof edges by keeping them free of ice accumulation caused by chronic build-up of ice from very slow melt of snow and ice off the exterior roof sheeting due to thermal bridging from the interior conditioned space and through the compressed thermal insulation. That uses a subterranean air tubing and air conditioning system to pre-condition incoming ventilation air in all seasons to save energy and to also to simultaneously remove water vapor from warm, humid, incoming air during the summer cooling season, thereby reducing both the latent and sensible cooling loads required to maintain the interior conditioned space temperature and humidity at desired levels. That simplifies the installation process and eliminates the requirement for any fastening from the interior of the building during the integrated process of installing the insulation support sheet material, the roof insulation and the exterior sheeting panels of the building roof. That eliminates thermal bridging through the roof insulation to support the insulation layer. That eliminates thermal bridging through the wall insulation layer for support of the insulation. That reduces the need for energy for building environmental space conditioning to such a low level, that for practical investment payback reduces the building life cycle cost to a degree that renewable energy generation may be added to the building project so that it annually requires a net total of zero or less purchased energy for typical building conditioning and lighting loads, excluding other user loads, if any. SUMMARY OF THE INVENTION The present invention provides a building insulation system, which includes better insulating properties than that of the prior art and which removes humidity typically trapped in the walls, roof and insulation of the building. A solar heat pump building preferably includes a building, at least one air gap heat collection layer, a tension supported flexible sheet material layer, a material insulation layer retained by the sheet material, a plurality of air ducts, a plurality of air duct dampers, a plurality of heat collection pipes, and an active mechanical heat pump collection, concentration, transfer and distribution system. The building is preferably a metal building, but other types of buildings may also be adapted for use with the invention. The typical metal building includes a plurality of rafter columns, a plurality of end columns, a plurality of girts, a plurality of girt clips, a plurality of rafters, a plurality of purlins, a plurality of purlin clips, a plurality roof panels, a plurality of wall panels, and a plurality of bolts, nuts, fasteners, flashings and sealants. The plurality of rafter columns and the plurality of end columns are attached to a foundation to form a perimeter of the metal building. The plurality of girts are retained by clips extending off the exterior surfaces of the rafter columns and by a plurality of girt clips extending off the exterior surfaces of the end wall columns with girts spanning between adjacent pairs of the plurality of rafter columns girt clips and between adjacent pairs of the plurality of end wall column girt clips. The plurality of rafters are attached to a top of the plurality of rafter columns. Rafters are attached to the top of the building corner rafter columns at the end walls and also are attached between building corner rafters columns to the tops of a plurality of the end wall columns. The plurality of roof purlins are retained by a plurality of purlin clips extending above the exterior surface of the plurality of rafters. The plurality of ceiling sheet material support struts are retained spanning between, or over, adjacent pairs of the plurality of rafters. The solar heat pump building roof system includes the exterior roof sheeting panels, a purlin structural support system, an air gap heat collection layer, a material insulation layer, at least one insulation supporting sheet material, sheet material support struts and eave inside corner sheet material support struts. Each ridge sheet material support strut is attached spanning between adjacent pairs of rafters and supported by the building rafters. At least one sheet material support strut is attached below a ridge of the building roof and defines the inside sheet material ceiling line below the ridge. Each sheet material eave support strut is attached in an inside corner between two adjacent rafters/rafter columns and defines the inside corner of the ceiling and wall junction of the sheet material in the building. For ease of installation a sheet material may extend continuously from a ridge sheet material support strut around the outside of an eave support strut to a termination point at a floor of the building or alternatively to a termination point created between the floor and the inside corner support strut. The ceiling sheet material is attached at opposing termination points with adhesive, a tensioning device or any other suitable attachment devices and methods. At least one tensioning device is preferred for each sheet material to control and manage deflection of the sheet material within desirable limits. Alternatively, the sheet material extends from the floor of one side of the building around the exterior of one inside corner eave support strut, over a ridge support strut, around the exterior of the opposite wall inside corner eave support strut and downward for attachment to the floor on an opposing side of the building. Alternatively the ceiling sheet material may be terminated at an intermediate ceiling, eave or wall support strut. Intermediate support struts may be attached spanning between or over two adjacent roof rafters, between to adjacent rafter columns or between two roof purlin clips or wall girt clips. The ceiling material insulation layer is inserted between at least one ceiling sheet material and a bottom of the plurality of roof sheets and preferably a bottom of the roof purlins with a air gap layer created to the exterior side of the material insulation layer. A plurality of vent spacer blocks may be attached to the interior or exterior facing flanges of the purlins prior to installation of the exterior metal roof panels. The vent spacer blocks have vent holes to insure the heat and convection air naturally flows between the roof air gap layer spaces between adjacent purlins within the solar heat pump building roof. The plurality of thermally conductive metal roof panels are attached to the outer surface flanges of a plurality of the roof purlins. The building air gap heat collection layer is thereby created between an outer surface of the ceiling insulation layer and the inside surface of the roof metal sheeting panels. The purlin clips on the rafters may be extended to provide the desired distance for the ceiling insulation layer without compression of the designed insulation thickness. The typical metal building ridge cap may be used to complete the roof at the building ridge but with less efficiency than the optional multi-vent. An optional ridge mounted multi-vent extends through a ridge of the roof and extends any length of the roof desired by the designer. The ridge mounted multi-vent replaces the typical metal building ridge cap and is located between two ridge purlins or at the high side of the building if the building is a single slope building. The multi-vent provides heat collection, heat concentration, heat transfer, ventilation, dehumidification, day-lighting and building management functions. The solar heat pump building wall system preferably includes an exterior metal wall panel, thermally conductive metal girts, an air gap heat collection layer, vent spacer blocks on interior girt flanges, a first exterior sheet material which is typically an extension of the ceiling sheet material, a material insulation layer, a second interior wall sheet material which covers the wall material insulation layer from the exposure to the building interior space, and a means of using the concentrated heat within the air gap layer(s). The solar heat pump building end wall systems contain the same general components as a side wall system. The solar heat pump buildings preferably include a plurality of inner girt vent spacers and may also include a plurality of outer girt vent spacers containing a plurality of air vent holes to ensure the natural concentration of heat energy at the top of the wall air gap layer and allow convection air flows between girt spaces within the wall heat collection air gap layer of a system. Solar collected heat rises naturally and concentrates at the highest points of the wall and roof air gap layer(s) that it can achieve. A plurality of outer girt vent spacers may be attached to the exterior facing flanges of the girts prior to installation of the exterior metal wall sheeting panels. The inner girt vent spacers are attached to the interior facing flanges of the girts prior to installation of the first (exterior) sheet material which defines the interior surface of the wall air gap layer. A plurality of rigid formed insulation hangers are then attached to the interior facing surface of the first (exterior) wall sheet material. A material insulation layer is attached in substantial contact without the interior-most surface of the first (exterior) wall sheet material using the pre-installed insulation hangers. The material insulation is impaled on the rigid formed insulation hangers designed for this purpose which are completely supported by the exterior wall sheet material and not fastened to the building girts to eliminate thermal bridging to the material insulation layer. A top of each second (interior) wall sheet material is securely attached to the ceiling sheet material, such that it's outer surface is in substantial contact with an inner-most surface of the wall material insulation layer. A bottom of each interior wall sheet material is attached to floor with adhesives, tensioning device, or other other suitable attachment means, such that it contacts the wall material insulation layer. The material insulation layer is thereby sandwiched between the first and second wall sheet material layers. The solar heat collecting wall air gap layer is thereby created between an inner surface of the exterior wall panel and the outer surface of the first (exterior) wall sheet material layer The solar heat pump building wall heat collection air gap layer is preferably connected to the roof heat collecting air gap layer at their intersection at the building eave area so that the concentrated wall heat may be naturally transferred to the roof air gap layer, preferably on demand, by using a damper system at this junction, and the wall heat energy therefore used to keep the building roof heat absorbing surfaces fully exposed to absorb solar energy by keeping the roof surfaces free of snow and ice with free solar heat. The plurality of wall ducts include side wall ducts and end wall ducts. The plurality of side wall ducts preferably include two side wall eave line roof ducts, two side wall upper wall ducts, two side wall base ducts and two side wall subterranean air ducts. The plurality of end wall ducts preferably include two upper wall ducts and two end base wall ducts. Each duct includes a rectangular (preferably square) tube, which preferably includes a plurality of air flow holes formed through the sides thereof. A damper strip slot is formed in all four sides to receive a sliding damper strip. The damper strip also includes a plurality of air flow holes. The hole locations and hole sizes in the damper strip are engineered to equalize the collection (intake) and distribution (exhaust) of air flows evenly through the wall and roof air gap layers along the length of each duct to maximize the collection and concentration efficiency of heat energy rising through the walls and roof of the solar heat pump building. A damper strip actuation device is used to open and close the plurality of air flow holes of the various air flow paths on demand by sliding the damper strips in a damper slot of a duct. Duct end caps are used to enclose the air streams between the ends of duct sections as desired. Each side wall eave roof duct is located at the top of the wall air gap layer to communicate with the roof air gap layer. Each side wall upper wall duct is located immediately below a side wall eave roof duct and communicates with the wall air gap layer. The side wall eave roof ducts are capable of receiving outside air through its air flow holes or a branch duct which communicates the upper wall duct or with the outside air. The side wall eave roof ducts are also capable of receiving heat and air through its air flow holes or a branch duct which communicates with an upper side wall duct. The upper side wall ducts and upper end wall ducts collect heat energy and air from the respective wall heat collecting air gap layers through the air flow holes which communicate with the wall air gap layer below the respective upper wall ducts. The side wall and end wall base ducts are at the base of the respective wall heat collecting air gap layers. A wall base duct is located adjacent the wall sheeting panels, above the floor, with air flow holes which communicate with the wall air gap layer. A side wall or end wall base duct is capable of receiving outside air through its air flow holes or a branch duct which communicate with the outside air. The side wall or end wall base duct is also capable of receiving interior space air through its air flow holes or a branch duct which communicate with the interior space air. The side wall and end wall base ducts are capable of supplying air to the bottom end of the wall heat collection air gap layer from either the outside air or the inside air or both, through its air flow holes which communicate with the wall air gap layer. The air flows are preferably controlled by an active damper in a damper slot or in the branch duct, as applicable. Two subterranean air ducts are located adjacent to the interior foundation walls at two opposite building walls, at or below floor level and extend substantially the length of each respective opposing building wall. A wall subterranean air duct communicates with the interior space air through air flow holes or branch ducts. The opposite subterranean air duct communicates with the outside ambient air through a branch duct, containing a damper and an internal, air stream mounted fan powered by energy. A plurality of subterranean tubing is located below a floor of the building preferably at a depth of six to eight feet with each opposing tube end connected to the opposing subterranean duct located near the floor adjacent to the opposing foundation walls of the building. Warm outside air flowed through the plurality of subterranean ducts and subterranean tubing will be cooled by a cooler ground temperatures during the cooling season. Outside warm humid air flowed through a plurality of the cooler subterranean ducts and subterranean tubes will be naturally dehumidified by the cooler earth ground temperatures during the cooling season. Cooler air flowed through the plurality of subterranean ducts and subterranean tubes will be warmed by a warmer earth ground temperature during the heating season. It is preferable that the plurality of subterranean ducts be oriented either parallel to the ends of the building or parallel to the sides of a building which are substantially opposite each other and the plurality of the subterranean tube ends connect between the to opposing wall subterranean ducts. It is preferred that each subterranean tube be sloped to a low point and connected to a common drain pipe to collect seasonal condensation and pipe it to run by gravity to a common collection reservoir for recycling for other uses. The ridge mounted multi-vent device includes a plurality of vent modules attached in series. The plurality of vent modules are connected to each other end-to-end with any suitable attachment device or method such as installing bolts or screws. Each vent module includes a box unit. The box unit includes a vent base, two end walls, two side walls and two box side flanges. The two end walls extend upward from opposing ends of the vent base and the two side walls extend upward from opposing sides of the vent base. A single flange extends outward from a top of each box side wall. At least one opening is formed through each end wall to allow the flow of air between adjacent modules. A hole may also be formed through each end wall to receive a heat collecting pipe apparatus. This pipe apparatus would include pipe, heat collecting fins, condensation collecting trough, joint connectors, support brackets and drain tubing. The top and bottom covers include a cover portion and a pair of cover side flanges. The cover side flange extends from each side of the cover portion. A sealing material may be placed between the cover side flanges and the box side flanges. A sealing material may be placed between the cover ends and the box end panels. The cover is fabricated from a material, which is light collecting, light diffusing, light transmitting, light concentrating, light reflecting or opaque to light. The box unit may have side wall and end wall wall extensions with are adapted to make the overall height of the box unit fit the thickness of the building roof assembly to close any air leaks between the interior space air and the roof insulation and air gap layer. Damper strip slots are formed in the box side wall panels to receive a sliding damper strip similar to that of the wall ducts. A plurality of air flow holes are formed through the box side wall panels within the slot. The damper strip includes a plurality air flow holes, which generally align with the plurality air flow holes in the box unit side walls. A continuous damper strip may be installed spanning between multiple multi-vent modules to be operated by a single damper actuator. The damper strip may be shifted in the damper slot with a damper strip actuation device to allow the air flow holes to be opened or closed to any degree by sliding a damper strip in the damper slot. The collected solar heat entering the multi-vent is naturally concentrated from the roof solar heat collection air gap layer of the roof on either side of the ridge or both. The solar heat collected in the wall air gap layer may be extracted at the top of the wall air gap layer or passed on upward into the roof solar heat collection air gap layer to be carried further upward and concentrated below the ridge cap or in the multi-vent for extraction for direct use as heated air, for extraction for indirect use by a heat absorption pipe of a heat pump for space heating, for heating process water, for the generation of power, for other useful purposes or may simply be exhausted to the atmosphere to cool the building roof. The optional multi-vent forms a heat and air collection duct when joined end-to-end which can be connected to an in-line branch duct containing a powered fan or to an air handler unit to efficiently move and concentrate the solar heated air of the solar heat pump building air gap layers for useful purposes, rather than simply wasted as is the current state of the art. Accordingly, it is an object of the present invention to provide a building insulation system, which creates an air gap layer between the roof and wall thermal insulation layer and the conductive exterior sheeting and framing materials to operably manage the intrinsic air mixtures, the heat and air flows and the collection of solar heat from the adjacent heat absorbing surfaces of the exterior building sheeting panels and thermally bridged to conductive roof purlins and wall girts. It is a further object of the present invention to provide a building insulation system, which creates a continuous insulation layer without having structural thermal bridged fasteners inserted through the insulation layer to retain the insulation system layer. It is another object of the present invention to provide a building insulation system, which has an insulation layer without fasteners being installed from the interior side through a sheet material to roof purlins or wall girt framing. It is yet a further object of the present invention to provide a building insulation system, which does not require the installation of bottom side fasteners during the process of installation of the insulation and roofing of a building. It is yet a further object of the invention to provide a method of installation of a ceiling sheet by tensioning a sheet material over underlying support struts to safely support it's designed loads below the purlin or joist structures of a building without the need for fasteners to be installed from the interior side during the process of installing the material insulation layer and roof sheeting materials to complete a building roof system. It is yet a further object of the invention to provide a building insulation system with a tensioned ceiling sheet that will provide fall protection safety for workmen installing building construction materials above the upper surface of an installed tensioned ceiling sheet. It is yet a further object of the invention to provide a building insulation system with a tensioned ceiling sheet material system structure, which will support a 400 pound weight object, nominally 30 inches plus or minus two inches in diameter, dropped from height not less than 42 inches above the plane of the tensioned ceiling sheet material without the weight falling more than six feet below the bottom plane of the sheet material. It is yet a further object of this invention to provide a building insulation system with an installer safe fall prevention feature employing a tensioned ceiling sheet material building structure that will support in tension, between opposing attachment points, a minimum of 1000 pounds of static weight superimposed on a upper side of the sheet material. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building structure which provides for the natural concentration of heat energy within the defined air gap spaces created within the roof or wall assemblies, where heat can be actively managed and collected from the defined spaces by any of several methods and used to reduce energy consumption for the building, its occupants or for other processes. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building structure for water vapor collection and control within the roof and wall defined air gap layer to concentrate the water vapor by natural means and actively condense and collect the liquid water from the roof and wall defined air gap layer spaces of the building. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building structure, which maximizes the absorption, collection and transfer of solar heat energy hitting the exterior surfaces of the building for the active use of the solar energy to reduce the consumption of purchased energy for the building interior space conditioning and processes. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building structure, which uses an active heat collection piping system installed at desirable locations within the defined air gap spaces created within a wall or roof assembly as a source for naturally concentrated heat energy to be used directly with active air circulation and/or through the use of an active indirect heat exchanger system. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building, which would facilitate the collection, concentration and storage of the solar heat energy in water stored in reservoirs for off peak demand use for space heating and for hot water processes. It is yet a further object of the present invention to provide a building insulation system to create a solar heat pump building, which uses a subterranean air tubing as an air conditioning system to pre-condition incoming ventilation air in any season to save energy and to also to simultaneously remove water vapor from incoming humid air. Finally, it is another object of the present invention to provide a building insulation system to create a solar heat pump building, which reduces the need for energy for the building environmental space conditioning to such a low level, that for very practical investment, renewable energy generation may be added to the building so that it annually requires zero or less net purchased energy for typical space conditioning and lighting needs excluding other user loads. These and additional objects, structures, advantages, features and benefits of the present invention will become apparent from the following specification. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective cutaway view of a typical metal building. FIG. 1 a is a perspective cutaway view of a typical metal building with a plurality of ducts installed. FIG. 2 is a cross sectional end view of a metal building, before installation of a tensioned ceiling or wall sheet material in accordance with the present invention. FIG. 3 is a cross sectional end view of a metal building, as a sheet material is partially installed over sheet material support struts in accordance with the present invention. FIG. 4 is a cross sectional end view of a metal building, after installation of a sheet material when a sheet material is terminated at a ridge sheet material support strut in accordance with the present invention. FIG. 4 a is an enlarged cross sectional end view of a ridge ceiling support strut for retaining a ceiling sheet material in a metal building with a termination of the sheet material at one of two adjacent ridge ceiling sheet material support struts in accordance with the present invention. FIG. 4 b is an enlarged cross sectional end view of an eave inside corner support strut for retaining a ceiling sheet material in a metal building in accordance with the present invention. FIG. 5 is a top view of a metal building containing purlins and ceiling sheet material support struts, prior to the installation of a ceiling sheet material, a thermal insulation layer and roof sheeting panels in accordance with the present invention. FIG. 6 is a cross-sectional top view of a metal building below purlins with at one ceiling sheet material installed and another in a cut-a-way view showing underlying ceiling sheet material support struts in accordance with the present invention. FIG. 7 is a cut-a-way top view of a metal building with a ceiling insulation layer installed on top of at least one ceiling sheet material prior to the installation of any roof sheeting panels in accordance with the present invention. FIG. 8 is a cut-a-way top view of a metal building with a ceiling insulation layer installed on top of at least one ceiling sheet material and a roof panel installed on top of a plurality of purlins, an air gap layer is formed between a ceiling insulation layer and a roof sheeting panel in accordance with the present invention. FIG. 9 is a cross sectional end view of a metal building with subterranean air conditioning ducts and tubing installed below a floor with a condensate drain pipe and water collection reservoir in accordance with the present invention. FIG. 10 is a partial cross sectional end view at a side wall column location of a metal building illustrating a side wall from a foundation and floor to the eave and roof of the building in accordance with the present invention. FIG. 10 a is a turnbuckle tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 b is a right angle take-up tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 c is a hook and treaded rod tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 d is a ratchet strap tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 e is a turning shaft tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 f is a single adjustable strut tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 g is a bidirectional adjustable strut tensioning device for tensioning a wall or ceiling sheet material. FIG. 10 h is a strap winch tensioning device for tensioning a wall or ceiling sheet material. FIG. 11 is a partial cross sectional view of a metal building illustrating an end wall from foundation and floor to a gable end eave and roof of a building at the location of a ceiling sheet material support strut in accordance with the present invention. FIG. 12 is a top view looking into a side wall or an end wall of a metal building illustrating an air gap layer, a material insulation layer and a girt with interior and exterior flange mounted vent spacers in accordance with the present invention. FIG. 13 is an end view looking into a side wall or an end wall of a metal building illustrating an air gap layer, a material insulation layer and a girt with interior and exterior flange mounted vent spacers in accordance with the present invention. FIG. 14 is an enlarged cross sectional end view of a heat collecting dehumidifier pipe with square fins retained above a water collection trough in a ridge air gap layer or in a ridge mounted multi-vent, which may also be used in an upper wall air gap layer or upper wall duct to collect heat and dehumidify the wall or roof air gap air in accordance with the present invention. FIG. 15 is an enlarged cross sectional end view of a heat collection coil/dehumidifier retained above a water collection trough in a wall duct or a multi-vent in accordance with the present invention. FIG. 16 is an exploded perspective view of a single duct module with an end cap, but without damper strips in accordance with the present invention. FIG. 17 is a perspective view of a damper strip for insertion into a damper strip slot of a duct module or multi-vent module in accordance with the present invention. FIG. 18 is an exploded perspective view of a ridge mounted multi-vent, a similar multi-vent turned ninety degrees may be mounted in place of an upper wall duct in a sidewall or end wall to function for system inspection, wall daylighting purposes and other uses in accordance with the present invention. FIG. 19 is an end view of a box unit of a ridge mounted multi-vent with a damper slot formed in the opposing sides thereof to retain two operable damper strips in accordance with the present invention. FIG. 20 is an end view of a box end panel extension of a ridge mounted multi-vent in accordance with the present invention. FIG. 21 is a cross-sectional end view of a typical metal building ridge cap made of a formed corrugated roof panel in a building ridge, which matches the corrugation configuration of roof panels. FIG. 22 is an alternative cross-section end view of a typical metal building ridge cap formed into two flat planes and two formed metal closures to fill in the corrugation profile of the roof sheeting panels, a closure installed on each side of a ridge, the ridge cap does not need to match the roof panel corrugation with this design. FIG. 23 is a perspective view of a modular duct connection coupling in accordance with the present invention. FIG. 24 is a side view of a duct module with the duct connect coupling installed on one end in accordance with the present invention. FIG. 25 is a perspective view of a bi-directional insulation hanger device designed to quickly impale and suspend from a wall sheet material on one side and to support an impaled insulation layer on the opposing side without any thermal bridging to a metal wall girts or to the interior space air in accordance with the present invention. FIG. 26 is a rear view of the bi-directional insulation hanger device illustrated in FIG. 25 in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to the drawings, and particularly to FIGS. 1 and 10 , there is shown a cut-away perspective view of a metal building 100 . With reference to FIGS. 10 , 11 , the metal building 100 preferably includes a heat collection air gap layer 10 , 12 , air vent spacers 36 , 38 , an insulation retaining sheet material 14 , 30 , a material insulation layer 16 , 32 , 34 and a plurality of ducts 40 , 42 , 44 , 48 , 50 . The metal building 100 is shown, but other types of buildings may also be used. The metal building 100 includes a plurality of rafter columns 102 , a plurality of end columns 104 , a plurality of wall girts 106 , a plurality of rafters 108 , a plurality of purlins 110 , 128 , 134 , a plurality roof exterior sheeting panels 112 , a plurality of wall exterior sheeting panels 114 and a peripheral base channel 116 . The plurality of rafter columns 102 and the plurality of end columns 104 are attached to the peripheral base foundation 118 . The peripheral base channel 116 is attached to a foundation 118 to form a perimeter of the metal building 100 . The plurality of girts 106 are retained between horizontally extended girt clips 111 , off the exterior surfaces of the plurality of rafter columns 102 and end columns 104 . The plurality of rafters 108 are attached to a top of the plurality of rafter columns 102 . The plurality of purlins 110 , 128 , 134 are retained between vertically extended purlin clips 113 above the exterior faces the plurality of rafters 108 . With reference to FIGS. 10 and 16 , the heat collecting air gap layers include a roof heat collecting ceiling air gap layer 10 and a wall heat collecting air gap layer 12 , which communicate with each other on demand through duct damper holes 56 to increase the total heat collector surface area available to absorb solar heat. The solar heat from the east, west, south or north walls can be individually directed through ducts 40 , 42 , 48 through damper holes 56 to the solar exposed roof 120 , to melt snow and ice, thereby maximizing the total heat absorption surface area to achieve greatest volume and heat energy concentration. With reference to FIGS. 2-8 , the composite roof assembly preferably includes at least one ceiling sheet material 14 , a ceiling material insulation layer 16 , at least two intermediate ceiling support struts 18 , at least two ridge ceiling support struts 20 and at least two eave inside corner ceiling support struts 22 . Each intermediate ceiling support strut 18 and eave inside corner ceiling support strut 22 are attached between two adjacent rafters 108 . Each ridge ceiling support strut 20 is attached to two adjacent rafters 108 adjacent a ridge 122 of the roof 120 and vertically aligned below the roof 120 ridge purlins 128 . Each eave inside corner ceiling sheet material support strut 22 is attached to define an inside corner between a roof 120 and a side wall 124 sheet materials 14 , 30 of the metal building 100 . One end of the ceiling sheet material 14 is inserted behind the eave inside corner ceiling sheet material support strut 22 , above the intermediate ceiling sheet material support struts 18 , above the ridge ceiling sheet material support strut 20 adjacent a ridge 122 of the roof 120 and securely attached to the nearest ridge ceiling support strut 20 with fasteners or the like. The other end of the ceiling sheet material 14 is attached to either a foundation 118 or a floor 126 of the metal building 100 with adhesive, a tensioning device 24 or any other suitable means. With reference to FIGS. 10 a - 10 h , a variety of tensioning devices include a turnbuckle tensioning device 202 , a right angle take-up tensioning device 204 , a hook and threaded rod tensioning device 206 , a ratchet strap tensioning device 208 , a turning shaft tensioning device 210 , a single adjustable strut tensioning device 212 , a bi-directional adjustable strut tensioning device 214 and a strap winch tensioning device 216 . Alternatively, one end of the sheet material 14 is secured to the foundation 118 or the floor 126 on one side of the metal building 100 and the other end of the sheet material 14 is inserted around the exterior side of one eave inside corner ceiling support strut 22 , inserted over the intermediate ceiling sheet material support strut(s) 18 , inserted over the two ridge ceiling sheet material support struts 20 , inserted over the opposite side intermediate ceiling sheet material support strut(s) 18 , inserted over the opposite side eave inside corner, ceiling sheet material support strut 22 and finally secured with a tensioning device 24 or any other suitable means to the foundation 118 or floor 126 on an opposing side of the metal building 100 . Significant tension is typically required to limit deflection when supporting the load of the material insulation layer without the intermediate fasteners and the resultant thermal bridging common to all known prior art. The ceiling insulation layer 16 is laid on the at least one ceiling sheet material 14 and includes an insulation thickness that extends upward to near the bottom of the plurality of purlins 110 . Although not required, an air flow path is desired between the material insulation layer 16 and the bottom of the plurality of purlins 110 to allow cooler, more dense air to flow toward the eave purlin 134 to more efficiently complete the movement of the heat energy up over the purlins 110 to the ridge 122 and allow the cooler, more dense air is allowed to flow back down toward the eave purlin 134 . Open web purlins and joists are not shown, but allow the heat energy, humidity and air to flow in all directions without this efficiency concern. FIGS. 12-13 show a plurality of inner vent spacers 38 that include air vent holes 39 which would be installed on the under side of the bottom flange 132 of the plurality of solid web purlins 110 , 128 to ensure an air circulation path from ridge to eave. The ceiling heat collecting air gap layer 10 is created between a top of the ceiling material insulation layer 16 and a bottom of the roof panel 112 . Preferably the roof sheeting panels 112 are connected to the tops of the purlins 110 with a plurality of thermal conductive fasteners 26 to maximize thermal conduction from the plurality of thermally conductive roof sheeting panels 112 into the plurality of conductive, radiative roof purlins 110 , 128 , 134 . With reference to FIG. 14 , maximizing conduction will enhance the heat transfer, enhance the heat collection in the air gap layer 10 , enhance the heat concentration at the highest point of the air gap layer 10 closest the ridge 122 and enhance overall efficiency of heat energy collection at the heat collection fins 94 of the heat transfer pipe 92 of the metal building building 100 . Heat transfer fluid 93 circulates inside the heat transfer pipe 92 powered by either a pump or compressor (not shown). FIGS. 18-20 illustrate a preferred alternative multi-vent 74 to a typical metal roof ridge cap 77 , 79 of FIGS. 21-22 . The ridge mounted multi-vent 74 extends through the ridge 122 of the roof 120 and preferably extends a length of the roof ridge 122 . The ridge mounted multi-vent 74 is located between two ridge purlins 128 and between the two ridge ceiling support struts 20 . FIG. 20 illustrates a plurality of multi-vent box side panel extensions 154 and a plurality of multi-vent box end panel extensions 152 which attach to the bottoms of the plurality of multi-vents modules 74 to fill the open space to the bottoms of the two ridge ceiling support struts 20 shown in FIG. 4 . If the preferred multi-vent is not used and a typical ridge cap 77 , 79 is used. a single ridge ceiling support strut centered below the ridge line is sufficient to support the ceiling sheet material and the overlying material insulation layer. With reference to FIGS. 12-13 , each metal building 100 composite wall structure includes an exterior metal wall sheeting panel 114 , an optional exterior girt mounted vent spacer 36 , a girt 106 in the air gap 12 , the interior mounted girt vent spacer 38 , an exterior side wall sheet material which may typically be an extension of the ceiling sheet material 14 , or may be an independent exterior wall sheet material 30 , a material insulation layer 32 , 34 , and an interior wall material 28 , 31 . A plurality of optional girt exterior flange mounted vent spacers 36 include a plurality of through air flow openings 37 , if desired to increase the heat flow area upward around the girts. The interior girt flange mounted vent spacers 38 are attached to an interior flange 132 of the girt 106 . The interior girt spacers 38 include a plurality of through air flow openings 39 , if desired to increase the heat flow area around the interior girt flanges. An exterior surface of the wall sheet material 14 , 30 abuts the plurality of interior flange mounted girt spacers 38 . With reference to FIGS. 25-26 , a wall material insulation layer 32 , 34 is secured to a vertical portion of the wall sheet material 14 , 30 with bi-directional impaling hangers 156 by first impaling the sheet material impaling arrows 160 through the sheet material 14 , 30 for support and then impaling the insulation layer 32 , 34 on the opposite side hanger insulation impaling arrows 162 with any suitable method or device. A top edge of each side wall interior insulation covering sheet material 28 is preferably attached to the ceiling sheet material 14 with adhesive, fasteners or other suitable attachment means, such that the exterior surface of insulation covering wall sheet material 28 contacts an interior surface of the wall insulation layer 32 which is typically fiber glass blanket or batt insulation. A bottom edge of each interior insulation covering wall sheet material 28 is attached at its base with a tensioning device 24 , adhesive, fasteners or any other suitable attachment method. A plurality of wall heat collecting air gap layers 12 are created between an interior facing surfaces of the exterior wall sheeting panels 114 and the exterior facing surfaces of the side wall sheet material layer 14 which are typically extensions of the ceiling sheet layer 14 . The outer end wall sheet material 30 abuts to the plurality of inner girt flange vent spacers 38 . A top end of first installed exterior end wall sheet material 30 is preferably attached to the ceiling sheet material 14 with adhesive, fasteners or other suitable attachment means, but may alternatively be attached to the end wall rafter 108 or to end wall girts 106 as limited by accessibility of an individual application. A bottom end of each first installed, exterior end wall sheet material 30 is attached to the foundation 118 or floor 126 with the tensioning device 24 , adhesive or any other suitable attachment device and methods. FIGS. 10 a - 10 h illustrate various styles of tensioning devices which may be used to apply tension to the ceiling or wall sheet material 28 , 31 . Wall material insulation layers 32 , 34 preferably are suspended from the interior surfaces of the first installed, exterior wall sheet material 14 , 30 . The plurality of bi-directional impaling suspension hangers 156 are used to suspend the wall material insulation layers 32 , 34 without any conductive thermal bridges to the wall girts 106 . The exterior facing impaling arrows 160 impale the exterior wall sheet material for support. The insulation layer 32 , 34 is impaled on the opposing impaling arrows 162 to support the insulation in suspension without any thermal bridging to the exterior wall girts and panels. A top end of each second installed, interior wall sheet material 28 , 31 is preferably attached to the ceiling sheet material 14 with adhesive, fasteners or other suitable attachment means, such that its exterior surface contacts an interior surface of the wall insulation layer 32 , 34 . A bottom end of each second installed, interior wall sheet material 28 , 31 is attached at its base with a tensioning device 24 or any other suitable attachment device and method. The end wall heat collecting air gap layer 12 is created between an interior facing surface of the exterior end wall sheeting panels 114 and the exterior facing surface of the first installed, exterior end wall sheet material 30 . The side wall heat collecting air gap layer 12 is created between an interior facing surface of the exterior wall sheeting panels 114 and the exterior facing surface of the first installed, exterior side wall sheet material 14 , 30 . With reference to FIGS. 1 a , 10 - 11 , 16 - 17 and 23 - 24 the plurality of wall ducts include side wall ducts and end wall ducts. The ducts are joined in series with a plurality of connection couplings 57 . The plurality of side wall ducts 40 , 42 , 44 generally have a horizontal orientation. The plurality of side wall ducts preferably include two side wall eave roof ducts 40 , two sidewall upper wall ducts 42 , two sidewall base ducts 44 . The side wall eave roof ducts 40 provide an independent air flow path from the exterior air to the roof air gap layer. The upper side wall air flow duct provides and independent air flow path which communicates with the exterior air and the air gap layer 12 . The plurality of end wall ducts include upper wall ducts 48 with an orientation generally matching the roof slope along the top of the end wall air gap layer 12 . The plurality of the end wall base ducts 50 have a horizontal orientation along the base of the air gap layer 12 . The plurality of end wall ducts preferably include two upper wall ducts 48 and two end wall base ducts 50 . Two subterranean air ducts 46 and subterranean tube ducts 72 connected between the two opposite wall subterranean air ducts 46 also may be installed to pre-condition air used for ventilation, heating, cooling and dehumidification. Each duct 40 - 50 is preferably fabricated from an extruded rectangular (preferably square) tube 54 illustrated in FIG. 16 . The tube 54 preferably includes a plurality of air flow holes 56 formed through one or more sides thereof. With reference to FIG. 17 , a damper strip slot 58 is formed in at least one sides side of the tube 54 to receive a damper strip 60 . The damper strip 60 includes a plurality of holes 62 , which may be aligned with the plurality of air flow holes 56 to allow air flow into the tube 54 or to prevent air flow into the tube 54 . Any suitable duct actuation device 64 may be used to slide the damper strip 60 in the damper strip slot 58 . FIG. 1 illustrates a cut-away perspective view of the general spacial locations of the wall duct and eave line roof duct communicating with the air gap layers 10 , 12 of the metal building 100 . The ducts need not be installed continuously, nor the full lengths of the building walls but only as desired to provide a useful function. Each sidewall eave roof duct 40 is located below a lengthwise eave purlin 134 . The side wall eave roof duct 40 may be constructed of any suitable material and used to replace the eave purlin 134 and provide the intended combined functions of both the eave line roof duct 40 and the eave purlin 134 . Each end wall upper wall duct 48 is located below an end wall eave channel 136 or below the ends of the roof purlins 110 , 128 , 134 if there is no end wall eave channel 136 . The side wall, end wall, and subterranean ducts 40 , 42 , 44 , 46 , 48 , 50 are capable of receiving outside air or interior space air through either air flow holes 56 or through branch ducts 63 . Typically there would be an operable damper strip 60 or an operable louver 67 to open or close the air flow holes 56 or branch ducts 63 to air flows. The side wall upper wall duct 42 is located below the sidewall eave roof ducts 40 . The upper wall ducts 42 , 48 and base wall ducts 44 , 50 communicate with the air gap layers 12 of the walls. The upper side wall ducts 42 allow heat and air in the wall air gap layers 12 to communicate with the roof air gap layers 10 directly or through eave line roof duct 40 . With reference to FIG. 15 , a heat collection coil/dehumidifier 66 is preferably retained inside the sidewall upper wall air gap layer 12 or inside the upper wall ducts 42 at this same general location. An coil bracket 68 is secured to one edge of the side wall heat collection/dehumidifier coil 66 and a lower mounting bracket 70 is secured to the other edge of the heat collection/dehumidifier coil 66 . With reference to FIG. 10 , a blower 65 may be used to transfer heat and air from the wall heat collection air gap layer 12 to an interior space of the metal building 100 . The side wall base ducts 44 and the end wall base duct 50 are located adjacent the wall panel 114 and above the floor 126 . Ends of the side wall ducts 40 , 42 , 44 and ends of the end ducts 48 , 50 are preferably closed with a duct end cap 59 illustrated in FIG. 16 . The base ducts 44 , 50 may be made of a suitable material and used to replace a base support channel (not shown) and provide the intended functions of both the base ducting 44 , 50 and of the base structural support channel 116 . With reference to FIG. 9 , the two opposing side wall subterranean air ducts 46 are located at a base perimeter of the metal building 100 , preferably at or below floor level and which extends the side wall length of the metal building 100 . One side wall subterranean air duct 46 communicates with the interior air space of the metal building 100 through at least one branch duct 63 or the plurality of duct modules tubes 54 air flow holes 56 . The opposing side wall subterranean duct communicates with the exterior air through at least one opposing branch duct 63 to the exterior air. A plurality of subterranean tubing 72 is located below the floor 126 of the building at a depth of about 6 to 9 feet, which run parallel to each other in the earth with the opposing subterranean tubing 72 ends connected to the two opposing subterranean ducts 46 . Air flowed through the subterranean ducts 46 flows through the subterranean tubing 72 under the building floor 126 will be cooled by a reduced temperature of the earth in contact with the subterranean tubing 72 . One end of the plurality of subterranean tubing 72 is connected to one of the two lengthwise subterranean air tubing ducts 46 and the other end of the plurality of foundation tubing 72 is connected to a second of the two lengthwise subterranean air tubing ducts 46 . It is preferable that the plurality of foundation tubing 72 be oriented either parallel to the end walls of the building or parallel to the side walls of the building. It is preferred that the plurality of subterranean tubing 72 be connected to either the opposing sidewall subterranean ducts 46 or to opposing end wall subterranean tubing ducts (not shown). It is possible to use more than one subterranean duct and tubing system under the floor 126 of the metal building 100 at different depths to condition additional volumes of ventilation air flowing through them. The subterranean tubes 72 should be sloped to a low point and connected to a liquid water drain pipe 71 which connects to a liquid water reservoir 73 from which the condensation water can be stored and recycled for other uses. With reference to FIGS. 9 , 18 - 20 , the ridge mounted multi-vent 69 includes a plurality of vent modules 74 attached to each other end to end in series. The plurality of vent modules 74 are secured in series to each other with bolts or any suitable attachment device or method. Each vent module 74 includes a box unit 76 and a cover 78 . The box unit 76 includes a vent base 80 , two end walls 82 , two side walls 84 and two box side flanges 86 . The two end walls 82 extend upward from opposing ends of the vent base 80 and two side walls 84 extend upward from opposing sides of the vent base 80 . A single flange 86 extends outward from a top of each box side wall 84 . At least one air opening 88 may be formed through each end wall 82 to allow the flow of air between the vent modules 74 . With reference to FIG. 14 , a heat transfer pipe hole 90 may also be formed through each end wall 82 to receive a heat transfer pipe 92 . A plurality of heat fins 94 are attached along a length of the heat transfer pipe 92 . A trough 96 is placed under the heat transfer pipe 92 to catch and channel condensation to a drain (not shown) along its length. The cover 78 includes a cover portion 98 and a pair of cover side flanges 99 disposed on opposing side edges thereof. The cover portion 98 preferably includes a curved cross section. The cover side flange 99 extends from each side of the cover portion 98 . A first sealing material (not shown) may be placed between the cover side flanges 99 and the box side flanges 86 . A second sealing material (not shown) may be placed between the cover portion ends 98 and the box end wall 82 top edges. The cover 78 is preferably fabricated from a material, which is light translucent, light collecting, light diffusing or opaque. A damper slot 150 may be formed into each side wall 84 to slidably retain the damper strip 60 . A plurality of air flow holes are formed through the side walls 84 in the damper slot 150 . The damper strip 60 of FIG. 17 may be shifted in the damper slot 150 with an actuation device to allow air to flow through air flow holes 62 and 95 . With reference to FIGS. 21-22 , the covers 78 of the plurality of vent modules 74 are secured through their flanges 99 to ridge roof sheeting panel closures 75 or to the roof ridge purlins 128 structures with fasteners 26 or any suitable attachment device or method. With Reference to FIGS. 18-20 , the box unit 76 may have two end wall extension panels 152 which attach to base of the end walls 82 , and two side wall extension panels 154 which attach to the base of the side wall panels 84 . These extension panels fill any gap between the ridge support struts 20 and the base 80 of the multi-vent box unit side walls 84 and end walls 82 . A cover 78 with two opposing side flanges 99 may be attached to the side wall extensions from the interior side. The cover 78 is preferably fabricated from a material, which is light translucent, light collecting, light diffusing or opaque. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

A building insulation system for roofs and walls supported from the interior side of the building, which eliminates thermal bridges and bottom side ceiling fasteners to support the insulation system materials during the insulation and exterior sheeting process of the building construction. The insulation system creates an air gap space layer in roofs and in walls between the exterior wall and roof sheeting panels and the interior sheet material, which supports the insulation material layer. An air gap space enables active solar energy collection and its use to reduce the overall purchased energy for operation of the building. The insulation system preferably includes a support sheet material, a sheet material tensioning devices, an insulation material layer, insulation hanger retention devices, heat and air collection and distribution ducts, dampers, louvers, pipes, dehumidification and condensate collection devices used in the air gap layers of the building to improve the building energy efficiency.

FIELD OF THE INVENTION [0001] This invention relates to a chemical process and apparatus for producing inorganic fullerene-like nanoparticles. LIST OF REFERENCES [0002] The following references are considered to be pertinent for the purpose of understanding the background of the present invention: 1. L. Rapoport, Yu. Bilik, Y. Feldman, M. Homyonfer, S. Cohen and R. Tenne, Nature, 1997, 387, 791; 2. C. Schffenhauer, R. Popovitz-Biro, and R. Temie, J. Mater. Chem. 2002, 12, 1587-1591; 3. Jun. Chen, Suo-Long Li, Zhan-Liang Tao and Feng Gao, Chem. Commun. 2003, 980-981; 4. WO 97/44278; 5. Y. Feldman, V. Lyakhovitskaya and R. Tenne, J. Am. Chem. Soc. 1998, 120, 4176; 6. A. Zak, Y. Feldman, V. Alperovich, R. Rosentsveig and R. Tenne, J. Am. Chem. Soc. 2000, 122, 11108; 7. Y. Feldman, A. Zak, R. Popovitz-Biro, R. Tenne, Solid State Sci. 2000, 2, 663; 8. WO 01/66462; 9. WO 02/34959; 10. Xiao-Lin Li, Jian-Ping Ge and Ya-Dong Li, Chem. Eur. J. 2004, 10, 6163-6171; and 11. T. Tsirlina and V. Lyakhovitskaya, S. Fiechter, and R. Tenne, J. Mater. Res. 2000, 15, 2636-2646 BACKGROUND OF THE INVENTION [0014] Carbon nanoparticles having a layered configuration are known as fullerene nanoparticles. Generally, there are three main types of fullerene-related carbon particles: fullerenes (C 60 , C 70 , etc.); nested-fullerene nanoparticles (in the form of onions), and nanotubes. Analogous fullerene-like nanoparticles can be obtained from a number of inorganic materials with layered structure, and are known as inorganic fullerene-like materials. [0015] Inorganic fullerene-like (abbreviated hereinafter “IF”) nanoparticles and nanotubes are attractive due to their unique crystallographic morphology and their interesting physical properties. [0016] Layered transition-metal dichalcogenides MS 2 (such as WS 2 and MoS 2 ) are of great interest as they act as host lattices by reacting with a variety of guest atoms or molecules to yield intercalation compounds, in which the guest is inserted between the host layers. Accordingly, IF transition metal dichalcogenides may be used for instance, for hydrogen storage. [0017] Furthermore, disulfides of molybdenum and tungsten belong to a class of solid lubricants useful in vacuum, space and other applications where liquids are impractical to use. IF nanoparticles can be used as additives to various kinds of oils and greases to enhance their tribological behavior 1 . Furthermore, different coatings with impregnated IF nanoparticles were shown to exhibit self-lubricating behavior. [0018] IF nanoparticles may also be used for other possible applications such as battery cathodes, catalysis, nanoelectronic and magnetic information storage. [0019] The first closed-cage fullerene-like nanoparticles and nanotubes of WS 2 were obtained via sulfidization of thin films of the respective trioxides in 1992, followed by MoS 2 and the respective diselenides. [0020] Numerous IF nanostructures have been synthesized using different metodologies. The first report related to IF-MS 2 (IF-NbS 2 ) structures obtained by the reaction of the metal chloride (NbCl 5 ) and H 2 S 2 . Later on, Jun Chen et al. 3 used a low-temperature gas reaction to synthesize TiS 2 nanotubes. The reaction involved heating TiCl 4 , H 2 , and H 2 S inside a horizontal furnace at a relatively low temperature of 450° C., and in the absence of oxygen and water. [0021] Another method and apparatus for preparing inorganic fullerene-like nanoparticles of a metal, e.g. transition metal chalcogenide having a desired size and shape in high yields and macroscopic quantities, is described in WO 97/44278 4 . This method utilizes (a) dispersing solid particles of at least one non-volatile metal oxide material having the preselected size and shape; and (b) heating the solid particles of the non-volatile metal material in a reducing gaseous atmosphere containing at least one chalcogen material for a time and a temperature sufficient to allow the metal material precursor and the chalcogen material to react and form at least one layer of metal chalcogenide, the at least one layer of metal chalcogenide encaging the surface of the solid particles to form the fullerene-like particles. [0022] The synthesis of IF-WS 2 involves a solid-gas reaction, where the nanocrystalline tungsten oxide, serving as a precursor, reacts with H 2 S gas at elevated temperatures 5 . In a different procedure, IF-MoS 2 nanoparticles are prepared in the gas phase, upon in-situ reduction and condensation of the MoO 3 vapor and subsequent sulfidization by H 2 S 6 . [0023] The availability of fullerene-like MoS 2 and WS 2 nanoparticles in large amounts paved the way for a systematic investigation of their properties. Both IF-WS 2 and IF-MoS 2 nanoparticles were found to provide beneficial tribological behavior under harsh conditions 1 , suggesting extensive number of tribological applications for these nanoparticles, eliciting substantial industrial interest. [0024] Mass production of IF-WS 2 was enabled by the construction of first a falling bed and subsequently fluidized bed reactors 7 . [0025] Reactors for mass production of IF-WS 2 and IF-MoS 2 are described in WO 01/66462 and WO 2/34959, respectively 8,9 . [0026] The reported IF-WS 2 and IF-MoS 2 5-7 were synthesized from their corresponding oxide crystallite that served as a template for the growth of the sulfide nanoparticles. The growth of the sulfide layers in each particle starts on the top surface of the partially reduced oxide nanoparticle terminating in its core. This diffusion-controlled reaction is rather slow, lasting a few hours. The final nanoparticles consist of dozens of sulfide layers and a hollow core occupying 5-10% of the total volume of the nanoparticles. [0027] In another research, large-scale MoS 2 and WS 2 IF nanostructures (onion-like nanoparticles and nanotubes) and three-dimensional nanoflowers were selectively prepared through an atmospheric pressure chemical vapor deposition process from metal chlorides (e.g. MoCl 5 and WCl 6 ) and sulfur 10 . In this technique, selectivity was achieved by varying the reaction temperature, with 750° C. favoring the nanotubes and 850° C. the fullerene-like nanoparticles. [0028] In a further research, tungsten diselenide closed-cage nanoparticles were synthesized by the reaction of prevaporized Se with WO 3 powder in a reducing atmosphere 11 . The selenium vapor was brought to the main reaction chamber by a carrier gas. The growth mechanism of the IF-WSe 2 nanoparticles was outside-in. This growth mode is analogous to the previously reported growth of IF-WS 2 using the reaction between WO 3 nanoparticles and H 2 S gas 5 . SUMMARY OF THE INVENTION [0029] There is a need in the art to facilitate production of inorganic fullerene-like particles by providing a novel process and apparatus with improved capability to control the shape and size of the structure being produced. Also, there is a need in the art to produce nanoparticles having spherical shape, thus having improved properties, such as tribological, optical, etc. [0030] It was found by the inventors that the known mechanisms for the synthesis of IF-WS 2 from metal trioxide powder and the synthesis of IF-MoS 2 from the evaporated metal trioxide, are not suitable for other metals such as titanium. For instance, the titanium dioxide can not be easily sulfidized even at the relatively high temperature of up to 1450° C. Also, although the sulfidization of tungsten or molybdenum dioxide results in respective disulfide, the desired morphology of the particle is not obtained. [0031] Furthermore, the inventors have found a more rapid way for making the synthesis of IF nanoparticles that yields a desired spherical shape and a relatively narrow size distribution of produced nanoparticles. The IF nanopartieles synthesized by the technique of the present invention have smaller hollow core (substantially not exceeding 5-10 nm) and they contain many more layers (typically, 50-120 layers) as compared to those synthesized from the metal oxides, which have a relatively large hollow core (more than 20 nm) and fewer number of layers (20-40). Therefore, the presently synthesized IF nanoparticles are expected to reveal improved tribological behavior, which is confirmed by preliminary measurements. [0032] Thus, the present invention provides a process for producing inorganic fullerene-like (IF) nanoparticles having well defined size and shape, from commercially available reactants and in a rather fast reaction. The large number of molecular layers, i.e. 50-120 in the present synthesis is advantageous for tribological applications where the lifetime of the nanoparticle is determined by the gradual deformation and peeling-off of the outer layers of the nanoparticle. [0033] The process of the present invention occurs in the gas phase, and is suitable for mass production of inorganic fullerene-like nanoparticles of metal chalcogenides. The process is based on a reaction between a metal precursor, e.g. metal halide, metal oxyhalide, metal carbonyl or organo-metallic compound (hereinafter termed “metal containing precursor” or “metal precursor”) and a reacting agent, e.g. chalcogen material, both in the gas phase. The use of metal carbonyls, for example, has the advantage that its decomposition in the reactor leads to the release of CO which is a strongly reducing agent and allows to overcome the sensitivity of this reaction to oxidizing atmosphere. [0034] Thus according to a first aspect thereof, the present invention provides a process for producing inorganic fullerene-like (IF) metal chalcogenide nanoparticles, the process comprising: [0035] (a) feeding a metal precursor selected from metal halide, metal carbonyl, organo-metallic compound and metal oxyhalide vapor into a reaction chamber towards a reaction zone to interact with a flow of at least one chalcogen material in gas phase, the temperature conditions in said reaction zone being such as to enable the formation of the inorganic fullerene-like (IF) metal chalcogenide nanoparticles. [0036] According to a preferred embodiment, the process comprises: [0037] (b) controllably varying the flow of said metal precursor into said reaction chamber to control the amount, shape and size of the so-produced IF fullerene-like metal chalcogenide nanoparticles in solid form. [0038] Preferably, the vapor of the metal precursor is fed into the reaction chamber to flow towards the reaction zone along a vertical path, e.g. along an upward/downward direction that is opposite with respect to that of the chalcogen material that is being fed in a downward/upward direction. [0039] The nanoparticles produced by the process of the invention are characterized by narrow size distribution and large number of molecular layers. [0040] The invention also provides IF metal chaleogenide nanoparticies having a plurality of molecular layers and characterized in that the number of said molecular layers exceeds 40, preferably exceeds 50 and at times exceeds 60 and even 70 layers. According to one embodiment of the invention there is provided a product comprising a plurality of IF metal chalcogenide nanoparticles, a substantial portion of which having a number of molecular layers exceeding 40, preferably exceeds 50 and at times exceeds 60 and even 70 layers. The substantial portion is typically more than 40% out of the nanoparticles, preferably more than 50%, 60%, 70%, 80% and at times even more than 90% out of the total number of the IF nanoparticles. [0041] Furthermore, the IF fullerene-like metal chalcogenide nanoparticles produced by the process of the present invention optionally have no hollow core or a very small hollow core (not exceeding 5-10 nm). [0042] The term “very small hollow core” as used herein means that the nanoparticles produced by the process of the present invention have a hollow core which is not exceeding 5 nm or occupying no more than 0-5% of the total volume of the nanoparticles. [0043] The term “nanoparticles” as used herein refers to multi-layered, spherical, or close to spherical particle having a diameter in the range from about 10 nm to about 300 nm, preferably from about 30 nm to about 200 nm. The nanoparticles of the invention may typically have 50-120 concentric molecular layers. [0044] The nanoparticles obtained by the process of the present invention have a spherical, or close to spherical shape and optionally have no hollow core. The provision of a very small hollow core or even absence of such core may be explained by the mechanism of growth of the nanoparticles, namely from the central portion (nucleai of product) towards the peripheral portion, rather than the opposite direction carried out in the known processes. [0045] Preferably, the term “metal” as used herein refers to In, Ga, Sri or a transition metal. [0046] A transition metal includes all the metals in the periodic table from titanium to copper, from zirconium to silver and from hafnium to gold. Preferably, the transition metals are selected from Mo, W, V, Zr, Hf, Pt, Pd, Re, Nb, Ta, Ti, Cr and Ru. [0047] A chalcogen used in the invention is S, Sc or Te, and the chalcogen material is selected from a chalcogen, a compound containing a chalcogen, a mixture of chaleogens, a mixture of compounds containing a chalcogen, and a mixture of a chalcogen and a compound containing a chalcogen. [0048] The chalcogen material is preferably a chalcogen compound containing hydrogen, more preferably H 2 S, H 2 Se and/or H 2 Te. Alternatively, instead of H 2 X (X═S, Se, Te) it is possible to use elemental chalcogen under the flow of hydrogen with H 2 X being formed in-situ during the reaction time. The chalcogen material may optionally be mixed with a reducing agent such as hydrogen and/or CO. [0049] In a preferred embodiment of the invention, an inert carrier gas is used to drive a flow of the chalcogen material and a flow of the vaporized metal precursor into the reaction chamber. Non limiting examples of inert gases that may be used in the process of the present invention are N 2 , He, Ne, Ar, Kr and Xe. [0050] The term “precursor” as used herein means any suitable starting material or materials. The precursor in the process of the present invention may be any metal containing compound that can be vaporized without or with its decomposition. Suitable metal containing precursors that may be used in the process of the present invention are, for example, metal halides, metal carbonyls, organo-metallic compounds and metal oxyhalides. More specifiC examples of metal containing precursors that may be used in the process of the present invention are TiCl 4 , WCl 6 , WCl 5 , WCl 4 , WBr 5 , WO 2 Cl 2 , WOCl 4 , MoCl 5 , Mo(CO) 5 and W(CO) 6 , Ga(H 3 ) 3 , W(CH 2 CH 3 ) 5 , In(CH 3 ) 3 and the like. [0051] A list of metal precursor compounds that can be used in the process of the present invention is given in Table 1 below. [0000] TABLE 1 Examples of metal precursors Name Formula mp, ° C. bp,° C. Chromium carbonyl Cr(CO) 6 130 (dec) subl Chromium (III) iodide CrI 3 500 (dec) Chromium (IV) chloride 600 (dec) Chromium (IV) fluoride CrF 4 277 Chromium (V) fluoride CrF 5  34 117 Chromium (VI) fluoride CrF 6 100 (dec) Cromyl chloride CrO 2 Cl 2 −96.5 117 Trimethylgallium Ga(CH 3 ) 3 −15.8  55.7 Hafnium bromide HfBr 4 424 (tp) 323 (sp) Hafnium chloride HfCl 4 432 (tp) 317 (sp) Hafnium iodide HfI 4 449 (tp) 394 (sp) Trimethylindium In(CH 3 ) 3  88 133.8 Molybdenum carbonyl Mo(CO) 6 150 (dec) subl Molybdenum (V) chloride MoCl 5 194 268 Molybdenum (V) fluoride MoF 5  67 213 Molybdenum (V) oxytrichloride MoOCl 3 297 subl Molybdenum (VI) fluoride MoF 6  17.5  34 Molybdenum (VI) oxytetrafluoride MoOF 4  98 Molybdenum (VI) oxytetrachloride MoOCl 4 101 Molybdenum (VI) dioxydichloride MoO 2 Cl 2 175 Niobium (IV) chloride NbCl 4 Niobium (IV) fluoride NbF 4 350 (dec) Niobium (IV) iodide NbI 4 503 Niobium (V) bromide NbBr 5 254 360 Niobium (V) chloride NbCl 5 204.7 254 Niobium (V) fluoride NbF 5  80 229 Niobium (V) iodide NbI 5 200 (dec) Niobium (V) oxybromide NbOBr 3 320 (dec) subl Niobium (V) oxychloride NbOCl 3 subl Niobium (V) dioxyfluoride NbO 2 F Palladium (II) bromide PdBr 2 250 (dec) Palladium (II) iodide PdI 2 360 (dec) Platinum (II) bromide PtBr 2 250 (dec) Platinum (II) chloride PtCl 2 581 (dec) Platinum (II) iodide PtI 2 325 (dec) Platinum (III) bromide PtBr 3 200 (dec) Platinum (III) chloride PtCl 3 435 (dec) Platinum (IV) bromide PtBr 4 180 (dec) Platinum (IV) chloride PtCl 4 327 (dec) Platinum (IV) fluoride PtF 4 600 Platinum (IV) iodide PtI 4 130 (dec) Platinum (VI) fluoride PtF 6  61.3  69.1 Rhenium carbonyl Re 2 (CO) 10 170 (dec) Rhenium (III) bromide ReBr 3 500 (subl) Rhenium (III) chloride ReCl 3 500 (dec) Rhenium (III) iodide ReI 3 (dec) Rhenium (IV) chloride ReCl 4 300 (dec) Rhenium (IV) fluoride ReF 4 300 (subl) Rhenium (V) bromide ReBr 5 110 (dec) Rhenium (V) chloride ReCl 5 220 Rhenium (V) fluoride ReF 5  48 220 Rhenium (VI) chloride ReCl 6  29 Rhenium (VI) fluoride ReF 6  18.5  33.7 Rhenium (VI) oxytetrachloride ReOCl 4  29.3 223 Rhenium (VI) oxytetrafluoride ReOF 4 108 171 Rhenium (VII) fluoride ReF 7  48.3  73.7 Rhenium (VII) trioxycloride ReO 3 Cl  4.5 128 Rhenium (VII) trioxyfluoride ReO 3 F 147 164 Rhenium (VII) dioxytrifluoride ReO 2 F 3  90 185 Rhenium (VII) oxypentafluoride ReOF 5  43.8  73 Ruthenium dodecacarbonyl Ru 3 (CO) 12 150 (dec) Ruthenium (III) bromide RuBr 3 400 (dec) Ruthenium (III) chloride RuCl 3 500 (dec) Ruthenium (III) fluoride RuF 3 600 (dec) Ruthenium (III) iodide RuI 3 Ruthenium (IV) fluoride RuF 4  86.5 227 Ruthenium (V) fluoride RuF 5  54 Tantalum (V) bromide TaBr 5 265 349 Tantalum (V) chloride TaCl 5 216 239.35 Tantalum (V) fluoride TaF 5  95.1 229.2 Tantalum (V) iodide TaI 5 496 543 Titanium (III) bromide TiBr 3 Titanium (III) chloride TiCl 3 425 (dec) Titanium (IV) bromide TiBr4  39 230 Titanium (IV) chloride TiCl 4 −25 136.45 Titanium (IV) fluoride TiF 4 284 subl Titanium (IV) iodide TiI 4 150 377 Tungsten carbonyl W(CO) 6 170 (dec) subl Tungsten (II) bromide WBr 2 400 (dec) Tungsten (II) chloride WCl 2 500 (dec) Tungsten (II) iodide WI 2 Tungsten (III) bromide WBr 3  80 (dec) Tungsten (III) chloride WCl 3 550 (dec) Tungsten (V) bromide WBr 5 286 333 Tungsten (V) chloride WCl 5 242 286 Tungsten (V) fluoride WF 5  80 (dec) Tungsten (V) oxytribromide WOBr 3 Tungsten (V) oxytrichloride WOCl 3 Tungsten (VI) bromide WBr 6 309 Tungsten (VI) chloride WCl 6 275 246.75 Tungsten (VI) dioxydibromide WO 2 Br 2 Tungsten (VI) dioxydichloride WO 2 Cl 2 265 Tungsten (VI) dioxydiiodide WO 2 I 2 Tungsten (VI) fluoride WF 6  2.3  17 Tungsten (VI) oxytetrabromide WOBr 4 277 327 Tungsten (VI) oxytetrachloride WOCl 4 211 227.55 Tungsten (VI) oxytetrafluoride WOF 4 106 186 Vanadium carbonyl V(CO) 6  60 (dec) subl Vanadium (IV) chloride VCl 4 −25.7 148 Vanadium (IV) fluoride VF 4 325 (dec) subl Vanadium (V) fluoride VF 5  19.5  48.3 Vanadyl bromide VOBr 480 (dec) Vanadyl chloride VOCl 700 (dec) Vanadyl dibromide VOBr 2 180 (dec) Vanadyl dichloride VOCl 2 380 (dec) Vanadyl difluoride VOF 2 Vanadyl tribromide VOBr 3 180 (dec) Vanadyl trichloride VOCl 3 −79 127 Vanadyl trifluoride VOF 3 300 480 Zirconium chloride ZrCl 4 437 (tp) 331 (sp) Zirconium fluoride ZrF 4 932 (tp) 912 (sp) Zirconium iodide ZrI 4 499 (tp) 431 (sp) Abbreviations: (dec)—decomposes (sp)—sublimation point (subl)—sublimes (tp)—triple point [0052] According to a preferred embodiment of the invention, the process further comprises at least one, preferably both of the following steps: [0053] (c) terminating the feeding of the metal precursor vapor into the reaction chamber by stopping heating of the metal precursor; [0054] (d) cooling the reaction zone and collecting the obtained fullerene-like metal chalcogenide nanoparticles. [0055] In another preferred embodiment, the process may comprise driving a flow of an inert gas into the reaction zone after step (c) and before step (d). [0056] In a further preferred embodiment, the process may further comprise annealing to allow the precursor to react completely. [0057] As indicated above, the temperature profile (conditions) used in the reaction zone is preferably such so as to enable the formation of the nanoparticles such that the nuclei of the nanoparticles have essentially no or very small hollow core. This results, among others, from the fact that formation of the nanoparticles is thorough a mechanism involving growth of the nanoparticles from the central portion (nuclei of product) towards the peripheral portion. [0058] Preferably, the temperature within the reaction zone is in the range of 500° C. to 900° C., depending on the particular material being synthesized by the process (see examples below). The gradient of the temperature within the reactor provides lowering of the temperature towards the filter. [0059] In the process of the present invention, the amount, morphology and size of the nanoparticles are controlled by the flow of the metal precursor vapor. This flow may be controlled by adjusting the rate of the flow of an inert gas driving the vapor into the reaction chamber; and/or adjusting the temperature used for heating the metal precursor to obtain a vapor thereof. [0060] The heating temperature of the metal precursor is preferably very close to its boiling point. More specifically, it is in the range of between 50 degree below the boiling point and up to the boiling point of said metal precursor. [0061] The process described above allows the preparation of nanoscale inorganic fullerene-like (IF) metal chalcogenides having spherical shape optionally with a very small or no hollow core. The metal chalcogenides are preferably selected from TiS 2 , TiSe 2 , TiTe 2 , WS 2 , WSe 2 , WTe 2 , MoS 2 , MoSe 2 , MoTe 2 , SnS 2 , SnSe 2 , SnTe 2 , RuS 2 , RuSe 2 , RuTe 2 , GaS, GaSe, GaTe, In 2 S 3 , In 2 Se 3 , In 2 Te 3 InS, InSe, Hf 2 S, HfS 2 , ZrS 2 , VS 2 , ReS 2 and NbS 2 . [0062] According to one preferred embodiment of the invention, novel TiS 2 nanoparticles with fullerene-like structure having quite a perfectly spherical shape and consisting of up to 120 concentric molecular layers, were obtained by the reaction of TiCl 4 and H 2 S, using a vertical reactor. The obtained IF-TiS 2 exhibited excellent tribological behavior resulting probably from their close to a spherical shape which promotes rolling friction. [0063] An apparatus of the present invention includes a reaction chamber, and a separate evaporation chamber, which is operated and whose connection to the reaction chamber is controllably operated to control the shape, size and amount of the product being produced. The control of the output parameters of the process (the shape, size and amount of the nanoparticles) is significantly improved by utilizing a vertical configuration of the reaction chamber. Thus, the present invention provides according to a further aspect thereof, an apparatus for preparing IF nanostructures, the apparatus comprising: a reaction chamber having inlets for inputting reacting gases and an outlet; a separate evaporation chamber for separately preparing a precursor vapor; and a control unit configured and operable for controlling the precursor vapor flow into the reaction chamber. [0064] Preferably, the reaction chamber is a vertical chamber with the gas inlet accommodated so as to provide the reacting gases flow in opposite directions towards a reaction zone where they meet and react with each other. Preferably, the control unit comprises a bypass arrangement associated with the evaporation chamber. This bypass is configured and operable to provide a flow of clean inert gas instead of one enriched with vaporized precursor at certain moments of the reaction as described for instance, in Example 1 below. This improvement is of importance for the synthetic procedure preventing the flow of the highly reactive precursor during the heating up and cooling down steps of the synthesis. [0065] According to yet another broad aspect of the invention, there is provided an apparatus for preparing IF nanostructures, the apparatus comprising: (i) a reaction chamber configured to be vertically oriented during the apparatus operation, and having gas inlets located at top and bottom sides of the chamber so as to direct a precursor vapor and the other reacting gas in opposite directions towards a reaction zone where the gases meet and react with each other; (ii) a separate evaporation chamber configured and operable for separately preparing the precursor vapor and feeding it to the respective inlet of the reaction chamber; and (c) a control unit configured and operable for controlling the precursor vapor flow into the reaction chamber. BRIEF DESCRIPTION OF THE DRAWINGS [0066] In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which: [0067] FIG. 1 exemplifies a preferred configuration of an apparatus of the present invention utilizing a vertical reaction chamber associated with a separate evaporation chamber. [0068] FIG. 2 is a schematic illustration of an apparatus utilizing a horizontal reaction chamber. [0069] FIG. 3 is the TEM image of IF-TiS 2 nanoparticle, produced in a horizontal reactor. [0070] FIG. 4 is the TEM image of a typical IF-TiS 2 nanoparticle, produced in a vertical reactor. The interlayer distance is 5.8 Å and the diameter of the nanoparticie is larger than 70 nm. [0071] Insert shows the Fast Fourier Transform (FFT) of the shown nanoparticle. [0072] FIG. 5A is the HRTEM image of a part of an IF-TiS 2 nanoparticle produced in a vertical reactor with an overlay of the simulated TiS 2 pattern (view down [110], simulation with thickness 20 nm and defocus of −20 nm). [0073] FIG. 5B shows the measurement of the interlayer distance by HRTEM. [0074] FIG. 6 shows the typical IF-WS 2 obtained from WO 2 Cl 2 and H 2 S in a horizontal reactor. [0075] FIG. 7A is the magnified TEM image of a group of IF-WS 2 nanoparticles received in a reaction of WCL 4 and H 2 S in a vertical reactor. [0076] FIG. 7B is the TEM image of individual closed-caged LF-WS 2 nanoparticle received in a reaction of WCL 4 and H 2 S in a vertical reactor. [0077] FIG. 8 shows the WS 2 nanoparticle obtained from WCl 5 precursor in a vertical reactor. [0078] FIG. 9 is a TEM image of a small WS 2 nanoparticles obtained from WCl 6 in a vertical reactor [0079] FIG. 10A is a TEM image of a group of MoS 2 nanoparticles obtained from MoCl 5 in a vertical reactor. [0080] FIG. 10B is a TEM image of small (20 nm) IF-MoS 2 obtained from MoCl 5 in a vertical reactor. [0081] FIG. 11A shows IF-WS 2 synthesized from WO 3 by methods known in the art. [0082] FIG. 11B shows IF-TiS 2 synthesized from TiCl 4 . Each nanoparticle has a diameter ca. 60 nm. [0083] Note the difference between FIGS. 11A and 11B in topology, number of layers and the absence of a hollow core in IF-TiS 2 . DETAILED DESCRIPTION OF THE INVENTION [0084] The principles of the process of the present invention will be explained hereinbelow with reference to the preparation of closed-cage IF nanoparticles of TiS 2 . However, it should be understood that the discussion is not limited to that specific material but it applies to IF metal chalcogenides in general. [0085] IF nanoparticles of TiS 2 were synthesized through the reaction of TiCl 4 and H 2 S. The obtained nanoparticles have no or very small hollow core and they consist of 80-100 molecular sheets with quite a perfect spherical shape. The IF nanoparticles were prepared by two reactor assemblies: a horizontal reactor and a vertical reactor. [0086] Reference is made to FIG. 1 exemplifying a preferred configuration of an apparatus, generally designated 10 , of the present invention suitable to be used for synthesis of IF-nanoparticles with expected superior tribological behavior. The apparatus 10 includes a vertical reaction chamber 12 for mounting into an oven 15 , a separate evaporation chamber 14 , and a control unit 16 . An outlet 17 of the evaporation chamber 14 is connectable to an inlet IN 1 of the reaction chamber 12 via a connecting gas-flow pipe (not shown here). [0087] In the present example, the oven 15 is designed as a two-zone oven, operable to control the temperature profile in the reaction chamber. The reaction chamber 12 has independent inlets IN 1 and IN 2 at opposite ends of the chamber 12 for inputting two reaction gases (agents), respectively, e.g., TiCl 4 and H 2 S, and a gas outlet GO. Flows of these reaction agents in opposite directions towards a reaction zone in the reaction chamber are assisted by inert gas, N 2 , and a mixture of TiCl 4 and H 2 S gases is formed in the reacting zone. The control unit 16 includes, inter alia, a mass flow controller 16 A (e.g., TYLAN model FC260 commercially available from Tylan General, USA) operable for controlling the flow-rate of H 2 S, and a suitable flow controller 16 B for controlling the flow of additional gas to dilute the H 2 S by mixing it with a stream of inert gas or inert gas mixed with a reducing agent. Further provided in the apparatus 10 is a filter 18 appropriately configured and accommodated to collect the product (nanoparticles). The filter 18 is preferably spatially separated from the inner walls of the reaction chamber 12 . [0088] The precursor (TiCl 4 ) vapors were prepared in advance in the separate evaporation chamber 14 . The latter includes a gas-washing bottle 14 A, a temperature source (not shown here) appropriately accommodated adjacent to the bottle 14 A and operable to controllably heat the TiCl 4 liquid while in the bottle 14 A. Valve arrangements 14 B and 14 C are provided to present a bypass for the nitrogen flow. This bypass provides a flow of clean nitrogen instead of one enriched with TiCl 4 at certain moments of reaction. This improves the synthetic procedure since it prevents the flow of the highly reactive TiCl 4 precursor during the heating up and cooling down steps of the synthesis. To this end, each valve is shiftable (either by an operator or automatically) between its position I (used for flushing the apparatus with pure nitrogen gas) and its position II (used for stopping the flush of the pure nitrogen gas) during the reaction. The precursor (TiCl 4 ) vapor was carried from the evaporation chamber 14 to the reaction chamber 12 by an auxiliary gas flow. The carrier gas is inert gas, which can be mixed with a reducing agent (H 2 or/and CO). [0089] The control unit 16 is configured for controlling the gas flows and the temperature sources' operation. The preheating temperature was found to be a very significant factor, determining the amount of precursor supplied to the reaction chamber 12 . The flow-rate of nitrogen through the bottle 14 A affects the stream of the titanium tetrachloride precursor as well. [0090] This two-chamber design apparatus with the vertical configuration of the reaction chamber considerably improves the size and shape control of the synthesized nanoparticles. The nucleation and growth mechanism established with the vertical reaction chamber ( FIG. 1 ) provide nanoparticles with quite a perfect spherical shape; small or no hollow core and many layers, which are ideally suited for alleviating friction and wear, as well as other different applications such as ultra strong nanocomposites, very selective and reactive catalysts, photovoltaic solar cells, etc. [0091] Using similar reactions, the nucleation and growth mechanism is likely to provide many other kinds of IF nanoparticles with expected superior tribological behavior. [0092] FIG. 2 shows another example of an apparatus, generally at 100 . The apparatus 100 includes a horizontal reaction chamber 112 associated with a single-zone oven 115 , and a separate evaporation chamber 14 configured as described above. The reaction chamber 112 has an inlet arrangement IN (for inputting reaction agents TiCl 4 and H 2 S) and an outlet arrangement OA. A control unit 16 is used for controlling the operation of the oven 115 to thereby control the temperature profile in the reaction chamber 112 . The flow-rate of H 2 S, as well as that of N 2 , is appropriately controlled as described above. The TiCl 4 vapors were obtained by preheating the liquid TiCl 4 in a gas-washing bottle (evaporation chamber). The TiCl 4 vapor is carried from the evaporation chamber 14 to the reaction chamber 112 by an auxiliary N 2 gas flow. The resulting product (TiS 2 powder) is collected for analysis on the surface of the reaction chamber. EXAMPLES Example 1 Preparation of IF-TiS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0093] In order to maintain a water and oxygen free atmosphere, the reaction chamber 12 was permanently maintained at 500° C. and a flow of N 2 gas (20 ml/min) until shortly before the run starts, when it is withdrawn from the oven 15 . At this point, the reaction chamber 12 was opened and cleaned. At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (titanium tetrachloride), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . This procedure eliminates most of the residual atmospheric gases, like water vapor and oxygen from the reaction chamber. This step is very important for the synthesis, since both the final product (TiS 2 ) and especially the precursor (TiCl 4 ) are very sensitive to moisture. Subsequently, the reactor was inserted into the oven 15 . [0094] Independent inlets IN 1 and IN 2 for both reaction gases i.e. TiCl 4 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The flow-rate of H 2 S (3-20 cc/min) was controlled by means of a TYLAN model FC260 mass flow-controller 16 A. The H 2 S was diluted by mixing this gas with a stream of N 2 gas (10-200 cc/min in this reaction) using another flow-controller 16 B. The TiCl 4 vapors were obtained by preheating the liquid TiCl 4 in the gas-washing bottle 14 A of the evaporation chamber 14 . The TiCl 4 vapor was carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the TiCl 4 source was kept usually between 100 and 130° C., which is close to its boiling point of 136.5° C. As indicated above, the preheating temperature is a significant factor, determining the amount of precursor supplied to the reaction zone. The flow-rate of nitrogen through the bottle 14 A (10-100 cc/mill) affects the stream of the titanium tetrachloride precursor as well. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reactor. [0095] The temperature in the reaction chamber zone, where the two gases (TiCl 4 and H 2 S) mix and react, and near the filter 18 was usually varied between 650-750° C. This temperature was chosen based on the properties of the Ti-S system. [0096] Several experiments have been run at higher temperatures (up to 800° C.) in the reaction chamber. [0097] The reaction started with the flow of TiCl 4 vapor for 30-60 min and was interrupted by terminating the preheating of the TiCl 4 precursor and using the bypass system, which provides continuous N, flow for flushing the system. A short annealing period (10-15 min) followed, allowing the last portions of the supplied titanium tetrachloride precursor to react completely. Afterwards, the reactor was moved down for cooling. The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reactor. Example 2 Preparation of Fullerene-Like Nanostructures of TiS 2 in a Horizontal Reactor Based Apparatus of FIG. 2 [0098] The reaction chamber 112 was cleaned in a similar manner as described in Example 1 above in order to maintain a water and oxygen free atmosphere. Subsequently, the reaction chamber was inserted into the oven 115 . [0099] The temperature in the horizontal reaction chamber 112 was controlled by means of a single-zone oven 115 . The TiCl 4 vapor was prepared in the separate evaporation chamber ( 14 in FIG. 1 ) and supplied to the reaction chamber 112 in the similar way as was done in the above-described Example 1. The temperature of the reaction chamber 112 , where the two gases (TiCl 4 and H 2 S) mix and react, was varied in the range of 650-750° C. The resulting TiS 2 powder was collected for analysis on the surface of the reactor boat. However, the product collection was impeded as the product was swept by the carrier gas to the trap. Example 3 Preparation of Fullerene-Like Nanostructures of WS 2 in a Horizontal Reactor Based Apparatus of FIG. 2 [0100] The reaction chamber 112 was cleaned in a similar manner as described in Example 1 above in order to maintain a water and oxygen free atmosphere. Subsequently, the reaction chamber was inserted into the oven 115 . [0101] The temperature in the horizontal reaction chamber 112 was controlled by means of a single-zone oven 115 . The chosen precursor WO 2 Cl 2 was heated up to 270-290° C. in the separate evaporation chamber ( 14 in FIG. 1 ) and its vapor was supplied to the reaction chamber 112 in the similar way as was done in the above-described Example 1. The temperature of the reaction chamber 112 , where the two gases (metal-containing precursor and H 2 S) mix and react, was varied in the range of 700-850° C. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0102] The resulting WS 2 powder was collected for analysis on the surface of the reactor boat. However, the product collection was impeded as the product was swept by the carrier gas to the trap. The resulting nanoparticles are shown in FIG. 6 . As can be noted, the IF-WS 2 obtained in the present example are not so perfect and have hollow core. This can be explained by the inhomegenity of the reaction parameters in the chosen horizontal reactor. [0103] In other experiments the forming gas, containing 1-10% of H 2 in N 2 , was used instead of clean nitrogen for either caring the metal-containing precursor or diluting the H 2 S. [0104] Furthermore, similar series of experiments were carried out using horizontal reactors starting with WBr 5 (boils at 333° C., preheated at 290-330° C.). Different combinations of carrier gas (clear nitrogen or hydrogen-enriched nitrogen) were used. The resulting material consisted from IF-nanoparticles together with byproducts (platelets amorphous materials), as revealed by TEM analysis. Different nanoparticles both hollow-core and non-hollow core were observed. Example 4 Preparation of IF-WS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0105] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (WBr 5 ), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . Subsequently, the reactor was inserted into the oven 15 . [0106] Independent inlets IN 1 and IN 2 for both reaction gases i.e. WBr 5 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The WBr 5 vapors were obtained by preheating the WBr 5 precursor in the gas-washing bottle 14 A of the evaporation chamber 14 and were carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the WBr 5 source was kept usually between 290 and 330° C., which is close to its boiling point of 333° C. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0107] The temperature in the reaction chamber zone, where the two gases (WBr 5 and H 2 S) mix and react, and near the filter 18 was usually varied between 700-850° C. [0108] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reaction chamber. Example 5 Preparation of IF-MoS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0109] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (Mo(CO) 5 ), were supplied to the inlets flushing the system for 10-15 min. Subsequently, the reaction chamber was inserted into the oven 15 . [0110] Independent inlets IN 1 and IN 2 for both reaction gases i.e. Mo(CO) 5 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The Mo(CO) 5 vapors were obtained by preheating the liquid Mo(CO) 5 in the gas-washing bottle 14 A of the evaporation chamber 14 and was carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the Mo(CO) 5 source was kept usually between 160 and 200° C., which is over its melting point of 150° C. [0111] The temperature in the reaction chamber zone, where the two gases (Mo(CO) 5 and H 2 S) mix and react, and near the filter 18 was usually varied between 650-850° C. [0112] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reactor. Example 6 Preparation of IF-WS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0113] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (WCl 4 ), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . Subsequently, the reactor was inserted into the oven 15 . [0114] Independent inlets IN 1 and IN 2 for both reaction gases i.e. WCl 4 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The WCl 4 vapors were obtained by preheating the precursor in the gas-washing bottle 14 A of the evaporation chamber 14 and were carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the WCl 4 source was kept usually between 200 and 400° C. in order to provide the necessary amount of precursor supplied to the reaction. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0115] The temperature in the reaction chamber zone, where the two gases (WCl 4 and H 2 S) mix and react, and near the filter 18 was usually varied between 700-850° C. [0116] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reaction chamber. Example 7 Preparation of IF-WS 2 Nanoparticies in the Vertical Reactor Based Apparatus of FIG. 1 [0117] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (WCl 5 ), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . Subsequently, the reactor was inserted into the oven 15 . [0118] Independent inlets IN 1 and IN 2 for both reaction gases i.e. WCl 5 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The WCl 5 vapors were obtained by preheating the WCl 5 precursor in the gas-washing bottle 14 A of the evaporation chamber 14 and were carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the WCl 5 source was kept usually between 250 and 285° C. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0119] The temperature in the reaction chamber zone, where the two gases (WCl 5 and H 2 S) mix and react, and near the filter 18 was usually varied between 700-850° C. [0120] Since the formal valence of tungsten in the precursor (WCl 5 ) differs from the one in the expected product (WS 2 ), additional reduction of metal was required. The excess of H 2 S in the reaction atmosphere acts as the reduction agent, however in part of the experiments additional flow of H 2 was used for this purpose. The additional flow of hydrogen (1-10% of hydrogen within nitrogen instead of pure N 2 ) was supplied either together with precursor or mixed with H 2 S. [0121] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reaction chamber. Example 8 Preparation of IF-WS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0122] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (WCl 6 ), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . Subsequently, the reactor was inserted into the oven 15 . [0123] Independent inlets IN 1 and IN 2 for both reaction gases i.e. WCl 6 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The WCl 6 vapors were obtained by preheating the WCl 6 precursor in the gas-washing bottle 14 A of the evaporation chamber 14 and were carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the WCl 6 source was kept usually between 275 and 345° C. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0124] The temperature in the reaction chamber zone, where the two gases (WCl 6 and H 2 S) mix and react, and near the filter 18 was usually varied between 700-850° C. [0125] Since the formal valence of tungsten in the precursor (WCl 6 ) differs from the one in the expected product (WS 2 ), additional reduction of metal was required. The excess of H 2 S in the reaction atmosphere acts as the reduction agent, however in part of the experiments additional flow of H 2 was used for this purpose. The additional flow of hydrogen (1-10% of hydrogen within nitrogen instead of pure N 2 ) was supplied either together with precursor or mixed with a H 2 S. [0126] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reaction chamber. Example 9 Preparation of IF-MoS 2 Nanoparticles in the Vertical Reactor Based Apparatus of FIG. 1 [0127] At the beginning of the process, the reaction chamber 12 was closed hermetically from outside the oven, and the reaction gases, except for precursor (MoCl 5 ), were supplied to the inlets flushing the system for 10-15 min. The slight overpressure (ca. 1.1 bars) was maintained at a constant value by the gas trap in the exit GO of the gases from the reaction chamber 12 . Subsequently, the reactor was inserted into the oven 15 . [0128] Independent inlets IN 1 and IN 2 for both reaction gases i.e. MoCl 5 and H 2 S were used, with the mixture of the reagents being formed in the reaction chamber itself. The H 2 S (3-20 cc/min) was mixed with a stream of N 2 gas (10-200 cc/min in this reaction). The MoCl 5 vapors were obtained by preheating the precursor in the gas-washing bottle 14 A of the evaporation chamber 14 and were carried to the reaction chamber 12 by an auxiliary N 2 gas flow. The temperature of the MoCl 5 source was kept usually between 200 and 265° C. A small overpressure (1.1 bar) was maintained by using a gas trap filled with NaOH (5%) solution in the gas outlet of the reaction chamber. [0129] The temperature in the reaction chamber zone, where the two gases (MoCl 5 and H 2 S) mix and react, and near the filter 18 was usually varied between 700-850° C. [0130] Since the formal valence of tungsten in the precursor (MoCl 5 ) differs from the one in the expected product (WS 2 ), additional reduction of metal was required. The excess of H 2 S in the reaction atmosphere acts as the reduction agent, however in part of the experiments additional flow of H 2 was used for this purpose. The additional flow of hydrogen (1-10% of hydrogen within nitrogen instead of pure N 2 ) was supplied either together with precursor or mixed with a H 2 S. [0131] The main portion of the synthesized material was collected on the filter. In addition, small portions of the product powder were found sticking to the surfaces of the quartz reaction chamber. [0132] Analysis of the Synthesized Materials [0133] The products were analyzed mainly by means of various electron microscopy techniques. The following microscopes were used: environmental scanning electron microscope (Philips FEI-XL30 E-SEM); transmission electron microscope (Philips CM120 TEM), equipped with EDS detector (EDAX-Phoenix Microanalyzer); high resolution transmission electron microscope (HRTEM) with field emission gun (FEI Technai F30), equipped with a parallel electron energy loss spectrometer (Gatan imaging filter-GIF (Gatan)). Simulation of the HRTEM micrographs of TiS 2 was obtained using the MacTempas image-simulation software. Complementary analyses were carried, out by powder X-ray diffraction (XRD). [0134] TEM examination of the powder obtained in the horizontal set-up (Example 2) revealed the presence of closed cage nanostructures in the product ( FIG. 3 ). The typically observed particle-size was about 100 nm, with nanoparticles ranging in size between 50 and 150 nm. The wide size distribution is a reflection of the inhomogenity of the reaction conditions in this set-up. The yield of the closed-cage nanoparticles in those experiments was up to 30%, depending on the reaction conditions. The remaining material, as revealed by SEM and TEM, was made of TiS 2 platelets, a few tens of nanometers to 0.5 micron in size, each. [0135] The product of the vertical set-up (Example 1) was found to contain an appreciably larger fraction of the IF-TiS 2 phase with yields approaching 80%. Furthermore, the size distribution of the synthesized nanoparticles was found to be appreciably narrower in the vertical set-up, as compared to the horizontal reactor. The product of the vertical reactor ended up also to be more spherical ( FIG. 4 ). Tilting the sample in different viewing angles did not reveal any significant changes in the shape of the observed nanoparticles. These findings emphasize the advantage of using the vertical set-up for the synthesis of the IF-nanophase materials. Varying the synthesis time did not seem to have an appreciable influence on the size distribution of the IF-TiS 2 nanoparticles. [0136] The resulting IF-nanoparticles were found to consist of a large number of concentric layers displaying relatively smooth curvature. For instance, the nanoparticle shown in FIG. 4 consists of approximately 80 concentric and spherical layers. These layers were continuous with no visible holes or edge dislocations observed. The hollow core, which was observed in the IF-WS 2 (MoS 2 ) nanoparticles, did not exist in the present nanoparticles. A careful examination of the synthesized nanoparticles did not reveal a spiral growth mode of the molecular layers of the material. Instead, a quasi-epitaxial, layer by layer growth mode could be deciphered. The observed layers are complete and are separated one from the others. [0137] In several cases the cores of the observed TiS 2 nanoparticles were found to be made of a number of tiny spherical IF centers, which are stacked together. As a rule, such nanoparticles were preferably found in the experiments with definitely higher flow rate of TiCl 4 precursor (preheating at 130-140° C.). For instance several such centers are visible in the TEM image of the nanoparticle shown in FIG. 3 . The borders between those nuclei can be clearly distinguished in the core of the nanoparticle, while the peripheral layers envelope the divided core into a single spherical moiety. [0138] HRTEM image of a part of a closed TiS 2 fullerene-like nanoparticle is shown in FIG. 5A together with its simulated image. A satisfactory agreement between the real and simulated images is indicative of the correct assignment of the nanoparticle's structure. It should be nonetheless noted, that the simulation refers to the bulk (1T) material, which is flat, while the IF-TiS 2 nanoparticles are curved and their structure is not fully commensurate, because the number of atoms is different in each of the concentric nested layers. [0139] The interlayer distance obtained from either Fourier analysis (insert of FIG. 4 ), or a direct measurement ( FIG. 5B ) was found to be 0.58 mu. This value represents an expansion of about 1.8% in comparison to the layer to layer separation in bulk 1T-TiS 2 (0.57 nm). The interlayer distance did not seem to vary along the entire volume of the nanoparticle. This result is in a good agreement with XRD experiments, in which the synthesized material was identified as 1T-TiS 2 . It nevertheless stands in a sharp contrast with the synthesized IF-WS 2 and MoS 2 nanoparticles, synthesized by reacting H 2 S with the respective oxides, were often large gaps are observed between the molecular sheets. These gaps can be associated with strain-induced brisk changes in the topology of the layers from evenly folded to faceted structure. This topology was found to be typical for nanoparticles which are produced by the reaction of H 2 S with the respective oxide, which starts on the surface of the nanoparticle and progresses inwards consuming the oxide core. [0140] At high temperature experiments (800° C.), nanoparticles having distorted shape were observed. Also, the overall yield of the IF-TiS 2 at high temperatures was low (app. 10%), the main portion being TiS 2 platelets. [0141] A number of other precursors were tested for their aptitude to obtain fullerene-like materials in similar way. The resulting nanoparticles of both MoS 2 and WS 2 ( FIGS. 6-10 ) were obtained from variety of starting materials. Most of the newly-obtained nanoparticles were found to differ from their analogs, obtained by reduction-sulfidization of oxide templates. More specifically, the nanoparticles obtained from the vapors of metal-containing precursors were more spherical, with little amount of defects. Moreover, they had a small hollow core, if any, like it was found in the case of TiS 2 . [0142] Tribological Experiments [0143] A ball on flat tester 1 was used for the present tribological experiments. A load of 50 grams was used in these experiments. The friction coefficient was measured in the end of the 20 cycles run, were steady tribological regime prevailed. [0144] To test the efficacy of the IF-TiS 2 particles produced by the process of the present invention, as a solid lubricant a series of tribological experiments were conducted. It was found that the addition of a small amount (1%) of the IF-TiS 2 powder decreases significantly (10 times) the friction coefficient of the pure oil-from 0.29 to 0.03. A similar test with 1% bulk powder (1T-TiS 2 ) added to the oil, leads to a friction coefficient of 0.07, i.e. twice that of the IF-phase. It must be emphasized here that the portion used for the tribological tests contained no more than 50% IF-TiS 2 , the rest being platelets of 1T-TiS 2 . The collected data suggests that the shape of the IF-TiS 2 of the invention might play a major role in lowering the friction coefficient. The quite perfectly spherical nanoparticles with sizes ranging in the 30-70 nm and up to 100 molecular layers thick obtained with the vertical set-up could provide effective rolling friction and sliding. It is emphasized the important role played by the spherical shape of the nanoparticles in providing rolling friction with a reduced friction coefficient and wear. These nanoparticles are also stable and compliant. Comparison Between if Nanoparticles Obtained in the Process of the Present Invention and Known if Nanoparticles: [0145] The IF-TiS 2 nanoparticles obtained by the process of the present invention in a vertical reactor, typically consist of about hundred layers and are formed fast, over a period of a few minutes or less, only. They are spherical in shape, and their lattice parameter (c) is constant along the radial axis of the nanoparticle, which suggests that they suffer from relatively minor strain. Table 2 together with FIG. 11 make a concise comparison between the morphology and some of the properties of the IF-TiS 2 nanoparticles obtained by the process of the present invention and IF-WS 2 nanoparticles obtained by processes known in the art. [0146] The following Table 2 compares the representative characteristics of fullerene-like WS 2 obtained by the known reaction of H 2 S gas with tungsten oxide nanoparticles, and TiS 2 nanoparticles obtained from titanium chloride vapor according to the present invention. [0000] TABLE 2 Comparison between representative characteristics of IF—WS 2 obtained by the known reaction and IF—TiS 2 nanoparticles obtained by the process of the present invention. IF—TiS 2 IF—WS 2 Typical size 60-100 nm 60-200 nm Number of layers 50-120 20-30 Core No core or very Empty hollow core small core observed Overall shape of the Substantially Partially faceted, nanoparticle spherical not spherical Estimated growth Minutes Hours duration Growth mechanism Nucleation and Synergetic growth sulfidization and reduction; diffusion controlled [0147] In contrast to the earlier synthesized IF-WS 2 (MoS 2 ) 5-7 , the closed-cage nanoparticles of titanium disulfide produced by the process of the present invention have a very small hollow core or do not possess such core. The interlayer distance (0.58 nm) is preserved along the entire volume of the nanoparticle. The present results are indicative of the fact that the titanium disulfide layers start to grow from a small nuclei, obeying thereby the ubiquitous nucleation and growth mechanism. The present synthesis of IF-TiS 2 may be envisaged as a homogeneous nucleation of the fullerene-like structures from embryonic clusters formed in the vapor phase, in contrast to the heterogeneous nucleation of IF-WS 2 (MoS 2 ) on the surfaces of the respective oxide templates. [0148] The vapor of TiCl 4 crosses the flux of H 2 S, coming out from an oppositely placed tube at relatively high temperature (650-750° C.), which provides a high reaction rate. Since the TiS 2 clusters formed in the gas phase are non-volatile, they condense into small nuclei. It is well established that shrinking the size of the graphene (or other layered material-like TiS 2 ) sheet makes the planar structure unstable resulting in folding and formation of a closed-cage structure. Once such closed-cage nuclei of TiS 2 are formed in the vapor phase of the reactor further TiCl 4 adsorb on its surface and react with the H 2 S gas. This reaction occurs in a highly controlled-quasi-epitaxial fashion, i.e. with a single growth front leading to a layer by layer growth mode. This growth mode entails minimal geometrical constraints, and hence the nanoparticles are appreciably more spherical than the previously reported IF nanoparticles. The spherical morphologies with relatively smooth curvature exhibited by these nanoparticles suggest that the bending of the molecular sheets results in continuously distributed dislocations or defects, in contrast to the more facetted structures, observed in the previously synthesized IF-WS 2 , where the defects are localized in grain boundaries. The rather large number of layers observed in the IF-TiS 2 nanoparticles undergoing van der Waals interactions may compensate for the bending and dislocation energies and add to the stability of such spherical nanoparticles. [0149] The small crystallites, formed during the initial stages of the gas-phase reaction collide in the vapor phase. When the kinetic energy of the collision is not sufficiently large to separate the colliding nanoparticles, they aggregate forming multi-nuclei cores. These aggregated nanoparticles serve as a template, which are subsequently enfolded by additional TiS 2 layers on their surface. A fullerene-like nanoparticle with multi-core is thus obtained (see FIG. 3 ). The fairly narrow size distribution of the IF-TiS 2 nanoparticles in the vertical set-up is particularly notable. Presently, two possible explanations for this effect can be invoked. Once the nanoparticles reach a critical size, which coincides with their thermodynamic stability, their growth rate slows down appreciably, while the smaller nuclei continue to grow fast until they reach a similar size. A further possible reason for the narrow size distribution is that the larger nanoparticles can not float in the vapor and they fall on the filter, where they are rapidly buried under the next layer of nanoparticles, and their growth slows down. [0150] The constancy of the distance between the layers (c) in the radial direction, and their quite perfectly spherical shape indicate that the present IF nanoparticles suffer little strain, only. This phenomenon is the result of the nucleation and growth mechanism accomplished in the present invention, and it has a favorable impact on the tribological behavior of such nanoparticles. [0151] Other IF metal chalcogenides, e.g. IF-WS 2 and MoS 2 nanoparticles, synthesized by a similar process as the above-exemplified one for TiS 2 , provide similar spherical nanoparticles consisting of many layers ( FIG. 6-10 ). It appears that the nanoparticles obtained from the vapors of metal-containing precursor follow the same growth mechanism (nucleation and growth). This topology favors rolling and sliding of the nanoparticles, providing improved tribological behavior for the IF solid lubricant. Since IF-WS 2 and MoS 2 are the materials of choice for such applications, the improved control of the nanoparticles morphology, as presented in the present invention for leads to a superior tribological behavior of these solid lubricants, too.

The present invention provides a process for obtaining fullerene-like metal chalcogenide nanoparticles, comprising feeding a metal precursor selected from metal halide, metal carbonyl, organo-metallic compound and metal oxyhalide vapor into a reaction chamber towards a reaction zone to interact with a flow of at least one chalcogen material in gas phase, the temperature conditions in said reaction zone being such to enable the formation of the fullerene-like metal chalcogenide nanoparticles product. The present invention further provides novel IF metal chalcogenides nanoparticles with spherical shape and optionally having a very small or no hollow core exhibiting excellent tribological behaviour. The present invention further provides an apparatus for preparing various IF nanostructures.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellicle, a producing method thereof and an adhesive, and more particularly, to a pellicle used for a purpose of preventing dusts from attaching to a mask or a reticle (hereinafer referred simply to as mask or the like) used in the photolithography step in a process for producing an integrated circuit, to a process for producing a pellicle, and to an adhesive for pellicles. 2. Description of the Related Art Based on the demand for rendering the line widths of integrated circuits finer, there is a request of using exposure light sources having extremely short wavelengths. When ultraviolet rays having such short wavelengths are used, the conventional pellicle films, such as cellulose, have severe degradation, and only insufficient durability is attained. Therefore, in recent years, pellicle films made of fluorine-containing polymers are used. However, practical adhesive strength was not attained using epoxy-based adhesives conventionally used for adhering pellicle films on pellicle frames due to the excellent detachabilities of the fluorine-containing polymers. Moreover, epoxy-based adhesives have only insufficient light resistance to the ultraviolet rays having short wavelengths. In order to solve such problems about the adhesives for pellicle films made of fluorine-containing polymers, a pellicle comprising a pellicle film made of a fluorine-containing organic substance adhered to a pellicle frame with an adhesive made of the same fluorine-containing organic substance has also been proposed (Japanese Patent Application Laid-open No. 6-67409). However, if such a conventional adhesive is used, three-hour air-drying is required after the application of a solution comprising a fluorine-containing organic substance dissolved in an solvent to a frame, and additionally, when a film and an adhesive are adhered together, it is necessary to heat them to a temperature of 100° C. or higher. For this reason, the adhering process takes time and effort. Furthermore, since heat is applied, there is a problem that members, such as a frame, are distorted. SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide an adhesive that has a sufficient light resistance to ultraviolet rays of short wavelengths, requires no heating at the time of adhering and exhibits a sufficient adhesive strength, a pellicle comprising an adhesive layer in which such an adhesive is used, and a process for producing such a pellicle. According to a first aspect of the present invention, there is provided an adhesive comprising a fluorine-containing polymer and an ultraviolet-curing fluorine-containing monomer. Further, according to a second aspect of the present invention, there is provided a pellicle comprising a pellicle film and a pellicle frame for supporting the pellicle film wherein the pellicle film is adhered to the pellicle frame through an adhesive layer comprising a fluorine-containing polymer and a substance resulting from curing of an ultraviolet-curing fluorine-containing monomer. Still, furthermore, according to a third aspect of the present invention, there is provided a producing method of a pellicle including a pellicle film and a pellicle frame for supporting the pellicle film, comprising a step of adhering the pellicle film to the pellicle frame through an adhesive comprising a fluorine-containing polymer and an ultraviolet-curing fluorine-containing monomer. The use of an adhesive containing an ultraviolet-curing fluorine-containing monomer as an adhesive for adhering a pellicle film to a pellicle frame makes it possible to adhere the pellicle film to the pellicle frame by polymerization-curing the fluorine-containing adhesive through ultraviolet irradiation. Therefore, it can simplify the process and can eliminate the necessity of heating at the time of adhering, and as a result, it makes it possible to effectively prevent a pellicle film from being damaged. Moreover, since not only an ultraviolet-curing fluorine-containing monomer but also a fluorine-containing polymer is contained in the adhesive, the adhesive strength of the adhesive can be further improved. Furthermore, since a fluorine-containing polymer and a substance resulting from the curing of an ultraviolet-curing fluorine-containing monomer are contained as an adhesive layer for adhering a pellicle film to a pellicle frame, it has a light resistance to the ultraviolet rays of short wavelengths. It is desirable that the pellicle film adhered with the above-mentioned adhesive comprises a fluorine-containing polymer. If the above-mentioned adhesive containing a fluorine-containing polymer and an ultraviolet-curing fluorine-containing monomer is used for adhering a pellicle film comprising a fluorine-containing polymer to a pellicle frame, it becomes possible to improve the adhesiveness of the pellicle film comprising a fluorine-containing polymer. It is desirable that the fluorine-containing polymer contained in the adhesive is a copolymer comprising structural units represented by the following formulas (4), (5), and (6). —C 2 F 4 —  (4) —C 3 H 6 —  (5) —C 2 H 2 F 2 —  (6) The desirable molecular weight of the fluorine-containing polymer used for the adhesive is a molecular weight such that a limiting viscosity [η] is 0.20 to 0.80 (dl/g). Here, with respect to the measurement conditions of the limiting viscosity [η], the solvent is THF and the temperature is 30° C. If the limiting viscosity [η] is too high (that is, if the molecular weight is too great), when the film is adhered, the spreadability of the adhesive on a frame becomes poor and it becomes difficult to adhere a film with good appearance. On the contrary, if the limiting viscosity is too low (that is, the molecular weight is too small), the strength of the adhesive after curing becomes poor and the adhesive layer is distorted by the tension of the film. More preferably, this copolymer is a fluorine polymer represented by the following formula (7) wherein each of a, b and c is a positive integer and, still more preferably, it is 1,1-difluoroethylene.teluoroethylene.propylene copolymer, where [η]=0.30−0.45 (dl/g). —(C 2 F 4 ) a —(C 3 H 6 ) b —(C 2 H 2 F 2 ) o —  (7) It is desirable that the ultraviolet-curing fluorine-containing monomer preferably contained in the adhesive used for adhering a pellicle film to a pellicle frame is preferably a (meta) acrylic ester of a fluorine-containing monomer or a fluorine-containing monomer having a hydroxyl group. At least one kind of monomer selected from the group consisting of general formulas (1), (2) and (3) presented below can be suitably used, in the formulas, R 1 and R 4 each independently representing hydrogen or a methyl group, R 2 and R 3 each independently representing hydrogen or a hydroxyl group, Rf being a fluorine-containing group, and l, m and n each being an integer. The desirable ratio between the fluorine-containing polymer and the ultraviolet-curing fluorine-containing monomer contained in an adhesive is fluorine-containing polymer:ultraviolet-curing fluorine-containing monomer=1:0.25 to 0.5 (weight ratio) in the case of monoacrylate fluorine-containing monomer represented by general formula (2); and fluorine-containing polymer:ultraviolet-curing fluorine-containing monomer=1:0.25 to 3 (weight ratio) in the case of diacrylate fluorine-containing monomer represented by general formula (3) or (4). If there are too much fluorine-containing monomer, the adhesive strength will become low. Conversely, if there is a too small amount of fluorine-containing monomer, when the film is adhered, the spreadability of the adhesive on a flame becomes poor and it becomes difficult to adhere a film with good appearance. In the ultraviolet-curing fluorine-containing monomer represented by general formula (1) (in the formula, R 1 is hydrogen or a methyl group, R 2 is hydrogen or a hydroxyl group, Rf is a fluorine-containing group, and 1 is an integer) presented below among the ultraviolet-curing fluorine-containing monomers preferably contained in the adhesive layer used for adhering a pellicle film to a pellicle frame, 1 is preferably an integer of 1 to 8. The fluorine-containing group Rf may preferably be —(CF 2 )CF 3 , —(CF 2 ) 7 CF 3 , —(CF 2 ) 3 CF 3 , —(CF 2 ) 2 CF(CF 3 ) 2 , —(CF 3 ) 2 , —(CF 2 ) 3 CF 2 H, —(CF 2 ) 9 CF 3 , —(CF 2 ) 8 CF(CF 3 ) 2 or the like. The ultraviolet-curing fluorine-containing monomer represented by general formula (1) is specifically exemplified by the following fluorine-containing monomers. CH 2 ═CH—CO 2 —CH 2 —CH 2 —(CF 2 ) 9 CF 3 CH 2 ═CH—CO 2 —CH 2 (CF 2 ) 4 CH 2 OH CH 2 ═CH—CO 2 —(CH 2 ) 6 —(CF 2 ) 5 CF 3 CH 2 ═CH—CO 2 —CH 2 —(CF 2 ) 5 CF 2 H CH 2 ═CH—CO 2 —(CH 2 ) 6 (CF 2 ) 3 CF 3 In the ultraviolet-curing fluorine-containing monomer represented by general formula (2) (in the formula, R 1 and R 4 each independently representing hydrogen or a methyl group, R 2 and R 3 each independently representing hydrogen or a hydroxyl group, Rf being a fluorine-containing group, and m and n each being an integer) presented below among the ultraviolet-curing fluorine-containing monomers preferably contained in the adhesive layer used for adhering a pellicle film to a pellicle frame, m is preferably an integer of 1 to 8 and n is preferably an integer of 1 to 8. The fluorine-containing group Rf may preferably be —CF 2 —, —(CF 2 ) 2 —, —(CF 2 ) 4 —, —(CF 2 ) 6 —, —(CF 2 ) 8 —, —CFCF 3 —, —(CF 2 ) 2 CFCF 3 —, —(CF 2 ) 4 CFCF 3 —, —(CF 2 ) 6 CFCF 3 — or the like. The ultraviolet-curing fluorine-containing monomer represented by general formula (2) is specifically exemplified by the following fluorine-containing monomers. CH 2 ═CH—CO 2 —CH 2 —(CF 2 ) 2 —CH 2 —CO 2 —CH═CH 2 CH 2 ═CH—CO 2 —CH 2 —(CF 2 ) 4 —CH 2 —CO 2 —CH═CH 2 CH 2 ═CH—CO 2 —CH 2 —(CF 2 ) 6 —CH 2 —CO 2 —CH═CH 2 CH 2 ═CH—CO 2 —CH 2 —(CF 2 ) 8 —CH 2 —CO 2 —CH═CH 2 CH 2 ═CH—CO 2 —(CH 2 ) n —(CF 2 ) 4 —(CH 2 ) m —CO 2 —CH═CH 2 (n and m are respectively 1 to 3) CH 2 ═C(CH 3 ) —CO 2 —(CH 2 ) n —(CF 2 ) 4 —(CH 2 ) m —CO 2 —CH═CH 2 (n and m are respectively 1 to 3) CH 2 ═C(CH 3 ) —CO 2 —(CH 2 ) n —(CF 2 ) 4 —(CH 2 ) m —CO 2 —C(CH 3 )═CH 2 (n and m are respectively 1 to 3) CH 2 ═CH—CO 2 —CH(OH)—(CF 2 ) 4 —(CH) n —CO 2 —CH═CH 2 (n is 1 to 3) In the ultraviolet-curing fluorine-containing monomer represented by general formula (3) (in the formula, R 1 and R 4 each independently representing hydrogen or a methyl group, R 2 and R 3 each independently representing hydrogen or a hydroxyl group, Rf being a fluorine-containing group, and m and n each being an integer) presented below among the ultraviolet-curing fluorine-containing monomers preferably contained in the adhesive layer used for adhering a pellicle film to a pellicle frame, m is preferably an integer of 1 to 8 and n is preferably an integer of 1 to 8. The fluorine-containing group Rf may preferably be —(CF 2 )CF 3 , —(CF 2 ) 7 CF 3 , —(CF 2 ) 3 CF 3 , —(CF 2 ) 2 CF(CF 3 ) 2 , —(CF 3 ) 2 , —(CF 2 ) 3 CF 2 H, —(CF 2 ) 9 CF 3 , —(CF 2 ) 8 CF(CF 3 ) 2 or the like. The ultraviolet-curing fluorine-containing monomer represented by general formula (3) is specifically exemplified by the following fluorine-containing monomers. In the adhesive used for adhering a pellicle film to a pellicle frame, a photoinitiator or a sensitizer can be used together with the aforementioned fluorine-containing polymer and ultraviolet-curing fluorine-containing monomer. The use of these agents makes the polymerization-curing caused by ultraviolet rays proceed rapidly and also increases the degree of polymerization so that it can improve the adhesive strength. As the photoinitiator, 2,2-diethoxyacetophenone, Darocur 1173 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 369 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 819 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 1700 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 1850 (manufactured by Ciba Specialty Chemicals K.K.) and Irgacure 184 (manufactured by Ciba Specialty Chemicals K.K.) are preferably used. Preparation of Adhesive As the sensitizer, benzoin, benzoin ethyl ether and benzoin isopropyl ether can be used suitably. Pellicle Film Preferably, a pellicle film used for a pellicle is that comprising a fluorine-containing polymer, and, is specifically exemplified by a fluorine polymer manufactured by Asahi Glass Company (trade name: CYTOP), a fluorine polymer manufactured by E. I. du Pont de Nemours and Company (trade name: Teflon AF), etc. The production of the pellicle film comprising a fluorine-containing polymer can be carried out by dissolving the above-mentioned fluorine-containing polymer using a fluorine-containing solvent, especially a perfluoro organic solvent such as perfluoro (2-butyltetrahydrofuran), perfluoro (2-propyltetrahydropyran), perfluorohydrofuran and perfluorooctane, so that the concentration of the polymer becomes 0.1 to 20% by weight, especially 0.3 to 10% by weight, and then coating the solution by a known cast film formation method such as the spin coat method and the knife coat method. It is generally recommended to cast a resin solution on a surface of a smooth substrate such as a glass plate to form a thin film and then dry it by means of hot air or infrared irradiation to remove the residual solvent. The thickness of the thin film formed can be easily changed by changing the viscosity of the solution, the rotating speed of the substrate, etc. It is generally recommended to set the thickness of a thin film so that the permeability to the wavelength of the light source used within the range of from 0.05 to 10 μm becomes high. Moreover, a pellicle film comprising a thin film made of a conventionally known pellicle film material such as nitrocellulose and an antireflection layer made of a fluorine-containing polymer laminated on the thin film can also be used suitably as well as the pellicle film made of a fluorine-containing polymer. Also in this case, even if the part coming into contact with an adhesive is the antireflection layer made of the fluorine-containing polymer, the above-mentioned adhesive containing a fluorine-containing polymer and an ultraviolet-curing fluorine-containing monomer shows an excellent adhesiveness and it is possible to obtain an effect the same as in the case of adhering a pellicle film made of a fluorine-containing polymer. Pellicle Frame All the known pellicle frames can be used as a pellicle frame, and that made of metals such as aluminum, aluminum alloy and stainless steel, that made of synthetic resin and that made of ceramic can be preferably used. Moreover, adhering a pellicle film to one side of the pellicle frame through the aforementioned adhesive and applying an adhesive or sticking a double-sided tape to the other side make the pellicle of the present invention possible to be attached onto a mask or the like. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIRST EXAMPLE Preparation of a Pellicle Film A 6-wt % solution was prepared by dissolving a completely fluorinated fluorine-containing resin, CYTOP (trade name, manufactured by Asahi Glass Company) in a fluorine-containing solvent, IL-263 (perfluorotrialkylamine (chemical formula: C n F 2n+1 ) 3 N) (manufactured by Tokuyama Corp. trade name) and then a thin film of 0.8 μm in thickness was formed using a spin coat method. Preparation of Adhesive In 1,1-difluoroethylene.tetrafluoroethylene. propylene copolymer (manufactured by Asahi Glass Company) (limiting viscosity: [η]=0.30 to 0.45 (dl/g)), butyl acetate and 2-(perfluorooctyl) ethyl acrylate (R-1820 manufactured by Daikin Fine Chemical Laboratory, trade name) were added and dissolved. Then, an adhesive was prepared by adding Darocur 1173 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 369 (manufactured by Ciba Specialty Chemicals K.K.) and 2,2-diethoxyacetophenone (manufactured by Wako Pure Chemical Industries, Ltd.) as photoinitiators. Refer to Table 1 for the composition. Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width) made of an aluminum alloy, an adhesive discharged from an application needle having an outer diameter of 2.0 mmφ and an inner diameter of 1.0 mmφ at a discharging rate of 16 sec/5 drops was applied at an application speed of 20 mm/second. The pellicle film formed was adhered 60 seconds after the completion of the application. After that, the pellicle film was irradiated using a UV irradiation device (manufactured by TOSHIBA LIGHTING & TECHNOLOGY CORPORATION; M2000L/81N (80 W/cm); spectral range: 220 to 600 nm) for 90 seconds, and thus, the adhesive was cured. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive Strength, Appearance Evaluation and Light Resistance of Pellicle Film) Evaluation (outwardly-blowing evaluation) was conducted by using a needle 1.0 mmφ in outer diameter and 0.65 mmφ in inner diameter and blowing an air having a pressure of 0.2 MPa, at a speed of about 2 mm/second, from a position 10 mm away from the front face of a thin film, at an angle of 65°, along the inside of the pellicle frame having the thin film adhered thereon. In the same manner, evaluation (inwardly-blowing evaluation) was conducted by blowing an air having a pressure of 0.2 MPa, at a speed of about 2 mm/second, from a position 10 mm away from the rear face of the thin film, at an angle of 45°, along the inside of the pellicle frame having the thin film adhered thereon. Moreover, the appearance was evaluated with a microscope under a fluorescent lamp. Furthermore, the light resistance was evaluated by irradiating an adhesion surface with ArF laser (wavelength: 193 nm, 1 (mJ/cm 2 )/pulse, 500 Hz) in the amount of 3000 J. The results are summarized in Table 1. TABLE 1 (Evaluation Results 1) adhesive composition (wt %) adhesive strength fluorine- evaluation containing R- butyl 1173/369/diet- outwardly- inwardly- appearance light comprehensive No. polymer*1 1820 acetate hoxyacetophenone*2 blowing blowing evaluation resistance*3 evaluation 1 17.0 8.5 74.2 0.3/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 2 17.0 4.3 78.6 0.1/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 3 17.0 8.5 73.9 0.6/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 4 17.0 8.5 73.9 0/0.6/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 5 17.0 8.5 73.9 0/0/0.6 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 6 17.0 8.5 73.9 0.3/0.3/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 7 17.0 8.5 73.9 0.2/0.2/0.2 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 8 17.0 8.5 73.9 0/0.3/0.3 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film *1 1, 1-difluoroethlene · teltrafluoroethylene · propylene copoylmer *2 1173:Darocur 1173, 369:Iracure 369, diethoxyacetophenone:2.2 diethoxyacetophenone *3 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mj, 500 Hz) in the amount of 3000 J. The results in Table 1 show that the aforementioned adhesive can adhere a frame and a film strongly, rapidly and with good appearance by irradiation of ultraviolet light after the application of the adhesive to the pellicle frame. The light resistance was also found to be excellent. In “Appearance evaluation” in Table 1, “no film cramp problem” refers to the case where a slight clamp that does not cause any problem in practical use is observed in appearance. The case where the evaluation “no film cramp problem is not found” is the case where no cramp was observed. “There was no irregularity in the film” indicates that there are no irregularities such as discoloration of the film and is the evaluation about whether the film itself was affected or not. These apply to Table 2 or later. Moreover, also in the following Examples and Comparative Examples, the formation of a pellicle film and evaluations of adhesive strength and appearance of the pellicle film were conducted in the same manner as Example 1. Therefore, the details about these items are omitted in the following Examples and Comparative Examples. SECOND EXAMPLE Preparation of Adhesive In 1,1-difluoroethylene.tetrafluoroethylene. propylene copolymer (manufactured by Asahi Glass Company), butyl acetate and 1H, 1H, 5H-octafluoropentyl acrylate (R-5410: manufactured by Daikin Fine Chemical Laboratory, trade name) were added and dissolved. Then, an adhesive was prepared by adding Darocur 1173 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 369 (manufactured by Ciba Specialty Chemicals K.K.) and 2,2-diethoxyacetophenone (manufactured by Wako Pure Chemical Industries, Ltd.) as photoinitiators. Refer to Table 2 for the composition. Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width) made of an aluminum alloy, an adhesive discharged from an application needle having an outer diameter of 2.0 mmφ and an inner diameter of 1.0 mmφ at a discharging rate of 16 sec/5 drops was applied at an application speed of 20 mm/second. The pellicle film formed was adhered 60 seconds after the completion of the application. After that, the pellicle film was irradiated using a UV irradiation device (manufactured by TOSHIBA LIGHTING & TECHNOLOGY CORPORATION; M2000L/81N (80 W/cm); spectral range: 220 to 600 nm) for 90 seconds, and thus, the adhesive was cured. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive strength, appearance evaluation and light resistance of pellicle film) The results are summarized in Table 2. TABLE 2 (Evaluation Results 2) adhesive composition (wt %) adhesive strength fluorine- evaluation containing R- butyl 1173/369/die- outwardly- inwardly- appearance light comprehensive No. polymer*1 5410 acetate thoxyacetophenone*2 blowing blowing evaluation resistance*3 evaluation 9 17.0 8.5 74.2 0.3/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 10 17.0 4.3 78.6 0.1/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 11 17.0 8.5 73.9 0.6/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 12 17.0 8.5 73.9 0/0.6/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 13 17.0 8.5 73.9 0/0/0.6 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 14 17.0 8.5 73.9 0.3/0.3/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 15 17.0 8.5 73.9 0.2/0.2/0.2 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 16 17.0 8.5 73.9 0/0.3/0.3 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film *1 1, 1-difluoroethlene · tetrafluoroethylene · propylene copoylmer *2 1173:Darocur 1173, 369:Iracure 369, diethoxyacetophenone:2.2 diethoxyacetophenone *3 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mJ, 500 Hz) in the amount of 3000 J. The results in Table 2 show that the aforementioned adhesive can adhere a frame and a film strongly, rapidly and with good appearance by irradiation of ultraviolet light after the application of the adhesive to the pellicle frame. THIRD EXAMPLE Preparation of Adhesive 2,2,3,3,4,4,5,5-octafluorohexane-1,6-diacrylate (hereafter referred to as DR7412) was synthesized by esterifying 2,2,3,3,4,4,5,5-octafluorohexane-1,6-diol (A-7412; manufactured by Daikin Fine Chemical Laboratory; trade name). Thereafter, in 1,1-difluoroethylene. tetrafluoroethylene.propylene copolymer (manufactured by Asahi Glass Company), butyl acetate and the synthesized DR7412 were added and dissolved. Then, an adhesive was prepared by adding Darocur 1173 (manufactured by Ciba Specialty Chemicals K.K.), Irgacure 369 (manufactured by Ciba Specialty Chemicals K.K.) and 2,2-diethoxyacetophenone (manufactured by Wako Pure Chemical Industries, Ltd.) as photoinitiators. Refer to Table 3 for the composition. Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width), an adhesive discharged from an application needle having an outer diameter of 2.0 mmφ and an inner diameter of 1.0 mmφ at a discharging rate of 16 sec/5 drops was applied at an application speed of 20 mm/second. The pellicle film formed was adhered 60 seconds after the completion of the application. After that, the pellicle film was irradiated using a UV irradiation device (manufactured by TOSHIBA LIGHTING & TECHNOLOGY CORPORATION; M2000L/81N (80 W/cm); spectral range: 220 to 600 nm) for 90 seconds, and thus, the adhesive was cured. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive Strength, Appearance Evaluation and Light Resistance of Pellicle Film) The results are summarized in Table 3. TABLE 3 (Evaluation Results 3) adhesive composition (wt %) adhesive strength fluorine- evaluation containing DR- ethyl 1173/369/diet- outwardly- inwardly- appearance light comprehensive No. polymer*1 7412 acetate hoxyacetophenone*2 blowing blowing evaluation resistance*3 evaluation 17 12.0 36.0 49.8 2.2/0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 18 22.0 44.0 31.4 2.6/0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 19 22.0 33.0 43.0 2.0/0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 20 22.0 22.0 54.7 1.3/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 21 17.0 8.5 74.2 0.3/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 22 17.0 4.3 78.6 0.1/0/0 no peeling no peeling no film cramp no ◯ problem irregularity no irregularity in the film 23 22.0 33.0 42.0 3.0/0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 24 22.0 33.0 44.0 1.0/0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 25 22.0 33.0 43.0 0/0/2.0 no peeling no peeling no irregularity no ◯ in the film irregularity 26 22.0 33.0 43.0 1.0/1.0/0 no peeling no peeling no irregularity no ◯ in the film irregularity 27 22.0 33.0 43.0 0/1.0/1.0 no peeling no peeling no irregularity no ◯ in the film irregularity 28 22.0 33.0 42.9 0.7/0.7/0.7 no peeling no peeling no irregularity no ◯ in the film irregularity *1 1, 1-difluoroethlene · teltrafluoroethylene · propylene copoylmer *2 1173:Darocur 1173, 369:Iracure 369, diethoxyacetophenone:2.2 diethoxyacetophenone *3 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mj, 500 Hz) in the amount of 3000 J. The results in Table 3 show that the aforementioned adhesive can adhere a frame and a film strongly, rapidly and with good appearance by irradiation of ultraviolet light after the application of the adhesive to the pellicle frame. COMPARATIVE EXAMPLE 1 Preparation of Adhesive An adhesive was prepared by adding butyl acetate as a solvent to an ultraviolet-curing adhesive not being any fluorine-containing monomer, 3083 (manufactured by Three Bond, Co., Ltd.). Refer to Table 4 for the composition of this adhesive. Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width) made of an aluminum alloy, an adhesive discharged from an application needle having an outer diameter of 0.7 mmφ and an inner diameter of 0.3 mmφ at a discharging rate of 30 sec/5 drops was applied at an application speed of 20 mm/second. The pellicle film formed was adhered 60 seconds after the completion of the application. After that, the pellicle film was irradiated using a UV irradiation device (manufactured by TOSHIBA LIGHTING & TECHNOLOGY CORPORATION; M2000L/81N (80 W/cm); spectral range: 220 to 600 nm) for 70 seconds, and thus, the adhesive was cured. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive Strength, Appearance Evaluation and Light Resistance of Pellicle Film) The results are summarized in Table 4. TABLE 4 (Evaluation Results 4) adhesive composition adhesive strength (wt %) evaluation butyl outwardly- inwardly- appearance light comprehensive No. 3083 acetate blowing blowing evaluation resistance*3 evaluation 29 100 0 peeling was peeling was no irregularity discoloration X observed observed in the film was observed 30 60 40 peeling was peeling was no irregularity discoloration X observed observed in the film was observed 31 40 60 peeling was peeling was no irregularity discoloration X observed observed in the film was observed *1 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mJ. 500 Hz) in the amount of 3000 J. The results summarized in Table 4 show that in the case of the aforementioned adhesive, rapid adhesion with good appearance was achieved, but only insufficient adhesive strength was attained. Further, the results also show that there is a light resistance problem. COMPARATIVE EXAMPLE 2 Adhesive A pellicle was prepared using Three Bond 3013C (manufactured by Three Bond, Co., Ltd.; trade name). Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width) made of an aluminum alloy, an adhesive discharged from an application needle having an outer diameter of 0.7 mmφ and an inner diameter of 0.3 mmφ at a discharging rate of 30 sec/5 drops was applied at an application speed of 20 mm/second. The pellicle film formed was adhered 60 seconds after the completion of the application. After that, the pellicle film was irradiated using a UV irradiation device (manufactured by TOSHIBA LIGHTING & TECHNOLOGY CORPORATION; M2000L/81N (80 W/cm); spectral range: 220 to 600 nm) for 90 seconds, and was heated for 10 minutes using a hot air dryer at 120° C. Thus, the adhesive was cured. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive Strength, Appearance Evaluation and Light Resistance of Pellicle Film) The results are summarized in Table 5. TABLE 5 (Evaluation Results 4) adhesive composition adhesive strength (wt %) evaluation Three Bond outwardly- inwardly- appearance light comprehensive No. 3013C blowing blowing evaluation resistance*3 evaluation 32 100 peeling was peeling was film was discolored diacoloration X observed observed near the frame. was observed resulting in color heterogeneity *1 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mJ. 500 Hz) in the amount of 3000 J. The results in Table 5 show that in the case of the aforementioned adhesive since there is a necessity of applying a high temperature for adhering the objects, the film was damaged. Further, only insufficient adhesive strength was attained. Still further, the results also show that there is a light resistance problem. COMPARATIVE EXAMPLE 3 Preparation of Adhesive CYTOP CTX type-A (manufactured by Asahi Glass Company; trade name) was dissolved in a solvent CTsolv160 (perfluorotrialkylamine (chemical formula: C n F 2n+1 ) 3 N) (manufactured by Asahi Glass Company; trade name) and the concentration was adjusted to 9% by weight. Preparation of Pellicle Onto an adhesion surface of a pellicle frame (149 mm in length, 122 mm in breadth, 5.8 mm in height and 2 mm in width) made of aluminum alloy, an adhesive discharged from an application needle having an outer diameter of 2.0 mmφ and an inner diameter of 1.0 mmφ at a discharging rate of 16 sec/5 drops was applied at an application speed of 20 mm/second. After the hot-air drying for 3 hours was conducted after the completion of the application, this aluminum frame was put on a 130° C. hot plate with the adhesive application surface up, and 5 minutes after, the film formed was put on the adhesive application surface to be adhered. Subsequently, the excessive film extending outside the pellicle frame was cut away with a cutter so that a pellicle was prepared. (Adhesive strength, appearance evaluation and light resistance of pellicle film) The results are summarized in Table 6. TABLE 6 (Evaluation Results 6) adhesive adhesive strength composition (wt %) -evaluation CTsolv outwardly- inwardly- light comprehensive No. CYTOP 160 blowing blowing appearance evaluation resistance*3 evaluation 33 9 91 no peeling no peeling film was discolored no X near the frame, irregularity resulting in Color heterogeneity *1 The light resistance was evaluated by irradiating an adhesion surface with ArF laser (1 mJ. 500 Hz) in the amount of 3000 J. The results in Table 6 show that in the case of the aforementioned adhesive since there is a necessity of applying a high temperature for adhering the objects, the film was damaged. Further, much time and work were required for preparing a pellicle. The entire disclosure of Japanese Patent Application No. 2000-399185 filed on Dec. 27, 2000 including specification, claims, drawings and abstract are incorporated herein by reference in its entirety. Although various exemplary embodiments have been shown and described, the invention is not limited to the embodiments shown. Therefore, the scope of the invention is intended to be limited solely by the scope of the claims that follow.

A pellicle comprises a pellicle film and a pellicle frame for supporting the pellicle film, wherein the pellicle film is adhered to the pellicle frame through an adhesive layer comprising a fluorine-containing polymer and a substance resulting from curing of an ultraviolet-curing fluorine-containing monomer. A producing method of a pellicle including a pellicle film and a pellicle frame for supporting the pellicle film, comprises a step of adhering the pellicle film to the pellicle frame through an adhesive comprising a fluorine-containing polymer and an ultraviolet-curing fluorine-containing monomer.

This invention relates to heavy duty loading and/or unloading devices of the type that can be used to load or unload heavy, bulky workpieces (such as automotive roof panels) into and out of the dies of industrial presses. It is the main purpose of the invention to provide a desired stroke pattern for devices of this type and, more particularly, to provide means to obtain desired vertical components at opposite ends of a long (e.g. 65") horizontal, straight line stroke. This and other objects of the invention are provided in part by means of a special mounting for the frame which carries the stroke arm and workpiece gripping means. This mounting, in preferred form, enables the frame to be tilted up and down as desired at opposite ends of the stroke thereby imparting a pre-selected vertical component of motion to the workpiece gripping means. An automatic leveler device may be mounted on the stroke arm to tilt the workpiece gripping means in such a way as to compensate for tilting of the frame or to provide additional tilt control over the gripping means. Other features and objects of the invention will become apparent upon consideration of the drawing and the detailed description of the invention. DESCRIPTION OF THE DRAWING The drawing is a side elevation, partly schematic and broken away, of a loading and/or unloading device embodying the invention. DETAILED DESCRIPTION OF THE INVENTION A presently preferred form of loading and/or unloading device 1 is shown in the drawing and it is intended for heavy duty usage to load and unload heavy and bulky workpieces, such as automotive roof panels, to and from industrial presses. The device may, for example, lift a workpiece (not shown) from a conveyor, move it up to 65" or so into the dies of the press, as well as lift it out of the dies and move it several feet to deposit it on another conveyor. The device 1 has a frame 3 that includes a pair of vertically extending, horizontally spaced plates 5. At their tops the plates are rigidly secured to a long, horizontal support tube 7, as shown at 9. Their lower portions are rigidly united by a cam follower mechanism 11 for the long, horizontally extending, tubular stroke arm member 13. The member 13 is preferably square in cross section and rides freely on, but is well supported by, cam roll means 15 of mechanism 11 engaging the flat sides of the member 13 and transferring load on the member into the plates 5. The member 13 extends through a tube 17 between the plates and it can be seen that it is confined to straight line, reciprocating motion in a horizontal direction that is perpendicular to the planes of plates 5. The frame also includes the angle shaped brace plates 19 that are rigid with plates 5 and tube 17 and with a long stroke fluid pressure cylinder 21 that drives the stroke member 13. The rear of the cylinder is supported on the support tube 7 by a cross plate 23. The forward end of tubular stroke arm member 13 is reduced to a rod section 25 that extends through but is also secured to a cross block 27 that is also secured to and moved by the front end of the rod 29 extending out of air cylinder 21 whereby operation of the cylinder 21 reciprocates the member 13. The block 27 has an upwardly extending flange 31 that engages a cushion means 33 extending between the front end of support tube 7 and the block and which therefore serves to cushion the retract or unloading stroke of member 13. The forward or loading stroke is cushioned by cushion means 35 on rear plate 5 that is engaged by the ring 37 secured to the rear end of the member 13. Longitudinal adjustment of ring 37 can also be used as a means to adjust the length of stroke of the member 13. A workpiece gripping or supporting means 39 is supported at the free end of the stroke member rod 25 whereby it is carried by the member 13 for stroke movement with it and for transferring load into it. The workpiece supporting means 39 may be of any desired and suitable arrangement, a framework 41 carrying vacuum cups 43 being illustrated. (Vacuum cup mechanisms are shown in U.S. Pat. Nos. 3,967,489 and 4,073,602 assigned to the assignee hereof). The framework 41 is pivoted on a horizontal axis at the end of rod 25 as shown at 45 and includes an upwardly extending arm 47. The top end of arm 47 is pivoted at 49 to the free end of piston rod 51 that extends out of the fluid pressure leveler cylinder 53, the cylinder 53 having a body pivoted at 55 to a bracket 57 that is rigidly clamped to the rod 25 (i.e., to stroke arm member 13). The leveler cylinder 53 can be actuated to tilt framework 41 about axis 45 to maintain the vacuum cups 43 in a level position (see phantom line portion in the drawing) or a desired orientation despite tilting of the frame 3 and stroke member 13 in a manner to be presently described. Adjacent the top of frame 3 is a stroke end motion actuating and load support mechanism 60 that includes and is supported on a first horizontal support bar 61 which is rigidly held parallel to the stroke arm member 13 by means of a pinch block clamp 63 that removably attaches it to support tube 7. The support bar 61 has rigid upstanding lug means 65 adjacent its left end that is pivoted at 67 to downwardly extending lug means 69 rigidly attached to a second horizontally extending support bar 71. Support bars 61 and 71 are also interconnected at their right ends by a first fluid pressure cylinder means 73 that includes a piston rod 75 which is pivoted at 77 to a rigid extension 79 on the first support bar 61. The cylinder means 73 also includes a body 81 that is pivotally affixed at 83 to a bracket 85 that forms a rigid extension of support bar 71. If pressure fluid is applied to cylinder means 73, the rod 75 will be forced out of the body 81 and the bar 61 and the frame 5 (including member 13 and workpiece gripping means 39) will be tilted in a downward, clockwise direction about axis 67. The maximum degree of this tilt can be positively controlled by an adjustable screw type stop 87 extending from the bottom of the left end of second support bar 71 in a position where it will be engaged by the left end of first support bar 61 as it pivots clockwise about axis 67. The second support bar 71 has a rigid, upstanding leg means 89 adjacent its right end and it is pivoted at 91 to a rigid, downwardly extending lug means 93 on a third horizontally extending support bar 95. Support bars 71 and 95 are also interconnected at their left ends by a second fluid pressure cylinder means 97 that includes a piston rod 99 which is pivoted at 101 to a rigid extension 103 on the second support bar 71. The cylinder means also includes a body 105 that is pivotally affixed at 107 to a bracket 109 that forms a rigid extension of support bar 95. The third support bar 95 has an upstanding flange means 111 that is pivoted at 113 to a hanger support bracket 115 which is rigidly affixed to and carried by a rigid structural member 117 of the machine or structure 119 on which the device 1 is mounted. The angle of incline of support bar 95 is adjustable by means of adjustment screw means 121 that is pivoted at 123 to flange means 111 and secured to a flange 125 extending from bracket 115. Because of mechanism 121, the third support bar 95 is fixed in selected horizontally extending position. Load of the device 1, and the workpieces it carries, is transferred by the mechanism 60 including the third support bar 95 into the bracket 115 and thus into structure 119. If the second pressure cylinder means 97 is actuated to retract piston rod 99, the left end of second support bar 71 will be pulled up so that the bar 71 and everything beneath it tilts in a clockwise direction around axis 91. If the cylinder means 97 is actuated to extend the rod 99, the maximum degree of movement can be positively controlled by the stop screw mechanism 127 extending from the bottom of the right end of support bar 95 in a position where it can be engaged by the right end of support bar 71. The degree of vertical movement can also be adjusted by the longitudinal position of the mechanism 60 on the support tube 7 of the frame 3. If, for example, the pinch clamp 63 is clamped on the tube 7 near its left end, instead of between frame plates 5, the vertical motion of work holding means 39 during tilting about axis 67 and axis 91 will be substantially greater than in the position illustrated. A suitable control system (not shown) is provided to control and synchronize operation of pressure cylinders 21, 53, 73, and 97 and the vacuum source for vacuum cups 43. The two cylinders 73 and 97 are always operated independently so that when one is operating the other is stopped whereby tilting takes place about only one of the first and second pivots 67 or 91. In operation as a loader, assume that in the retract position of the drawing the device 1 picks up a workpiece from a conveyor or the like andthat at the end of the extend stroke it releases the workpiece into the die of a press. Before operation, the work gripping means 39 is pre-set so that the vacuum cups 43 are on the right angle to pick up the workpiece from the conveyor. With the device in retract position, and the control cycle initiated, pressure cylinder means 73 and the vacuum source are activated simultaneously so that the work gripping means 39 moves down as rod 75 is extended. A timer is also activated and when the contact phase is timed out cylinder means 73 reverses, retracting rod 75, and raising the workpiece. The device stays in that position until it receives a signal that the die is ready to receive the workpiece. This activates cylinder 21 to move stroke arm member 13 to the right, starts timing means (1) to activate leveler cylinder 53 to rotate the work gripping means 39 to a desired orientation for the stroke and to enter the die, (2) to activate cylinder means 97 to retract rod 99 and set the workpiece down in the die when it reaches it, and (3) to release vacuum in cups 43 when the workpiece is set down in the die. When the workpiece is set down and released in the die, the timing means is timed out, vacuum is off, cylinder 97 is activated to extend rod 99 and raise the work holding means 39, cylinder 21 is activated to move the stroke member 13 and means 39 to the retract position, and leveler cylinder 53 is activated to rotate the means 39 back to the pre-set orientation. In operation as an unloader, the workpiece gripping means 39 is pre-set to the desired angle to properly contact the workpiece in the die. On initiation of an unloading cycle, the vacuum source is activated as is cylinder 21 to move the work holding means to the right and cylinder means 97 starts timing to retract the rod 99, which commences when the means 39 is in the die so that it drops on to the workpiece enabling cups 43 to grip it. The timing means causes cylinder 97 to reverse to extend rod 99 and raise the means 39 and workpiece off the die. At this point cylinder 21 is activated to retract the stroke arm 13 bringing the workpiece with it. This starts timing of cylinder 73 to extend rod 75 when the arm 13 is fully retracted and timing of the vacuum source to stop vacuum. When arm 13 is fully retracted rod 75 extends to move the workpiece down on to the conveyor, or otherwise, and vacuum is cut-off so it is released. As soon as this occurs, the cylinder 73 reverses, rod 75 is retracted, and the means 39 is raised up to normal position ready to repeat the unloading cycle. If desired or needed, the leveler cylinder 53 can be timed into the unloading cycle to control the orientation of the means 39 during the cycle as was mentioned in connection with the loading cycle. The invention produces a stroke pattern that is essentially flat between the two end points, i.e., left or retract end for pickup (loader mode) or release (unloader mode) and right or extended end for release (unloader mode) or pickup (loader mode). It is contemplated that the length of the stroke vary widely and can be long, e.g. 65"-84". Similarly, the vertical movement at each end can vary widely, from no vertical movement to movement in terms of feet. Various adjusting means with respect to these distances have been described above. Modifications may be made in the specific structure shown without departing from the spirit and scope of the invention.

A device for heavy duty use in loading or unloading industrial presses comprises a mechanism that tilts a frame (which carries a stroke arm and a work support) in a vertical plane at opposite ends of the stroke so as to provide a desired stroke pattern.

SUMMARY OF THE INVENTION This invention relates to a door construction and will have application to a recreational vehicle door which includes a roll up window. Previously, doors with roll up windows used in various recreational vehicles included peripheral frames which required extensive milling in order to provide for mounting channels to secure the cross rails and door panel to the frame. Further, the inner trim of previous door frames were of single piece construction, which made window replacement very difficult and expensive. The door of this invention includes a single piece extruded peripheral frame which includes preformed channel parts to accommodate the mounting screws for the cross rails and for the door panel. The frame also defines an outer channel which allows the inner trim rail mounting screws to be countersunk into the door frame. Also, the lower trim insert is removable from the rest of the trim to allow for rapid window replacement. Finally, the lower trim rail is stepped to provide a channel for the window to rest in and also to provide a drain for moisture and other debris which may accummulate inside the frame. Accordingly, it is an object of this invention to provide for a novel and improved vehicle door frame. Another object is to provide for a vehicle door which is economical to construct and easy to install. Another object is to provide for a vehicle door which allows rapid access to the window for repair or replacement purposes. Still another object is to provide a vehicle door which is aesthetically pleasing. Other objects of this invention will become apparent upon a reading of the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the door construction of this invention. FIG. 2 is a sectional view taken along line 2--2 of FIG. 1. FIG. 3 is an enlarged view of the door as seen in circle 3 of FIG. 2. FIG. 4 is an enlarged view of the door as seen in circle 4 of FIG. 2. FIG. 5 is an enlarged view of the door as seen in circle 5 of FIG. 2. FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 1. FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 1. FIG. 8 is an enlarged view of the door as seen in circle 8 of FIG. 2. FIG. 9 is a cross-sectional view taken along line 9--9 of FIG. 1. FIG. 10 is a cross sectional view taken along line 10--10 of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to enable others skilled in the art to utilize its teachings. Referring now to FIG. 1, reference numeral 10 refers generally to the door construction of this invention. As shown, door 10 includes an outer frame 12 which is preferably formed of extruded metal and which is secured in a conventional manner to a vehicle frame 14. Door 10 is generally adapted for use in motor homes, but will no doubt find usefulness in a wide variety of recreational vehicles and trucks which utilize similar type doors. Frame 12 as shown accommodates a sliding window assembly 16 which may be raised and lowered as desired to provide ventilation to the interior of the vehicle (not shown). Frame 12 is of the general cross-sectional configuration shown in FIGS. 6 and 9 and defines the sides and top boundaries of door 10. A bottom frame part 18 (see FIG. 8) is secured to frame 12 and defines the lower boundary of door 10. Frame 12 as shown defines inwardly oriented channels 20, 22 and 24. A pair of oppositely located grooves 26, 28 are defined in frame 12 with the grooves oriented in a transverse relationship with respect to channels 20, 22 and 24. Frame 12 may also include a mounting flange 30 which extends outwardly from the frame adjacent groove 26. It should be noted that all orientation descriptions are given as the door 10 is preferably oriented in the vehicle and are not intended to be limiting as to the specific shape of frame 12 or its orientation in the vehicle. Frame 12 is preferably bent into a desired configuration by conventional means in order to fit within the space allotted for the door 10 in vehicle frame 14. Window assembly 16, as is common in the industry, includes glazing panel 32 which is connected at its bottom edge 34 to support bracket 36. Glazing panel 32 slides between its up position and the full down position (shown in dotted lines in FIG. 1) within frame channel 22. A gasket seal 38 is fitted in channel 22, with glazing panel 32 riding in the seal. Support bracket 36 is slidable connected to a regulator assembly 40 which is shown as a power actuated assembly in the drawings. Assembly 40 is common in the industry and includes slide rod 42 which accommodates bracket 36 and is attached to bottom frame rail 18 through a bracket assembly 44. Assembly 40 also includes motor 46 and cables 48 which are arranged in a manner common to the automotive power window industry and will not be described in detail. Regulator assembly 40 is mounted inside door 10 as shown in FIG. 1. A plurality of cross braces 50, 52, 54 span door frame 12 and are fixed to opposite sides of the frame by fasteners 56, 58, 60 which extend through a respective cross brace and are seated in frame grooves 26. Motor 46 is mounted to braces 52, 54 by fasteners 57, 59 which extend through motor mounts 62, 64 as shown. Door 10 also includes a window guide brace 66 which spans frame 12 and is secured thereto by fasteners 67 which extend through channel 68 of the frame and into grooves 70 of the guide brace. Guide brace 66 carries weatherstripping 72 which seals against leakage into the interior compartment of the door. An inner protective panel 74 preferably formed of metal spans the lower portion of frame 12 and is secured in channels 20 by conventional means such as welding. An upper trim rail 76 is connected to panel 74 as shown in FIG. 5. An outer door panel 77 is connected to rail 76 through fastener 78 and molding strip 80. Weatherstripping 82 is secured to trim rail 76 by fasteners 84 and seals against leakage into the interior of the door 10. Window assembly 16 may be of either a one piece glazing panel 32 or of the two panel variety shown with panels 32 and 33. In the embodiment shown only panel 32 shifts between the down and up positions upon actuation of regulator 40 with window 33 fixedly mounted in frame 12 and upper rail 86. FIG. 7 illustrates the construction of lower frame insert 88 which is aligned continuously and is integral with frame 12. Frame insert 88 is similar to frame 12 with the exception that the walls which form channels 22, 24 are eliminated and replaced by insert piece 90 which is secured to insert 88 through fastener 92 which extends through the insert piece and is seated in groove 26. Insert piece 90 includes an integral flange 94 which serves to define channel 22 which houses gasket seal 38 and glazing panel 32 when the window is in the down position. Lower frame insert 88 allows for easy and rapid removal of glazing panel 32 should repair or replacement be necessary. By removing the inner door panel (not shown) which conceals regulator 40 and the other internal mechanical components of door 10, and then removing fastener 92 and insert piece 90, a broken or defaced glazing panel 32 may be slid out of gasket seal 38 and out of the door without further operations. FIG. 8 best illustrates the construction of lower frame rail 18. Frame rail 18 is substantially U-shaped and is secured to frame 12 by fasteners 96 which are seated in screw groove 26 as shown in FIG. 8. Frame rail 18 includes an integral stepped recess part 98 as shown in FIG. 8 which acts as both a safety well for glazing panel 32 with which it is aligned, and as a debris collector for dust and moisture which eventually accumulates inside door 10. Finally, door 10 includes common decorative trim molding 100 about its periphery. Molding 100 is secured to frame 12 by fasteners 102 which extend into grooves 28 as shown in FIGS. 6 and 9. It should be noted that door 10 may be connected in any common manner to vehicle frame 14, such as hinges, slides, or even fixed connections without departing from the spirit of the invention whose scope is defined in the following claims.

A vehicle door construction which includes a door frame which defines integral longitudinal screw grooves for seating fasteners used to mount cross braces to which the window regulator assembly is mounted. The frame may also include a lower recess to collect debris and an outer channel to allow fasteners mounting a window guide brace to be countersunk for easier mounting of the door frame in the vehicle. The frame may also include a removable insert which defines the window slide channel to allow rapid replacement of a broken window.

FIELD OF INVENTION [0001] The invention relates to an intermediate for the synthesis of caspofungin and a preparation method thereof. BACKGROUND FOR THE INVENTION [0002] Caspofungin is a new member of echinocandin antifungal drugs, which was developed in the early 21 st century and first marketed in the United States in February 2001. It has a novel acting mechanism, which kills the fungus by inhibiting the enzyme β-D-glucan synthase, thus disturbing the integrity of the fungal cell wall. Caspofungin has the advantages of broad antifungal activities, no cross resistance and low toxicity, and it can be used to treat systemic fungal infections, including various invasive candidiasis and aspergillosis. It is more effective than amphotericin B, especially toward common refractory candidiasis. [0003] Caspofungin has been semi-synthesized from the biologically fermented intermediate pneumocandin B0 (PB0). Various synthetic methods for caspofungin have been extensively described in patents such as U.S. Pat. No. 5,552,521, U.S. Pat. No. 5,936,062, US20100168415, WO2002083713, WO2007057141, CN101648994, CN101792486, etc. All these methods involve the key intermediate of formula I′ with the thiol substituted aromatic compound (HS—Ar), e.g. thiophenol, as a leaving group. [0000] [0000] Due to the regioselectivity in the replacement of thiol substituted aromatic compounds, multiple chromatography purifications were required to afford the pure intermediates and final product in the preparation of caspofungin, which led to low yield, high cost, complex operation, and the like. Thus, there is still a need to develop new preparation methods for caspofungin. DETAILED DESCRIPTION OF THE INVENTION [0004] This invention relates to an intermediate for the synthesis of caspofungin and a preparation method thereof. The synthesis process of caspofungin can be simplified, thus increasing its synthetic efficiency by the said intermediate. [0005] An object of the present invention is to provide an intermediate of formula (I) for the synthesis of caspofungin, [0000] [0000] wherein, R 1 is C(═O)NH 2 , CN, or CH 2 NR 3 R 4 ; R 2 is CN, CO 2 R 5 , C(═O)NR 6 R 7 or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 3 and R 4 are each independently hydrogen or amino protecting group, such as Boc or Cbz; R 5 is hydrogen, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 6 and R 7 are each independently hydrogen, amino, methoxy, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; or R 6 and R 7 together with a nitrogen atom form a five- to eight-membered heterocycle, preferably a five- or six-membered ring; and R 6 and R 7 are not amino or methoxy at the same time. [0006] Preferably, R 1 is C(═O)NH 2 , CN or CH 2 NH 2 ; R 2 is CN, CO 2 H, CO 2 Me, CO 2 Et, CO 2 Bu, CO 2 t Bu, CO 2 Ph, C(═O)NH 2 , C(═O)NMe 2 , C(═O)NHEt, C(═O)NHBu, C(═O)NHCH 2 CH 2 NH 2 , C(═O)NH c Pr, C(═O)NH i Pr, C(═O)NH c Pen, C(═O)NHBu, C(═O)NHPh or phenyl, more preferably R 2 is CO 2 H, CO 2 Me, or C(═O)NHCH 2 CH 2 NH 2 . [0007] In a preferred embodiment of the present invention, in formula (I), R 1 is CH 2 NH 2 ; R 2 is CO 2 Me. [0008] Another object of the present invention is to provide a preparation method of the intermediate of formula I, which involves the reaction of an intermediate of formula (II) with a thiol compound of formula (III) in the presence of organic boronic acid and organic sulfonic acid to afford intermediate I of formula (I); [0000] [0000] wherein, R 1 is C(═O)NH 2 , CN, or CH 2 NR 3 R 4 ; R 2 is CN, CO 2 R 5 , C(═O)NR 6 R 7 or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 3 and R 4 are each independently hydrogen or amino protecting group, such as Boc or Cbz; R 5 is hydrogen, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 6 and R 7 are each independently hydrogen, amino, methoxy, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; or R 6 and R 7 together with a nitrogen atom form a five- to eight-membered heterocycle, preferably a five- or six-membered ring; and R 6 and R 7 are not amino or methoxy at the same time. [0009] The present invention also provides a preparation method of caspofungin including the following steps: [0000] 1) Reaction of an intermediate of formula (II) with a thiol compound of formula (III) in the presence of organic boronic acid and organic sulfonic acid affords intermediate I of formula (I); [0000] [0000] wherein, R 1 is C(═O)NH 2 , CN, or CH 2 NR 3 R 4 ; R 2 is CN, CO 2 R 5 , C(═O)NR 6 R 7 or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 3 and R 4 are each independently hydrogen or amino protecting group, such as Boc or Cbz; R 5 is hydrogen, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 6 and R 7 are each independently hydrogen, amino, methoxy, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; or R 6 and R 7 together with a nitrogen atom form a five- to eight-membered heterocycle, preferably a five- or six-membered ring; and R 6 and R 7 are not amino or methoxy at the same time; 2) Reaction of an intermediate of formula (I) with ethylenediamine affords caspofungin finally, in which R 1 is reduced to CH 2 NH 2 or undergoes amino-deprotection before or after reaction with ethylenediamine when R 1 is not CH 2 NH 2 , [0000] [0000] wherein, R 1 is C(═O)NH 2 , CN, or CH 2 NR 3 R 4 ; R 2 is CN, CO 2 R 5 , C(═O)NR 6 R 7 or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 3 and R 4 are each independently hydrogen or amino protecting group, which preferably is Boc or Cbz; R 5 is hydrogen, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; R 6 and R 7 are each independently hydrogen, amino, methoxy, linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; or R 6 and R 7 together with a nitrogen atom form a five- to eight-membered heterocycle, preferably a five- or six-membered ring; and R 6 and R 7 are not amino or methoxy at the same time. [0010] In a preferred embodiment of the present invention, said method comprises the following steps: [0000] 1) Reaction of intermediate HA of formula (IIA) with thiol compound III of formula (III) in the presence of organic boronic acid and organic sulfonic acid affords intermediate IA of formula (IA), 2) Reaction of intermediate IA of formula (IA) with ethylenediamine affords caspofungin. [0000] [0011] In another preferred embodiment of the present invention, said method comprises the following steps: [0000] 1) Reaction of intermediate IIB of formula (IIB) with thiol compound III of formula (III) in the presence of organic boronic acid and organic sulfonic acid affords intermediate IB of formula (IB), 2) Reaction of intermediate IB of formula (IB) with ethylenediamine affords intermediate IVB of formula (IVB), and 3) Intermediate of formula (IVB) is reduced to caspofungin. [0000] [0012] In yet another preferred embodiment of the present invention, said method comprises the following steps: [0000] 1) Reaction of intermediate IIC of formula (IIC) with thiol compound III of formula (III) in the presence of organic boronic acid and organic sulfonic acid affords intermediate IC of formula (IC); 2) Reaction of intermediate IC of formula (IC) with ethylenediamine affords intermediate IVC of formula (IVC); and 3) Intermediate of formula (IVC) is reduced to caspofungin. [0000] [0013] The amino protecting groups in the present invention are known protecting groups suitable for protecting amino groups, referring to protection for the amino group in the literature (“Protective Groups in Organic Synthesis”, 5 Th . Ed. T. W. Greene & P. G. M. Wuts), preferably Boc or Cbz. [0014] The C 6-10 aromatic groups involved in the present invention can be a single, fused, or poly ring, such as phenyl or naphthyl. The C 6-10 aromatic group can be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2; R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0015] Heteroaryl group involved in the present invention refers to five- to ten-membered heteroaromatic systems containing one to four heteroatoms, wherein the heteroatoms may be oxygen, nitrogen or sulfur. Heteoaryl is preferably a five- or six-membered heteroaryl, for example, furyl, thienyl, pyridyl, pyrrolyl, N-alkyl pyrrolyl, pyrimidinyl, pyrazinyl, imidazolyl, tetrazolyl, etc. The heteroaromatic group can be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2; R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0016] The C 1-10 alkyl group in the present invention refers to saturated aliphatic hydrocarbon groups, for example, methyl, ethyl, propyl, 2-propyl, n-butyl, isobutyl, tert-butyl or pentyl, etc. A lower alkyl group containing one to four carbon atoms is more preferred, for example, methyl, ethyl, propyl, 2-propyl, n-butyl, isobutyl or tert-butyl. The alkyl group may be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2; R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0017] The C 3-8 cycloalkyl group in the present invention refers to a three- to eight-membered carbon monocyclic group which may contain one or more double bonds, but not a fully conjugated π-electron system, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexadienyl, cycloheptyl, cycloheptatrienyl, etc. The cycloalkyl group can be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2; R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0018] The C 3-10 alkenyl group in the present invention can be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2; R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0019] The C 3-10 alkynyl group in the present invention can be unsubstituted or substituted, with the substituent groups preferably being one or more groups independently selected from alkyl, alkoxyl, halogen, hydroxyl, nitro, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, —NR 6 R 7 , —C(O)OR 8 , —OC(O)R 8 , —O(CH 2 ) m C(O)OR 8 , —OC(O)NR 6 R 7 , carbonyl, —S(O) n R 8 , —OSO 2 R 8 , —SO 2 NR 6 R 7 , or —NHC(O)R 8 ; m is 0, 1 or 2; n is 0, 1 or 2. R 6 and R 7 are defined as in formula (I); R 8 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or substituted or unsubstituted C 6-10 aryl or heteroaryl; and halogen is fluorine, chlorine, bromine or iodine. [0020] The organic boronic acid in the present invention is R 9 B(OH) 2 , wherein R 9 is linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, C 3-8 cycloalkyl, or unsubstituted or substituted C 6-10 aryl or heteroaryl, for example, methyl, ethyl, propyl, butyl, phenyl, p-methylphenyl, p-methoxyphenyl, p-chlorophenyl, etc. [0021] The organic sulfonic acid in the present invention is R 10 SO 3 H, wherein R 10 is substituted or unsubstituted linear or branched C 1-10 alkyl, linear or branched C 3-10 alkenyl or C 3-10 alkynyl, substituted or unsubstituted C 3-8 cycloalkyl, or unsubstituted or substituted C 6-10 aryl or heteroaryl, for example, methyl, trifluoromethyl, phenyl, p-methylphenyl, etc. DETAILED DESCRIPTION OF THE INVENTION [0022] The present invention will appear clearly for the person skilled in the art upon the following specific examples. These examples only intend to illustrate the invention, while not limiting the scope of the present invention in any way. [0023] The number of the intermediate of formula (I) involved in the examples are shown in following table. [0000] (I) Number R 1 R 2 IA1 CH 2 NH 2 CO 2 Me IA2 CH 2 NH 2 C(═O)NHCH 2 CH 2 NH 2 IA3 CH 2 NH 2 C(═O)NMe 2 IA4 CH 2 NH 2 CN IB1 CN C(═O)NHEt IB2 CN C(═O)NMe 2 IB3 CN CO 2 Me IB4 CN CO 2 Bu IB5 CN CO 2 H IB6 CN C(═O)NH 2 IB7 CN C(═O)NHBu IB8 CN IC1 C(═O)NH 2 CO 2 Me IC2 C(═O)NH 2 CO 2 H IC3 C(═O)NH 2 CO 2 Bu IC4 C(═O)NH 2 CO 2 t Bu IC5 C(═O)NH 2 CO 2 c Pen IC6 C(═O)NH 2 CO 2 Ph IC7 C(═O)NH 2 C(═O)NH 2 IC8 C(═O)NH 2 C(═O)NMe 2 IC9 C(═O)NH 2 C(═O)NHEt IC10 C(═O)NH 2 C(═O)NHBu IC11 C(═O)NH 2 IC12 C(═O)NH 2 C(═O)NH c Pr IC13 C(═O)NH 2 C(═O)NH c Pen IC14 C(═O)NH 2 C(═O)NH i Pr IC15 C(═O)NH 2 C(═O)NHPh IC16 C(═O)NH 2 Ph t Bu = tert-butyl; i Pr = isopropyl; c Pr = cyclopropyl c Pen = cyclopentyl Example 1 Preparation of Compound IA1 [0024] A stirred suspension of compound IIA (3.0 g) (which was prepared according to a similar method of U.S. Pat. No. 5,378,804), phenyl boronic acid (0.72 g) and acetonitrile (120 mL) in a three-necked glass flask was mixed with methyl thioglycolate (1.0 g) at −20° C. The resulting mixture was stirred for 30 minutes at this temperature and trifluoromethanesulfonic acid (1.2 g) was added therein dropwise. The reaction mixture was further stirred at −20° C. for 5-6 hours followed by addition of an aqueous solution of sodium acetate. After stirring for another 1-2 hours, the reaction mixture was filtered and the filter cake was washed with aqueous acetonitrile, and dried under vacuum to give white solid product IA1 (2.8 g). [0025] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.74 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H) 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.63 (s, 3H), 3.04 (t, 2H), 2.42 (dd, 1H), 2.15-1.99 (m, 7H), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0026] MS: 1139.61 (M+H + ). Example 2 Preparation of Compounds IA2 [0027] A stirred suspension of compound IIA (3.0 g), phenyl boronic acid (0.72 g) and acetonitrile (120 mL) in a three-necked glass flask was mixed with N-(2-aminoethyl)mercaptoacetamide (1.26 g) at −20° C. The resulting mixture was stirred for 30 minutes at this temperature and trifluoromethanesulfonic acid (1.2 g) was added therein dropwise. The reaction mixture was further stirred at −20° C. for 5-6 hours followed by addition of an aqueous solution of sodium acetate. After stirring for another 1-2 hours, the reaction mixture was filtered and the filter cake was washed with aqueous acetonitrile, and dried under vacuum to give white solid product IA2 (3.1 g). [0028] MS: 1167.39 (M+H + ). Example 3 Preparation of Compound IA3 [0029] A stirred suspension of compound IIA (3.0 g), phenyl boronic acid (0.72 g) and acetonitrile (120 mL) in a three-necked glass flask was mixed with N,N-dimethyl-mercaptoacetamide (1.1 g) at −20° C. The resulting mixture was stirred for 30 minutes at this temperature and trifluoromethanesulfonic acid (1.2 g) was added therein dropwise. The reaction mixture was further stirred at −20° C. for 5-6 hours followed by addition of an aqueous solution of sodium acetate. After stirring for another 1-2 hours, the reaction mixture was filtered and the filter cake was washed with aqueous acetonitrile, and dried under vacuum to give white solid product IA3 (3.1 g). [0030] MS: 1152.81 (M+H + ). Example 4 Preparation of Compound IA4 [0031] A stirred suspension of compound IIA (3.0 g), phenyl boronic acid (0.72 g) and acetonitrile (120 mL) in a three-necked glass flask was mixed with mercaptoacetonitrile (1.5 g) at −20° C. The resulting mixture was stirred for 30 minutes at this temperature and trifluoromethanesulfonic acid (1.2 g) was added therein dropwise. The reaction mixture was further stirred at −20° C. for 5-6 hours followed by addition of an aqueous solution of sodium acetate. After stirring for another 1-2 hours, the reaction mixture was filtered and the filter cake was washed with aqueous acetonitrile, and dried under vacuum to give white solid product IA4 (3.0 g). [0032] 1 H NMR (CD 3 OD, 400 MHz) δ 7.15 (d, 2H), 6.79 (d, 2H), 5.34 (d, 1H), 5.04 (d, 1H), 4.64 (m, 3H), 4.53-4.42 (m, 4H), 4.43-4.32 (m, 3H), 4.31-4.25 (m, 5H), 4.23-4.18 (m, 1H), 3.99-3.95 (m, 1H), 3.90-3.8 (m, 3H), 3.73-3.65 (m, 2H), 3.58-3.65 (m, 2H), 3.05-3.18 (m, 2H), 2.40-2.50 (m, 1H), 2.35-2.23 (m, 4H), 2.21-1.98 (m, 6H), 1.97-1.80 (m, 3H), 1.78-1.60 (m, 2H), 1.58-1.41 (m, 2H), 1.40-1.26 (m, 14H), 1.21 (d, 3H), 1.20-1.13 (m, 3H), 0.95-0.85 (m, 10H), 0.68-0.76 (dd, 2H). [0033] MS: 1106.54 (M+H + ). Example 5 Preparation of Compound IB1 [0034] A suspension of compound IIB (100 mg, prepared according to the similar method of U.S. Pat. No. 5,378,804), phenyl boronic acid (35 mg), and N-ethyl-2-mercaptoacetamide (68 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. The reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB1. [0035] 1 H NMR (CD 3 OD, 400 MHz) δ 7.08 (d, 2H), 6.70 (d, 2H), 5.21 (d, 1H), 4.99 (d, 1H), 4.95 (d, 1H), 4.56-4.47 (m, 3H), 4.39-4.21 (m, 6H), 3.99-3.95 (m, 1H), 3.87-3.83 (m, 1H), 3.80-3.75 (m, 2H), 2.95-2.90 (q, 2H), 2.80-2.64 (m, 2H), 2.46 (m, 1H), 2.42 (m, 3H), 2.26-2.12 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (m), 0.81 (m). [0036] MS: 1148. 48 (M+H + ). Example 6 Preparation of Compound IB2 [0037] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and N,N-dimethyl-2-mercaptoacetamide (68 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB2. [0038] 1 H NMR (CD 3 OD, 400 MHz) δ 7.08 (d, 2H), 6.70 (d, 2H), 5.27 (d, 1H), 4.99 (d, 1H), 4.95 (d, 1H), 4.56-4.47 (m, 3H), 4.39-4.21 (m, 6H), 3.99-3.95 (m, 1H), 3.87-3.83 (m, 1H), 3.80-3.75 (m, 2H), 3.04 (s, 3H), 2.89 (s, 3H), 2.80-2.64 (m, 2H), 2.46 (m, 1H), 2.42 (m, 3H), 2.26-2.12 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (m), 0.81 (m). [0039] MS: 1148. 48 (M+H + ). Example 7 Preparation of Compound IB3 [0040] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and methyl-2-mercaptoacetate (61 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB3. [0041] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.69 (d, 2H), 5.28 (d, 1H), 4.99 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m, 3H), 4.39-4.21 (m, 6H), 3.99-3.95 (m, 1H), 3.87-3.83 (m, 1H), 3.80-3.75 (m, 2H), 3.66 (m, 3H), 3.56-3.52 (dd, 1H), 3.49-3.39 (dd, 1H), 2.80-2.64 (m, 2H), 2.46 (m, 1H), 2.42 (m, 3H), 2.26-2.12 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (m), 0.81 (m). [0042] MS: 1135.38 (M+H + ). Example 8 Preparation of Compound IB4 [0043] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and butyl-2-mercaptoacetate (85 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB4. [0044] 1 H NMR (CD 3 OD, 400 MHz) δ 7.08 (d, 2H), 6.70 (d, 2H), 5.29 (d, 1H), 4.99 (d, 1H), 4.95 (d, 1H), 4.56-4.47 (m, 3H), 4.39-4.21 (m, 6H), 3.99-3.95 (m, 1H), 3.87-3.83 (m, 1H), 3.80-3.75 (m, 2H), 3.58-3.56 (t, 2H), 3.56-3.52 (dd, 1H), 3.49-3.39 (dd, 1H), 2.80-2.64 (m, 2H), 2.46 (m, 1H), 2.42 (m, 3H), 2.26-2.12 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (m), 0.81 (m). [0045] MS: 1178.49 (M+H + ). Example 9 Preparation of Compound IB5 [0046] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and mercaptoacetic acid (60 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB5. [0047] MS: 1121.16 (M+H + ). Example 10 Preparation of Compound IB6 [0048] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and mercaptoacetamide (62 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB6. [0049] MS: 1120.44 (M+H + ). Example 11 Preparation of Compound IB7 [0050] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and N-butyl-2-mercaptoacetamide (86 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB7. [0051] MS: 1176.51 (M+H + ). Example 12 Preparation of Compound IB8 [0052] A suspension of compound IIB (100 mg), phenyl boronic acid (35 mg), and N-pyrrolyl-2-mercaptoacetamide (86 mg) in anhydrous acetonitrile (8 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (57.3 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was washed with acetonitrile/water, collected, and dried under vacuum to give product IB8. [0053] MS: 1174.58 (M+H + ). Example 13 Preparation of Compound IC1 [0054] A suspension of compound IIC (PB0, prepared by microbial fermentation) (500 mg), phenyl boronic acid (172 mg), and methyl mercaptoacetate (299 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC1. [0055] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.29 (d, 1H), 5.1 (d, 1H), 4.99 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.63 (s, 3H), 3.55-3.51 (dd, 1H), 3.36-3.40 (dd, 1H), 2.88 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0056] MS: 1153.26 (M+H + ). Example 14 Preparation of Compound IC2 [0057] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and mercaptoacetic acid (259 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC2. [0058] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 2.88 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0059] MS: 1139.18 (M+H + ) Example 15 Preparation of Compound IC3 [0060] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and butyl mercaptoacetate (417 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC3. [0061] MS: 1195.48 (M+H + ). Example 16 Preparation of Compound IC4 [0062] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and tert-butyl mercaptoacetate (417 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC4. [0063] MS: 1195.48 (M+H + ). Example 17 Preparation of Compound 105 [0064] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and cyclopentyl mercaptoacetate (431 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product 105. [0065] MS: 1207.49 (M+H + ). Example 18 Preparation of Compound 106 [0066] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and phenyl mercaptoacetate (431 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product 106. [0067] MS: 1215.48 (M+H + ). Example 19 Preparation of Compound IC7 [0068] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and mercaptoacetamide (259 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC7. [0069] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 2.88 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0070] MS: 1138.45 (M+H + ). Example 20 Preparation of Compound IC8 [0071] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N, N-dimethyl mercaptoacetamide (336 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC8. [0072] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.01 (s, 1H), 2.88 (s, 1H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0073] MS: 1166.52 (M+H + ). Example 21 Preparation of Compound IC9 [0074] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N, N-dimethyl mercaptoacetamide (259 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC9. [0075] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 2.88 (dd, 2H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0076] MS: 1166.52 (M+H + ). Example 22 Preparation of compound IC10 [0077] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N, N-dimethyl mercaptoacetamide (414 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC10. [0078] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 2.94-2.91 (t, 2H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 2H), 0.87 (d, 6H), 0.85 (d, 6H). [0079] MS: 1194.53 (M+H + ). Example 23 Preparation of Compound IC11 [0080] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N-pyrrolyl mercaptoacetamide (410 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC11. [0081] 1 H-NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.18-3.14 (m, 4H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.94-1.90 (m, 4H), 1.87-1.85 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 2H), 0.87 (d, 3H), 0.85 (d, 6H); [0082] MS: 1192.56 (M+H + ). Example 24 Preparation of Compound IC12 [0083] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N-cyclopropyl mercaptoacetamide (370 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC12. [0084] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.21-3.09 (dd, 1H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.87-1.85 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 2H), 0.87 (d, 3H), 0.85 (d, 6H) 0.68˜0.50 (m, 4H); [0085] MS: 1178.46 (M+H + ). Example 25 Preparation of Compound IC13 [0086] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N-cyclopentyl mercaptoacetamide (450 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC13. [0087] 1 H NMR (CD 3 OD, 400 MHz) δ 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.21-3.09 (dd, 1H), 2.68 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.94-1.90 (m, 4H), 1.87-1.85 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 2H), 0.89-0.85 (m, 15H); [0088] MS: 1206.50 (M+H + ). Example 26 Preparation of Compound IC14 [0089] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N-isopropyl mercaptoacetamide (370 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC14. [0090] MS: 1180.50 (M+H + ). Example 27 Preparation of Compound IC15 [0091] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and N-phenyl mercaptoacetamide (370 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC15. [0092] MS: 1214.65 (M+H + ). Example 28 Preparation of Compound IC16 [0093] A suspension of compound IIC (500 mg), phenyl boronic acid (172 mg), and benzyl mercaptan (350 mg) in anhydrous acetonitrile (30 mL) was added dropwise to a solution of trifluoromethylsulfonic acid (282 mg) in acetonitrile at −15° C. under nitrogen atmosphere. The reaction mixture was stirred at the same temperature for 4-6 hours to complete the reaction. After addition of sodium acetate aqueous solution and stirring for 1-2 hours, water (90 mL) was added to the reaction mixture followed by stirring for another one hour. Then the reaction mixture was filtered and the filter cake was collected and dried under vacuum to give product IC16. [0094] 1 H NMR (CD 3 OD, 400 MHz) δ 7.30-7.27 (d, 2H), 7.24-7.2 (t, 3H), 7.17-7.15 (d, 1H), 7.09 (d, 2H), 6.70 (d, 2H), 5.24 (d, 1H), 5.04 (d, 1H), 4.90 (d, 1H), 4.56-4.47 (m), 4.39-4.35 (m, 2H), 4.31-4.25 (m), 4.23-4.21 (m, 3H), 3.99-3.95 (m), 3.80-3.75 (m), 3.63 (s, 3H), 3.55-3.51 (dd, 1H), 3.36-3.40 (dd, 1H), 2.88 (dd, 1H), 2.46 (dd, 1H), 2.42 (dd, 1H), 2.26-2.18 (m), 2.10-2.03 (m), 1.97-1.90 (m), 1.63-1.52 (m), 1.51-1.46 (m), 1.45-1.39 (m), 1.38-1.20 (m), 1.14 (d), 1.12-1.03 (m), 0.91 (dt, 1H), 0.87 (d, 3H), 0.85 (d, 6H). [0095] MS: 1171.10 (M+H + ). Example 29 Preparation of Caspofungin [0096] Compound IA1 (70 mg) was dissolved in methanol (0.5 mL) at 15° C. Ethylenediamine (0.7 mL) was added to the solution at 5° C. and the resulting mixture was stirred at 40° C. for 20 hours. After evaporation of methanol, acetonitrile was added to the residue and the resulting mixture was stirred, and filtered under nitrogen atmosphere to give crude product as a solid which was dried under vacuum. Purification via a C-18 silica gel column gave final product caspofungin. [0097] MS: 1093.21 (M+H + ). Example 30 Preparation of Caspofungin Step 1): [0098] A stirring solution of compound IB1 (800 mg) in methanol (20 mL) in a three-necked glass flask was mixed with ethylenediamine (20 mL) at 30° C. and the resulting reaction mixture was stirred for 18 hours at this temperature. After concentration of the reaction solution, acetonitrile (40 mL) was added to the residue and the resulting mixture was stirred for 20-30 minutes and filtered. The filter cake was collected and dried to give product IVB. [0099] MS: 1089.22 (M+H + ). Step 2): [0100] A solution of compound IVB (100 mg) in ethanol (9 mL) and water (1 mL) was mixed with acetic acid (1 mL) and Pd/C (10%, 50 mg). The resulting reaction mixture was stirred for 10 hours under 3 atm of hydrogen pressure at 20° C. After filtration to remove the catalyst and evaporation to remove the solvent, the residue was dissolved in water (20 mL) and extracted with ethyl acetate (10 mL×2). The aqueous phase was collected and lyophilized to give crude caspofungin which was further purified via a C-18 silica gel column to give the final product caspofungin. [0101] MS: 1093.21 (M+H + ). Example 31 Preparation of Caspofungin Step 1): [0102] A stirring solution of compound IC1 (800 mg) in methanol (20 mL) in a three-necked glass flask was mixed with ethylenediamine (20 mL) at 30° C. and the resulting reaction mixture was stirred for 18 hours at this temperature. After concentration of the reaction solution, acetonitrile (40 mL) was added to the residue and the resulting mixture was stirred for 20-30 minutes and filtered. The filter cake was collected and dried to give product IVC. [0103] MS: 1107.29 (M+H + ). Step 2): [0104] A solution of compound IVC (100 mg) in anhydrous tetrahydrofuran (THF) (20 mL) in a three-necked glass flask was added with phenylboronic acid (33 mg) under nitrogen atmosphere and the resulting reaction mixture was stirred overnight and then cooled to 10° C. The reaction mixture was mixed with bis(trimethylsilyl)trifluoroacetamide (140 mg) and stirred for 3 hours. Then the reaction mixture was brought to −15° C. and mixed with borane in THF solution (1.0 M, 1.35 mL). The resulting mixture was stirred for 6 hours at −15° C. The reaction was quenched by addition of 2 N hydrochloric acid (2 mL) and then mixed with water (20 mL). The aqueous phase was separated and extracted with ethyl acetate (10 mL×2). The aqueous phase was collected and lyophilized to give crude caspofungin which was further purified via a C-18 silica gel column to give the final product caspofungin. [0105] MS: 1093.21 (M+H + ). [0106] Due to the detailed description of the particular embodiments of the present invention, some modifications and variants are obvious for the person skilled in the art and will be contained in the scope of the present invention.

The present invention relates to an intermediate, as represented by formula (I), for synthesizing caspofungin, and a preparation method thereof. The intermediate enables efficient preparation of caspofungin.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to heating appliances or appliances intended to be heated during the use thereof and comprising a self-cleaning coating. 2. Description of Related Art The term “heating appliance” is understood to mean, within the meaning of the present patent application, any appliance, article or utensil, which, during the functioning thereof, reaches a temperature at least equal to 65° C. (which is the minimum reheating temperature) and preferably at least equal to 90° C. The appliance can reach this operating temperature by means which are specific to it, such as, for example, a heating base incorporated in the appliance and equipped with heating elements, or by external means. It concerns in particular sole plates of irons, cooking appliances, ovens, grills and cooking utensils. Among these heating appliances, some, such as sole plates of irons or cooking appliances, exhibit qualities of ease of use and effectiveness which depend, inter alia, on the state and the nature of the surface of the coating thereof. As regards sole plates of irons, the latter have been able to be improved by virtue of the care contributed to the glide qualities of the ironing surface, in combination with those which make possible easier spreading of the laundry. One way of obtaining these qualities is to resort to sole plates enameled with an enamel having a smooth appearance, optionally with lines of excessive thickness for promoting the spreading of the fabric during the movement of the iron. It is also known to use metal sole plates which are treated mechanically and/or which are or are not covered with a deposit for facilitating the gliding. However, with use, the sole plate can become tarnished by carbonizing in a more or less diffuse fashion over its ironing surface, and, in a more or less incomplete fashion, various contaminants of organic origin (in particular in a particulate form) which are captured by the sole plate by rubbing over the ironed fabrics. The tarnishing of the sole plate, even in a not very visible way, results in an at least partial loss of its glide qualities. In addition, with the fouling, ironing becomes more difficult. Finally, the user dreads using a tarnished iron, fearing that it may detrimentally affect her laundry. Iron sole plate coatings, comprising a hard and resistant layer covered by a layer which improves the surface properties, are known, such as taught by the U.S. Pat. No. 4,862,609. However, this patent does not indicate a solution for combating fouling. This problem of fouling may also be encountered for other types of heating appliances, such as, for example, the walls of cooking appliances. It is known to cover them with an enameled layer having a smooth appearance, in order to prevent possible spat fat or food from adhering to the surface of these walls. In particular, enameled self-cleaning surfaces, which may in particular be encountered in ovens and cooking utensils, are known, such as taught, for example, by U.S. Pat. No. 4,029,603 or French patent FR 2 400 876. However, these surfaces are not entirely satisfactory as regards their self-cleaning properties. In order to improve these properties, the Applicant Company has previously developed a self-cleaning coating intended to coat a metal surface of a heating appliance which is more effective in terms of catalytic activity. This coating forms the subject matter of the French patent FR 2 848 290, which describes a heating appliance comprising a metal support, at least a portion of which is covered with a self-cleaning coating, which comprises an external layer in contact with the ambient air and comprising at least one oxidation catalyst chosen from platinum group metal oxides, and at least one internal layer, located between the metal support and the external layer, comprising at least one oxidation catalyst chosen from oxides of the transition elements of Group Ib. However, this self-cleaning coating exhibits the disadvantage of requiring a large amount of platinum group metal oxides in the external layer in order to achieve correctly satisfactory levels of catalytic activity, the consequence of which is in particular a significant increase in the coating cost and thus, in the end, in that of the heating appliance. SUMMARY OF THE INVENTION There thus exists the need for a coating for a heating appliance, such as a cooking appliance or an iron sole plate, in which the amount of platinum group metal oxides is appreciably lower but which is more effective in terms of catalytic activity (that is to say, a coating which makes it possible to keep the covered surface clean from any contamination by organic particles and which does not become fouled in normal use), this being the case without a deterioration in the other properties required (shiny appearance, gliding and resistance to abrasion of the coating). The term “catalytic activity of a coating” is understood to mean, within the meaning of the present invention, the ability of the external surface of this self-cleaning coating, in contact with the ambient air and with contaminants of organic origin, to incinerate these contaminants, which, once incinerated, lose any adhesion and become detached from the coating. The term “contaminants of organic origin” is understood to mean, within the meaning of the present patent application, any substance which is combustible or which can oxidize on contact with the ambient air, completely or partially. Mention may be made, by way of example, of any residue of synthetic fibers, such as used in textile articles, for example made of organic polymer, such as polyamide or polyester, any organic residue of washing product and optionally of softening product, or any organic substance, such as spat fats or foods. More particularly, a subject matter of the present invention is a heating appliance comprising a metal support, at least a portion of which is covered with a self-cleaning coating in contact with the ambient air and comprising at least one oxidation catalyst chosen from platinum group metal oxides, characterized in that said coating additionally comprises at least one dopant for said oxidation catalyst chosen from rare earth metal oxides. By virtue of the heating article according to the invention, an appliance is obtained, the self-cleaning coating of which exhibits a particularly excellent catalytic activity and the adhesion of which to the metal support is very good, and which additionally makes it possible for the organic particles in contact with the self-cleaning coating to be oxidized when the appliance is heated. For example, during ironing with an iron, the organic particles captured by the sole plate are oxidized. They are, in a way, incinerated when the iron is hot and the possible solid residue loses any adhesion and becomes detached from the sole plate. The sole plate is kept clean. Likewise, in a cooking appliance, such as an oven, for example, the spat fats present on the wall of the oven are oxidized under hot conditions and the solid residue becomes detached from the wall, which is kept clean. In addition, a synergistic effect has been found with regard to the catalytic activity when, in the self-cleaning coating, a dopant chosen from oxides of rare earth metals is combined with an oxidation catalyst chosen from platinum group metal oxides. Thus, in the present patent application, the catalytic activity of the self-cleaning coating is from three to five times greater than that obtained with the coating of FR 2 848 290, this being the case with an amount of platinum group metal oxides from two to four times lower. Thus, the surface of the coating is regenerated more rapidly than in the coatings described in FR 2 848 290. The term “platinum group metals” is understood to mean, within the meaning of the present patent application, the elements having properties analogous to those of platinum and in particular, in addition to platinum, ruthenium, rhodium, palladium, osmium and iridium. In practice, the oxidation catalysts of the platinum group metal oxides type are well known per se and the processes by which they are obtained, without it being necessary to describe in detail their methods of preparation respectively. Thus, by way of example, as regards platinum(IV) oxide as oxidation catalyst (platinum dioxide hydrate PtO 2 .H 2 O or Adams's catalyst), its catalytically active form can be obtained by melting hexachloroplatinic acid or its ammonium salt with sodium nitrate, followed by the thermal decomposition of the platinum nitrate obtained to give platinum(IV) oxide. Preferably, the oxidation catalyst is chosen from palladium oxides, platinum oxides and their mixtures. The term “dopant” is understood to mean, within the meaning of the present patent application, an element which is not a catalyst per se but which has the effect of increasing and of doping the catalytic activity of said catalyst and of stabilizing the hold of the catalyst on the substrate. In the context of the present invention, use is made, as dopant for the oxidation catalyst in the self-cleaning coating, of at least one rare earth metal oxide. The term “rare earth metals” is understood to mean, within the meaning of the present patent application, lanthanides and yttrium having properties analogous to those of lanthanum and in particular, in addition to lanthanum, cerium and yttrium. Preferably, the dopant is chosen from cerium oxides, yttrium oxide and their mixtures. Of course, any oxidation catalyst and any dopant selected according to the present invention will have to remain sufficiently stable at the operating temperature of the appliance and within the limits of the working lifetime of the appliance. According to a first advantageous embodiment of the present invention, the self-cleaning coating of the heating article according to the invention is a monolayer coating comprising at least one oxide of a platinum group metal doped by yttrium oxide. Preferably, the self-cleaning coating of the heating article according to the invention is composed of palladium oxide doped by yttrium oxide. Such a doping makes it possible to considerably reduce the amount of palladium oxide while achieving a catalytic activity at least equivalent to that of the coating of FR 2 848 290. If the amount of palladium oxide is identical to that of the coating of FR 2 848 290, then the catalytic activity is considerably improved. The effects of the doping on the catalytic activity of the coating are shown by the results of table 1 and example 4. According to a second particularly advantageous and preferred embodiment of the present invention, the self-cleaning coating of the heating article according to the invention is a bilayer coating comprising: an internal layer at least partially covering the metal support and comprising said dopant, and an external layer in contact with the ambient air and comprising the oxidation catalyst. The presence of a dopant of rare earth metal oxide type in an internal layer included between the support and the layer of the coating in contact with the ambient air and comprising the oxide of platinum group metal makes it possible to obtain an increase in the catalytic activity by virtue of the oxygen available in the rare earth metal oxide network which can diffuse into the layer of platinum group metal oxide. In this second bilayer embodiment, the self-cleaning coating according to the invention is preferably a coating which is composed of an internal layer of cerium oxide or yttrium oxide and of an external layer of palladium oxide. Preferably, the doping internal layer has a thickness, measured according to the RBS method described in the examples (measurement methods) of the patent application, ranging from 30 nm to 100 nm. The catalytic activity increases with the thickness of the internal layer. The external layer of the coating preferably has a thickness, also measured according to the RBS method described in the examples (measurement methods) of the present patent application, of between 10 nm and 500 nm, preferably of between 15 nm and 60 nm. The catalytic activity increases with the thickness of the layer until a threshold effect is reached. Whatever the embodiment of the self-cleaning coating according to the invention, the oxidation catalyst is distributed on and/or in the external layer and/or the monolayer of the self-cleaning coating, which is in continuous or noncontinuous contact with the contaminants. The metal support of the appliance according to the invention can be based on any metal commonly employed in the field of heating appliances, such as aluminum, stainless steel or titanium. This metal support can itself be covered with a protective layer, such as, for example, a layer of enamel, before being covered with the coating of the present invention. Thus, in a preferred embodiment of the invention, the appliance comprises an intermediate protective layer made of enamel located between the metal support and the self-cleaning coating, or its internal layer according to whether the self-cleaning coating is bilayer respectively, said intermediate protective layer being composed of a material chosen from aluminum alloys, enamel and their mixtures, so that said protection layer is catalytically inert as regards the oxidation. Preferably, the intermediate protective layer is made of enamel having a low porosity and/or roughness, at the micrometric and/or nanometric scale. The enamel is, for example, a vitreous enamel. The enamel should preferably be hard, have good gliding and withstand hydrolysis by hot steam. In a preferred embodiment of the heating appliance according to the invention, the heating appliance is in the form of an iron sole plate comprising an ironing surface and the coating covers the ironing surface. The term “ironing surface” is understood to mean, within the meaning of the present invention, the surface in direct contact with the laundry, allowing it to be smoothed out. In another preferred embodiment of the invention, the heating appliance is a cooking appliance comprising walls capable of coming into contact with contaminants of organic origin and the self-cleaning coating covers these walls. In a first operating mode of the heating appliance according to the invention, the catalyst acts at the operating temperature of the appliance and the coating is kept clean as the appliance is used. In a second operating mode of the heating appliance according to the invention, during a “self-cleaning” phase prior or subsequent to the use of the appliance, the latter is adjusted to a high temperature, equal to or greater than the highest operating temperatures, and is then left on hold for a predetermined time, during which the oxidation catalyst produces its effect. The user can thus regularly look after her appliance, without waiting for harmful fouling. Another subject matter of the present invention is a process for producing a heating appliance comprising a metal support, at least a portion of which is covered with a self-cleaning coating, comprising the following stages: i. the surface of the metal support to be covered is heated to a temperature comprised between 250° C. and 400° C. in an oven or under infrared radiation; ii. a solution of an oxidation catalyst precursor, which is chosen from salts of platinum group metals, and of a dopant precursor is sprayed over the surface of the metal support to be covered, in order to obtain a self-cleaning coating layer; iii. the surface of the metal support covered with the self-cleaning coating layer is baked in an oven or under infrared radiation for a few minutes, typically between 400° C. and 600° C.; said process being characterized in that it additionally comprises the doping of said self-cleaning coating layer by a dopant chosen from rare earth metal oxides. The term “doping of the oxidation catalyst” is understood to mean, within the meaning of the present invention, an increase in the catalytic activity of the oxidation catalyst and a stabilization of the hold of the catalyst to the substrate. This is possible by virtue of the oxygen available in the network of rare earth metal oxides which can be used by the platinum group metal oxide during the catalysis of the oxidation reaction. The term “precursor of the oxidation catalyst” is understood to mean, within the meaning of the present invention, any chemical or physicochemical form of the oxidation catalyst which is capable of resulting in the catalyst as such or of releasing it by any appropriate treatment, for example by pyrolysis. Mention may in particular be made, as example of precursor of the oxidation catalyst which can be used in the process according to the invention, of hexachloroplatinic acid, sold by Alfa Aesar under the trade name of dihydrogen hexachloroplatinate(IV) hexahydrate, ACS, Premium, 99.95%, Pt 37.5% min. The application to the metal support, covered or not covered with a layer of enamel, of the catalytically active layer or layers of the self-cleaning coating is preferably carried out by pyrolysis of an aerosol (technique usually denoted by the expression “thermal spray”) by heating the surface to be covered and then spraying, over this hot surface, a solution containing a precursor of the oxidation catalyst. According to a first advantageous embodiment of the process according to the invention, the doping of said self-cleaning coating layer is carried out during stage ii of the process according to the invention by addition, to the solution of oxidation catalyst precursor, of a dopant precursor chosen from rare earth metal salts, such as to form a monolayer self-cleaning coating. According to a second advantageous embodiment of the process according to the invention, the doping of said self-cleaning coating layer is carried out between stages i and ii as follows: i.1 a solution of a dopant precursor chosen from rare earth metal salts is sprayed over the surface of the metal support to be covered, in order to form an internal coating layer; i.2 the surface of the metal support covered with the internal layer is again heated to a temperature comprised between 250° C. and 400° C. in an oven or under infrared radiation. Typically, use is made, as dopant salts or oxidation catalyst salts, of chlorides or nitrates, sometimes acetates, if this is possible. Thus, in a particularly advantageous form of implementation of this second embodiment according to the invention, the surface of the metal support to be covered is heated in an oven to between 250° C. and 400° C. A solution of the precursor of the dopant is subsequently sprayed on the surface of the metal support. On contact with the surface, the water evaporates, the precursor is decomposed and the metal oxide formed becomes attached to the support. A layer with a thickness of between 30 nm and 100 nm is thus deposited. The support thus cooled is again heated in the oven or under infrared radiation to a temperature of between 250° C. and 400° C. for a few seconds. A solution of the precursor of the oxidation catalyst chosen is subsequently sprayed over the internal layer. A layer with a thickness ranging from 15 to 60 nm is deposited. The support thus covered is subsequently rebaked in an oven or under infrared radiation at between 400° C. and 600° C. for a few minutes, for example for five minutes. A support covered with a coating, the self-cleaning properties of which are particularly good, is then obtained. BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention will be obtained on reading the examples below and the appended drawings: FIG. 1 is a view in cross section of a first example of iron sole plate according to the invention, comprising a bilayer self-cleaning coating on a non-enameled support, FIG. 2 is a view in cross section of a second example of iron sole plate according to the invention having a bilayer self-cleaning coating on an enameled support, FIG. 3 is a view in cross section of a third example of iron sole plate according to the invention having a monolayer self-cleaning coating on a non-enameled support, FIG. 4 is a view in cross section of a fourth example of iron sole plate according to the invention having a monolayer self-cleaning coating on an enameled support, and FIGS. 5 to 8 represent a succession of bottom views of iron sole plates according to the invention, enameled beforehand and then coated with a non-stick coating, which have been subjected to a test for determination of the abrasion resistance according to the standard EN ISO 12947-1; these views serve to form a visual scale for evaluation of abrasion resistance (scale described in the examples, in the section “Method of determination of the abrasion resistance”). DETAILED DESCRIPTION OF THE INVENTION The identical elements represented in FIGS. 1 to 4 are identified by identical numerical references. In FIG. 1 , a first example of iron sole plate 1 , comprising a metal support 2 covered with an internal layer 3 and with an external layer 4 , has been represented in cross section, this internal layer 3 and this external layer 4 constituting the self-cleaning coating. The sole plate also comprises a heating base 6 equipped with heating elements 7 . The support 2 and the base 6 are assembled by mechanical means or by adhesive bonding. The internal layer 3 comprises a dopant chosen from rare earth metal oxides and the external layer 4 comprises an oxidation catalyst chosen from platinum group metal oxides. In FIG. 2 , a second example of iron sole plate 1 has been represented which differs from the example represented in FIG. 1 by the presence of an intermediate protective layer 5 made of enamel which covers the support 2 and which is itself covered by the internal layer 3 of the self-cleaning coating. In FIG. 3 , a third example of iron sole plate 1 , comprising a metal support 2 also covered with a self-cleaning coating, has been represented in cross section. Unlike the iron examples represented in FIGS. 1 and 2 , this self-cleaning coating 4 is not bilayer but monolayer. It comprises an oxidation catalyst chosen from platinum group metal oxides and a dopant chosen from rare earth metal oxides. Just as for the implementation examples represented in FIGS. 1 and 2 , the sole plate also comprises a heating base 6 provided with heating elements 7 , and the support 2 and the base 6 are also assembled by mechanical means or by adhesive bonding. In FIG. 4 , a fourth example of iron sole plate 1 has been represented which differs from the example represented in FIG. 3 by the presence of an intermediate protective layer 5 made of enamel which covers the support 2 and which is itself covered by the self-cleaning coating 4 . FIGS. 5 to 8 are commented on in the examples, in the section “Method of determination of the abrasion resistance”. EXAMPLES Products iron sole plates, made of aluminum, enameled (comparative example 1 and examples 1 to 3) or non-enameled (comparative example 2), silver nitrate, sold by Aldrich, copper acetate, sold by VWR with the Merck brand and under the commercial name copper acetate monohydrate, Pro analysi, Assay 99.0%, copper nitrate, sold by VWR with the Merck brand and under the commercial name copper nitrate trihydrate, Pro analysi, Assay 99.5%, cerium nitrate, sold by Alfa Aesar under the trade name of cerium(III) nitrate hexahydrate, REacton, 99.99%, yttrium nitrate, sold by Alfa Aesar under the trade name of yttrium(III) nitrate hydrate, 99.99% (REO), aqueous palladium nitrate solution stabilized by nitric acid, sold by Metalor under the trade name Palladium nitrate in solution, Procatalyse grade. Measurement Methods RBS (Rutherford Backscattering Spectroscopy) Method The RBS (Rutherford Backscattering Spectroscopy) method is an analytical technique based on the elastic interaction between a 4 He 2+ ion beam and the component particles of the sample. The high energy (2 MeV) beam strikes the sample and the backscattered ions are detected under an angle theta. The spectrum thus acquired represents the intensity of the ions detected as a function of their energy and makes it possible to determine the thickness of the layer. This method is described in W. K. Chu and G. Langouche, MRS Bulletin, January 1993, p 32. Method of Determination of the Catalytic Activity of the Self-Cleaning Coating The catalytic activity of the self-cleaning coating is measured in a closed chamber as follows: a sample is heated to 300° C., on which is deposited a molten piece of fiber made of organic polymer weighing 10 mg, representative of the contaminants which may contaminate the external surface (which is the catalytically active surface) of the self-cleaning coating; the initial amount of carbon dioxide gas in the chamber is assayed; The variation in the CO 2 content as a function of the time makes it possible to deduce the catalytic activity of the coating; the efficiency of the catalytically active surface of the self-cleaning coating is defined by the amount of carbon dioxide gas produced per hour inside the chamber by a 10 cm 2 sample. More specifically, the slope of the curve representing the variation in the CO 2 content as a function of the time makes it possible to deduce the catalytic activity of the coating, as is illustrated in table 1 and example 4. Method of Determination of the Abrasion Resistance The principle of this method consists in sliding a pad covered with a fabric over a portion of the coating for 3000 to-and-fro movements. The fabric is made of wool and is in accordance with the standard EN ISO 12947-1. The pad, fitted to the end of an oscillating arm and of circular shape, exhibits a contact surface area of 2.5 cm 2 and a weight of 1.64 kg. The apparatus used for the test is the model sold under the trade name Taber® Linear Abrasion Tester Model 5750 by Taber Industries. As a function of the wear of the coating observed after 3000 to-and-fro movements, a grade from 0 to 1 is assigned, in order to quantify the abrasion resistance, by observation of the wear using a stereoscopic microscope and under appropriate lighting: the grade 0 corresponds to an excellent abrasion resistance, for which the coated part does not exhibit any difference between the abraded surface and the remainder of the coating not subjected to the test; a grade between 0 and 0.5 corresponds to an abrasion resistance which can be regarded as acceptable; if the grade is greater than 0.5; the coatings are not regarded as suitable for the ironing function. A panel of samples characterizing the different grades was set up in order to facilitate the grading, which makes it possible to produce a visual scale corresponding to the grading scale indicated above and represented in FIGS. 5 to 8 : FIG. 5 corresponds to an abraded sole plate to which the grade 0 has been assigned; in this figure, no difference is observed between the abraded region (consisting of a band located between the two dotted lines on which the pad has slid for 3000 to-and-fro movements) and the nonabraded region; the abrasion resistance is regarded as being excellent; FIG. 6 corresponds to an abraded sole plate to which the grade 0.25 has been assigned; in this figure, a slight lightening of the abraded region (consisting of a band located between the two dotted lines) is observed in comparison with the nonabraded region; the abrasion resistance is regarded as being highly satisfactory; FIG. 7 corresponds to an abraded sole plate to which the grade 0.5 has been assigned; in this figure, a more marked lightening of the abraded region (consisting of a band located between the two dotted lines) is observed in comparison with the nonabraded region but which does not, however, result in the appearance of the underlying enamel; the abrasion resistance is regarded as being acceptable; FIG. 8 corresponds to an abraded sole plate to which the grade 0.75 has been assigned; in this figure, an even more marked lightening of the abraded region (consisting of a band located between the two dotted lines) is observed in comparison with the nonabraded region and which results in the appearance of the underlying enamel, the latter being visible by observation using an optical microscope or a stereoscopic microscope; the abrasion resistance is regarded as being bad and unacceptable. Samples For comparison purposes, the tests presented below were carried out with samples of iron sole plates which each comprise a metal support 2 , enameled 5 or non-enameled, fully covered with a bilayer self-cleaning coating (comparative examples 1 and 2 and examples 1 and 2 according to the invention) or a monolayer self-cleaning coating (example 3 according to the invention). Comparative Example 1 PdO Monolayer Coating on an Enameled Support According to the Prior Art A clean iron sole plate made of enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit as far as possible the variations in temperature. The assembly is heated to 400° C. in an oven. The sole plate, with the support, is placed for a few seconds under infrared radiation until a surface temperature of between 400° C. and 600° C. is achieved. An aqueous palladium nitrate solution stabilized with nitric acid is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 40 to 50 nm, measured according to the RBS method described above, is then deposited. After application, this single layer is rebaked under infrared radiation at 500° C. for three minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres to the sole plate and has a catalytic activity, while retaining its gliding qualities. This iron sole plate corresponds to that illustrated in FIG. 4 , which corresponds to an iron sole plate according to the invention with a monolayer self-cleaning coating on an enameled support. The only difference (which does not appear in this figure) is related to the absence of an oxidation catalyst in the internal layer of the self-cleaning coating, as is the case according to the present invention. The results in terms of catalytic activity are given in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Comparative Example 2 PdO/AgO Bilayer Coating on an Enameled Support According to the Prior Art FR 2 848 290 A clean iron sole plate made of enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit as far as possible the variations in temperature. The assembly is heated to 400° C. in an oven. The sole plate, with the support, is placed for a few seconds under infrared radiation until a surface temperature of between 400° C. and 600° C. is achieved. Silver nitrate is dissolved in water. This silver nitrate solution is subsequently sprayed over the sole plate using an air gun. A layer with a thickness of approximately 40 nm to 50 nm, measured according to the RBS method, is then deposited. After the application of this internal layer, the sole plate is again heated in the oven to 400° C. and is then placed for a few seconds under infrared radiation at a temperature of between 400° C. and 600° C. An aqueous palladium nitrate solution stabilized with nitric acid is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 40 to 50 nm, measured according to the RBS method described above, is then deposited. After application of this external layer, the assembly is rebaked under infrared radiation at 500° C. for three minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres to the sole plate and has a catalytic activity, while retaining its gliding qualities. This iron sole plate corresponds to that illustrated in FIG. 2 , which corresponds to an iron sole plate according to the invention with a bilayer self-cleaning coating on an enameled support. The only difference (which does not appear in this figure) is related to the nature of the oxidation catalyst of the internal layer of the self-cleaning coating, which is a silver oxide in this example and not a rare earth metal oxide, as is the case according to the present invention. The results in terms of catalytic activity are given in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Comparative Example 3 PdO/CuO Bilayer Coating on an Enameled Support According to the Prior Art FR 2 848 290 A clean iron sole plate made of enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit as far as possible the variations in temperature. The assembly is heated to 300° C. in an oven. The sole plate, with the support, is placed for a few seconds under infrared radiation until a surface temperature of between 400° C. and 600° C. is achieved. Copper acetate or copper nitrate is dissolved in water. This copper acetate or copper nitrate solution, respectively stabilized with acetic acid or nitric acid, is subsequently sprayed over the sole plate using an air gun. A layer with a thickness of approximately 40 nm to 50 nm, measured according to the RBS method, is then deposited. After the application of this internal layer, the sole plate is again heated in the oven to 400° C. and then placed for a few seconds under infrared radiation at a temperature of between 400° C. and 600° C. An aqueous palladium nitrate solution stabilized with nitric acid, sole by Metalor, is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 40 to 50 nm, measured according to the RBS method described above, is then deposited. After application of this external layer, the assembly is rebaked under infrared radiation at 500° C. for three minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres to the sole plate and has a catalytic activity, while retaining its gliding qualities. This iron sole plate corresponds to that illustrated in FIG. 2 , which is that of an iron sole plate according to the invention with a bilayer self-cleaning coating on an enameled support. The only difference (which does not appear in this figure) is related to the nature of the oxidation catalyst of the internal layer of the self-cleaning coating, which is a cupper oxide in this example and not a rare earth metal oxide, as is the case according to the present invention. The results in terms of catalytic activity are given and commented on in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Example 1 1st Example of PdO/CeO 2 Bilayer Coating According to the Invention on an Enameled Support A clean iron sole plate made of enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit, as far as possible, the variations in temperature. The assembly is heated in an oven to a temperature of 300° C. The sole plate, with the support, is placed under infrared radiation for a few seconds until a surface temperature of between 300° C. and 350° C. is achieved. Cerium nitrate is dissolved in water. This cerium nitrate solution is subsequently sprayed over the sole plate using an air gun. A layer with a thickness of approximately 50 nm to 100 nm, measured according to the RBS method, is then deposited. After the application of this internal layer, the sole plate is heated in the oven to 250° C. and then placed under infrared radiation at a temperature of between 280° C. and 350° C. for a few seconds. An aqueous palladium nitrate solution stabilized with nitric acid is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 15 to 50 nm, measured according to the RBS method described above, is then deposited. After application of this external layer, the assembly is rebaked under infrared radiation at a temperature of 480° C. for 4 minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres particularly well to the sole plate and has a very good catalytic activity, while retaining its gliding qualities. This iron sole plate is illustrated in FIG. 2 . The results in terms of catalytic activity are given and commented on in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Example 2 2nd Example of PdO/Y 2 O 3 Bilayer Coating According to the Invention on an Enameled Support A clean iron sole plate made of enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit, as far as possible, the variations in temperature. The assembly is heated in an oven to a temperature of 300° C. The sole plate, with the support, is placed under infrared radiation for a few seconds until a surface temperature of between 300° C. and 350° C. is achieved. Yttrium nitrate is dissolved in water. This yttrium nitrate solution is subsequently sprayed over the sole plate using an air gun. A layer with a thickness of approximately 50 nm to 100 nm, measured according to the RBS method, is then deposited. After the application of this internal layer, the sole plate is heated in the oven to 250° C. and then placed under infrared radiation at a temperature of between 280° C. and 350° C. for a few seconds. An aqueous palladium nitrate solution stabilized with nitric acid is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 15 to 50 nm, measured according to the RBS method described above, is then deposited. After application of this external layer, the assembly is rebaked under infrared radiation at a temperature of 500° C. for 4 minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres particularly well to the sole plate and has a very good catalytic activity, while retaining its gliding qualities. This iron sole plate is also illustrated in FIG. 2 . The results in terms of catalytic activity are given and commented on in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Example 3 Example of a Monolayer Coating (PdO+Y 2 O 3 ) According to the Invention on an Enameled Support A clean iron sole plate made of an enameled aluminum is placed on a thick support made of aluminum acting as heat reservoir in order to limit, as far as possible, the variations in temperature. The assembly is heated in an oven to a temperature of 250° C. The sole plate, with the support, is placed under infrared radiation for a few seconds until a surface temperature of between 280° C. and 350° C. is achieved. An aqueous palladium nitrate solution stabilized by nitric acid, to which yttrium nitrate is added as dopant, is sprayed over the sole plate using an air gun. A layer with a thickness of approximately 50 to 100 nm, measured according to the RBS method described above, is then deposited. After application of this external layer, the assembly is rebaked under infrared radiation at a temperature of 500° C. for 4 minutes. An iron sole plate is obtained, the self-cleaning coating of which adheres particularly well to the sole plate and has a very good catalytic activity, while retaining its gliding qualities. This iron sole plate is also illustrated in FIG. 4 . The results in terms of catalytic activity are given and commented on in table 1 and example 4. The results in terms of abrasion resistance are given in table 2 and example 5. Example 4 Determination of the Catalytic Activity The catalytic activity of the self-cleaning coating was determined, according to the method described above, for each of the coatings of comparative examples 1 to 3 and examples 1 to 3. The results, which are presented in table 1 below, are comparative results. They are given with respect to the catalytic activity of the self-cleaning coating of comparative example 1, to which the index 100 is assigned. The results in terms of catalytic activity which are presented in table 1 show that: when a dopant, such as yttrium oxide Y 2 O 3 , is used in a monolayer deposit (example 3), the amount of palladium oxide can be divided by four in order to obtain a catalytic activity equivalent to that which would be obtained with a monolayer PdO deposit on an enameled support (comparative example 1); when a dopant, such as yttrium oxide Y 2 O 3 , is used in a bilayer deposit (example 2), the amount of palladium oxide can also be divided by four in order to obtain a catalytic activity which is slightly better (index 100) than that which would be obtained with a PdO on Ago bilayer deposit on an enameled support (index 95 for comparative example 2); with the same amount of palladium oxide as in the coating of comparative example 1 and also using, as dopant, yttrium oxide Y 2 O 3 , the catalytic activity (examples 2 and 3) is from 1.3 to 1.4 times (according to whether a monolayer or bilayer is respectively present) greater than that of the coating of comparative example 1, finally, still with the same amount of palladium oxide as in the coating of FR 2 848 290 (example 1) but this time using cerium oxide CeO 2 as dopant, the catalytic activity (examples 2 and 3) is 3 times greater than that of the coating of comparative example 1. TABLE 1 Comparison of the catalytic activity of the coatings of comparative examples 1 to 3 and examples 1 to 3 Catalytic activity on enameled aluminum Comparative Comparative example 2 example 3 Example 1 Example 2 Example 3 Comparative Bilayer PdO/Ago Bilayer PdO/Cuo Bilayer PdO/CeO 2 Bilayer PdO/Y 2 O 3 Monolayer PdO + Y 2 O 3 example 1 coating on an coating on an coating on an coating on an coating on an Monolayer PdO enameled support enameled support enameled support enameled support enameled support coating on an according to according to according to according to according to Amount of PdO enameled support FR 2 848 290 FR 2 848 290 the invention the invention the invention 1 100 ~95 30 300 ~140 ~130 Reference value ½ 75 ~70 9 190 115 115 ¼ 65 60 ND 140 100 100 Key: ND: Not determined ~: approximately Example 5 Determination of the Abrasion Resistance The abrasion resistance of the self-cleaning coating was determined, according to the test described above in accordance with the standard EN ISO 12947-1, for each of the coatings of comparative examples 1 to 3 and examples 1 to 3. The results, which are presented in table 2 below, are comparative results. They are given in the form of a grade between 0 and 1, assigned on conclusion of the test, after: observation of the wear of the abraded region using a stereoscopic microscope and under appropriate lighting, then comparison with the grading scale represented in FIGS. 5 to 8 . The results in terms of abrasion resistance presented in table 2 show that: the abrasion resistance is judged to be excellent for a bilayer PdO/CeO 2 coating on an enameled support according to the invention, whatever the amount of palladium oxide; the abrasion resistance is judged to be excellent for a monolayer or bilayer coating on an enameled support according to the invention doped by yttrium oxide Y 2 O 3 and with an amount of palladium oxide divided by four with respect to that of comparative example 1 (dopant-free PdO monolayer); the abrasion resistance is judged to be very satisfactory for a monolayer or bilayer coating on an enameled support according to the invention doped by yttrium oxide Y 2 O 3 with an amount of palladium oxide which is equal or divided by two with respect to that of comparative example 1 (dopant-free PdO monolayer). TABLE 2 Comparison of the abrasion resistance of the coatings of comparative examples 1 to 3 and examples 1 to 3 Abrasion resistance of the coatings on enameled aluminum Comparative Comparative example 2 example 3 Example 1 Example 2 Example 3 Comparative Bilayer PdO/Ago Bilayer PdO/Cuo Bilayer PdO/CeO 2 Bilayer PdO + Y 2 O 3 Monolayer PdO/Y 2 O 3 example 1 coating on an coating on an coating on an coating on an coating on an Monolayer PdO enameled support enameled support enameled support enameled support enameled support coating on an according to according to according to according to according to Amount of PdO enameled support FR 2 848 290 FR 2 848 290 the invention the invention the invention 1 >0.75 0.25 to 0.5 0.25 to 0.5 0 0.25 0.25 ½ 0.75 0.25    0 to 0.25 0 0.25 0.25 ¼ 0.5 0.25 ND 0 0 0 Key: ND: Not determined

A heating appliance including a metal substrate, at least a part of which is covered with a self-cleaning coating including at least one oxidation catalyst selected from the platinoid oxides, and at least one dopant of said oxidation catalyst selected from the rare-earth oxides. The self-cleaning coating is a bilayer coating including: an inner layer at least partially covering the metal substrate and including the dopant; and an outer layer in contact with the ambient air and including the oxidation catalyst. Also provided is a method for producing such a heating appliance.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an implant which is useful for a variety of orthopedic applications. More particularly, the present invention relates to an implant useful for treating bone injuries, defects, etc., such as spinal disorders for which spinal fusion is indicated and the repair or replacement of ligaments, tendons and/or cartilage. 2. Description of Related Art A variety of implants having application as artificial bone, ligaments, tendons, cartilage, and the like, are known. U.S. Pat. No. 4,089,071 describes a material for making bone endoprostheses featuring a laminated structure of net-like construction. U.S. Pat. No. 5,092,887 describes an elongated artificial ligament made from demineralized bone which is said to exhibit compliant elasticity and high longitudinal strength. U.S. Pat. No. 5,263,984 describes a prosthetic ligament made up of a quantity of substantially aligned, elongated filaments each of which is a biocompatible, resorbable fibril made, e.g., of collagen, elastin, reticulin, cellulose, algenic acid or chitosan. U.S. Pat. No. 5,711,960 describes an implant, useful inter alia, as a prosthetic or filling for a defective bone, which utilizes, as a base material, a biocompatible bulk structure of a three-dimensionally woven or knitted fabric of organic fibers whose surfaces have been biologically activated or inactivated. U.S. Pat. No. 6,090,998 describes a bone implant, useful for the repair or replacement of ligaments, tendons and joints, which includes at least one mineralized segment and at least one demineralized, flexible segment. Developing cells are known to migrate along surfaces. When the surface is oriented, the potential exists to somewhat control the direction of growth. It has been observed by the inventors in animal studies that fibrous materials provide better osteoconduction than particle based materials. Therefore, a material which guides the formation of new tissue would have the ability to direct osteoconduction as well as other types of tissue growth. Such a material, by directing the formation of new tissue, would be expected to demonstrate improved strengthening effects. In addition, a fibrous implant, unlike particle-based implants, would tend to remain where placed in the body and would resist being dislodged therefrom. SUMMARY OF THE INVENTION It is an object of the present invention to provide an implant which is useful for the treatment of defects and injuries of bone, ligaments, tendons and cartilage. It is a further object of the invention to provide an implant that is biocompatible and will not be rejected by the host. It is still a further object of the invention to provide an implant for various orthopedic applications which can be combined with one or more separate therapeutically useful substances or structurally useful biomaterials, e.g., titanium wire or mesh. By way of attaining these and other objects of the invention, an implant is provided which comprises a quantity of flexible, elongated elements at least some of which possess connective tissue-healing activity, the elements being arranged in substantially common alignment along their longitudinal axis. Significant advantages of the implant flow from the substantial alignment of the elongated members along their longitudinal, or major, axis. Thus, when the elongated members are thus aligned to provide, e.g., a woven or braided structure, the result is an implant which is generally stronger than the elongated members from which the implant is made. In addition, the implant can be made to possess dimensions which could not be achieved with naturally occurring implant materials such as whole bone sections. Still another advantage resides in the ability of a particular implant to utilize combinations of different materials as sources for its elongated members. Selection from among a large variety of such materials expands the range of biological and/or mechanical properties that can be built into a given implant. The implant of the present invention, unlike conventional metallic implants, will not stress shield the bone at the implant site. Therefore, any tendency for already existing healthy bone to be resorbed at the implant site will be reduced. In addition, unlike metallic implants, the implant of this invention will not interfere with the use of postoperative plain film X-rays, MRI or CT scans. The expression “elongated elements” refers to the structural units constituting the implant of this invention and having the appearance of filaments, threads, strips and similarly elongated configurations. The elongated elements can be separate units for their entire length or two or more of the elements can have a common point of attachment, e.g., as shown in the implant of FIG. 1 a. The term “biocompatible” and expressions of like import shall be understood to mean the absence of unacceptable detrimental biological response, e.g., stimulation of a severe, long-lived or escalating biological response to an implant and is distinguished from a mild, transient inflammation which accompanies implantation of essentially all foreign objects into a living organism and is also associated with the normal healing response. Thus, materials which alone in appropriate quantities are generally considered nonbiocompatible can be considered biocompatible within the aforestated meaning if present in small enough quantities such that they do not elicit a significant level of undesirable or detrimental tissue response. The expression “connective tissue-healing activity” refers to the ability of the implant of the invention to participate in the repair, regeneration, healing, etc., of connective tissue, e.g., bone, ligament, tendon or cartilage, by one or more mechanisms including chondrogenesis, osteoinduction, osteogenesis and osteoconduction. The term “chondrogenic” as used herein shall be understood to refer to the ability of a material or substance to induce or otherwise participate in the formation of cartilage. The term “osteoinductive” as used herein shall be understood to refer to the ability of a material or substance to recruit cells from the host which have osteogenic potential and the ability to form ectopic bone. The term “osteogenic” as used herein shall be understood to refer to the ability of a material or substance to induce new bone formation via the participation of living cells from within the substance. The term “osteoconductive” as used herein shall be understood to refer to the ability of a material or substance or material to provide surfaces that are receptive to the growth of new host bone. The expression “substantially common alignment” refers to the relative orientation of the elongated elements constituting the implant and includes woven, knitted, braided, or twisted arrangements of individual elements as well as subassemblies of several elongated elements formed into yarns, twines, strands, etc. The term “resorbable” refers to the ability of materials to be broken down by normal biochemical and/or physical processes such as erosion, dissolution, etc. The term “remodeling” refers to the process whereby materials are broken down and then replaced by host tissue, e.g., by resorption of existing bone tissue by osteoclasts and formation of new bone tissue by osteoblasts. Other advantages of the present invention will become apparent to one skilled in the art from the following written description and accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1E are diagrammatic representations of implants in accordance with the present invention. In FIG. 1A , an elongated section of bone is cut or machined to provide three relatively wide elongated elements arranged in a braided pattern. In FIG. 1B , the elongated section of bone is cut or machined to provide elongated elements which are formed into yarns with the yarns subsequently being formed into braids. FIGS. 1C-1E schematically depict demineralized bone strips arranged into various other structures. As shown, the implants are substantially longer than they are wide, and substantially longer than they are thick. DETAILED DESCRIPTION OF THE INVENTION The implant of this invention is fabricated in whole or in part from flexible elongated elements, advantageously biocompatible in character, e.g., connective type tissues obtained from human and animal tissues and natural and synthetic fibers including, but not limited to, demineralized bone, tendon, ligament, collagen, elastin, reticulin, cellulose, alginic acid, chitosan, small intestine submucosa, silk, nonresorbable and resorbable synthetic polymeric fibers, and the like. The elongated elements can also be obtained from microorganisms, particularly genetically engineered microorganisms such as yeast and bacteria and genetically engineered eucaryotic cell cultures such as Chinese hamster ovary cell lines, HeLa cells, etc. For example, U.S. Pat. Nos. 5,243,038 and 5,989,894, each of which is incorporated herein by reference, describes the expression of spider silk protein, collagen proteins, keratins, etc., using genetically engineered microorganisms and eucaryotic cell lines. When the elongated elements are fabricated in whole or in part from tissues such as bone, tendon, ligament, small intestine submucosa tissue, and the like, such tissues are first processed to remove any blood and debris that may be associated therewith and the tissues are then sterilized employing routine procedures such as those described below. The processed tissues are then fashioned into elongated elements whose dimensions are selected so that when assembled into the implant, the latter will have sufficient length to span, and be affixed to, the implant site, and sufficient width and thickness to impart such desirable properties as toughness, flexibility and strength to the implant. The elongated tissue elements can be formed into implants having a variety of configurations such as those shown in FIGS. 1A-1E . For example, FIG. 1A schematically depicts one embodiment in which a sheet of bone is further cut or machined into three elongated elements of about the same width which are then formed into a braid. FIGS. 1B-1E schematically depict other embodiments wherein a section of bone is cut or machined to provide a quantity of elongated elements which are then assembled into the implants shown. The overall dimensions of the flexible elongated elements making up the implant of this invention can vary widely depending on the dimensions of the site to which the implant is to be affixed. Typically, these dimensions will range from about 1 cm to about 1 meter in length, preferably from about 3 cm to about 8 cm in length, from about 0.5 mm to about 30 mm in thickness, preferably from about 2 mm to about 10 mm in thickness, and from about 0.05 mm to about 150 mm in width, preferably from about 2 mm to about 10 mm in width. While fully mineralized bone, tendon, ligament, small intestine submucosa, collagen tissues, etc., in themselves are not particularly osteoinductive, such tissues can be rendered osteoinductive by subjecting the tissue to various procedures and/or incorporating one or more osteoinductive substances in the tissues. For example, the mineral content of bone tissue can be reduced by demineralization, a process which results in the removal of the inorganic components of the bone, largely hydroxyapatite, which gives bone its characteristic rigidity and structural properties. The resultant demineralized bone is both flexible and osteoinductive. Bone, tendon, ligament, small intestine submucosa and collagen tissues can be rendered osteoinductive by association with, or incorporation of, various osteoinductive materials which include, but are not limited to, growth factors such as bone-derived growth factor, bone morphogenic proteins, osteogenic proteins such as OP-1, hormones, growth hormone, platelet derived growth factor (PDGF), insulin-like growth factors (IGF-1)(IGF-2), DNA-encoding various therapeutic agents such as growth factors and hormones, gene activated matrix, i.e., a matrix containing DNA encoding therapeutic proteins utilized to promote cell growth, which in turn, promote DNA transfer into repair cells, demineralized bone in the form of particles, powder, gel, liquid, etc, ceramic powders of calcium phosphate and/or apatite (hydroxyapatite) and bioglasses. Bone morphogenic proteins can be obtained from Genetics Institute, Inc. (Cambridge, Mass.) and Stryker Corporation (Kalamazoo, Mich.) and may also be prepared by one skilled in the art as described, e.g., in. U.S. Pat. Nos. 5,187,076, 5,366,875, 4,877,864, 5,108,922, 5,116,738, 5,013,649, 5,106,748, WO93/00432, WO94/26893 and WO94/26892, each of which is incorporated by reference herein. All osteoinductive factors are contemplated whether they are obtained as above or isolated from bone or other human or animal tissues. Methods for isolating bone morphogenic protein from bone are described, e.g., in U.S. Pat. No. 4,294,753, incorporated herein by reference. Methods of preparing demineralized bone powder, demineralized bone particles, and demineralized bone in the form of a liquid, and demnineralized bone in the form of a gel are well known in the art as described, e.g., in U.S. Pat. Nos. 5,314,476, 5,507,813, 5,073,373, and 5,405,390, respectively, each of which is incorporated by reference herein. Methods of preparing osteogenic proteins, such as OP-1 are described, e.g., in U.S. Pat. No. 6,048,964 which is incorporated by reference herein. Methods of transferring DNA-encoding therapeutic proteins into repair cells utilizing gene activated matrix are described, e.g., in U.S. Pat. No. 5,962,427 which is incorporated by reference herein. Methods of preparing ceramic powders of calcium phosphate and/or hydroxyapatite are described, e.g., in U.S. Pat. Nos. 4,202,055 and 4,713,076, each of which is incorporated by reference herein. Methods of preparing bioglasses are described, e.g., in WO 98/44965, which is incorporated by reference herein. Suitable methods of incorporation or association of such osteogenic factors include coating, immersion saturation, packing, spraying, e.g., plasma spraying, injecting into the bone tissue, etc. When desirable, e.g., for preparing an implant suitable for soft tissue repair, the flexible elongated elements constituting the implant can be treated to so as to reduce their osteoinductive properties. For example, demineralized bone is known to possess osteoinductive characteristics. When desirable, such characteristics can be reduced or eliminated by appropriate further treatment. For example, the osteoinductive proteins in the demineralized bone can be denatured, and thus deactivated, by reaction with, for example, a chemical denaturant such as glutaraldehyde or formaldehyde. Demineralized bone treated in this way is known to support the formation of fibrous tissue and as such, exhibits connective tissue-healing activity although, of course, through a mechanism other than that of osteoinduction. The degree of denaturation can be controlled to give the desired physical and biological properties. Other denaturation methods include irradiation and thermal treatment. Alternatively, osteoinductive proteins can be extracted from the demineralized bone employing extractants such as guanidine hydrochloride. Implants of this invention containing bone or other tissue material can be further treated by tanning or other means known in the art to reduce their antigenicity. For example, glutaraldehyde treatment (see U.S. Pat. No. 5,053,049 which is incorporated by reference herein) can be used for this purpose. Employing a milling technique, elongated bone elements ranging in median length from about 2 up to about 200 mm or more (as in the case of the long bones), in median thickness from about 0.05 to about 2 mm and in median width from about 1 to about 20 mm can be readily obtained. Another procedure for obtaining the elongated bone particles herein, particularly useful for elements of bone of up to about 100 mm in length, is the bone milling apparatus described in U.S. Pat. No. 5,607,269 the contents of which are incorporated by reference herein. Use of this apparatus results in the production of long, thin bone strips which tend to curl lengthwise into tube-like structures. Depending on the procedure employed for producing the elongate bone elements, one can obtain a mass of bone elements containing at least about 60 weight percent, preferably at least about 70 weight percent, and most preferably at least about 80 weight percent of bone elements possessing a median length of from about 2 to about 200 mm or more and preferably from about 10 to about 100 mm, a median thickness of from about 0.05 to about 2 mm and preferably from about 0.2 to about 1 mm and a median width of from about 1 mm to about 20 mm and preferably from about 2 to about 5 mm. These bone elements can possess a median length to median thickness ratio of at least about 50:1 up to about 500:1 or more and preferably from about 50:1 to about 100:1 and a median length to median width ratio of from about 10:1 to about 200:1 and preferably from about 50:1 to about 100:1. If desired, the mass of elongated bone elements can be graded into different sizes to reduce or eliminate any less desirable size(s) of elements which may be present. In overall appearance, the elongated bone elements can be described as filaments, fibers, threads, slender or narrow strips, etc. As already noted and depending on the manner in which they are produced, these elongated elements may have a tendency to curl lengthwise into tube-like structures. When the implant of this invention is fabricated from bone, the bone is preferably chosen from a cortical bone such as the femur, tibia, fibula, radius or ulna. The bone elements can be obtained from cortical, cancellous and/or corticocancellous bone which can be of autogenous, allogenic and/or xenogeneic origin: Porcine bone is a particularly advantageous type of xenogeneic bone tissue which can be used as a source for the elongated bone elements of this invention. Following the shaving, milling or other technique whereby they are obtained, the elongated bone elements are subjected to demineralization in order to reduce their inorganic content and, as may be necessary for a particular embodiment, to increase their flexibility. Demineralization of the bone elements will ordinarily result in elongated elements of slightly smaller dimensions than those of the mineralized elements from which they were obtained. The elongated bone elements can be demineralized in accordance with known and conventional procedures. The mineral content of bone can be removed to varying degrees. The term “fully demineralized” as it applies to an elongated bone element refers to a bone element possessing less than about 8, preferably less than about 1, weight percent of its original inorganic mineral content. The term “partially demineralized” as it applies to an elongated bone element means that the bone element possesses from about 8 to about 90 weight percent of its original inorganic mineral content. The term “superficially demineralized” as it applies to an elongated bone element refers to a bone element possessing at least 90 weight percent of its original inorganic mineral content. The term “demineralized” as it applies to an elongated bone element includes any one or combination of the foregoing types of demineralized elongated bone elements. The use of superficially, partially or fully demineralized bone can, in some embodiments, be particularly advantageous since demineralized bone exhibits considerably greater initial osteoinductive activity than fully mineralized bone. Demineralization can precede or follow the cutting, slicing, milling, etc., of the bone into elongated elements. Thus, a whole section of bone, e.g., a diaphyseal shaft, can first be demineralized to the extent desired after which it is machined to provide the individual elongated bone elements. Alternatively, the whole bone can be subdivided into individual elongated bone elements which are thereafter demineralized to the desired level. Of course it will be understood by those skilled in the art that the bone elements will be demineralized to such an extent that they can be worked to form the implant of the invention herein. Therefore, when the bone elements are of such size as to be relatively inflexible prior to demineralization, they can be demineralized to the point where they are flexible and capable of being worked, e.g., woven, braided, spun, etc. When bone elements are of such dimensions that they are relatively flexible prior to demineralization, a lesser degree of demineralization may be appropriate. The extent of demineralization necessary to obtain a bone element that is workable can be readily determined by one skilled in the art employing routine experimentation. Demineralization of the elongated bone elements can be conducted using conventional procedures that are well known in the art, e.g., subjecting the bone section to strong acids such as hydrochloric acid as described, e.g., in Reddi et al., Proc. Nat. Acad. Sci. 69:1601-5 (1972), incorporated herein by reference. The extent of demineralization is a function of the strength of the acid solution, the shape of the bone and the duration of the demineralization treatment. Reference in this regard may be made to Lewandrowski et al., J. Biomed. Materials Res. 31:365-372 (1996), incorporated herein by reference. In a preferred demineralization procedure, the elongate bone elements are subjected to a defatting/disinfecting step which is followed by an acid demineralization step. A preferred defatting/disinfectant solution is an aqueous solution of ethanol, the ethanol being a good solvent for lipids and the water being a good hydrophilic carrier to enable the solution to penetrate more deeply into the bone particles. The aqueous ethanol solution also disinfects the bone by killing vegetative microorganisms and viruses. The preferred concentration range of the defatting solution is from about 60 to about 85 weight percent alcohol and most preferably about 70 weight percent alcohol. Following defatting, the bone elements are immersed in acid over time to effect their demineralization. Acids which can be employed in this step include inorganic acids such as hydrochloric acid and organic acids such as peracetic acid. Generally, the concentration of inorganic acid utilized to achieve demineralization is from about 0.1N to about 2N and more preferably from about 0.2 N to about 1.0 N. The time of exposure to the acid is increased for lower acid concentrations and decreased for the higher acid concentrations. After acid treatment, the demineralized bone elements are rinsed with sterile water for injection to remove residual amounts of acid and thereby raise the pH. The wet demineralized bone elements can then be immediately formed into the implant of this invention in accordance using methods well known in the art, e.g., those described in U.S. Pat. No. 5,263,984 the contents of which are incorporated by reference herein, or stored under aseptic conditions, advantageously in a lyophilized state, for processing at a later time. When the bone elements are shorter than the desired length of the implant, they can be combined with fibers and/or other materials such that a final implant of the desired length is produced. For example, the relatively short bone elements can be combined with other materials in a known manner, e.g., to form a spun yarn, which can then be woven to form the implant of the invention. Thus, the short bone elements can be combined with demineralized bone elements of greater length or with bioresorbable polymeric fibers, ceramic or glass fibers, or biocompatible metal fibers of suitable length to produce a composite yarn which can then be woven using standard techniques to produce the implant of the invention. Optionally, the short bone elements can be combined with bioresorbable thermoplastic material that is formed into spun-bonded and/or non-woven fabrics. For example, after the bioresorbable thermoplastic material has been formed into a first web, the short bone elements can be applied to the first web and then sandwiched with a second web to form a controlled elastic composite material. The methods of forming a composite material disclosed in U.S. Pat. Nos. 6,124,001 and 6,132,871 are incorporated by reference herein and are suitable for forming the aforedescribed elastic composite. In one embodiment, the bone comprises a plurality of elongated bone elements. Typically, the bone is obtained from a suitable vertebrate and processed by conventional techniques to remove blood and lipid from the bone. The bone can then be cut into elongated sections by techniques which are well known in the art e.g., longitudinally cutting an entire bone section or relatively large portion of bone into elongated sections using a band saw or a diamond-bladed saw, or milling the surface of an entire bone or relatively large portion of bone. Alternatively, the bone can be cut by making transverse cuts to prepare a bone section of the appropriate length, followed by longitudinal cuts using a band saw or a diamond cut saw. As stated above, elongated elements of bone can be further cut or machined into a variety of different shapes. In overall appearance the elongated bone elements can be described as narrow or thick strips, segments, sheets, rods, struts, etc. The elongated elements can be further processed to remove residual blood and lipid residue. Prior or subsequent to cutting or milling of the bone into elongated elements, the bone is preferably demineralized to reduce its inorganic content utilizing the defatting/demineralization procedure described herein above. After acid treatment, the elongated bone elements are rinsed with sterile water for injection, buffered with a buffering agent to a final predetermined pH and then finally rinsed with water for injection to remove residual amounts of acid and buffering agent or washed with water to remove residual acid and thereby raise the pH. In a particularly useful embodiment, the elongated bone elements can be segmentally demineralized employing procedures known in the art as described, e.g., in U.S. Pat. No. 6,090,998, which is incorporated herein by reference. Alternatively, the end portions of the elongated bone elements can be surface demineralized by any convenient method. For example, the bone elements can be subjected to demineralization conditions for a period of time sufficient to demineralize only their surfaces. In an alternative embodiment, demineralized bone sections (approximately 6 bone sections) are combined longitudinally into three small bundles, each having from about 1 to about 3 bone sections. The three bundles are then braided. Various methods of braiding and types of braids any of which may be useful in producing the material of the invention herein are also described, e.g., by Shaw, KNOTS—Useful & Ornamental , Bonanza Books, New York (1983), incorporated herein by reference. The ends of the braided demineralized bone section can then be glued together using a fixation agent to prevent their unraveling or they can be held together with a biocompatible polymer or metal band. In another embodiment, demineralized bone strips can be cut from sheets composed of elongated bone particles, commercially available as GRAFTON® Flex (Osteotech, Eatontown, N.J.) as described, e.g., in U.S. Pat. No. 5,507,813, the contents of which are incorporated by reference herein. To increase the mechanical strength of bone strips fabricated from bone, chemical linkages can be formed between adjacent bone elements employing, e.g., any of the procedures for accomplishing this disclosed in U.S. Pat. No. 6,123,731, the contents of which are incorporated herein by reference. Medically/surgically useful substances which promote or accelerate healing can be incorporated in the implant of this invention. Useful substances of this kind which can be incorporated into the implant include, e.g., collagen, insoluble collagen derivatives, etc., and soluble solids and/or liquids dissolved therein, e.g., antiviral agents, particularly those effective against HI and hepatitis; antimicrobials and/or antibiotics such as erythromycin, bacitracin, neomycin, penicillin, polymyxin B, tetracyclines, viomycin, chloromycetin and streptomycins, cefazolin, ampicillin, azactam, tobramycin, clindamycin, and gentamicin, etc.; biocidal/biostatic sugars such as dextran, glucose, etc.; amino acids; peptides; vitamins; inorganic elements; co-factors for protein synthesis; hormones; endocrine tissue or tissue fragments, synthesizers; enzymes such as collagenase, peptidases, oxidases, etc.; polymer cell scaffolds with parenchymal cells; angiogenic drugs and polymeric carriers containing such drugs; collagen lattices; antigenic agents; cytoskeletal agents; cartilage fragments, living cells such as chondrocytes, bone marrow cells, mesenchymal stem cells; natural extracts; genetically engineered living cells or otherwise modified living cells; tissue transplants; demineralized bone powder (or “demineralized bone matrix” as it may also be referred to); DNA delivered by plasmid or viral vectors; autogenous tissues such as blood, serum, soft tissue, bone marrow, etc.; bioadhesives; bone morphogenic proteins; osteoinductive factor; fibronectin; transforming growth factor-beta; endothelial cell growth factor; cementum attachment extracts; ketaserin; insulin-like growth factor; platelet derived growth factors; epidermal growth factor, interleukin; human alphathrombin; fibroblast growth factors; periodontal ligament chemotactic factor; human growth hormone; animal growth hormone; growth hormones such as somatotropin; bone digesters; antitumor agents; immuno-suppressants; permeation enhancers, e.g., fatty acid ester such as laureate, myristate and stearate monoesters of polyethylene glycol, enamine derivatives, alpha-keto aldehydes, etc.; and, nucleic acids. Preferred biomedically/surgically useful substances are bone morphogenic proteins and DNA delivered by plasmid or viral vector. Suitable methods of incorporation include coating, immersion saturation, packing, co-lyophilization wherein the substance is placed on the bone graft and lyophilized, spraying, injecting, etc. The amounts of medically/surgically useful substances utilized can vary widely with optimum levels being readily determined in a specific case by routine experimentation. The implant herein can also be fabricated in whole or in part from tendon, ligament and/or small intestine submucosa tissues. These tissues are not osteoinductive but can be made so by incorporating various osteoinductive materials as described above. Tendon tissue useful for fabricating the material includes, but is not limited to, fascia lata, semitendinosus, achilles tendon and patella tendon tissue. Ligament tissue can consist of an entire excised ligament or elongated section thereof. Small intestine submucosa tissue can be obtained and processed as described in U.S. Pat. No. 4,902,508, the contents of which are incorporated by reference herein. The tendon, ligament and small intestine submucosa tissues can be obtained from autogeneic, allogeneic or xenogeneic sources and preferably are obtained from an autogeneic or allogeneic source. The tissues can be excised and cut into a plurality of elongated elements employing methods known in the art. Reduction of the antigenicity of allogeneic and xenogeneic tissue can be achieved by treating the tissues with various chemical agents, e.g., extraction agents such as monoglycerides, diglycerides, triglycerides, dimethyl formamide, etc., as described, e.g., in U.S. Pat. No. 5,507,810, the contents of which are incorporated by reference herein. Medically/surgically useful substances as described above can also be incorporated in or associated with the tendon, ligament and small intestine submucosa tissue as described above with respect to elongated elements obtained from bone. The implant can also be fabricated from collagen tissue which can be obtained from any autogeneic, allogeneic or xenogeneic source, preferably from an autogeneic or allogeneic source. Collageneous tissue sources include, but are not limited to, skin, tendon, intestine and dura mater obtained from animals, transgenic animals and humans. Collagenous tissue can also be obtained by genetically engineering microorganisms to express collagen as described, e.g., in aforementioned U.S. Pat. No. 5,243,038. Procedures for obtaining and purifying collagen are well known in the art and typically involve acid or enzyme extraction as described, e.g., in U.S. Pat. No. 5,263,984, the contents of which are incorporated by reference herein. Collagen is also commercially available (Pentapharm). The purified collagen is then subjected to further processing to obtain collagen fibers or collagen threads, which can optionally be treated with crosslinking agents, e.g., glutaraldehyde, to improve their strength and/or with various medically/surgically useful substances as described above. The collagen threads can be arranged to form various structures, such as a woven or non-woven fabric, bundle or braid, etc. by various techniques known in the art as described, e.g., in U.S. Pat. Nos. 5,171,273 and 5,378,469, each incorporated herein by reference, to provide the implant of the invention. For example, U.S. Pat. No. 5,171,273 describes the preparation of high-strength collagen fibers by dissolving Type I collagen in dilute hydrochloric acid, extruding the solution into a specific fiber formation buffer to reconstitute the collagen fibers. The reconstituted collagen fibers are subsequently crosslinked with glutaraldehyde or other chemical agents and treatments. The fibers are then processed into woven or non-woven materials. U.S. Pat. No. 5,378,469 describes methods for the production of high strength collagen threads wherein collagen is extruded into a dehydrating agent, e.g., polyethylene glycol, which has a higher osmotic pressure than that of the collagen solution and a pH from about 5 to 10 which results in the formation of collagen threads. If desired, the collagen threads can be crosslinked using various chemical agents. The collagen threads are then utilized to form braided constructs, plied into yarn, and knitted to provide the implant of this invention. Various constructs of the elongate elements, fibers and threads can be formed utilizing well known techniques, e.g., braiding, plying, knitting, weaving, that are applied to processing natural fibers, e.g., cotton, silk, etc., and synthetic fibers made from synthetic bioabsorbable polymers, e.g., poly(glycolide) and poly(lactic acid), nylon, cellulose acetate, etc. See, e.g., Mohamed, American Scienitist, 78: 530-541 (1990). For example, aforementioned U.S. Pat. No. 5,378,469 describes the braiding of crosslinked and noncrosslinked collagen threads using a harness braiding machine (New England Butt Co., Providence, R.I.). Specifically, collagen thread is wound onto cylindrical stainless steel spools. The spools are then mounted onto the braiding carousel, and the collagen thread is then assembled in accordance with the instructions provided with the braiding machine. In one particular run, a braid was formed of four collagen threads, which consisted of two threads of uncrosslinked collagen and two threads of crosslinked collagen. The elongate particles, fibers, and threads can also be plied into yarns using the same methods and same machinery known to those skilled in the art in plying threads made out of other material, e.g., cotton, polyester, etc. For example, aforementioned U.S. Pat. No. 5,378,469 describes the production of a 60 ply yarn from noncrosslinked collagen threads. Therein, 4 collagen threads were twisted together. Three of the resultant 4-ply strands were then twisted together in the opposite direction, and then 5 of the resultant 12 ply strands were twisted in the opposite direction. The elongated elements and/or fibers and/or threads and/or braided threads or plied yarns can then be knitted into tubular or flat fabrics by using techniques known to those skilled in the art of producing fabrics manufactured from other types of threads. Various medically/surgically useful substances as described above can be incorporated in, or associated with, the braided, knitted, or woven materials. The implant can also be fabricated in whole or in part from a synthetic biocompatible bioabsorbable polymer or copolymer, a synthetic biocompatible non-bioabsorbable polymer or copolymer, and combinations thereof. As used herein, “bioabsorbable polymer” refers to a polymer or copolymer which is absorbed by the body. “Non-bioabsorbable polymer” refers to a polymer or copolymer which remain in the body without substantial bioerosion. Examples of synthetic biocompatible bioabsorbable polymers or copolymers include, but are not limited to, poly(lactide), poly(glycolide), poly(epsilon-caprolactone), poly(p-dioxanone), poly(epsilon-caprolactone-co-p-dioxanone) and poly(lactide-co-glycolide) as described, e.g, in U.S. Pat. Nos. 5,705,181 and 5,393,594, each incorporated herein by reference; bioabsorbable block copolymers made of hard phase forming monomers, e.g., glycolide and lactide, and soft phase monomers, e.g., 1,4 dioxane-2-one and caprolactone, as described, e.g., in U.S. Pat. No. 5,522,841, incorporated herein by reference; and natural materials such as cotton, and catgut. Examples of synthetic biocompatible non-bioabsorbable polymers include, but are not limited to, homopolymers and copolymers of polypropylene, polyamides, polyvinylchlorides, polysulfones, polyurethanes, polytetrafluoroethylene, etc. The biocompatible material fabricated from the biocompatible polymer can have incorporated within, or be associated with, osteogenic materials such as demineralized bone particles or demineralized bone powder and medically/surgically useful substances as described above. The implant can also be fabricated in whole or in part from a synthetic biocompatible, optionally bioabsorbable, ceramic or glass, or biocompatible metal. Examples include fibers of phosphate/silica glasses (bioglass), fibers of calcium phosphate, and metal fibers such as titanium or titanium nickel alloys (shape-memory metals). In a particularly useful embodiment, the aforementioned material making up the implant can be wrapped with a monolithic piece, e.g., strips or sheets, fabricated from a suitable material that is remodeled by the body and replaced over time with new bone tissue. For example, the material can be wrapped or surrounded with demineralized bone strips cut from sheets which are composed of elongated bone particles, commercially known as GRAFTON® Flex (Osteotech, Eatontown, N.J.) as described, e.g., in aforementioned U.S. Pat. No. 5,507,813. These demineralized bone strips can be affixed to the biocompatible osteogenic material by any convenient method, e.g., adhering the strips to the material utilizing adhesives, suturing the strips to the biocompatible osteogenic material, braiding the strips around the biocompatible osteogenic material, etc. The implants of this invention can be utilized in a wide variety of orthopedic, neurosurgical and oral and maxillofacial surgical procedures such as the repair of simple and compound fractures and non-unions, external and internal fixations, joint reconstructions such as arthrodesis, general arthroplasty, cup arthroplasty of the hip, femoral and humeral head replacement, femoral head surface replacement and total joint replacement, repairs of the vertebral column including spinal fusion and internal fixation, tumor surgery, e.g. deficit filling, discectomy, laminectomy, excision of spinal cord tumors, anterior cervical and thoracic operations, repair of spinal injuries, scoliosis, lordosis and kyphosis treatments, intermaxillary fixation of fractures, mentoplasty, temporomandibular joint replacement, alveolar ridge augmentation and reconstruction, inlay bone grafts, implant placement and revision, sinus lifts, repair of ligaments or tendons in the hand, elbow, knee, foot, ankle or any other anatomical location, etc. These materials can be sutured or stapled in place for anchoring purposes and serve in guided tissue regeneration or as barrier materials. It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the disclosure herein.

An implant for orthopedic applications includes a quantity of flexible, elongated elements at least some of which possess connective tissue-healing activity, the elongated elements being arranged in substantially common alignment along their longitudinal axis.

This is a continuation of application Ser. No. 07/572,942, filed Sep. 20, 1990, now abandoned. BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to the preparation of 3-alkyl- or fluroalkyl-3-(4-pyridyl) piperidine-2, 6-diones of formula (1): ##STR2## wherein R represents an alkyl group having 2 to 10 carbon atoms or a fluoroalkyl group having 2 to 5 carbon atoms, and A represents hydrogen or an alkyl group having 1 to 4 carbon atoms, many of which are known compounds, useful in anti-cancer therapy, specifically the treatment of oestrogen-dependent breast tumours. 2. DESCRIPTION OF THE PRIOR ART The compound of formula (1) wherein R is ethyl and X is hydrogen is 3-ethyl-3-(4-pyridyl)piperidine-2,6-dione, conveniently called "pyridogluthethimide" for short, and is the subject of UK Pat. No. 2151226 B (NRDC). The same patent also covers derivatives thereof wherin A is alkyl of 1 to 4 carbon atoms. Analogues of pyridogluthethimide in which R is an alkyl group having 3 to 10 carbon atoms or a fluoroalkyl group having 2 to 5 carbon atoms are the subject of UK Pat. No. 2162177 B (NRDC). In UK Pat. No. 2151226 B pyridoglutethimide is prepared by a 3-step process illustrated by Scheme 1 below: ##STR3## This method of preparation suffers from the disadvantage that the starting 4-pyridylacetonitrile is readily dialkylated, leading to a poor yield requiring a separation step. In the final stage of Scheme 1, the reaction can be visualised as proceeding by a mechanism in which the cyano groups are hydrolysed to amido groups and then cyclised to single amido group with elimination of a molecule of ammonia. UK Pat. No. 2151226 B generalises on this reaction scheme as involving the cyclisation of a compound of formula (2): ##STR4## wherein at least one of Y and Z is cyano or amido and the other, if not also cyano or amido, can be a carboxylic acid group or a non-amide derivative thereof such as an ester. The preparation of compounds of formula (2) in which Y and Z are other than cyano is not described. UK Pat. No. 2162177 B describes an improved method of carrying out the first step of Scheme 1, in which 4-pyridylacetronitrile is reacted with a primary alcohol, a trivalent rhodium salt and triphenylphosphine under mildly alkaline conditions. This gives the monoalkylated product, substantially free of dialkylated by-product. Other compounds were made using an alkyl bromide or fluoroalkyl iodide and caesium carbonate in the first step of Scheme 1. However, rhodium and caesium salts are relatively expensive reagents. SUMMARY OF THE INVENTION It has been found that pyridoglutethimide and its analogues can be prepared in good yield without the use of expensive inorganic salts or other esoteric reagents. In the process of the invention, it has been found possible to avoid production of a dialkylated intermediate and to carry out the whole process in only two reaction steps, which, under preferred conditions, can be carried out sequentially in the same reaction vessel. The present invention provides a process for the preparation of 3-alkyl- or fluoroalkyl-3-(4-pyridyl)piperidine-2,6-diones of formula (1): ##STR5## wherein R represents an alkyl group having 2 to 10 carbon atoms or a fluoroalkyl group having 2 to 5 carbon atoms and A represents hydrogen or an alkyl group having 1 to 4 carbon atoms, said process comprising alkylating a 4-pyridylacetic acid alkyl ester, optionally substituted at the 2-position of the pyridine ring by an alkyl group having 1 to 4 carbon atoms, with an alkyl or fluoroalkyl halide of formula RX, X being iodo, bromo or chloro, in the presence of a sterically bulky base of a sodium, potassium or ammonium cation and reacting the product of said alkylation reaction, with acrylamide in the presence of a sodium or potassium branched chain alkoxide, until cyclisation occurs. What is novel and inventive herein comprises: (1) the use of a sterically hindering, bulky, but nevertheless predominantly ionic, type of base in the alkylation reaction, so that excessive dialkylation is avoided, 2) reaction of monoalkylated ester with acrylamide, rather than acrylonitrile and (3) the critical selection of an appropriate base in which to carry out the reaction with acrylamide. (This criticality is explained in more detail below.). DESCRIPTION OF PREFERRED EMBODIMENTS The process of the invention is illustrated by Scheme 2 below, which shows the preparation of pyridoglutethimide using potassium t-butoxide, the preferred base, in both the alkylation and acrylamide reaction steps. ##STR6## Referring to Scheme 2, the starting material shown is ethyl 4-pyridylacetate. This is a compound known in the literature and is obtainable from Lancaster Synthesis Ltd., Morecambe, UK. While the ethyl ester is convenient, any desired alkyl ester can be used, the essential criterion being that the ester group has to be a leaving group in the cyclisation, where it is displaced at the ketonic carbon atom by an amido group. In particular, it can most conveniently be any other alkyl ester in which the alkyl group has 1 to 4 carbon atoms. The first reaction step is the introduction of the angular alkyl or fluoroalkyl group, conveniently referred to herein as "alkylation". (The term "alkylation" is used herein in this context to cover introduction of an alkyl or fluoroalkyl group and the product is correspondingly referred to as "alkylated" regardlesss of whether the substituent introduced is alkyl or fluoroalkyl). Alkylation is normally carried out using the iodide of the alkyl or fluoroalkyl substituent which it is wished to introduce, the iodide being a better leaving group than bromide or chloride. In the alkylation reaction, the objective is to substitute the alpha-carbon atom, marked with an asterik in Scheme 2, by only a single alkyl or fluoroalkyl group: dialkyl or difluoroalkyl substitution is to be avoided, since this produces an unwanted side-product which at one stage or another has to be separated. It is essentially a question of choosing a base which provides just the right amount of proton abstraction at the alpha carbon atom, whereby the region of the alpha carbon atom becomes somewhat electron rich, enabling it to act as a nucleophile for displacement of halide ion from the alkyl halide. A variety of bases work well in this reaction, especially sodium or potassium branched alkoxides and most especially potassium t-butoxide. Quaternary ammonium hydroxides of formula R 1 R 2 R 3 R 4 N + OH - where R 1 to R 4 represent any of a variety of organic radicals can be used. Conveniently R 1 is benzyl and R 2 , R 3 and R 4 , which may be same or different, are straight chain alkyl groups, most conveniently methyl. Benzyltrimethylammonium hydroxide, (commercially available as "Triton B") is particularly preferred. Potassium fluoride, immobilised on alumina, can also be used. The above-defined base is predominantly ionic. Alkyl lithiums, e.g. butyl lithium, can produce dialkylation or reaction with the ester group. Conventional nitrogenous bases such as triethylamine and diazobicyclooctane (DABCO) do not give any reaction. The reaction with the base is normally carried out in a solvent. When an alkoxide is used as the base, an alcohol will usually be the most appropriate solvent; otherwise, a polar, non-protic solvent such as dimethyl sulphoxide or dimethylformamide (DMF) is preferred. Frequently, the reaction can be initiated very easily at room temperature. The reaction temperature is liable to rise rapidly after a short time, since the reaction is exothermic, but this is not harmful if reasonable control is exercised over the rise in temperature. Clearly, an over-vigorous reaction which might lead to dialkylation is best avoided. For this purpose, when scaling up the process, we have found it preferable first to dissolve the base such as potassium t-butoxide in the 4-pyridylacetic ester and then to add the iodide to that solution. The immediate product of the alkylation reaction is an alpha-alkyl-4-pyridylacetic ester. The simpler compounds of this class are known per se. The second step of the process of the invention is the reaction with acrylamide. After considerable experiment, it has been found that this reaction works best with a sodium or potassium branched-chain alkoxide such as potassium t-butoxide, which, coincidentally, is preferred in the alkylation reaction too. In the result it has been further found that is is possible to carry out the alkylation and reaction with acrylamide sequentially in the same reaction vessel, without isolating the intermediate alpha-alkyl-4-pyridylacetic ester. This feature makes the process of the invention particularly attractive for use on an industrial scale. Referring now to the acrylamide reaction, this is in principle a quasi-Michael addition, but is particularly tricky for this reason. It is necessary to maintain the electronegativity of the alpha- carbon atom asterisked in Scheme 2, whereby, the slightly electropositive beta-carbon atom of acrylamide will add successfully to the alpha-alkyl 4-pyridylacetic ester. Unfortunately, there is a tendency of bases to abstract a proton from the alpha-carbon atom of acrylamide, leading to unwanted by-products and a diminution in the yield of the desired piperidine-2,6-dione. Thus, quaternary ammonium hydoxides give low yields, potassium fluoride on alumina also produces a relatively poor yield, as do sodium methoxide or ethoxide. On the other hand, alkyl lithiums again react preferentially with the ester group, metal hydrides produce no product and there is no reaction with organic amine bases. The acrylamide reaction can again be initiaed at room temperature and is again accompanied by an exotherm. Generally, both reactions are conducted at an average temperature within the range -10 to +60° C. The acrylamide reaction with the branched chain alkoxide base is preferably carried out in an alcoholic solvent, the alcohol usually but not necessarily being the same alcohol as that from which the alkoxide is derived. Potassium t-butoxide in t-butanol is preferred. A polar, aprotic solvent such as DMF is particularly useful when the R group is higher than ethyl. While the reaction will usually go to completion fairly easily at room temperature and in an alcoholic solvent, it may on occasion be found to proceed under such conditions only as far as an intermediate, the alpha-amidoethyl-alpha-alkyl-4-pyridylacetic acid alkyl ester of formula (3) below: ##STR7## where R 5 represents an alkyl group (R 5 is not necessarily the same alkyl group as in the starting 4-pyridylacetic ester, since it is liable to become transesterified with the ester of any alcoholic solvent which may be used, e.g. to become a methyl ester if methanol is used as solvent during isolation of the intermediate of formula (3)). In case of difficulty in effecting cyclisation in one step, more severe conditions, for example higher temperature or use of an aprotic solvent such as DMF, should be used in this step. If desired, one can, of course, isolate the intermediate and then change the conditions to complete the reaction. In working up the product, a continuous solvent extraction procedure is preferable and a convenient solvent for that purpose is toluene. In both the alkylation and the acrylamide reactions; the bases are preferably present in a slight excess, e.g. in an equivalent ratio of 1.1:1 with the starting 4-pyridylacetic ester. In the second reaction, the acrylamide is preferably present in a considerable excess with respect to the 4-pyridylacetic ester or its alpha-alkyl intermediate derivative, as the case may be, an excess of between 20 and 100 percent, preferably about 50 percent, reckoned on equivalents, being preferred. The process of the invention is particularly applicable to the preparation of compounds of formula (1) in which R is alkyl of 2 to 8 atoms, most especially to pyridoglutethimide. The following Examples illustrate the invention. Example 6 illustrates the currently most preferred mode of carrying out the process of the invention. EXAMPLE 1 3-Ethyl-3-(4-pyridyl)piperidine-2,6-dione ("pyridoglutethimide") Ethyl 4-pyridylacetate (5.0 g, 30 mmol) and ethyl iodide (2.4 ml, 30 mmol) were stirred in dry t-butanol under argon. The flask was placed in a water bath at 20° C. Potassium t-butoxide (4.02 g, 33 mmol) was added. The reaction was exothermic and in 2 min. the temperature rose to 58° C. and then started to fall. After 40 minutes acrylamide (3.20 g, 45 mmol) was added, follwed by potassium t-butoxide (4.02 g, 33 mmol). There was a small exotherm, the temperature rising from 20 to 32° C. After 30 min. the reaction was worked-up as follows. Water (20 ml) was added, followed by 2 M HCL (18 ml), to give pH 7.0-8.0. Saturated brine (40 ml) was added and the solution was extracted with ethyl acetate (3×80 ml). The combined organic extracts were washed with saturated brine (40 ml), dried over magnesium sulphate and evaporated to give a slightly yellow solid. This solid was recrystallised twice from isopropanol to give white crystals of pyridoglutethimide (3.65 g, 56%), m.p. 134-136° C. (UK Pat. No.s 2151226 B and 2162177 B and Foster et al., J. Med. Chem. 28, 200-204 (1985): 138-139° C.). NMR δ (CDCL 3 ) 0.87 (t, J=7Hz, 3H, Me,CH 2 ), 1.80-2.80 (M, 6H, MeCH 2 , and H-4,4 and H-5,5), 7.15 (m, 2H, H-3 and H-5 of pyridine ring), 8.55 (m, 2H, H-2 and H-6 of pyridine ring, 9.10 (br. s, 1H, NH), in agreement with Foster et al., supra. EXAMPLE 2 This Example shows that the process can be carried out, although with a low yield, using a KF/alumina basic catalyst. Ethyl-4-pyridyl acetate (0.5 g, 3 mmole), ethyl iodide (0.25 ml, 3 mmole), and KF alumina (3.65 g, ca. 15 mmole of KF) were stirred in DMF (10 ml) at room temperature under nitrogen for 2 hours. (The KF/alumina base was prepared by mixing KF with a large excess of alumina in water and evaporating off the water). Diethyl ether was added, and the mixture extracted with water (×20 ml), and the ether layer dried and then concentrated to yield 175 mg of the desired monoethylated product (30% yield). EXAMPLE 3 This example shows that the process can be carried out, although with a low yield, using the quaternary ammonium hydroxide "Triton B". Ethyl-4-pyridyl acetate (0.5 g, 3 mmole), ethyl iodide (0.25 ml, 3 mmole), and "Triton B" (0.5 ml, 40% solution in methanol) were stirred in DMF (10 ml) under nitrogen at room temperature for 1 hour. The reaction mixture was worked-up as before to provide 200 mg of the desired monoethylated product (approx. 35% yield). EXAMPLE 4 (COMPARATIVE) This example shows that use of sodium ethoxide as the strong base gives a mixture of mono- and di- ethylated products. Ethyl-4-pyridyl acetate (0.5 g, 3 mmole) and ethyl iodide (0.25 ml, 3 mmole) were stirred in dry t-butanol under nitrogen at room temperature in the presence of sodium ethoxide (0.25 g, 35 mmole). After 1.5 hour, the reaction was worked up as before to yield a mixture of the monoethylated and diethylated products (ratio 2:1, total yield 45%). EXAMPLE 5 3-Octyl-3-(4-pyridyl)piperidine-2.6-dione Ethyl 4-pyridylacetate (5.00 g, 30 mmol) and n-octyl iodide (7.90 g, 33 mmol) were stirred in dry t-butanol (100 ml) under nitrogen. The flask was placed in a water bath at 20° C. before potassium t-butoxide (4.02 g, 33 mmol) was added. An exothermic reaction was noted. After 40 minutes, acrylamide (3.20 g, 45 mmol) was added, followed by potassium t-butoxide (4.02 g, 33 mmol). Another, smaller, exothermic reaction was noted. After one hour the reaction was worked-up as described in Example 1 to give a yellow oil. This oil was flash-chromatographed on a silica gel column, eluting with diethyl ether:petrol (19:1 v/v) to remove any unreacted ethyl 4-pyridylacetate and octyl iodide. The uncyclised product was removed from the column by elution with pure (AnalaR) methanol, thereby forming the methylester derivative at the same time. This was concentrated, taken up in dry DMF (50 ml) and potassium t-butoxide (4.02 g, 33 mmol) added. The reaction mixture was stirred overnight at room temperature, before acidification to pH 5-6 with 2 M HCl. After a further two hours stirring, the mixture was worked-up. Water (40 ml) was added, before extraction into ethyl acetate (3×50 ml). Drying over magnesium sulphate and concentration gave a gummy yellow oil (6.20 g, 68%). This was crystallised from pentane giving a white solid, m.p. 58° C. (Leung et al., J. Med. Chem. 30, 1550-1554 (1987): 60-62° C.). NMR δ (CDCL 3 ) 0.87 (t, J=7Hz, 3H, MeCH 2- ), 1.24 (s, 12H, Me(CH 2 ) 6- ), 1.8--2.1 (m, 2H, CH 2- C-), 2,3--2.80 (m, 4H, H-4,4 and H-5,5), 7.26 (m, 2H, H-3and H-5 of pyridine ring), 8.64 (m, 2H, H-2 and H-6 of pyridine ring), 9.37 (br. s, 1H, NH). EXAMPLE 6 3-Ethly-3-(4-pyridyl)piperidine-2,6-dione("pyridoglutethimide") Ethyl 4-pyridyl acetate (100 g., 0.6 mole) was dissolved in tert-butanol (1000 ml). Potassium tert-butoxide (80 g. 0.66 mole) was added portionwise to the stirred solution. The solution became yellow and there was a rise in temperature of a few degrees. Once the potassium tert-butoxide was fully dissolved, ethyl iodide (48 ml, 0.6 mole) was added dropwise. The temperature rose to about 45° C., and the mixture was stirred over a period of 1.5 hours, during which the temperature returned to room temperature. Acrylamide (64 g., 0.9 mole) was then added together with a further 500 ml of tert-butanol. This was followed by potassium tert-butoxide (80 g. 0.66 mole), and there was a slight rise in temperature. The reaction mixture was stirred for a period of 2.5 hours. Water (400 ml) was added to the reaction mixture and it was then neutralised to (pH 7-8) with 4N HCl. The total mixture was now continuously extracted with hot toluene overnight (20 hours), and the toluene extract reduced in volume to induce crystallisation. The crude product weighed 80 g, and after one recrystallisation from isopropanol yielded 61 g. (ca. 46%) of pure pyridoglutethimide.

3-Alkyl- or fluoroalkyl-3-(4-pyridyl)piperidine-2,6-diones, useful in the treatment of breast cancer, of formula ##STR1## wherein R represents an alkyl group having 2 to 10 carbon atoms or a fluoroalkyl group having 2 to 5 carbon atoms and A is hydrogen or an alkyl group having 1 to 4 carbon atoms, are prepared by reacting a 4-pyridylacetate with an alkyl or fluoroalkyl iodide, chloride or bromide, in the presence of a sterically bulky base and reacting the product with acrylamide in the presence of a sodium or potassium branched chain alkoxide. Preferably potassium t-butoxide is used in both stages and they are carried out sequentially at room temperature in an alcoholic or polar, aprotic solvent in a single reaction vessel.

CLAIM OF PRIORITY [0001] The present application claims priority under 35 U.S.C. §119 to Provisional U.S. Patent Application Ser. No. 62/324,847, filed Apr. 19, 2016, entitled, “Systems and Methods for Optimizing Content Creation on a Mobile Platform Using Mobile Multi-Timeline-Optimized Editing,” to inventors Ethan Montoya et al. The contents of Provisional U.S. Patent Application Ser. No. 62/324,847 are hereby incorporated by reference as if set forth fully herein. TECHNICAL FIELD [0002] The technical field relates to content creation and editing on mobile devices and/or platforms, and more particularly to content creation and editing techniques optimized for mobile devices and/or platforms. BACKGROUND [0003] Mobile devices often allow people to capture video or access stored videos. Though many mobile devices provide video editing capabilities, video editing applications are often not optimized for mobile platforms. Mobile publishing platforms typically lack an embedded, sophisticated video editor. Users of these platforms are typically forced to either cope with poor quality or to go to laptops, desktops, etc. to edit and publish videos. Additionally, many standalone video editing applications were not made to fit within the natural creative processes of video editors. Video logging (“vlogging”) and/or voiceover narration are often implemented awkwardly or inefficiently on mobile platforms. It would be desirable to optimize video editing for mobile platforms. Doing so may help users share and/or publish creative content generated on mobile devices with friends, social connections, and/or the general public. The introduction of advanced video editing tools for mobile will lead to the creation of longer user-generated videos. Watching longer user-generated videos on their phones represents a behavioral change for viewers, and it will create the need for additional viewer interest content to keep them engaged. SUMMARY [0004] An embedded editing system allows mobile video capture, editing, and sharing/publishing. The systems and methods disclosed herein may facilitate mobile multi-track timeline video editing. The systems and methods disclosed herein may allow for easy creation of picture-in-picture videos and/or other forms of video and/or other forms of creative or expressive content, particularly content captured from mobile devices. Additionally, video logging (“vlogging”) in public is highly awkward for many people. In various implementations, a multiple-timeline editing system enables video creators to add narration after they have filmed a video, which avoids the need to narrate vlogs in public. Additionally, vlogging in public previously led to poor audio quality due to environmental and other sources of noise. In some implementations, a multiple-timeline editing system enables creators to control the volume of their narration. Voiceover narration, previously the only solution for adding voice narration on a mobile device, is a technically inferior solution to various implementations, which allow for multi-track timeline video editing because voiceover narration requires exact timing alignment and it does not enable the display of users' faces in video. The systems and methods discussed herein provide technical solutions of allowing people to interact with digital video; feedback interactions captured at a viewer device may be used as the basis of viewer interest content provided to a user capturing and publishing video content and/or to third parties. The feedback interactions may visually represent content-level feedback against interactive portions of video content. [0005] A technical problem was that these functions were previously not possible on mobile platforms. A technical solution includes creating various functionalities to be available on a mobile platform. Additional technical solutions relate to the ability to proliferate video editing capabilities on mobile platforms. [0006] These and other advantages will become apparent to those skilled in the relevant art upon a reading of the following descriptions and a study of the several examples of the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 shows an example of a mobile multi-track timeline optimized editing system, according to some implementations. [0008] FIG. 2 shows an example of a flowchart of a method for accessing mobile multi-track timeline optimized editing processes on a mobile device, according to some implementations. [0009] FIG. 3 shows an example of a flowchart of a method for performing a single-track editing process on a mobile device, according to some implementations. [0010] FIG. 4 shows an example of a flowchart of a method for performing a multi-track editing process on a mobile device, according to some implementations. [0011] FIG. 5 shows an example of a flowchart of a method for performing voiceover recording over a video on a mobile device, according to some implementations. [0012] FIG. 6 shows an example of a flowchart of a method for sharing/publishing content created on a mobile device, according to some implementations. [0013] FIG. 7 shows an example of screen captures taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. [0014] FIG. 8A shows an example of screen captures taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. [0015] FIG. 8B shows an example of screen captures taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. [0016] FIG. 9 shows an example of screen captures taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. [0017] FIG. 10 shows an example of a computer system, according to some implementations. [0018] FIG. 11 shows an example of a screen capture taken on a mobile device having an application implementing touch feedback design, according to some implementations. [0019] FIG. 12 shows an example of a flowchart of a method for performing a touch feedback video editing process on a mobile device, according to some implementations. [0020] FIG. 13 shows an example of a flowchart of a method for performing a re-editable mobile video system process on a mobile device, according to some implementations. [0021] FIG. 14 shows an example of a flowchart of a method for performing a proxy editing process on a mobile device, according to some implementations. [0022] FIG. 15 shows an example of a flowchart of a method for displaying viewer interest content for video content, according to some implementations. DETAILED DESCRIPTION [0023] FIG. 1 shows an example of a mobile multi-track timeline optimized editing system 100 , according to some implementations. The mobile multi-track timeline optimized editing system 100 may include a computer network 102 , a mobile video editing system 104 , a video editing management system 106 , a video sharing/publication system 108 , a social media system 110 , and video interaction system(s) 112 . In the example of FIG. 1 , the computer network 102 is shown coupled to the mobile video editing system 104 , the video editing management system 106 , the video sharing/publication system 108 , the social media system 110 , and the video interaction system(s) 112 . It is noted that this coupling, and any coupling referenced herein is shown by way of example only, and that various implementations may include more, less, or different couplings than explicitly shown. [0024] The computer network 102 and other computer readable mediums discussed in this paper are intended to represent a variety of potentially applicable technologies. For example, the computer network 102 can be used to form a network or part of a network. Where two components are co-located on a device, the computer network 102 can include a bus or other data conduit or plane. Where a first component is co-located on one device and a second component is located on a different device, the computer network 102 can include a wireless or wired back-end network or LAN. The computer network 102 can also encompass a relevant portion of a WAN or other network, if applicable. [0025] The computer network 102 , the mobile video editing system 104 , the video editing management system 106 , the video sharing/publication system 108 , social media system 110 , and the video interaction system(s) 112 , and other applicable systems or devices described in this paper can be implemented as a computer system or parts of a computer system or a plurality of computer systems. A computer system, as used in this paper, is intended to be construed broadly. In general, a computer system will include a processor, memory, non-volatile storage, and an interface. A typical computer system will usually include at least a processor, memory, and a device (e.g., a bus) coupling the memory to the processor. The processor can be, for example, a general-purpose central processing unit (CPU), such as a microprocessor, or a special-purpose processor, such as a microcontroller. [0026] The memory can include, by way of example but not limitation, random access memory (RAM), such as dynamic RAM (DRAM) and static RAM (SRAM). The memory can be local, remote, or distributed. The bus can also couple the processor to non-volatile storage. The non-volatile storage is often a magnetic floppy or hard disk, a magnetic-optical disk, an optical disk, a read-only memory (ROM), such as a CD-ROM, EPROM, or EEPROM, a magnetic or optical card, or another form of storage for large amounts of data. Some of this data is often written, by a direct memory access process, into memory during execution of software on the computer system. The non-volatile storage can be local, remote, or distributed. The non-volatile storage is optional because systems can be created with all applicable data available in memory. [0027] Software is typically stored in the non-volatile storage. Indeed, for large programs, it may not even be possible to store the entire program in the memory. Nevertheless, it should be understood that for software to run, if necessary, it is moved to a computer-readable location appropriate for processing, and for illustrative purposes, that location is referred to as the memory in this paper. Even when software is moved to the memory for execution, the processor will typically make use of hardware registers to store values associated with the software, and local cache that, ideally, serves to speed up execution. As used herein, a software program is assumed to be stored at an applicable known or convenient location (from non-volatile storage to hardware registers) when the software program is referred to as “implemented in a computer-readable storage medium.” A processor is considered to be “configured to execute a program” when at least one value associated with the program is stored in a register readable by the processor. [0028] In one example of operation, a computer system can be controlled by operating system software, which is a software program that includes a file management system, such as a disk operating system. One example of operating system software with associated file management system software is the family of operating systems known as Windows® from Microsoft Corporation of Redmond, Wash., and their associated file management systems. Another example of operating system software with its associated file management system software is the Linux operating system and its associated file management system. The file management system is typically stored in the non-volatile storage and causes the processor to execute the various acts required by the operating system to input and output data and to store data in the memory, including storing files on the non-volatile storage. [0029] The bus can also couple the processor to the interface. The interface can include one or more input and/or output (I/O) devices. Depending upon implementation-specific or other considerations, the I/O devices can include, by way of example but not limitation, a keyboard, a mouse or other pointing device, disk drives, printers, a scanner, and other I/O devices, including a display device. The display device can include, by way of example but not limitation, a cathode ray tube (CRT), liquid crystal display (LCD), or some other applicable known or convenient display device. The interface can include one or more of a modem or network interface. It will be appreciated that a modem or network interface can be considered to be part of the computer system. The interface can include an analog modem, ISDN modem, cable modem, token ring interface, satellite transmission interface (e.g. “direct PC”), or other interfaces for coupling a computer system to other computer systems. Interfaces enable computer systems and other devices to be coupled together in a network. [0030] The computer systems can be compatible with or implemented as part of or through a cloud-based computing system. As used in this paper, a cloud-based computing system is a system that provides virtualized computing resources, software and/or information to end user devices. The computing resources, software and/or information can be virtualized by maintaining centralized services and resources that the edge devices can access over a communication interface, such as a network. “Cloud” may be a marketing term and for the purposes of this paper can include any of the networks described herein. The cloud-based computing system can involve a subscription for services or use a utility pricing model. Users can access the protocols of the cloud-based computing system through a web browser or other container application located on their end user device. [0031] A computer system can be implemented as an engine, as part of an engine or through multiple engines. As used in this paper, an engine includes one or more processors or a portion thereof. A portion of one or more processors can include some portion of hardware less than all of the hardware comprising any given one or more processors, such as a subset of registers, the portion of the processor dedicated to one or more threads of a multi-threaded processor, a time slice during which the processor is wholly or partially dedicated to carrying out part of the engine's functionality, or the like. As such, a first engine and a second engine can have one or more dedicated processors or a first engine and a second engine can share one or more processors with one another or other engines. Depending upon implementation-specific or other considerations, an engine can be centralized or its functionality distributed. An engine can include hardware, firmware, or software embodied in a computer-readable medium for execution by the processor. The processor transforms data into new data using implemented data structures and methods, such as is described with reference to the FIGS. in this paper. [0032] The engines described in this paper, or the engines through which the systems and devices described in this paper can be implemented, can be cloud-based engines. As used in this paper, a cloud-based engine is an engine that can run applications and/or functionalities using a cloud-based computing system. All or portions of the applications and/or functionalities can be distributed across multiple computing devices, and need not be restricted to only one computing device. In some embodiments, the cloud-based engines can execute functionalities and/or modules that end users access through a web browser or container application without having the functionalities and/or modules installed locally on the end-users' computing devices. [0033] As used in this paper, datastores are intended to include repositories having any applicable organization of data, including tables, comma-separated values (CSV) files, traditional databases (e.g., SQL), or other applicable known or convenient organizational formats. Datastores can be implemented, for example, as software embodied in a physical computer-readable medium on a specific-purpose machine, in firmware, in hardware, in a combination thereof, or in an applicable known or convenient device or system. Datastore-associated components, such as database interfaces, can be considered “part of” a datastore, part of some other system component, or a combination thereof, though the physical location and other characteristics of datastore-associated components is not critical for an understanding of the techniques described in this paper. [0034] Datastores can include data structures. As used in this paper, a data structure is associated with a particular way of storing and organizing data in a computer so that it can be used efficiently within a given context. Data structures are generally based on the ability of a computer to fetch and store data at any place in its memory, specified by an address, a bit string that can be itself stored in memory and manipulated by the program. Thus, some data structures are based on computing the addresses of data items with arithmetic operations; while other data structures are based on storing addresses of data items within the structure itself. Many data structures use both principles, sometimes combined in non-trivial ways. The implementation of a data structure usually entails writing a set of procedures that create and manipulate instances of that structure. The datastores, described in this paper, can be cloud-based datastores. A cloud-based datastore is a datastore that is compatible with cloud-based computing systems and engines. [0035] The mobile video editing system 104 may include any digital device. In some implementations, the mobile video editing system 104 may comprise a mobile phone, a tablet computing device, or an Internet of Things (IoT) device. In an implementation, the mobile video editing system 104 is configured to implement mobile multi-track timeline optimized editing processes. The mobile video editing system 104 may include a network access engine 114 , a user interface engine 116 , a video gathering engine 118 , a video editing engine 120 , a video sharing/publication engine 122 , and a video datastore 124 . [0036] The network access engine 114 may facilitate access to the computer network 102 . The user interface engine 116 may support a user interface for a user of the mobile video editing system 104 . The video gathering engine 118 may facilitate gathering captured or stored video (e.g., live captured video captured from a camera of the mobile video editing system 104 or stored video stored on storage of the mobile video editing system 104 ). [0037] The video editing engine 120 may support a video editing application on the mobile video editing system 104 . In an implementation, the video editing application comprises a mobile application. The video editing application may comprise an embedded application. The video editing engine 120 may include an edit access engine 126 , a single-track edit engine 128 , a multi-track edit engine 130 , a voiceover management engine 132 , a video sharing/publication interface engine 134 , a touch feedback engine 136 , a re-editable mobile video engine 138 , and a proxy editing engine 140 . [0038] The edit access engine 126 may allow access to editing. In an implementation, the edit access engine 126 may access one or more processors of the mobile video editing system 104 and may access memory on the mobile video editing system 104 configured to instruct the one or more processors to perform the computer-implemented shown in FIG. 2 . [0039] The single-track edit engine 128 may facilitate single-track editing processes. In an implementation, the single-track edit engine 128 may access one or more processors of the mobile video editing system 104 and may access memory on the mobile video editing system 104 configured to instruct the one or more processors to perform the computer-implemented method shown in FIG. 3 . [0040] The multi-track edit engine 130 may facilitate multi-track editing processes. In an implementation, the multi-track edit engine 130 may access one or more processors of the mobile video editing system 104 and may access memory on the mobile video editing system 104 configured to instruct the one or more processors to perform the computer-implemented method shown in FIG. 4 . [0041] The voiceover management engine 132 may facilitate voiceover processes. In an implementation, the voiceover management engine 132 may access one or more processors of the mobile video editing system 104 and may access memory on the mobile video editing system 104 configured to instruct the one or more processors to perform the computer-implemented method shown in FIG. 5 . [0042] The video sharing/publication interface engine 134 may facilitate content sharing and/or publication. In an implementation, the video sharing/publication interface engine 134 may access one or more processors of the mobile video editing system 104 and may access memory on the mobile video editing system 104 configured to instruct the one or more processors to perform the computer-implemented method shown in FIG. 6 . [0043] The touch feedback engine 136 may facilitate touch feedback. The touch feedback features referenced herein may be shown further in FIG. 11 . The touch feedback engine 136 may operate to allow viewers to interact with the screen while watching a video. Interactions from all viewers may be captured along with the time in the video at which they occurred. Examples of interactions are: like, dislike, mood, tagging of people, content, or semantic meaning, presence of copyrighted content. Interactions from all users may be combined and displayed as a visual “interest graph” which informs viewers on the most compelling portions of time in the video. In some implementations, viewers, especially teenagers, may have a limited attention span for videos longer than 6 seconds. A visual “interest graph” may let users know what's coming ahead in the video, so they relax or skip ahead. Viewers can be bored during longer videos, so giving them something to touch/play with during the video makes their overall experience more entertaining. This may give viewers a participatory role in a content community is important, because they often feel left out if they are not video creators. The touch feedback engine 136 may advantageously allow content creators to make longer videos on mobile because viewers will now watch them. The touch feedback engine 136 may support higher engagement for viewers. The touch feedback engine 136 may implement the computer-implemented method shown in FIG. 12 . [0044] The re-editable mobile video engine 138 may facilitate re-editable mobile video. The re-editable mobile video engine 138 may operate to solve the problem that users often want to re-edit videos after publishing but are unable to do so without deleting and re-publishing the video. That is, users often delete the component footage from published videos, so they are unable to edit the component parts. Further, users often want to use a portion of a previous video in a new video, but not the whole video. These situations require a lot of work for a user to manually deconstruct a video into its component parts, and it would be impossible for most editing operations beyond splitting the clip into smaller pieces. Additionally, for creators, the video feels final. This inhibits creativity, and makes it less likely that people will create video versus text. The re-editable mobile video engine 138 may allow users to experiment with content, and encourages them to edit it later and/or recycle content. The re-editable mobile video engine 138 may provide re-editable mobile video services. More specifically, in some implementations, the second user may edit a video using a video editing application supported by the mobile video editing system 104 . The video editing application may save editing meta-data when the first user creates the video in its editor. Users (e.g., the second user) can download the video from the mobile video editing system 104 after they have published the video. The mobile video editing system 104 may re-create the video's component parts for re-editing in its editor. The re-editable mobile video engine 138 may implement the computer-implemented method shown in FIG. 13 . [0045] The proxy editing engine 140 may facilitate proxy video editing. The proxy editing engine 140 may operate to provide remote-controlled/“proxy” editing services. For instance, a user may have video footage, perhaps at high resolution or a large archive of footage. This footage may be too big or there is too much of it to effectively store on a video interaction system 112 of the user. The footage may be uploaded to the mobile video editing system 104 , either from the video interaction system 112 itself or from another device (desktop computer, network-attached storage, another server) attached to the video interaction system 112 . The mobile video editing system 104 may prepare low resolution “proxies” of the videos that have been uploaded. These proxies may be downloaded to the video interaction system 112 . The user may edit the proxy representations of the clips, editing, trimming and combining them. The video interaction system 112 may transmit a stream of these changes back to the mobile video editing system 104 and the changes may be performed there on the full-resolution footage. In this way the user may be able to edit footage too large to process on a mobile device using a familiar mobile video editing interface. Advantages include the ability to edit footage that would not otherwise fit on phones. Users can use intuitive editor software to edit footage that would conventionally require a trained operator and a sophisticated desktop editing suite. The proxy editing engine 140 may implement the computer-implemented method shown in FIG. 14 . [0046] The video editing management system 106 may include one or more engines and/or datastores to support the video editing engine. The video editing management system 106 may support the edit access engine 126 , the single-track edit engine 128 , the multi-track edit engine 130 , the voiceover management engine 132 , and/or the video sharing/publication interface engine 134 . The video sharing/publication system 108 may facilitate sharing or publication of content created on the mobile video editing system 104 . The video sharing/publication system 108 may, more particularly, support the video sharing/publication engine 122 . The social media system 110 may support social media and/or social networking. In various implementations, the social media system 110 supports a social media and/or a social networking application on the mobile video editing system 104 . The video interaction system(s) 112 may include one or more digital devices configured to view content created on the mobile video editing system 104 . The video interaction system(s) 112 may include a first video interaction system 112 - 1 through an Nth video interaction system 112 -N. The video interaction system(s) 112 may include one or more of a mobile phone, a tablet computing device, an IoT device, a laptop computer, and a desktop computer. [0047] FIG. 2 shows an example of a flowchart of a method 200 for accessing mobile multi-track timeline optimized editing processes on a mobile device, according to some implementations. The method 200 may be managed, performed, etc. by the edit access engine 126 . It is noted the operations in the method 200 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0048] At an operation 202 , video footage may be captured. At an operation 204 , footage may be saved. At an operation 206 , the clip may be automatically appended to the end of a timeline. At an operation 208 , the application may import all footage from the user's phone. At an operation 210 , the application may display a list of clips to the user. At an operation 212 , the user may drag a clip from the tray into the timeline. At an operation 214 , the user may have a timeline with the clips. At an operation 216 , the timeline may be drawn to scale. [0049] FIG. 3 shows an example of a flowchart of a method 300 for performing a single-track editing process on a mobile device, according to some implementations. The method 300 may be managed, performed, etc. by the single-track edit engine 128 . It is noted the operations in the method 300 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0050] At an operation 302 , the user may have a timeline with clips. At an operation 304 , the timeline may be drawn to scale. At an operation 306 , a clip may be moved from one position to another. At an operation 308 , a clip may be duplicated. At an operation 310 , a clip may be removed. At an operation 312 , a clip may be trimmed. At an operation 314 , a clip may be zoomed. At an operation 316 , a clip may be cropped. At an operation 318 , the composition may be played. At an operation 320 , the composition may be paused. At an operation 324 , the seek needle may be moved. At an operation 326 , the player may seek to a new time. [0051] FIG. 4 shows an example of a flowchart of a method 400 for performing a multi-track editing process on a mobile device, according to some implementations. The method 400 may be managed, performed, etc. by the multi-track edit engine 130 . It is noted the operations in the method 400 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0052] At an operation 402 , a user may have a timeline with clips. At an operation 404 , all tracks of the timeline may be drawn with a common timescale. At an operation 406 , the composition may be played. At an operation 408 , the seek needle may be removed. At an operation 410 , the current player time may be incremented. At a decision point 412 , it is determined if there is a clip at the current player time in both tracks. At a decision point 414 , it is determined whether picture-in-picture is enabled. At an operation 416 , picture-in-picture is drawn. At an operation 418 , the highest-priority track only is drawn. At an operation 420 , the active clip only is drawn. At an operation 422 , the picture-in-picture is turned on/off. At an operation 424 , the picture-in-picture is dragged to move. At an operation 426 , the picture-in-picture is pinched to resize. At an operation 428 , the picture-in-picture is tapped to change shape. At an operation 430 , playback is paused. [0053] FIG. 5 shows an example of a flowchart of a method 500 for performing voiceover recording over a video on a mobile device, according to some implementations. The method 500 may be managed, performed, etc. by the voiceover management engine 132 . It is noted the operations in the method 500 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0054] At an operation 502 , the user may have a timeline with clips. At an operation 504 , all tracks of the timeline are drawn with a common timescale. At an operation 506 , the seek needle may be moved. At an operation 508 , the system is ready to record. At an operation 510 , the record button may be pressed. At an operation 512 , the recording needle may start at the needle position. At an operation 514 , the playback may start at the needle position. At an operation 516 , the record button may be pressed to stop recording. At an operation 518 , the newly-recorded clip may be inserted into the composition. At an operation 520 , the playback may start at the beginning of the newly recorded clip. At an operation 522 , the user may press delete. At an operation 524 , the user may press accept. At an operation 526 , the playback may reach the end of the newly recorded clip. At an operation 528 , the newly-recorded may be deleted from the composition. [0055] FIG. 6 shows an example of a flowchart of a method 600 for sharing/publishing content created on a mobile device, according to some implementations. The method 600 may be managed, performed, etc. by the voiceover management engine 132 . It is noted the operations in the method 600 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0056] At an operation 602 , the user may have a timeline with clips. At an operation 604 , the user may press a “share” button in an application. At an operation 606 , the user may enter a descriptive tagline. At an operation 608 , the user may choose a social network to share. At an operation 610 , the video may be post-processed and saved to a file on the user's device. At an operation 612 , the user may manually share the video to a social network. At an operation 614 , the video may be uploaded to a server. At an operation 616 , the server may automatically share the video to a social network selected by the user. At operation 618 , 620 , and 622 , the video is shared to social networks A, B, and C. At an operation 624 , viewers access the video on social networks A, B, and C. [0057] FIG. 7 shows an example of screen captures 700 taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. The screen captures 700 may include a first screen capture 702 of a system home and central navigation. The first screen capture 702 may include user interface elements for scrolling a feed of user videos, discovering talent and videos, accessing the editor and/or the camera, receiving system notifications and/or alerts, and accessing a user profile. A second screen capture 704 may show the camera/editor and may include user interface elements for accessing publishing tools, for turning the camera on or off, for turning multi-track timeline capture on or off, and for allowing timeline playback/review. A third screen capture 706 may show save or publish options including options to share, save, save drafts, open drafts, clear timelines, a tutorial and cancel. A fourth screen capture 708 may show publishing/sharing options on, e.g., various social networks. [0058] FIG. 8A and FIG. 8B show examples of screen captures 800 A and 800 B taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. A first screen capture 802 may show how recording clips adds them directly to a timeline. A second screen capture 804 may show how sliding up a timeline may expose clips in the camera roll. A third screen capture 806 may show how dragging clips from the camera roll can place the clips in the timeline. A fourth screen capture 808 may show how dropping clips in the timeline may activate preview. A fifth screen capture 810 may show how dragging and dropping multiple clips into a timeline may occur. A sixth screen capture 812 may show how long-pressing a clip in a timeline may re-arrange, duplicate, or remove the clip. A seventh screen capture 814 may show how double tapping a clip on the timeline may enable trimming of the clip. [0059] FIG. 9 shows an example of screen captures 900 taken on a mobile device having an application implementing mobile multi-track timeline optimized editing processes, according to some implementations. A first screen capture 902 may show how to record video for a second timeline to create a picture-in-picture video. A second screen capture 904 may show options to accept or reject the recording. A third screen capture 906 may show options to transform the video-in-picture into different shapes and sizes. A fourth screen capture 908 may show options to double tap a clip from a second timeline to adjust the audio between the two tracks. A fifth screen capture 910 may show options to move/drag clips along each timeline to create transitions between the two timelines. FIG. 10 shows an example of a computer system 1000 . In the example of FIG. 10 , the digital device 1000 can be a conventional computer system that can be used as a client computer system, such as a wireless client or a workstation, or a server computer system. The digital device 1000 includes a computer 1005 , I/O devices 1010 , and a display device 1015 . The computer 1005 includes a processor 1020 , a communications interface 1025 , memory 1030 , display controller 1035 , non-volatile storage 1040 , and I/O controller 1045 . The computer 1005 can be coupled to or include the I/O devices 1010 and display device 1015 . [0060] The computer 1005 interfaces to external systems through the communications interface 1025 , which can include a modem or network interface. It will be appreciated that the communications interface 1025 can be considered to be part of the digital device 1000 or a part of the computer 1005 . The communications interface 1025 can be an analog modem, ISDN modem, cable modem, token ring interface, satellite transmission interface (e.g. “direct PC”), or other interfaces for coupling a computer system to other computer systems. [0061] The processor 1020 can be, for example, a conventional microprocessor such as an Intel Pentium microprocessor or Motorola power PC microprocessor. The memory 1030 is coupled to the processor 1020 by a bus 1050 . The memory 1030 can be Dynamic Random Access Memory (DRAM) and can also include Static RAM (SRAM). The bus 1050 couples the processor 1020 to the memory 1030 , also to the non-volatile storage 1040 , to the display controller 1035 , and to the I/O controller 1045 . [0062] The I/O devices 1010 can include a keyboard, disk drives, printers, a scanner, and other input and output devices, including a mouse or other pointing device. The display controller 1035 can control in the conventional manner a display on the display device 1015 , which can be, for example, a cathode ray tube (CRT) or liquid crystal display (LCD). The display controller 1035 and the I/O controller 1045 can be implemented with conventional well known technology. [0063] The non-volatile storage 1040 is often a magnetic hard disk, an optical disk, or another form of storage for large amounts of data. Some of this data is often written, by a direct memory access process, into memory 1030 during execution of software in the computer 1005 . One of skill in the art will immediately recognize that the terms “machine-readable medium” or “computer-readable medium” includes any type of storage device that is accessible by the processor 1020 and also encompasses a carrier wave that encodes a data signal. [0064] The digital device 1000 is one example of many possible computer systems which have different architectures. For example, personal computers based on an Intel microprocessor often have multiple buses, one of which can be an I/O bus for the peripherals and one that directly connects the processor 1020 and the memory 1030 (often referred to as a memory bus). The buses are connected together through bridge components that perform any necessary translation due to differing bus protocols. [0065] Network computers are another type of computer system that can be used in conjunction with the teachings provided herein. Network computers do not usually include a hard disk or other mass storage, and the executable programs are loaded from a network connection into the memory 1030 for execution by the processor 1020 . A Web TV system, which is known in the art, is also considered to be a computer system, but it can lack some of the features shown in FIG. 10 , such as certain input or output devices. A typical computer system will usually include at least a processor, memory, and a bus coupling the memory to the processor. [0066] FIG. 11 shows an example of a screen capture 1100 taken on a mobile device having an application implementing touch feedback design, according to some implementations. The black space at the top is for a video. The red dots under the video indicate clusters of positive feedback (green dots) and clusters of negative feedback (red dots) from the community of viewers. This graph has units of time in the horizontal axis, and units of magnitude indicated by the size of the dots. However this is just an example, any units of measure to indicate interest and relevancy to a portion of the video could be used. The red and green faces at the bottom are touch feedback triggers. Our current designs would feature invisible touch triggers over a full screen video. [0067] FIG. 12 shows an example of a flowchart of a method 1200 for performing a touch feedback video editing process on a mobile device, according to some implementations. In some implementations, the method 1200 may be performed by instructions provided by the touch feedback engine 136 . The method 1200 may include a first method 1210 executed on a first mobile device and a second method 1250 executed on a second mobile device. Each of the first mobile device and the second mobile device may correspond to a video interaction system 112 , as noted herein. [0068] At an operation 1212 , a first user may be watching a video. At an operation 1214 , the first user may see something in the video that they want to provide feedback to. At an operation 1216 , the first user may press a feedback mechanism. At an operation 1218 , the first user's feedback may be sent to the mobile video editing system 104 . At an operation 1220 , the mobile video editing system 104 may perform processing to update an aggregate snapshot (e.g., a visual feedback representation) of the received feedback. [0069] At an operation 1252 , the second user may connect to the mobile video editing system 104 . At an operation 1254 , the second user may download the aggregate snapshot of the received feedback. At an operation 1256 , the second mobile device may display the feedback snapshot visually to the second user (e.g., as a visual interest graph). At an operation 1258 , the second user may begin watching the video. At an operation 1260 , the second player may advance time in the video. At an operation 1262 , the application in the second user device may display time-specific portions of the aggregated snapshot of the received feedback to the second user. [0070] FIG. 13 shows an example of a flowchart of a method 1300 for performing a re-editable mobile video system process on a mobile device, according to some implementations. In some implementations, the method 1300 may be performed by instructions provided by the re-editable mobile video engine 138 . The method 1300 may include a first method 1310 executed on a first mobile device and a second method 1350 executed on a second mobile device. Each of the first mobile device and the second mobile device may correspond to a video interaction system 112 , as noted herein. [0071] At an operation 1312 , a first user may create an edited video work. At an operation 1314 , the video may be post-processed and saved to a file on the first user device. At an operation 1316 , the video visual data may be uploaded to the mobile video editing system 104 . At an operation 1318 , the application on the first mobile device may generate a metadata package describing the editing steps that produced the video. At an operation 1320 , the metadata may be uploaded to the mobile video editing system 104 . [0072] At an operation 1352 , the second mobile device may connect to the mobile video editing system 104 . At an operation 1354 , the second mobile device may download the video visual data. At an operation 1356 , the second mobile device may download the metadata package. At an operation 1358 , an application on the second mobile device may read the metadata and use it to reconfigure an editor. At an operation 1360 , the second mobile device may now have an approximation of the state of the editor when the first mobile device published the video. At an operation 1362 , the second user on the second mobile device may make further edits, creating a derivative work that is based on the edited video from the first user on the first mobile device. [0073] FIG. 14 shows an example of a flowchart of a method 1400 for performing a proxy editing process on a mobile device, according to some implementations. In some implementations, the method 1400 may be performed by instructions provided by the proxy editing engine 140 . [0074] At an operation 1402 , a user has a large library of videos. At an operation 1404 , the user transfers the videos to the video datastore 124 of the mobile video editing system 104 . At an operation 1406 , the proxy editing engine 140 generates small, fast proxies of the videos. At an operation 1408 , a user of a video interaction system 112 may connect to the mobile video editing system 104 with a lightweight client (e.g., an application, a website, etc.). At an operation 1410 , the mobile video editing system 104 may transfer the proxies to the video interaction system 112 . [0075] At an operation 1412 , the video interaction system 112 may receive some of the proxies from the mobile video editing system 104 . At an operation 1414 , the video interaction system 112 may display the proxies in the editor. At an operation 1416 , the user of the video interaction system 112 may perform an editing operation. At an operation 1418 , the editor may update to show the result of the edit operation. At an operation 1420 , the video interaction system 112 may transmit (operation 1422 ) the edit operation to the mobile video editing system 104 . At an operation 1424 , the proxy editing engine 140 may keep an internal representation of the in-progress video. At an operation 1426 , the proxy editing engine 140 may receive the edit operation. At an operation 1428 , the proxy editing engine 140 may update the in-progress video to reflect the edit operation. At an operation 1430 , the user of the video interaction system 112 may finish editing. At an operation 1432 , the user may send a command to post-process the video to the proxy editing engine 140 . At an operation 1434 , the proxy editing engine 140 may receive the command to post-process the video. At an operation 1436 , the proxy editing engine 140 may post-process the original video footage to create the final product. [0076] FIG. 15 shows an example of a flowchart of a method 1500 for displaying viewer interest content for video content, according to some implementations. The method 1500 may be executed by the touch feedback engine 136 and/or other modules of the mobile video editing system 104 . It is noted the operations in the method 1500 are by way of example only, and that various implementations may have more or less operations than those explicitly shown. [0077] At an operation 1502 , an interactive portion of first video content displayed on a first mobile device associated with a first user may be identified. The first video content may include second video content gathered from a second mobile device associated with a second user. An “interactive portion,” as used herein, may comprise any portion of video content configured to receive user input from a viewer. Interactive portions may include specific times in video content that a user can provide annotations, gestures, voice input, etc. Interactive portions may include portions of a timeline that a user can interact with. In some implementations, interactive portions include portions of video content that can receive edits. In some implementations, the first video content and the second video content may be substantially time-synchronized, e.g., may have similar content at start points, end points, and/or intermediate points. In some implementations, the first video content and the second video content may be streamed from video interaction system(s) 112 . [0078] At an operation 1504 , one or more feedback interactions performed by the first user on the interactive portion of the first video content may be identified. The one or more feedback interactions may be associated with content-level feedback performed by the first user on the first video content. A “feedback interaction,” as used herein, may include any user interaction that provides feedback about content (e.g., content-level feedback) to another user. Feedback interactions may include, without limitation, positive sentiment feedback interactions (e.g., likes), negative sentiment feedback interactions (e.g., dislikes), mood interactions (showings of love, sadness, anger, etc.), user tagging interactions (e.g., associating another user with an interactive portion), semantic meaning interactions (e.g., providing written and/or other explanations for an interactive portion), copyright notice interactions (e.g., providing notice that video content infringes a copyright or other intellectual property), etc. [0079] At an operation 1506 , one or more visual feedback representations of the one or more feedback representations may be gathered. The one or more visual feedback interactions configured to visually represent the content-level feedback. In some implementations, the virtual feedback representations comprise annotations, icons, etc. that provide visual depictions of the feedback representations. [0080] At an operation 1508 , the one or more visual feedback representations may be incorporated into viewer interest content. The viewer interest content may visually represent interest of the first user in the interactive portion of the first video content. “Viewer interest content,” as used herein, may include any content configured to represent interest of user(s) in interactive portions of video content. Viewer interest content may include a visual interest graph of aggregated feedback from a plurality of users of the video interaction system(s) 112 . In some implementations, the visual interest graph comprises a visual depiction of popularity of interactive portion(s) of the first video content. The visual interest graph may further comprise a visual depiction of one or more of the most popular portions of the first video content. As an example, the visual interest graph may comprise a depiction of specific time(s), specific objects, specific people, specific subjects, etc. that are popular relative to similarly situated items. In some implementations, the visual interest graph comprises a visual depiction of time-specific portions of a visual depiction of one or more most popular portions of the first video content. [0081] At an operation 1510 , first instructions to display the viewer interest content on a third mobile device associated with a third user may be provided. The first instructions may configure a video interaction system 112 to display the viewer interest content. As noted herein, the viewer interest content may comprise a visual interest graph of aggregated feedback from a plurality of users of the video interaction system(s) 112 . The viewer interest content may be configured to be displayed in a mobile application executing on the video interaction system(s) 112 . At an operation 1512 , second instructions to display the viewer interest content on the second mobile device may be provided. More specifically, the viewer interest content may be displayed on a second of the video interaction system(s) 112 and/or other devices. At an operation 1514 , first publication instructions to publish the viewer interest content on a social media system may be provided. At an operation 1516 , second publication instructions to publish the viewer interest content on a video sharing/publication system may be provided. [0082] Some portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. [0083] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. [0084] Techniques described in this paper relate to apparatus for performing the operations. The apparatus can be specially constructed for the required purposes, or it can comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program can be stored in a computer readable storage medium, such as, but is not limited to, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. [0085] For purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the description. It will be apparent, however, to one skilled in the art that embodiments of the disclosure can be practiced without these specific details. In some instances, modules, structures, processes, features, and devices are shown in block diagram form in order to avoid obscuring the description. In other instances, functional block diagrams and flow diagrams are shown to represent data and logic flows. The components of block diagrams and flow diagrams (e.g., modules, blocks, structures, devices, features, etc.) may be variously combined, separated, removed, reordered, and replaced in a manner other than as expressly described and depicted herein. [0086] Reference in this specification to “one embodiment”, “an embodiment”, “some implementations”, “various implementations”, “certain embodiments”, “other embodiments”, “one series of embodiments”, or the like means that a particular feature, design, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of, for example, the phrase “in one embodiment” or “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, whether or not there is express reference to an “embodiment” or the like, various features are described, which may be variously combined and included in some implementations, but also variously omitted in other embodiments. Similarly, various features are described that may be preferences or requirements for some implementations, but not other embodiments. [0087] The language used herein has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments is intended to be illustrative, but not limiting, of the scope, which is set forth in the claims recited herein.

An embedded editing system allows mobile video capture, editing, and sharing/publishing. The systems and methods disclosed herein may facilitate mobile multi-track timeline-based video editing. The systems and methods disclosed herein may allow for easy creation of picture-in-picture videos and/or other forms of video and/or other forms of creative or expressive content, particularly content captured from mobile devices. Feedback interactions captured at a viewer device may be used as the basis of viewer interest content provided to a user capturing and publishing video content and/or to third parties. The feedback interactions may visually represent content-level feedback against interactive portions of video content.

FIELD [0001] This disclosure relates to an exhaust gas aftertreatment system and a doser system used with the aftertreatment system to inject a dosing agent into exhaust gas in the aftertreatment system. BACKGROUND [0002] The use of an aftertreatment system to treat exhaust gas before the exhaust gas is exhausted to atmosphere is known. One known aftertreatment system uses a diesel oxidation catalyst (DOC) device that is intended to react with the exhaust gas to convert nitric oxide to nitrogen dioxide. In the case of diesel exhaust, a diesel particulate filter (DPF) can also be provided downstream of the DOC to physically remove soot or particulate matter from the exhaust flow. [0003] When exhaust gas temperatures are sufficiently high, soot is continually removed from the DPF by oxidation of the soot. When the exhaust gas temperature is not sufficiently high, active regeneration is used. In the case of diesel engine exhaust, one form of active regeneration occurs by injecting fuel into the exhaust gas upstream of the DOC. The resulting chemical reaction between the fuel and the DOC raises the exhaust gas temperature high enough to oxidize the soot in the DPF. [0004] A doser system that includes a doser injector is used to inject the fuel into the exhaust gas. Deterioration of the doser injector can occur over its lifetime, for example due to doser tip carboning or a reduction of doser stroke. It is currently believed by the inventors that doser deterioration is the most frequent mode of failure in aftertreatment systems. A known doser monitoring method that attempts to determine the efficiency of the doser injector senses the temperature difference across the DOC. However, the effectiveness of this method is decreased by deterioration of the DOC which cannot be independently monitored. SUMMARY [0005] A real time doser efficiency monitoring method is described that measures the average instant pressure difference within one duty cycle of the doser injector. The disclosed method results in improved doser efficiency monitoring. The disclosed method can be implemented in a number of areas. For example, in a diesel truck application, the doser efficiency can be monitored accurately, for example within 5% error, all the time, no matter whether the truck is in a transient or steady state. [0006] In one embodiment, a method of monitoring the efficiency of a doser injector that is configured and arranged to inject a dosing agent into exhaust gas comprises determining the average instant pressure difference of the dosing agent at a dosing agent shut-off valve assembly within a duty cycle of the doser injector. The doser injector is preferably pulse-width modulation controlled. [0007] In another embodiment, a method of monitoring the efficiency of a doser injector that is configured and arranged to inject a dosing agent into exhaust gas comprises, in a single duty cycle of the doser injector, measuring a pressure of the dosing agent when the doser injector is off and measuring a pressure of the dosing agent when the doser injector is on, each pressure measurement occurring at a dosing agent shut-off valve assembly. The difference between the dosing agent pressure when the doser injector is off and the dosing agent pressure when the doser injector is on is then determined and used to calculate the average instant pressure difference. [0008] The method can be implemented by a doser system that comprises a doser injector that is configured and arranged to inject a dosing agent into exhaust gas, a dosing agent supply line connected to the doser injector, and a dosing agent shut-off valve assembly connected to the supply line that is configured and arranged to control the flow of the dosing agent in the supply line and to the doser injector. The valve assembly includes a pressure sensor for detecting dosing agent pressure in the valve assembly. A controller monitors the efficiency of the doser injector, with the controller determining the average instant pressure difference of the dosing agent at the dosing agent shut-off valve assembly within a duty cycle of the doser injector. [0009] The dosing agent can be fuel, for example diesel fuel, alcohols, urea, ammonia, natural gas, and other agents suitable for use in aftertreatment of exhaust gases. [0010] The disclosed method can complete monitoring within fraction of seconds, which works well even during transient engine operations and dosing. The disclosed method also has increased accuracy. The average instant pressure difference is the maximum pressure drop so it has a better signal-to-noise ratio. The disclosed method is also independent of the performance, e.g. degradation, of individual aftertreatment components as is the current temperature based efficiency monitoring method. Further, the disclosed method is independent of the dosing command. [0011] The disclosed method permits compliance with the on-board diagnostics requirement for the year 2010, which requires independent monitoring for each aftertreatment component. In addition, the higher efficiency achieved by the disclosed method reduces the injection of excess fuel, called hydrocarbon slip, thereby avoiding violation of hydrocarbon emission regulations. Further, the occurrence of false detected “bad” dosers is reduced, thereby reducing warranty costs of doser replacement. DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 illustrates an exemplary doser system that can implement the real time doser efficiency monitoring method. [0013] FIG. 2 illustrates the shut-off valve assembly. [0014] FIG. 3 is detailed view of the portion in box 3 of FIG. 2 illustrating the trim orifice in the shut-off valve assembly. [0015] FIG. 4 depicts a pressure reading over one cycle period of the doser injector. [0016] FIG. 5 is a graph of the dosing agent pressure versus time at different dosing rates. [0017] FIG. 6 is a graph of the doser efficiency versus instant pressure difference for 6 doser injectors with differing deterioration levels. [0018] FIG. 7 is a graph of dosing agent pressure and dosing rate versus time. DETAILED DESCRIPTION [0019] With reference to FIG. 1 , a doser system 10 for an exhaust gas aftertreatment system is illustrated. For sake of convenience in describing the unique concepts, this description will describe the doser system 10 as being a hydrocarbon doser system for a diesel fuel engine that injects diesel fuel into exhaust gas from the engine. However, it is to be realized that the unique concepts described herein can be applied to other doser systems that inject other types of dosing agents. [0020] The basic configuration and operation of the doser system 10 and aftertreatment system are well known to persons of ordinary skill in the art. The doser system 10 includes a doser injector 12 that is connected to an exhaust gas connection tube 14 connected to the exhaust from an engine (not illustrated). As part of the aftertreatment system, exhaust gases in the connection tube 14 flow to a diesel oxidation catalyst (DOC) device that is intended to react with the exhaust gas to convert nitric oxide to nitrogen dioxide. A diesel particulate filter (DPF) is provided downstream of the DOC to remove soot or particulate matter from the exhaust flow. [0021] The doser injector 12 is configured and arranged to inject a dosing agent, which in this exemplary embodiment is diesel fuel, into the exhaust gas in the tube 14 to increase the temperature of the DOC. The fuel is supplied via a fuel supply line 16 . A shut-off valve assembly 18 is connected to the supply line 16 and is configured and arranged to control the flow of fuel in the supply line 16 and to the doser injector 12 . [0022] Details of the shut-off valve assembly 18 are illustrated in FIGS. 2 and 3 . The assembly 18 includes a fuel inlet port 20 , a fuel outlet port 22 connected to the supply line 16 , and a drain port 24 . A pressure sensor 26 connected to the valve assembly 18 senses fuel pressure in the assembly 18 . A trim orifice 28 is provided to keep the fuel pressure in the assembly 18 more stable. The construction and operation of the valve assembly 18 illustrated in FIGS. 2 and 3 are conventional. [0023] Returning to FIG. 1 , a controller 30 is connected to the pressure sensor 26 and receives pressure readings therefrom. The controller 30 monitors the efficiency of the doser injector 12 by determining the average instant pressure difference of the fuel at the shut-off valve assembly 18 within one duty cycle of the doser injector which is pulse-width modulation (PWM) controlled. The controller 30 , which can be an electronic control module (ECM), can also control the aftertreatment system. The doser injector 12 is controlled by a separate PWM controller 32 . [0024] The fuel dosing rate is controlled by the duty cycle of the PWM controller. FIG. 4 shows one cycle period T of doser pressure, with P off and P on being the fuel pressure measured by the pressure sensor 26 when the doser injector is turned off and on, respectively. All references to pressure herein and the pressures shown in FIGS. 5-7 are the fuel pressure measured by the pressure sensor 26 in the valve assembly 18 . P avg is the average pressure when the doser injects fuel at that duty cycle, calculated as follows: [0000] P avg  = P on · T on + P off · ( T - T on ) T = P on · R D   C + P off · ( 1 - R DC )   where   R DC = T on T   Radio   of   duty   cycle ( Eq .  1 ) [0025] The average pressure difference, ΔP avg , can be calculated as follows: [0000] Δ   P avg = P off - P avg = P off - P on · R DC - P off · ( 1 - R DC ) = ( P off - P on ) · R DC = Δ   P ins · R DC ( Eq .  2 ) [0026] The average instant pressure difference, ΔP ins , is the average pressure difference by a factor of duty cycle. The average instant pressure difference is substantially independent of dosing rate. This is evident from FIG. 5 which depicts a graph of dosing agent pressure versus time at different dosing rates. From FIG. 5 , it can be seen that the instant pressure difference (i.e. the difference between the maximum pressure P off and the minimum pressure P on ) remains substantially constant even with dosing rate changes. [0027] FIG. 6 is a graph of the doser efficiency versus average instant pressure difference for 6 doser injectors with differing deterioration levels. From this graph, it can be determined that under the conditions set forth (e.g. at a supply pressure of about 1200 kPa) in the graph, a 10 kPa variation in instant pressure difference means approximately a 3.1% doser efficiency error. It is believed by the inventors that this level of accuracy is not achievable by doser efficiency monitoring methods in existence at the time of filing this application. [0028] FIG. 7 is a graph depicting pressure measurements when the fuel dose rate changes from about 1.4 g/s to about 0.8 g/s within 2.2 seconds at a supply pressure of about 1950 kPa. The graph plots the individual instant pressure readings 40 versus time, the average pressure 42 versus time, the average instant pressure 44 versus time, and the dose rate 46 versus time. [0029] First, looking at the average instant pressure difference method described herein, relying upon the average instant pressure difference within a single duty cycle eliminates duty cycle error. In addition, the average instant pressure difference method relies upon a relatively large range of instant pressure difference, shown in FIG. 7 as about 256 kPa, over the single duty cycle. This helps to minimize the impact of pressure variations on the doser efficiency. From FIG. 7 , the average instant pressure 44 while the doser is off holds relatively steady at about 1950 kPa, which is the assumed supply pressure. The variation in instant pressure difference while the doser injector is on varies by about 10 kPa. Assuming that the doser used in FIG. 7 is a 100% efficient doser, and assuming that a 100% efficiency doser at 1950 kPa supply pressure has an instant pressure difference of 256 kPa, then the doser efficiency error can be determined by taking the variation in instant pressure difference, 10 kPa, and dividing it by the pressure difference range of 256 kPa. The doser efficiency error for the average instant pressure difference method is thus about 4.1%. [0030] In contrast, looking at the instant pressure 40 and the average pressure 42 , one doser efficiency monitoring method in existence at the time of filing this application relies upon the average pressure 42 to determine doser efficiency. In the average pressure difference method, the dynamic range of the average pressure difference is the dynamic range of the pressure difference multiplied by a factor of duty cycle. In FIG. 7 , the duty cycle is about 0.15 seconds. The dynamic range of the average pressure difference (i.e. the maximum average pressure minus the minimum average pressure) is about 38.5 kPa. This is a much smaller range than the average instant pressure difference method which means that pressure variations have a much greater impact on the doser efficiency. Relying on the same assumptions in the preceding paragraph, and assuming that the variation in instant pressure difference while the doser injector is on varies by about 10 kPa as above, the doser efficiency error of the average pressure difference method is 10 kPa divided by 38.5 kPa, or about 27.5%. If one factors in duty cycle error, that error becomes even larger. [0031] Although the average instant pressure difference method has been described with respect to diesel fuel as the dosing agent, the concepts described herein can be applied to other dosing agents. For example, the dosing agent can be one or more of other types of fuels including hydrocarbon fuels, or other dosing agents such as alcohols, urea, ammonia, and natural gas. [0032] The monitoring method described herein can be implemented in a number of different ways. For example, the monitoring method can be implemented by software residing in an aftertreatment system controller, for example in the controller 30 . Alternatively, the monitoring method can be implemented by hardware such as electronic circuitry at or near the pressure sensor 26 . [0033] The concepts described herein may be embodied in other forms without departing from its spirit or characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

A real time doser efficiency monitoring method is described that measures the average instant pressure difference within one duty cycle of the doser injector. The disclosed method results in improved doser efficiency monitoring. The disclosed method can be implemented in a number of areas. For example, in a diesel truck application, the doser efficiency can be monitored accurately, for example within 5% error, all the time, no matter whether the truck is in a transient or steady state.

BACKGROUND OF THE INVENTION The present invention relates generally to an improved technique for the preparation of protein enriched yeast products, and more particularly to a method of producing such products from whey fermentation systems. The process of the present invention provides finished products which are high in protein content, low in ash and essentially free of carbohydrates, especially reducing sugars. It is generally acknowledged that the world is entering an era of protein shortage. Accordingly, various techniques have been explored for the protein enrichment of food products both for human and animal consumption. Since the recognition of the fermentation process by Pasteur, considerable effort has been made to develop single cell protein systems to provide protein materials of high nutritional quality. Only modest gains have been made in accomplishing this goal due to the inherent limitations of the amino acid profiles of the various single cell protein. Bacteria are low in cystine and tryptophan, yeast are low in cystine and methionine, while algae are low in cystine, methionine and isoleucine content. Of the various processes for producing single cell proteins, yeast is one of the more desirable microorganisms, since in most cases, proteins in the fermentation medium are either not utilized or only modestly utilized as a nutrient by the yeast. Consequently, a yeast fermentation is the process of choice in this invention, although the basic concept could be foreseeably applied with other microbial propagation processes where elimination of an undesirable constituent could be accomplished. To maintain the protein quality of the enriched final product, cheese whey is the preferred fermentation substrate. There is currently over 30 billion pounds of liquid whey available annually in the United States of America and whey proteins are known for their exceptional nutritional quality. Whey from the manufacture of cheese contains most of the nutrients essential for yeast fermentation (respiration) and yeast products have already been shown to provide products with some applications in both foods for human consumption and for animal feeds. Utilization of single cell protein products have been limited for a variety of reasons. Nucleic acid content must be restricted to less than 2 grams in the average dietary intake. The maximum protein content of single cell proteins is species specific in that bacteria may contain 47-87% protein; fungi (molds) 40%; yeast 50-54%; and algae only 40%. Cell walls and protein/ash ratios also reduce the amounts that can be used effectively in food systems, and these protein ingredients should additionally possess appropriate functional properties for promoting utilization. All of the essential amino acids must be present in adequate amounts to provide the desired quality for human and animal nutrition. To overcome some of these impediments, the present practice includes blending microbial protein products with other ingredients. Milk, casein, caseinates, whey, modified whey, lactalbumin, soy concentrates and isolates, egg products, corn, wheat and other flours are typical of the ingredients used in these mixtures. However, an additional problem is encountered in that each of these ingredients contain varying amounts of carbohydrates. In particular, the milk or dairy products contribute the reducing sugar, lactose, to the blend and lactose intolerance is a problem in certain sectors. For certain animals and insects, lactose ingestion can result in growth retardation and even death. In the winter feeding of bees, for example, products containing lactose are considered lethal and cannot be used. In accordance with the present invention, however, residual carbohydrates are removed, and specifically residual lactose is removed from the finished product. Another problem with residual carbohydrates in ingredients used in food product systems is the browning reaction due to the combination of reducing sugars with amino acids during heat treatments. Thus, a high protein content product devoid of reducing sugars can promote increased food utilization. One system has partially satisfied the above parameters, wherein, in the fermentation of cheese whey, the whey portions (lactoglobulins) are coagulated (heat denatured) with these proteins being recovered with the yeast cells at the separation step. Even in this system (Mayer, B. M., 1970, Whey Fermentation. Proceedings Whey Utilization Conference, U.S.D.A.--ARS Publ. No. 76-36, p. 48), the yeast product contains only 57-60% protein. In accordance with the present procedure, however, higher protein contents are obtainable and, as previously indicated, residual carbohydrates are essentially removed. In accordance with the present invention, therefore, the above limitations are essentially overcome. Any protein enriching substance may be added to the fermentation at an appropriate point in the process to allow removal (utilization by the cells) of the carbohydrates, while increasing the protein content and improving the amino acid balance of the final product. A wide variety of products are possible by this technique. Undenatured or denatured proteins, high protein/ash ratios and functional properties may be altered to satisfy specific requirements for use. SUMMARY OF THE INVENTION Therefore, in accordance with this invention, microbial cells (yeast) are grown under conditions favoring respiration such that a proteinaceous ingredient is added at a stage in the process, such as just after separation of the cells (usually by centrifugation) and storage. Specifically, a respiration formulation is prepared and the respiration operation is promoted until the operation is substantially complete, it being important, however, that certain active cells remain. Thereafter, a protein enriching ingredient, either soluble or insoluble, is added to the cell slurry after separation of most of the cells from the respiration or fermentation medium. These operations occur prior to further concentration and drying to allow utilization of any carbohydrates which may be present in the enriching medium, (more particularly lactose and lactic acid) with the resultant product being high in protein, low in ash content and negligible in carbohydrate concentration. It is understood that this is a respiration process primarily wherein sugar is oxidized to carbon dioxide and cell substance. This is in contrast to a fermentation process wherein sugar is converted to alcohol and carbon dioxide. The basic respiration process follows the procedures described by A. E. Wasserman ("The Rapid Conversion of Whey to Yeast", Dairy Eng., 1960, 77:374). This, as well as other respiration or fermentation processes, may be employed. Although the process of the present invention is applicable to microorganisms of all types, the lactose respiring yeasts are of major interest. Klyveromyces (Saccharomyces) fragilis or K. lactis are particularly suitable for propagation in cheese whey media. While this invention is applicable to batch systems, it is readily adaptable to continuous respiration (fermentation) systems. The whey proteins (lactoglobulins) may be denatured prior to inoculation of the yeast to the growth medium and additional insoluble or denatured protein ingredients may be added at this stage. Alternatively, during the fermentation, insoluble or denatured proteinaceous substances may be added as supplementation. Following separation (centrifugation) of the cells and insoluble protein matter, either soluble and/or insoluble protein ingredients may also be added. At any of the three stages mentioned, the protein enriching ingredient or combination may be added with the ultimate effect of producing the characteristics desired. The respiration (fermentation) is completed once all the carbohydrate is consumed and the separated slurry is concentrated further and dried by conventional means. Other and further objects of the present invention may become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawing. BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a flow diagram illustrating the major operations involved in the method of producing protein enriched yeast products with the points of protein ingredient addition as related to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Various procedures for fermentation or respiration of microbial cells are well known to those skilled in the art and the present invention may be incorporated into any of these systems to improve the nutritional and functional properties of these single cell protein products. The yeast production processes of basic concern in this invention have been ably described by P. Vananuvat and J. E. Kinsella ("Production of Yeast Protein from Crude Lactose", J. of Food Sci., 1975, 40, 336-341); A. E. Wasserman, W. J. Hopkins and N. Parges ("Whey Utilization. Growth Conditions for S. fragilis", Sewage and Ind. Wastes, 1958, 30, 913-920) and numerous others. In accordance with the preferred embodiment of the present invention, there are three stages in the yeast propagation system at which the protein enriching ingredient may be added. Dependent upon the amount of protein desired in the final product, a readily calculable amount of protein enriching ingredient can be added based upon the known amount of recoverable solids considered consistent with the particular propagation system. As an example, the yeast solids recovery in a fermentation system normally produces 25 grams of solids for each liter of fluid whey. The yeast solids, on a dry (moisture-free) basis, contains 50% protein. To the fermentation is added 20 grams of the protein enriching ingredient which contains 90% protein. For simplicity, assume 100% recovery of the added protein ingredient which is normally realistically approached. Thus, 45 grams of product is obtained (25+20) containing 67.8% protein (50×25) plus (90×20). For example: ##EQU1## The following table shows some of the combinations which provide protein enriched yeast products with improved protein/ash ratios and substantially reduced lactose. TABLE 1______________________________________ Protein Ash Protein/ Lactose Percent Percent Ash Percent______________________________________A. Washed whey grown yeast 55 10 5.5 <0.2%B. Casein, Caseinates 91 (av.) 3.35 (av.) 27 0.6 (av.)% A % B50 50 73 6.7 10.9 <0.2%90 10 58.6 9.3 6.3 <0.2%10 90 87.4 4.0 21.9 <0.2%C. Lactalbumin 80 2.5 (av.) 32 5.5 (av.)% A % C50 50 67.5 6.2 10.9 <0.2%90 10 57.5 9.1 6.3 <0.2%D. Whey Protein Concentrate 35 2.4 14.6 56.6% A % D50 50 70 (1) 6.4 10.9 <0.2%______________________________________ (1) Lactose conversion to yeast protein is about 45%. In the A/D (50:50) product, 45% of the 56.6% lactose will contribute an additional 25% protein. Thus, 25% protein from ingredients lactose plus 45% protein from the protein constitutents of a and D give 70% protein. (2) All values are calculated on a dry, moisturefree basis. Protein level shown would be somewhat lower when the nitrogen analysis factor is 6.25 instead of 6.38. Kjeldahl nitrogen analysis factors: Nitrogen 33 0 6.25 for yeast protein; Nitrogen × 6.38 for milk proteins. Selection of the particular protein enriching ingredient and amount to add is important when a specific amino acid profile or functional property is desired in the final product. If a higher level of the essential amino acid, leucine, is required in the final product, a caseinate is used, or to increase the phenylalanine content, egg albumin may be added (the carbohydrate, glucose, would be consumed in the fermentation). Therefore, the protein efficiency ratios of single cell proteins can be dramatically improved. Recognition of the contribution of B complex vitamins from the yeast portion of the product should also be considered in the determination of total nutritional quality of the product. In accordance with the teachings of this invention, there is the option to add soluble or insoluble (denatured) proteinaceous ingredients such that the functional properties (e.g. emulsification, gellation, water binding, etc.) are enhanced. The only precaution is that only insoluble (denatured) proteins should be added at the beginning or during the actual fermentation, so that they are readily recovered later. Soluble proteins may be appropriately added following the general separation of the yeast cells from the fermentation medium, since they will not be lost and the carbohydrate will still be consumed during storage of the separated yeast cell slurry prior to final concentration and drying. In order to better comprehend the various features of the present invention, the following specific example showing the preferred embodiment of the present invention is given: EXAMPLE I Cheese whey is gathered and maintained in a storage vessel and steam is injected until a temperature of 93° C. is achieved and maintained for approximately 25 minutes. This achieves precipitation of the whey proteins, with the cheese whey initially containing between 6% and 6.5% solids, and with the solids containing approximately 12% protein. Nutrients are added prior to precipitation of the whey proteins, with 0.5% dibasic potassium phosphate and brewer's yeast extract in an amount of 10 grams (0.1%) per liter of cheese whey. Thereafter, Klyveromyces (Saccharomyces) is added at approximately 5×10 8 cells per ml. of cheese whey, and following inoculation, the temperature of the slurry is maintained at approximately 30° C., with ammonia and air being pumped into the slurry to promote fermentation. In order to provide the quantity of ammonia necessary, ammonium sulfate in a quantity to produce a concentration of 0.5 mols per liter. Also, oxygen in the form of air is passed through the medium to maintain the oxygen content at a level of about 5 mM oxygen. During this respiration operation, the lactose and lactic acid are essentially consumed with the total consumption occurring in approximately 8 hours. Prior to the completion of the respiration operation, 6 hours after inoculation, respiration is substantially 90% complete. The pH of the slurry is maintained at approximately 5.7 with sulfuric acid being added as required. In the event the pH drops below approximately 6.5, the pH level may be corrected by pumping in ammonia gas, or a suitable water soluble base such as sodium hydroxide may also be utilized. At the 8-hour point, the cells are separated from the slurry medium through a centrifuge, with approximately 95% of the cells being removed, the effluent being discarded as a liquid fertilizer. This slurry medium with the cells is transferred from the centrifuge to a storage vessel at which time an additional quantity of dried milk solids in an amount of 20 grams per liter of centrifuged slurry medium (15% total solids), with the material then being maintained in the storage vessel at a temperature of approximately 30° C. to aeration until respiration is completed. During this second phase of the respiration operation, the carbohydrate content due essentially to the reducing sugar lactose is substantially entirely consumed and converted to protein. Also, at this point the protein/ash ratio has reached approximately 87:4. Following completion of the second respiration operation, the slurry is pasteurized, concentrated and passed through a conventional dryer to an exit temperature below 40° C. until excess water is removed. As has been shown, a fermentation (respiration) process is provided which enables the production of protein enriched products substantially devoid of carbohydrates. These products have a wide variety of application, especially as highly nutritional and functional food supplements for man, animals, and insects wherein there is low lactose tolerance or other problems related to the presence of carbohydrates. It will be appreciated, of course, that conventional drying techniques are employed, with temperatures being controlled so as to avoid damage to the constituents of the final product. Drying conditions for protein enriched products are, of course, well known in the art and no unusual drying treatment is required. With regard to the process flow diagram illustrated in the FIGURE, it will be seen that the cheese whey together with an insoluble protein enrichment ingredient are mixed together, and thereafter are sterilized, or optionally with the soluble proteins being denatured during the sterilization or pasteurization process. The culture is then inoculated, and this is followed by the respiration operation. Cells are separated from the medium, and thereafter the materials are stored prior to concentration and drying. It will be appreciated that the insoluble protein enrichment ingredient may be added at any suitable time, with suitable products being obtained with the addition of such an ingredient prior to final concentration drying as set forth in the flow diagram of the FIGURE, or as an alternative, in the respiration operation prior to completion thereof. When soluble protein enrichment ingredients are considered for addition to the treated material, such additions must be made during storage so as not to lose them in the effluent during centrifugal separation.

The present invention concerns methods for producing food products consisting of highly nutritional proteins and yeast which are substantially devoid of objectionable carbohydrates. The process pertains to the addition of proteinaceous materials at appropriate stages of a yeast fermentation so as to enable the yeast to utilize the carbohydrate constituents of the protein material while recovering the protein with the yeast cells. These protein enriched yeast products are low in ash content with essentially no residual carbohydrates and are useful for fortifying foods and feeds.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a method of determining the lethality of defects in the circuit pattern inspection, a method of selecting defects to be treated as review objects, and the circuit pattern inspection system involved with these methods. Particularly, the invention relates to a method of efficiently determining, in a manufacturing process to form semiconductor devices on a semiconductor wafer, whether a defect detected by an appearance/particle inspection instrument is lethal in accordance with the characteristics of circuit patterns of the semiconductor devices, a method of efficiently selecting a defect that should be treated as a review object when defects are detected, in accordance with the characteristics of defects generated on each process, and the system involved with the above methods. [0003] 2. DESCRIPTION OF THE RELATED ART [0004] In the semiconductor manufacturing process, it is essential for maintaining or enhancing the yield to detect the cause of a failure as quickly as possible and feedback the countermeasure to the process and/or the manufacturing facilities. In order to establish the countermeasure, it is important to detect a failure by an inspection instrument and analyze the inspection data. [0005] As the conventional technique in this field, defects such as pattern shorts and a pattern missing which are generated on the wafer process, and particles are automatically inspected by, for example, the inspection instruments using an image processing and dark field irradiation by laser beams. [0006] These inspection instruments output the coordinate data of defects and particles in the semiconductor wafer, and the sizes of the defects to an analysis system that stores these data. Next, the inspected wafer is moved onto a stage of an optical microscope or scanning electron microscope, the stage is moved to the position corresponding to the coordinate data of a detected defect, and the defect is classified by the magnified image thereof. This classification work is called the review. [0007] This review has two objects. [0008] One is to classify defects detected in accordance with the characteristics of the defects themselves, such as pattern missing, pattern shorts, film residue, particles, etc. [0009] Another one is to determine whether a defect leads to a lethal defect for the function of the semiconductor device, and from the result to classify the defect into a lethal defect or non-lethal defect. [0010] After completing the review, a review station outputs the classification identifiers predetermined in accordance with the classification and lethality/non-lethality of the defects themselves to the analysis system that analyzes the data. [0011] The foregoing conventional technique has become an essential technique for enhancing the yield when forming circuit patterns on a semiconductor wafer through the micro fabrication. [0012] On the process of manufacturing a semiconductor wafer, if a defect is detected, occasionally the defect cannot be any obstacle to the operation. If there are particles on the wafer, to regard all the semiconductor chips made therefrom as failure is to treat even the normally operating chips as failure. That is impractical. [0013] Therefore, the determination as to whether the defect is lethal or not is specially important in the inspection process. However, the conventional technique involves the following problems in the determination of the defect being lethal or not. [0014] In the conventional technique, the review and the determination of lethality are carried out by human hands and brains, and therefore, the work needs a considerable time, which will become a hindrance to enhancing the throughput of the total inspection process. [0015] In regard to the determination of lethality, the inspector needs to have the knowledge of functions and structures of the circuit patterns of a defective area as well as the discrimination of the defects themselves, and the work is entrusted to specialists having those specific knowledge. Further, the determination criterion of lethality differs among these specialists, and the result of determination varies depending on the inspector, which is a problem. [0016] If the determination of lethality by the review is not conducted at all on the pretext of the throughput, or the determination of only a part of defects is conducted, the following inconveniences will arise. [0017] This problem will be described with reference to FIG. 19. FIG. 19 illustrates a graph in which a relation between the total number of defects and the yield is plotted, and a graph in which the total number of defects produced in time series on each of inspection wafers is plotted. [0018] As shown in FIG. 19 ( a ), there is not a correlation between the total number of defects and the yield of the semiconductor chips, and thereby a significant control limit cannot be introduced. Here, the control limit signifies the number of defects that is provided for controlling the quality. The yield indicates the rate of non-defectives against all the chips on a wafer. [0019] Accordingly, as shown in FIG. 19 ( b ), although the total defect number by each inspection wafer is plotted in time series to thereby predict the abnormality of the yield and to thereby take a countermeasure in an earlier stage, since the total defect number does not function as a monitor value, the setting of a control limit will not bring about a good detection of abnormality. In the example of this drawing, since the total defect number exceeds the control limit in every point, all the defects are to be determined as abnormal. [0020] During the review, it is necessary to view an enlarged image by the optical microscope or scanning electron microscope, which accompanies the works of moving the stage, bringing the defect into the field of view, focusing and the like. Therefore, to carry out the reviews of all the defects detected by the inspection instrument will be a contradiction against the requirement for enhancing the throughput in the inspection process. Accordingly, it is necessary to reduce the number of the defects of the review object, however, this work to reduce the number is entrusted to the review operator; and the selection results of the review object will differ depending on the operators, which is a problem. [0021] The present invention has been made to resolve the foregoing problems, and it is therefore an object of the invention to provide a method of determining the lethality of defects, which enhances the efficiency of inspection by automatically determining the lethality of defects without conducting the review when inspecting circuit patterns formed on a substrate of a semiconductor wafer or the like, and an inspection system to implement the same. [0022] Another object of the invention is to provide a method of automatically selecting defects to be reviewed in order to efficiently perform the review in the inspection of the circuit patterns while maintaining the quality of the inspection itself, and an inspection system to implement the same. SUMMARY OF THE INVENTION [0023] In order to accomplish the foregoing objects, the invention sets forth a construction relating to a method of determining a lethality of defects in an inspection of circuit patterns formed on a substrate, as follows. At an inspection stage, inspection data of the defects produced on the circuit patterns are generated, the inspection data generated are inputted to be processed; and thereby, the lethality of the defects corresponding to the inspection data are determined. [0024] In detail, the foregoing method of determining the lethality employs the coordinate data of the circuit patterns and the sizes of the defects as the inspection data. [0025] Further in detail, the foregoing method of determining the lethality of defects segments each of the circuit patterns into several areas having different characteristics, and serves the data to determine the lethality of the defects as determination rules each provided for each of the areas of the circuit patterns. [0026] To achieve the foregoing objects, the invention sets forth a further detailed construction relating to the method of determining a lethality of defects, as follows. When each of the circuit patterns is segmented into several areas having different characteristics, area coordinate data of the circuit patterns and data to determine the lethality of the defects produced in the areas on the circuit patterns are held, and the coordinate data of the defects detected and the sizes of the defects can be obtained at an inspection stage, the method of determining of a lethality of defects comprises the following steps. [0027] (1) accepting the area coordinate data of the circuit patterns, [0028] (2) accepting the data to determine the lethality of the defects produced in the areas on the circuit patterns, [0029] (3) accepting the coordinate data of the defects detected on the circuit patterns and the sizes of the defects, [0030] (4) identifying the areas to which the defects belong, from the coordinate data of the defects detected on the circuit patterns, and [0031] (5) comparing the sizes of the defects detected with the data to determine the lethality of the defects produced in the areas on the circuit patterns where the defects belong to thereby determine the lethality of the defects. After the step (1) through the step (3), the step (4) is executed, and thereafter the step (5) is executed. [0032] In detail, the foregoing method of determining a lethality employs length data, area data, and brightness data which are served as indexes when detecting the defects as the sizes of the defects. [0033] Further in detail, the foregoing method of determining a lethality employs pattern widths or pattern spaces in the areas as the data to determine the lethality of the defects produced in the areas on the circuit patterns. [0034] Further in detail, in the foregoing method of determining a lethality, when the area coordinate data of the circuit patterns and pixel coordinates for display are brought into correspondence and inherent class values according to the characteristics of the areas are individually assigned to each of the areas, the foregoing step (4) is comprised of the steps of: [0035] (4 a ) writing in advance class values in an array to express pixel coordinates, [0036] (4 b ) obtaining the pixel coordinates corresponding to the coordinate data of the defects detected, and [0037] (4 c ) determining the areas where the defects belong from the pixel coordinates. [0038] To achieve the foregoing objects, the invention sets forth a construction relating to a method of selecting a review object of defects detected in an inspection of circuit patterns formed on a substrate, as follows. At an inspection stage, inspection data of the defects produced on the circuit patterns are generated, the inspection data generated are inputted to be processed; and thereby, the data to determine the lethality of the defects corresponding to the inspection data are generated, and the data to determine the lethality of the defects and the inspection data are compared, and thereby, the review object is selected among the defects produced. [0039] In detail, the foregoing method of selecting a review object employs the coordinate data of the circuit patterns and the sizes of the defects as the inspection data. [0040] Further in detail, the foregoing method of selecting a review object segments each of the circuit patterns into several areas having different characteristics, and serves the data to determine the lethality of the defects as determination rules each provided for each of the areas of the circuit patterns. [0041] To achieve the foregoing objects, the invention sets forth a further detailed construction relating to the method of selecting a review object, as follows. When each of the circuit patterns is segmented into several areas having different characteristics, area coordinate data of the circuit patterns and data to determine the lethality of the defects produced in the areas on the circuit patterns are held, and coordinate data of the defects detected and sizes of the defects can be obtained at an inspection stage, the method of selecting a review object comprises the following steps. [0042] (11) accepting the area coordinate data of the circuit patterns, [0043] (12) accepting the data to determine the lethality of the defects produced in the areas on the circuit patterns, [0044] (13) accepting the coordinate data of the defects detected on the circuit patterns and the sizes of the defects, [0045] (14) identifying the areas to which the defects belong, from the coordinate data of the defects detected on the circuit patterns, and [0046] (15) calculating ratios of the sizes of the defects detected against the data to determine the lethality of the defects produced in the areas on the circuit patterns where the defects belong. After the step (11) through the step (13), the step (14) is executed, thereafter the step (15) is executed, and the review object is selected, while the ratios are served as the indexes to indicate severity of the defects. [0047] In detail, in the foregoing method of selecting a review object, the defects selected as the review object are confined to the defects corresponding to a specific number of the ratios obtained at the step (15), sorted in the descending order. [0048] Further in detail, in the foregoing method of selecting a review object, the defects selected as the review object are the defects corresponding to the ratios which are obtained at the step (15) and have respectively a specific value or more. [0049] Further in detail, the foregoing method of selecting a review object employs length data, area data, and brightness data which are served as indexes when detecting the defects as the sizes of the defects. [0050] Further in detail, the foregoing method of selecting a review object employs pattern widths or pattern spaces in the areas as the data to determine the lethality of the defects produced in the areas on the circuit patterns. [0051] Further in detail, in the foregoing method of selecting a review object, when the area coordinate data of the circuit patterns and pixel coordinates for display are brought into correspondence and inherent class values according to the characteristics of the areas are individually assigned to each of the areas, the foregoing step (14) is comprised of the steps of: [0052] (14 a ) writing in advance class values in an array to express pixel coordinates, [0053] (14 b ) obtaining the pixel coordinates corresponding to the coordinate data of the defects detected, and [0054] (14 c ) determining the areas where the defects belong from the pixel coordinates. [0055] Further in detail, the foregoing method of selecting a review object, in selecting the defects treated as the review object for each process, further comprises a step that compares coordinate data of the defects having been detected as the defects in a previous process to a process where the review is being executed at present with coordinate data of the defects having been detected as the defects in the concerned process where the review is being executed at present, and selects only the defects having non-coincident coordinate data in the result of the comparison as candidate defects of the review object in the concerned process where the review is being executed. [0056] Further in detail, the foregoing method of selecting a review object further comprises a step that classifies the defects produced on the circuit patterns into cluster defects having a clustered mode and random defects produced at random from the mode in which the defects are produced, and selects the review object with different treatments for the cluster defects and the random defects. [0057] Further in detail, the foregoing method of selecting a review object selects several defects of the cluster defects as the review object, and assumes the review result of the several defects as the review result of all the defects belonging to the cluster to thereby simplify the review for the cluster defects. [0058] Further in detail, the foregoing method of selecting a review object, in selecting the defects treated as the review object for each process, when the cluster defects detected in the previous process and the cluster defects detected in the subsequent process have an overlapping part, treats both of the cluster defects as the cluster defects detected in the previous process. [0059] In order to accomplish the foregoing objects, the invention sets forth a system of determining a lethality of defects in an inspection of circuit patterns formed on a substrate, which comprises: means to input inspection data of the defects produced on the circuit patterns, which are detected at an inspection stage; means to process the inspection data inputted; and means to determine the lethality of the defects corresponding to the inspection data. [0060] In detail, the foregoing system of determining a lethality employs the coordinate data of the circuit patterns and the sizes of the defects as the inspection data. [0061] Further in detail, the foregoing system of determining the lethality segments each of the circuit patterns into several areas having different characteristics, and serves the data to determine the lethality of the defects as determination rules each provided for each of the areas on the circuit patterns. [0062] To achieve the foregoing objects, the invention sets forth a further detailed construction relating to the method of determining a lethality of defects, as follows. When each of the circuit patterns is segmented into several areas having different characteristics, the system comprises: an inspection instrument that obtains coordinate data of the defects detected and sizes of the defects, and an analysis system that analyzes the data to determine the lethality. The analysis system here includes a control unit, a memory to temporarily hold the data, a storage unit to permanently store the data, an operation unit, and an input/output interface. The analysis system further comprises: means to store the area coordinate data of the circuit patterns; means to store the data to determine the lethality of the defects produced in the areas on the circuit patterns; means to store the coordinate data of the defects detected on the circuit patterns and the sizes of the defects; means to identify the areas to which the defects belong, from the coordinate data of the defects detected on the circuit patterns; and means to compare the sizes of the defects detected with the data to determine the lethality of the defects produced in the areas on the circuit patterns where the defects belong to thereby determine the lethality of the defects. [0063] In detail, the foregoing system of determining a lethality employs length data, area data, and brightness data which are served as indexes when detecting the defects as the sizes of the defects. [0064] Further in detail, the foregoing system of determining a lethality employs pattern widths or pattern spaces in the areas as the data to determine the lethality of the defects produced in the areas on the circuit patterns. [0065] Further in detail, in the foregoing system of determining a lethality, the inspection instrument and the analysis system are connected by a network, so that the data and commands can be exchanged. [0066] Further in detail, in the foregoing system of determining a lethality, when the area coordinate data of the circuit patterns and pixel coordinates for display are brought into correspondence and inherent class values according to the characteristics of the areas are individually assigned to each of the areas, the analysis system, further containing a pixel coordinate storage unit, comprises means to write class values in an array to express the pixel coordinates, means to obtain the pixel coordinates corresponding to the coordinate data of the defects detected, and means to determine the areas where the defects belong from the pixel coordinates. [0067] In order to accomplish the foregoing objects, the invention sets forth a system of selecting a review object of defects detected in an inspection of circuit patterns formed on a substrate, which comprises: means to input inspection data of the defects produced on the circuit patterns, which are detected at an inspection stage; means to process the inspection data inputted; means that generate the data to determine the lethality of the defects corresponding to the inspection data; and means that compare the data to determine the lethality of the defects with the inspection data. The system selects the review object among the defects produced, by using the means that compare the data to determine the lethality of the defects with the inspection data. [0068] In detail, the foregoing system of selecting a review object employs the coordinate data of the circuit patterns and the sizes of the defects as the inspection data. [0069] Further in detail, the foregoing system of selecting a review object segments each of the circuit patterns into several areas having different characteristics, and serves the data to determine the lethality of the defects as determination rules each provided for each of the areas of the circuit patterns. [0070] In order to accomplish the foregoing objects, the invention sets forth a further detailed system of selecting a review object, which comprises: an inspection instrument that obtains coordinate data of the defects detected and sizes of the defects; and an analysis system that analyzes the data to select the review object. The analysis system includes a control unit, a memory to temporarily hold the data, a storage unit to permanently store the data, an operation unit, and an input/output interface, which further comprises: means to store the area coordinate data of the circuit patterns; means to store the data to determine the lethality of the defects produced in the areas on the circuit patterns; means to store the coordinate data of the defects detected on the circuit patterns and the sizes of the defects; means to identify the areas to which the defects belong, from the coordinate data of the defects detected on the circuit patterns; and means to calculate the ratios of the sizes of the defects detected against the data to determine the lethality of the defects produced in the areas on the circuit patterns where the defects belong. With this construction, the system of selecting a review object of the invention selects the review object, using the ratios as the indexes to indicate severity of the defects. [0071] In detail, in the foregoing system of selecting a review object, the defects selected as the review object are confined to the defects corresponding to a specific number of the ratios obtained by the means to calculate the ratios, sorted in the descending order. [0072] Further in detail, in the foregoing system of selecting a review object, the defects selected as the review object are the defects corresponding to the ratios obtained by the means to calculate the ratios and have respectively a specific value or more. [0073] Further in detail, the foregoing system of selecting a review object employs length data, area data, and brightness data which are served as indexes when detecting the defects as the sizes of the defects. [0074] Further in detail, the foregoing system of selecting a review object employs pattern widths or pattern spaces in the areas as the data to determine the lethality of the defects produced in the areas on the circuit patterns. Further in detail, the foregoing system of selecting a review object further comprises a review station to perform the review; and the review station, the inspection instrument, and the analysis system are connected by a network, so that the data and commands can mutually be exchanged. [0075] Further in detail, in the foregoing system of selecting a review object, the analysis system, further containing a pixel coordinate storage unit, comprises means to write class values in an array to express the pixel coordinates, means to obtain the pixel coordinates corresponding to the coordinate data of the defects detected, and means to determine the areas where the defects belong from the pixel coordinates. [0076] Further in detail, the foregoing system of selecting a review object, in selecting the defects treated as the review object for each process, further comprises means that compare coordinate data of the defects having been detected as the defects in a previous process to a process where the review is being executed at present with coordinate data of the defects having been detected as the defects in the concerned process where the review is being executed at present, and selects only the defects having non-coincident coordinate data in the result of the comparison as candidate defects of the review object in the concerned process where the review is being executed. [0077] Further in detail, the foregoing system of selecting a review object further comprises means that classify the defects produced on the circuit patterns into cluster defects having a clustered mode and random defects produced at random from the mode in which the defects are produced, and selects the review object with different treatments for the cluster defects and the random defects. [0078] Further in detail, the foregoing system of selecting a review object selects several defects of the cluster defects as the review object, and assumes the review result of the several defects as the review result of all the defects belonging to the cluster to thereby simplify the review for the cluster defects. [0079] Further in detail, the foregoing system of selecting a review object, in selecting the defects treated as the review object for each process, when the cluster defects detected in the previous process and the cluster defects detected in the subsequent process have an overlapping part, treats both of the cluster defects as the cluster defects detected in the previous process. [0080] Based on the foregoing construction of the invention, the following effects will be achieved. [0081] The foregoing method of determining a lethality makes it possible to automatically determine the lethality of the defects detected by the inspection instrument, without making a review of an enlarged image by using an optical microscope or scanning electron microscope. Accordingly, the determination of the lethality of the defects can be carried out at a high speed, and the lethality of all the defects detected can be determined. [0082] Here, the advantage to determine the lethality of defects will be explained with reference to FIG. 20. [0083] [0083]FIG. 20 illustrates a graph in which the relation between the number of defects determined as lethal and the yield is plotted, and a graph in which the number of defects determined as lethal that are produced in time series for each inspection wafer is plotted. [0084] To determine the lethality of defects is to weight with a filter the defects determined as lethal from all the defects detected. If the lethality of the defects is determined and the number of the defects determined as lethal is obtained, as shown in FIG. 20( a ), the number of the defects determined as lethal is found to possess a correlation with the yield of the chips. Therefore, a control limit can be introduced from the value of the yield, which is different from the case with the total defect number as shown in FIG. 19. [0085] Accordingly, to control the abnormality of each inspection wafer with the number of the defects determined as lethal will detect abnormalities with a high accuracy. As shown in FIG. 20( b ), when the number of lethal defects exceeds the control limit, the inspection wafer can be determined as abnormal. Thus, based on the control by the number of lethal defects, it becomes possible to detect abnormalities having correlation with the yield with a high accuracy, and thereby a countermeasure to raise the yield can be taken in an earlier stage. [0086] In the foregoing description, the number of lethal defects is employed to control abnormalities, however, the rate of lethal defects may be employed. Here, the rate of lethal defects is the ratio of the number of the chips having lethal defects against the number of all the chips formed on the wafer. [0087] Further, to correlate the area coordinates with the pixel coordinates, and assign in advance the class values to the pixel coordinate data makes it possible to swiftly determine the areas where the defects produced belong. [0088] Next, according to the method of selecting a review object of defects detected in an inspection of circuit patterns of the invention, it becomes possible to automatically select a review object in the order of the importance of the review. Accordingly, the review can be performed with a high efficiency, while maintaining the quality of the review. [0089] Further, the method of selecting a review object of the invention has a step that stores the coordinate data of the defects detected and the size data thereof, and thereafter, compares the coordinate data of the defects detected in the previous process with the coordinate data of the defects detected in the concerned process, and selects only the defects having non-coincident data as the defects produced in the concerned process. [0090] Thereby, the defects already reviewed in the previous process cannot be selected again, thus avoiding a useless work. [0091] Further, the method of selecting a review object of the invention has a step that classifies the defects having non-coincident coordinate data of the defects detected in the previous process and the defects detected in the concerned process into cluster defects and random defects from the coordinate data of the defects detected, and selects the defects to be reviewed from the defects thus classified. [0092] Accordingly, the defects belonging to the same cluster that should be treated as the same classification cannot be selected repeatedly as the review object, thus eliminating a useless work. [0093] Furthermore, the method of selecting a review object of the invention has a step that, after the classification of the cluster defects and random defects in the concerned process, compares the coordinate data of the cluster defects detected in the previous process with those of the cluster defects detected in the concerned process, and when the coordinate data of the cluster defects detected are coincident in more than one, puts all the defects contained in the clusters of the cluster defects in the previous process and the cluster defects in the concerned process into the same classification. [0094] Thereby, the defects produced in the concerned process that result from the cluster defects produced in the previous process can be excluded from the review object, and a review result can be obtained with efficiency. BRIEF DESCRIPTION OF DRAWINGS [0095] [0095]FIG. 1 is a block diagram of a circuit pattern inspection system relating to the first embodiment of the present invention; [0096] [0096]FIG. 2 is a chip layout to illustrate a structure of circuit semiconductor devices; [0097] [0097]FIG. 3 is a table to illustrate X-Y coordinates and class values corresponding to each of areas; [0098] [0098]FIG. 4 is a table to illustrate a determination rule corresponding to each of class values; [0099] [0099]FIG. 5 is a typical chart to illustrate the measurement principle of defects of the inspection instrument; [0100] [0100]FIG. 6 is a typical chart to illustrate the principle of the dark field detection; [0101] [0101]FIG. 7 is a chart to illustrate the distribution of a brightness being the output of a defect by the dark field detection; [0102] [0102]FIG. 8 is a flowchart to illustrate a method of determining the lethality of defects in the circuit pattern inspection relating to the first embodiment of the invention; [0103] [0103]FIG. 9 is a block diagram of a circuit pattern inspection system relating to the second embodiment of the invention; [0104] [0104]FIG. 10 is a flowchart to illustrate a processing to assign a class value to each of the pixels corresponding to the are image coordinates; [0105] [0105]FIG. 11 is a flow chart to illustrate a method of determining the lethality of defects in the circuit pattern inspection relating to the second embodiment of the invention; [0106] [0106]FIG. 12 is a block diagram of a circuit pattern inspection system having a function to select a defect treated as a review object of the invention; [0107] [0107]FIG. 13 is a flow chart to illustrate a processing procedure of a method of selecting a defect treated as a review object; [0108] [0108]FIG. 14 is a bar graph to illustrate a transition of the number of defects treated as a review object by each process; [0109] [0109]FIG. 15 is a typical chart to illustrate an example of a method to specify a process that causes a defect; [0110] [0110]FIG. 16 is a typical chart to illustrate a state in which a review object is selected out of cluster defects; [0111] [0111]FIG. 17 is a chart to specify the process that causes cluster defects, which points out the problem in the conventional technique; [0112] [0112]FIG. 18 is a typical chart to illustrate cluster defects generated in each process; [0113] [0113]FIG. 19 illustrates a graph in which a relation between the total number of defects and the yield is plotted, and a graph in which the total number of defects generated in time series on each of inspection wafers is plotted; and [0114] [0114]FIG. 20 illustrates a graph in which a relation between the number of defects determined as lethal and the yield is plotted, and a graph (control chart of the lethal defect number) in which the number of defects determined as lethal generated in time series on each of inspection wafers is plotted. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0115] The preferred embodiments relating to the invention will now be described with reference to FIG. 1 through FIG. 18. [0116] The preferred embodiments will be described on the assumption of an example in which semiconductor devices are formed on a semiconductor wafer, and the similar technique can be applied to a process that manufactures a liquid crystal display, a thin film head for a hard disc drive, or the like. [First Embodiment] [0117] The first embodiment relating to the invention will be described with reference to FIG. 1 through FIG. 8. [0118] First, referring to FIG. 11 the construction of the circuit pattern inspection system of this embodiment will be described. [0119] [0119]FIG. 1 is a chart to illustrate a system construction of the circuit pattern inspection system relating to the first embodiment of the invention. [0120] The circuit pattern inspection system relating to this embodiment is comprised of an analysis system 1 and an inspection instrument WI, which are connected to each other through a network Nt that enables them to exchange the commands and the data. [0121] The inspection instrument WI is equipment to inspect a semiconductor wafer W. The semiconductor wafer W is processed through a deposition system, exposure system, and etching system. Here, assuming that the semiconductor wafer W after etching is inspected, for example, the semiconductor wafer W is returned to the processing process that resumes from the deposition system. The data of the defects detected by the inspection instrument WI, for example, the coordinates of the defects, and the data of the sizes thereof are stored in an inspection data storage unit 21 provided in the analysis system 1 . [0122] On the other hand, the analysis system 1 is provided with a communication control unit 3 , data input/output unit 4 , retrieval unit 5 , memory 6 , input/output interface 7 , program memory unit 8 , operation unit 9 , main control unit 10 , display unit 11 . Further, as the data storage, the analysis system 1 contains the inspection data storage unit 21 , a storage unit for coordinate data chip areas 23 , and a storage unit for determination rule data 24 . [0123] The communication control unit 3 is a part to control the communications by the foregoing network. [0124] The data input/output unit 4 inputs/outputs data transmitted through the network. [0125] The retrieval unit 5 has a function to retrieve the data stored in the inspection data storage unit 21 , the storage unit for coordinate data chip areas 23 , and the storage unit for determination rule data 24 . [0126] The memory 6 is a part to temporarily memorize the data retrieved by the retrieval unit 5 . [0127] The input/output interface 7 is an interface to coordinate the timing of data exchange with the inspection data storage unit 21 , the storage unit for coordinate data chip areas 23 , and the storage unit for determination rule data 24 . [0128] The main control unit 10 administers the whole controls in the analysis system 1 , and the data input/output unit 4 , retrieval unit 5 , memory 6 , operation unit 9 , and program memory unit 8 are connected to the main control unit 10 and receive commands therefrom. [0129] The program memory unit 8 contains programs as the software to execute necessary processing. The program is read out at any time by the main control unit 10 to be executed. On the basis of this program, the operation unit 9 executes necessary operations. [0130] The display unit 11 is connected to the data input/output unit 4 to display the data from the inspection data storage unit 21 , the storage unit for coordinate data chip areas 23 , and the storage unit for determination rule data 24 . The display unit 11 is able to display and confirm these various inspection data, and also able to display the control chart of the lethal defect number as shown in FIG. 20 ( b ). [0131] Further, the display unit 11 may be installed in a different place from the analysis system 1 , and connected to the communication control unit 3 and data input/output unit 4 through the network Nt. [0132] The inspection data storage unit 21 , the storage unit for coordinate data chip areas 23 , and the storage unit for determination rule data 24 normally store the data in the auxiliary storage units such as a hard disk, optical disk, and floppy disk; and these data may be stored in different storage media or in the same storage media. [0133] Further, the analysis system 1 may be connected to a different system through the network Nt so as to transmit and receive the data of the inspection data storage unit 21 , the storage unit for coordinate data chip areas 23 , and the storage unit for determination rule data 24 . The different system is, for example, a system to calculate a statistical data from these data. [0134] Further, the analysis system 1 of this embodiment may be incorporated into the inspection instrument WI without the network Nt intervening between them. [0135] The operation unit 9 and the main control unit 10 may be formed as one and the same semiconductor circuit, or as different semiconductor circuits. The retrieval unit 5 , memory 6 , data input/output unit 4 , and communication control unit 3 may be formed as the same semiconductor circuit, or as different semiconductor circuits. [0136] Next, the principle of the method of determining the lethality of defects in the circuit pattern inspection of this invention will be described with reference to FIG. 2 through FIG. 7. [0137] [0137]FIG. 2 is a chip layout to illustrate a structure of circuit semiconductor devices. [0138] [0138]FIG. 3 is a table to illustrate X-Y coordinates and class values corresponding to each of areas. [0139] [0139]FIG. 4 is a table to illustrate a determination rule corresponding to each of class values. [0140] [0140]FIG. 5 is a typical chart to illustrate the measurement principle of defects in the inspection instrument. [0141] [0141]FIG. 6 is a typical chart to illustrate the principle of the dark field detection. [0142] [0142]FIG. 7 is a chart to illustrate the distribution of a brightness being the output of a defect by the dark field detection. [0143] The chip areas indicate areas formed by dividing a chip into a plurality of areas according to, for example, the circuit pattern width in use, as shown in the chip layout in FIG. 2, and the areas each are illustrated in rectangles. Each of the areas is expressed by the coordinate at the lower left of the rectangle and the coordinate at the upper right thereof. For example, the area RO can be expressed by the coordinates C 01 and C 02 , the area R 10 by the coordinates C 101 and C 102 , and the area R 40 by the coordinates C 401 and C 402 . [0144] The analysis system 1 of this embodiment divides a chip into each of the areas using the coordinates as shown in FIG. 3, and holds the class values corresponding to each of the areas. The class values are provided as the segments for inspecting for each of the areas. The analysis system contains a rule whereby the lethality of defects is determined for each of the class values, as described later. [0145] The records in the table shown in FIG. 3 includes the area No., the lower left coordinates (X1,Y1) and upper right coordinates (X2, Y2) of each of the areas as the coordinate data of the chip areas, and the area class to indicate the classes of areas. The coordinate data of the chip areas are written in by a manual input, or by reading in a file from a CAD data. The origin of coordinates C 01 of the coordinate data chip areas is converted so as to coincide with the origin of the chip coordinates of the inspection instrument WI. [0146] Next, the rule of determining the lethality of defects will be described with reference to FIG. 4 through FIG. 7. [0147] The determination rule lethality of defects is the rule provided for each of the areas, whereby the size of a defect, namely, the lethality of a semiconductor defect is determined in the inspection. [0148] This will be explained along with a concrete measurement method of the inspection instrument WI. [0149] A defect on a semiconductor wafer is measured by way of the size or the area of the defect that is illustrated by the vertical and horizontal dimensions as shown in FIG. 5. [0150] The defect becomes larger, as the X, Y becomes larger. [0151] If the size of the defect is conceived to be expressed by the area A detected by the inspection instrument, the following expression 1 is introduced. S s ={square root}{square root over (A)}   (expression 1) [0152] Or, if the size of the defect is expressed by the length, the following expression 2 and expression 3 are given. S L ={square root}{square root over (X·Y)}   (expression 1) S L =Max (X, Y)   (expression 3) [0153] From another view, the size of the defect can be expressed by the brightness of the defect when detected. FIG. 6 illustrates the principle of the dark field detection. This detection method is to detect a defect 202 on a semiconductor wafer W in such a manner that a laser beam source 200 irradiates laser beams 201 on the semiconductor wafer W, and a detecting device 203 detects the brightness of laser beams reflecting from the defect. That is, as the defect is larger, the light area becomes wider; and the location and size of the defect can be measured from the shape of the graph shown in FIG. 7. In this example, the size of the defect is classified into L-size, M-size, and S-size, and when a measured brightness exceeds the lines (indicated by S, M, L), the defect is classified as a defect of the concerned size. [0154] With these concepts, the determination rule is established such that when, to the area corresponding to the class value, the measured value thereat exceeds the value given in the table in FIG. 4, the defect is considered as lethal. [0155] [0155]FIG. 4 is a table that illustrates the correspondence between the data and the class values pertaining to this determination rule, concretely in terms of the length, area, and brightness. [0156] Accordingly, in terms of the length, if the following expression 4 is met, the defect is determined as lethal. S L ≧R L   (expression 4) [0157] In terms of the area, if the following expression 5 is met, the defect is determined as lethal. S S ≧R S   (expression 5) [0158] In terms of the brightness, if the brightness exceeding the L, M, S size in the table is measured, the defect is determined as lethal, and it is characterized by the following expression 6 . S B ≧R B   (expression 6) [0159] Here, S B is the maximum value of the brightness of the graph illustrated in FIG. 7, and R B assumes either one of the brightness of L-size, M-size, and S-size. [0160] These values R L , R S , R B , can be conceived as the thresholds defect size that indicate the thresholds of the size of a defect relating to the area corresponding to the class value. [0161] The data in this table can be determined from the design value of the representative pattern width or pattern spacing in the area to be measured. The threshold defect size R L , may take the equal value to the design value of the pattern width or pattern spacing. For example, as shown in FIG. 4, when the pattern width of a semiconductor circuit in an area is 0.25 [μm], the threshold defect size R L can be set to the same value 0.25 [μm] at the class value 0 . [0162] Next, referring to FIG. 8, the method of determining the lethality of defects in the circuit pattern inspection relating to this embodiment will be described. [0163] [0163]FIG. 8 is a flow chart to illustrate the method of determining the lethality of defects in the circuit pattern inspection relating to the first embodiment of the invention. [0164] The determination method lethality defect will be explained along with the flow chart in FIG. 8. [0165] First, the retrieval unit 5 retrieves the inspection data relating to the inspection process, coordinates of defects, sizes of defects, etc. stored in the inspection data storage unit 21 shown in FIG. 1, and the analysis system 1 accepts them in the memory 6 (S 202 ). The defect No. is assumed to be assigned to each of the defects. [0166] The analysis system 1 accepts the coordinate data chip areas from the storage unit for coordinate data chip areas 23 (S 101 ). [0167] The retrieval unit 5 retrieves the determination rule data corresponding to the inspection process accepted at step S 202 from the storage unit for determination rule data 24 , which are accepted in the memory 6 (S 203 ). [0168] The determination rule data are the data as already shown in FIG. 4. [0169] Next, a defective area is determined from the defect coordinates (x, y) accepted at step S 202 , and the class value L corresponding to the defective area is written in the memory 6 (S 206 ). [0170] This is a preparation for determining the lethality of defects that switches the determination rule data referring to the class value corresponding to this area. [0171] The determination of a defective area depends on whether the following expression 7 is satisfied for each area No., using the data in FIG. 3. X1<x<X2, Y1<y<Y2   (expression 7) [0172] The class value corresponding to a chip area is arranged to be overwritten in the order of the area No. With this arrangement, the class value corresponding to the larger area No. of the areas satisfying the expression 7 will automatically be written in the memory as the class value of the defect. [0173] After completing the preparation, the lethality of defects is determined (S 207 ). [0174] That is, the class value L corresponding to the area of the defect of the defect No. N is read out, and the threshold defect size corresponding to the foregoing class value shown in FIG. 4 is compared with the measured value, thus determining the lethality. Concretely, the threshold defect size includes the length, area, and brightness, and the determination is made with the expressions 4, 5, and 6, as mentioned above. [0175] If the defect is determined as lethal, the classification identifier F for the lethal defect is written in the memory 6 in correspondence with the defect of the defect No. N (S 208 ). If the defect is determined as non-lethal, the classification identifier NF for the non-lethal defect is written in the memory 6 in correspondence with the defect of the defect No. N (S 209 ). [0176] Further, N is assigned by N+1 (N=N+1), and the counter is incremented(S 210 ). If defect data are still present (S 211 ), the process returns to the step S 206 to continue the loop. [0177] If defect data are not present (S 211 ), the classification identifier F for the lethal defect and the classification identifier NF for the non-lethal defect which are written in the memory 6 at step S 208 and S 209 , and the class value written in the memory 6 at step S 206 are each written in the inspection data storage unit 21 in correspondence with each defect No. (S 212 ). [Second Embodiment] [0178] The second embodiment relating to this invention will be described with reference to FIG. 9 through FIG. 11. [0179] In the first embodiment, the coordinates brought into on a semiconductor wafer are employed in order to search defects on the semiconductor wafer. In the second embodiment, however, the coordinates on the semiconductor wafer are converted into the coordinates on the pixels, and thereafter the retrieval of defects and the assignment of class values are made. [0180] First, referring to FIG. 9, the system construction of the circuit pattern inspection system relating to this embodiment will be described in detail as to the different parts from the first embodiment. [0181] [0181]FIG. 9 illustrates a system construction of the circuit pattern inspection system relating to the second embodiment of the invention. [0182] The circuit pattern inspection system of this embodiment is not substantially different from the first embodiment, however, the analysis system 1 further includes an image data storage unit chip areas 22 , in addition to the construction of the first embodiment. [0183] The image data storage unit chip areas 22 allows data read and data write in accordance with the instruction of the main control unit 10 through the input/output interface 7 . [0184] Next, referring to FIG. 10, a processing to assign a class value to each of the pixels of area image coordinates will be described. [0185] [0185]FIG. 10 is a flowchart to illustrate a processing to assign the class value to each of the pixels corresponding to the area image coordinates. [0186] This processing can be called as the preparation processing in the method of determining the lethality of this embodiment. [0187] First, the initial value is set in the counter (S 100 ), and the retrieval unit 5 retrieves the coordinate data of chip areas stored in the storage unit for coordinate data chip areas 23 , and the analysis system 1 accepts them in the memory 6 (S 101 ). [0188] Next, of the coordinate data of chip areas accepted at step S 101 , the area data of the area No. n is converted into the coordinates (pixel coordinates) of the area image data (S 102 ). [0189] That is, the lower left coordinates (X1, Y1) and the upper right coordinates (X2, Y2) of the areas corresponding to the coordinate data chip areas shown in FIG. 3 are converted into the pixel coordinates according to the following expression 8 . IX 1 =Int (X 1/ P ) IX 2 =Int (X 2/ P ) IY 1 =Int (Y 1/ P )   (expression 8) IY 2 =Int (Y 2/ P ) [0190] Here, P represents a preset pixel pitch, and Int represents the function to round down after the decimal point. The pixels in X, Y directions are assumed to take on the same scale pitch. [0191] Next, the data of the class L are written in pixels IP (I, J) inside the area of a rectangle expressed by the converted pixel coordinates (IX1, IY1) and (IX2, IY2) (S 103 ). [0192] Further, the area No. n is assigned by n+1 (n=n+1), and the counter is incremented (S 104 ), and whether the data of the area No. n are still present in the coordinate data chip areas is determined (S 105 ). If the data are not present, the write-in is ended, the process goes out of the loop; and if the data are still present, the process returns to the step S 102 to continue the loop. [0193] The foregoing steps S 102 to S 104 is executed by the operation unit 9 , and the determination at the step S 105 is executed by the main control unit 10 . If the main control unit 10 determines that the write-in is ended, the main control unit 10 stores the area image data IP (I, J) having been stored in the memory 6 into the image data storage unit chip areas 22 through the data input/output unit 4 and input/output interface 7 . [0194] Further, it may be arranged to save the memory capacity of the image data storage unit chip areas 22 in such a manner that the image data chip areas are compressed to be written in the image data storage unit chip areas 22 and uncompressed to be read out. [0195] Next, the method of determining the lethality of defects in the circuit pattern inspection relating to this embodiment will be described with reference to FIG. 11. [0196] [0196]FIG. 11 is a flow chart to illustrate the method of determining the lethality of defects in the circuit pattern inspection relating to the second embodiment of the invention. [0197] The different parts from the first embodiment will mainly be described, referring to the flow chart in FIG. 11. [0198] First, the retrieval unit 5 retrieves the image data chip areas stored in the image data storage unit chip areas 22 , and the analysis system 1 accepts them in the memory 6 (S 201 ). The data here are the data in which the class values are assigned to the pixel coordinates, as mentioned above. [0199] Next, the retrieval unit 5 retrieves the inspection data relating to the inspection process, coordinates of defects, sizes of defects, etc. stored in the inspection data storage unit 21 shown in FIG. 1, which are accepted in the memory 6 (S 202 ). [0200] Further, the retrieval unit 5 retrieves the determination rule data corresponding to the inspection process accepted at step S 202 from the storage unit for determination rule data 24 , and the analysis system 1 accepts them in the memory 6 (S 203 ). The determination rule data are the data as already shown in FIG. 4, in which the thresholds defect size R L , R S , R B corresponding to the class value L are written in. [0201] Next, the counter of the defect No. N is initialized by N=1 (S 204 ). [0202] The defect coordinates (x, y) of the defect No. N are converted into the pixel coordinates (KX, KY) by the following expression 9 (S 205 ). KX=Int (x/P ) KY=Int (y/P )   (expression 9) [0203] Here, P represents a preset pixel pitch, which assumes the same value as in the expression 8. [0204] Further, IP (KX, KY) corresponding to the value of the pixel coordinates (KX, KY) of the area image data accepted at step S 201 , namely, the class value L corresponding to the concerned area is written in the memory 6 (S 206 ). [0205] Next, the lethality is determined from the defect sizes (S L , S S , S B ) of the defect No. N based on the determination condition (expression 4 ), (expression 5 ), (expression 6 ), and thresholds defect size (R L , R S , R B ) corresponding to the class values L (S 207 ). [0206] If the defect is determined as lethal, the classification identifier F for the lethal defect is written in the memory 6 in correspondence with the defect of the defect No. N (S 208 ). If the defect is determined as non-lethal, the classification identifier NF for the non-lethal defect is written in the memory 6 in correspondence with the defect of the defect No. N (S 209 ). [0207] Next, N is assigned by N+1 (N=N+1), and the counter of the defect No. N is incremented (S 210 ). [0208] Whether the inspection data still include defects to be investigated is determined (S 211 ); and if the data still remain, the process returns to the step S 205 to continue the loop. If the defects to be investigated do not remain, the process will be finished. Here, the classification identifier F for the lethal defect and the classification identifier NF for the non-lethal defect which are written in the memory 6 at step S 208 and S 209 , and the class value L written in the memory 6 at step S 206 are each written in the inspection data storage unit 21 in correspondence with each defect No., as the final step (S 212 ). [0209] As in this embodiment, to assign the class values in advance to the image data so as to utilize them makes it possible to acquire the class value corresponding to the very defective area in a higher speed, which is advantageous. [Third Embodiment] [0210] Next, the third embodiment relating to the invention will be described with reference to FIG. 12 through FIG. 18. [0211] First, referring to FIG. 12, the construction of the circuit pattern inspection system having a function to select a defect treated as a review object of this invention. [0212] [0212]FIG. 12 illustrates a system construction of the circuit pattern inspection system having the selection function of a defect treated as a review object of the invention. [0213] The circuit pattern inspection system having the selection function of a defect treated as a review object relating to this embodiment is provided with an analysis system 2 , the inspection instrument WI, and a review station RS, which are connected to each other through the network Nt so as to exchange commands and data. [0214] The review station is equipment that views the enlarged images of defects such as pattern shorts, pattern missing, particles, etc., from the optical microscope, scanning electron microscope, and the like to classify the defects. [0215] The inspection instrument WI is equipment to inspect a semiconductor wafer w. The semiconductor wafer W is processed through a deposition system, exposure system, and etching system. Here, assuming that the semiconductor wafer when the etching is completed is inspected, for example, the semiconductor wafer W is transferred to the review station RS, where the wafer W is reviewed and the defects are classified and analyzed. After the foregoing process is finished, the wafer W is returned to the processing process that resumes from the deposition system. [0216] The coordinates of the defects and the data of the sizes outputted from the inspection instrument WI are stored in the inspection data storage unit 21 provided in the analysis system 2 . The review station RS receives the coordinate data of defects to be reviewed from a review object data storage unit 25 , and moves the stage to the position of a defect. [0217] On the other hand, the analysis system 2 is similar to the construction of the second embodiment, and further contains the review object data storage unit 25 . [0218] As for the communication function, the analysis system 2 has the function to communicate with the inspection instrument WI, and in addition the function to communicate with the review station RS for exchanging commands and data, thereby exchanging review object data. [0219] Further, the analysis system 2 of this embodiment has the function to select the review object, in addition to merely inspect the circuit patterns; and therefore, the analysis system 2 holds the programs to carry out these functions in the program memory unit 8 . [0220] Next, the method of selecting a defect treated as a review object in the circuit pattern inspection of this invention will be described with reference to FIG. 13. [0221] [0221]FIG. 13 is a flow chart to illustrate a processing procedure of the method of selecting a defect treated as a review object. [0222] Here, the principle of selecting a review object will also be explained along with FIG. 13. Here, to simplify the explanation, the defect size takes on the length, the value defect size is given by S L , and the threshold defect size is given by R L ; in the similar manner, the defect size may take on the area or the brightness in the dark field detection. [0223] Here, it is assumed that before starting the process to select a defect treated as a review object, the process to determine the lethality of defects described in the first and second embodiment has be performed, and the classification identifiers of defects and the class values L have already been analyzed and written in the inspection data. [0224] First, the inspection process to be reviewed and the defect selection number Nmax review object are inputted into the analysis system 1 by an input means such ad a keyboard (not illustrated). The analysis system 1 transfers the inputted data through the data input/output unit 4 to the memory 6 , which stores them (S 301 ). Here, the defect selection number Nmax review object is the upper limit number such that more than this number of reviews will not be executed. [0225] Next, on the basis of the inspection process stored at step S 301 , the retrieval unit 5 retrieves the defect coordinates, defect sizes, and class values L of the concerned inspection process stored in the inspection data storage unit 21 , and the analysis system 1 accepts them in the memory 6 (S 302 ). [0226] Next, the retrieval unit 5 retrieves the determination rule data from the storage unit for determination rule data 24 , which are accepted in the memory 6 (S 303 ). [0227] Further, the ratio S L /R L of the defect size S L against the threshold defect size R L corresponding to the class value L is calculated for each defect. Generally, as this ratio is greater, the defect can be considered as more critical, namely, as having more necessity of the review. Accordingly, the ratio S L /R L is sorted in the descending order (S 304 ). [0228] Next, Nmax number of defects are selected from the top of the data sorted in the descending order at step S 304 (S 305 ), which are written in the review object data storage unit 25 (S 306 ). [0229] In this case, the upper limit number treated as the review object data is determined at the first stage; however, when the ratio S L /R L is more than a certain value, the defects may be regarded as critical to be selected as the review objects. Further, the order of the class having the priority in the review selection may be inputted at step S 301 , and the defects may be sorted on the basis of the order of the class having the priority at step S 304 . [0230] This principle makes it possible to select a defect of the chip area to which a review operator should give a higher priority of the review. [0231] Further, the maximum review selection number Icmax per chip in a wafer is inputted at step S 301 , and if the review selection number per chip exceeds Icmax during the selection of defects at step S 305 , a process may be added, wherein the selection of defects of the number exceeding Icmax is not allowed as the review object. [0232] Thus, setting the upper limit of the review number per chip makes it possible to appropriately select the defects of review object from the whole wafer, even when defects cluster in one and the same chip. [0233] Up to now have been described the method, principle, and processing procedure of selecting defects to be reviewed in the circuit pattern inspection of this invention, however, further improvements of this invention will be described next. [0234] First, the method of selecting an appropriate review object in view of defects emerging by each process will be described with reference to FIG. 14 and FIG. 15. [0235] [0235]FIG. 14 is a bar graph to illustrate a transition of the number of defects review object by each process. [0236] [0236]FIG. 15 is a typical chart to illustrate an example of a method to specify a process that causes a defect. [0237] Generally, semiconductor devices are manufactured by repeating the processes of the deposition, exposure, and etching, while the inspection is carried out at each process. [0238] The relation of cause and effect between the process and the number of emerging defects treated as review objects will now be examined. Suppose that a process A, process B, and process C are carried out in this order. Then, the number of the defects treated as review objects that are detected by each of the processes has a tendency as shown in FIG. 14. That is, as the proceeding advances to the subsequent processes, the defects generated in the previous processes are detected in accumulation. [0239] Accordingly, in the review of defects performed after the subsequent process is finished, it is inefficient to consider the defects caused by the previous process. Therefore, in the selection of review objects, it is important to detect the defects generated by the concerned process only and treat the detected therein as the review objects. [0240] Therefore, in this invention, each of the defects produced by each process is segmented and processed as follows. [0241] [0241]FIG. 15 plots the coordinates of defects generated in a by semiconductor wafer W typically by each process. The coordinate data 212 of defects detected in the previous process are expressed by □ and Δ, and the coordinate data 213 of defects generated only in the subsequent process (current process) are expressed byX. The coordinate data 211 of defects detected in the current process are the sum of the foregoing two coordinate data. [0242] Therefore, the coordinate system of the coordinate data 211 of defects in the current process is aligned with that of the coordinate data 212 of defects in the previous process; and on the identical coordinate system, from all the coordinate data 211 of defects detected in the current process are subtracted the coordinate data 211 of defects in the current process that are coincident with or close within a preset allowance to the coordinate data 212 of defects detected in the previous process. As the result of the foregoing subtraction, the coordinate data 213 of defects that are newly generated in the current process are obtained, which are stored in the data storage unit review object 25 as defect data to be reviewed. [0243] With this arrangement, only the defects generated in the current process can be selected as the review objects, and therefore, the defects already reviewed at the previous process will not be reviewed again, thus avoiding waste. [0244] Next, the method of selecting a defect treated as a review object in which the relation between the process and the outbreak mode of defects is taken into consideration will be described with reference to FIG. 16 through FIG. 18. [0245] [0245]FIG. 16 is a typical chart to illustrate a state in which a review object is selected out of cluster defects. [0246] [0246]FIG. 17 is a chart to specify the process that causes cluster defects, which points out the problem in the conventional technique. [0247] [0247]FIG. 18 is a typical chart to illustrate cluster defects generated in each process. [0248] If a semiconductor wafer includes large defects, for example, scratches or the like, the inspection instrument WI detects the defects as groups of multiple defects, namely, cluster defects. The cluster defects are contrasted with the random defects that appear on a semiconductor wafer at random. [0249] The conventional technique was inefficient to review the cluster defects, because the cluster defect data are registered as individual defect data in the inspection data storage unit 21 , individual defects constituting a large defect have to be reviewed one by one, even if one and the same cause generates the large defect. [0250] Accordingly in this invention, when cluster defects are detected, the review objects of the defects are classified in a reasonable manner as follows. [0251] As shown in FIG. 16, the defects whose coordinate data are close are classified into cluster defects on a certain criterion. In FIG. 16, there are two cluster defects, which are classified into the cluster classification number 1 and the cluster classification number 2 ; and the other defects, namely, the random defects are given the cluster classification number 0 . [0252] On this condition, all the defects in one cluster are not made to be reviewed, and some of them are made to be reviewed. Here, it is assumed that the defect C is selected as a review object and the review classification number 100 is assigned thereto as the result of the review. The review classification number is a code to classify the results of the review (for example, pattern missing, pattern short-circuited, particles being present, etc.). [0253] The defects having the same cluster classification number will not be reviewed, and the same review classification number as that of the defect C is assigned thereto. In this example, the review classification number 100 is also assigned to the defect A and defect B, the same as the defect C. [0254] If a plurality of defects belonging to the same cluster are reviewed to acquire different review classification numbers, it is only needed to determine a rule in which a review classification number most found, for example, is picked up and that classification number is assigned to the defects belonging to the concerned cluster. [0255] Thus, even if a wafer includes cluster defects being large defects such as scratches, it becomes possible to assign a review classification number for the whole cluster to all the defects belonging to the cluster only by the review of some defects constituting the cluster. [0256] Further, in the foregoing cluster, a cluster of defects in a short distance is treated as a group. However, the grouping may be arranged such that the physical properties of defects such as the size, brightness, color, shape, and the like of defects detected by the inspection instrument are stored in the inspection data storage unit 21 , and the defects are classified on the basis of these physical properties. Thus, in the other case than the cluster defects, the grouping of defects having the same physical properties and only the review of some defects in a group make it possible to assign a review classification number for the whole group to all the defects belonging to the group, in the same manner as the foregoing. [0257] Next, a method of the review when the cluster defects generated in each process overlap will be described with reference to FIG. 17 and FIG. 18. [0258] Here, it is assumed that the process A is the previous process and the process B is the current process. [0259] In the defects on a semiconductor wafer, the previous process is likely to trigger a defect that will give an influence on the subsequent processes. Assuming that the defects in this case are in diffusion, the cluster mode will become such that the cluster 216 of the process B encloses the cluster 217 of the process A, as shown in FIG. 18( a ). [0260] Although the cluster mode does not become the enclosure as shown in FIG. 18( a ), there can be a case such that a part of the cluster is shared with each other as shown in FIG. 18( b ), in case a defect of the process A induces a defect in the process B. Further, if the inspection instrument WI involves differences of the detection sensitivity between the processes; for example, if the detection sensitivity at the previous process A is lower than the detection sensitivity at the subsequent process B, there can be a case that the defect having already been generated in the previous process A is detected at the subsequent process B. [0261] In such a case, to subtract the coordinate data formally as shown in FIG. 15 will hardly lead to a correct classification for the review. That is, in the cluster mode of FIG. 18( a ), to subtract the cluster 217 of the previous process A from the cluster 216 of the current process B gives a doughnut-type cluster, as shown in FIG. 17; however, if this is regarded as the cluster of defects generated in the current process, it will be contrary to the fact. [0262] Accordingly, when the same cluster defects are detected across the processes in this manner, the defects are assumed to be the ones that have been generated in the previous process. The review classification number obtained therein is made to be assigned to the defects belonging to both the clusters. This arrangement will eliminate the cluster defects detected across the processes from being reviewed individually in each process, and will further cancel the differences of sensitivities of the inspection instrument between the processes and enable the review in accordance with the cause to generate the cluster defects; and therefore, it becomes possible to maintain the quality of the review and enhance the efficiency of the review. [0263] In an actual processing, based on the coordinates of individual defects belonging to the clusters of the process A and the process B, a cluster defective area is expressed as, for example, the maximum/minimum values of the coordinates of defects in the cluster (namely, the cluster is apprehended as a plane). If the cluster defective area of the process A includes an overlapping part with the cluster defective area of the process B, it is needed to add a processing that gives the same review classification number as that of the defects belonging to the cluster of the process A to all the defects belonging to the cluster of the process B. [0264] In another processing, the whole wafer is divided into blocks each of which has about some hundred μm 2 to allocate addresses to the blocks, and the block that holds cluster defects is expressed as the address. If the cluster defective area of the process A includes an overlapping block with the cluster defective area of the process B, it may be arranged to add a processing which gives the same review classification number as that of the defects belonging to the cluster of the process A to all the defects belonging to the cluster of the process B. SUMMARY OF THE EMBODIMENTS [0265] The invention will provide the method of determining the lethality of a defect that automatically determines the lethality of the defect without performing the review to enhance the efficiency of the inspection, when circuit patterns formed on a substrate such as a semiconductor wafer are inspected, and the inspection system to achieve the foregoing method. [0266] Further, the invention will provide the method of automatically selecting a defect to be reviewed, whereby the review in the circuit pattern inspection can efficiently be performed and the quality of the inspection itself can be maintained, and the inspection system to achieve the same.

A method of reviewing defects on a substrate. The method includes inputting information of defects on a substrate detected by a detection apparatus, identifying cluster of defects detected on the substrate by using the inputted information, selecting defects to be reviewed from the cluster identified, reviewing the selected defects, and classifying the reviewed defects.

FIELD OF THE INVENTION [0001] The present invention relates generally to semiconductor wafer fabrication and more particularly but not exclusively to process control methodologies for maintaining consistent oxide thickness control. BACKGROUND OF THE INVENTION [0002] Demand for semiconductors, wafers, integrated circuits and semiconductor devices (i.e., collectively “semiconductors”) continues to rapidly increase. With the continued market demand, there remain market pressures to increase the number of wafers that can be processed, reduce the geometries of finished wafers and their associated chip footprints, and increase component counts in the reduced geometries. Being able to sustain and meet the market demands with a reliable and consistent offering is a challenge however, in part because wafer manufacture is an environment that is both process sensitive and equipment intensive. [0003] The fabrication of wafers (i.e., fabrication, fab, or fab environment) requires advanced processing equipment, unique toolings and extensive research efforts. Process tools (i.e., toolings) in these environments may often run in parallel or have multiple components to produce similar products (i.e., yields or outputs). Yet these same process tools, even when of the same manufacturer or source, may have unique variances in their individual performances which may create substantial or measurable differences in the quality of the products produced if unaccounted for. [0004] A process tool may include a furnace, a furnace having a plurality of chambers, a furnace bank, a furnace tube, a processing chamber in which a wafer is acted upon, a processing activity point in a fab line where a wafer may be received or acted upon, and the like. In other aspects, a process tool may further include a controller or control mechanism for controlling a process tool and the tool's acts or actions with respect to the fab activity, in response to one or more commands, instruction sets, hardware or software commands, or other control-based directions of the controller. [0005] As a result, in a traditional approach, it is often attempted to match the tool performance characteristics (TPCs), including machine characteristics, between process tools performing similar operations in one or more fab operations. With this approach, it is incorrectly believed that matched TPCs between similar process tools, even if identical in manufacturer and type, will result in identical or near-similar yields from each of the matched process tools. Unfortunately, even with matched process tools, yields are often subject to significant variance in what may otherwise appear to be an identical fab process. [0006] An attempt to improve upon the traditional approach has also proven unfavorable where oxidation time of a particular process tool is adjusted in relation to the yield result so as to achieve a desired yield output and characteristic. Unfortunately, even with this attempted improvement, the traditional approach remains faulted as these time adjustments are limited to a single fab process for a single fab recipe on a particular process tool. This approach is not suited to accommodate typical fab production runs and foundry services having tens or hundreds of distinct processes being performed across tens or hundreds of process tools. [0007] FIG. 1A depicts an example of a typical wafer 100 produced by a process tool in a process. In FIG. 1A , the wafer 100 has elements which may vary with respect to the type of process tooling and fab process undertaken in its manufacture, including a substrate 120 and a memory cell area 130 . A memory cell often includes two or more field oxide areas (i.e., isolation regions) 110 which are often grown areas of oxide formed by a local oxidation of silicon (LOCOS) process. [0008] The LOCOS process is in effect an isolation scheme commonly used in metal oxide semiconductors (MOS) and complementary MOS (CMOS) technology in which a thick pad of thermally grown SiO2 separates adjacent devices such as P-channel MOS and N-channel MOS transistors. Local oxidation is often accomplished by using silicon nitride to prevent oxidation of silicon in predetermined areas, and silicon is typically implanted between a silicon nitride region to form channel stops. [0009] From FIG. 1A , the memory cell 130 is formed above an active area 140 of the substrate 120 and is situated typically between the adjacent field isolation regions 110 . The memory cell 130 typically comprises a gate insulation layer 135 (i.e., tunnel oxide layer), a floating gate electrode 145 (often of polysilicon), a composite inter-poly insulation layer 150 , and a control gate electrode 160 (often of polysilicon). In many implementations of the example of FIG. 1A , the insulation layer 150 is also known as an oxide-nitride-oxide (ONO) layer as it is often comprised of a layer of silicon dioxide 151 , a layer of silicon nitride 152 and a layer of silicon dioxide 153 , though other variations are also known. [0010] From FIG. 1A , the thickness and dielectric constants of the floating gate electrode 135 and the layers of each of the ONO layer (i.e., 151 , 152 and 153 ) may affect the overall performance of the memory cell and the associated integrated or electronic circuitry, depending on their thickness and formation details. Similarly there are also other characteristics of the memory cell related to physical structures, thickness, conductivity, uniformity, capacitance, band voltage, resistance, and growth impacts due to temperature and/or pressure during the deposition process, which may affect performance which directly results from a process tool's operation on the wafer (i.e., collectively “performance variables,” “performance variances” or “performance characteristics”). [0011] Further, in the semiconductor fabrication field in particular, APC (advanced process control) may be employed in device manufacturing below 100 nm. The APC activities typically will need a stable thermal process, such as the one that significantly reduces wafer-to-wafer, batch-to-batch, and furnace-to-furnace differences, such that minimizing parameter variance is important when fabs process the same recipe, in multiple tools, for productivity and cycle time. [0012] In a traditional furnace or furnace bank, there may exist more than one furnace tube in which a predetermined number of furnace tubes perform a similar process. FIG. 1B depicts a typical eight-tube furnace bank arrangement 190 . [0013] By example, the furnace bank of FIG. 1B is a process tool having two four-furnace banks at 191 a and 191 b , totaling eight similar separate tubes (i.e., furnace tubes) ( 191 a , 191 b , 191 c , 191 d , 191 e , 191 f , 191 g , and 191 h ), each arranged to perform a furnace-based activity on a wafer set in the fab process. In a typical arrangement 190 , each tube is arranged to receive a set of silicon wafers ( 192 a , 192 b , 192 c , 192 d , 192 e , 192 f , 192 g , and 192 h ) which are typically received by the respective tube of the arrangement 190 . In FIG. 1B , by example, wafer set 192 h is about to be received into the proper bay area of furnace tube 191 h , while all other wafer sets have been properly positioned in their respective tube bay. At 193 a , 193 b , 193 c , 193 d , 193 e , 193 f , 193 g , and 193 h are controllers each of which controls its respective furnace tube along 194 a or 194 b . A heat source is also an integral feature of a typical furnace (not shown). Once the wafers are inserted into the their respective tubes, the wafers are acted upon in accordance with the designated process, and thereafter removed. Once removed, yield variations of the wafers may be determined and compared. [0014] Variances in the yield (e.g., produced semiconductor or memory cell) are often quantitatively determinable, even after attempting to traditionally match process tool or machine TPCs between similar process tools. Some of the yield variances can be determined quantitatively in the produced wafer's film thickness, stress, and dopant percentages, each of which is also directly associated with predictable comparative performances of the produced wafer. [0015] With these traditional approaches, there are a number of limitations, however. [0016] For instance, since yield variations and the associated results are uniquely dependent on at least both their respective process tools and specific fab recipes, in high capacity operations having substantial furnaces and recipe demands, significant numbers of recipes and/or equipment may need to be uniquely tailored and tuned for each process step. In such operations, even after these unique tunings are performed, further tunings may further be required in each tool every time there is even a minor adjustment needed to a tool, a recipe, or process. [0017] In yet other instances, the traditional approaches are limited for furnace oxidation sequences where the oxidation time is varied for the same single recipe. With this approach, different oxidation times will yield oxides having different characteristics as each of the oxides in their respective tools are in effect growing at different rates and are therefore different. As a result time and temperature are not accurately controlled in the process sequence which is contrary to what is desired. [0018] Therefore, optimally producing high-quality products in fab environment yielding consistency in produced wafers, fewer performance variances in process steps and reduced steps for recipe and process-specific tool variations, is desired. Additionally, limiting such performance variances commonly across a set of similar process tools, and in particular, improving consistency in yield output for similar-functioning but different process tools in a fab environment is also needed. Further, it is highly is desired to be able to match multiple differing line tools, such as furnaces, to develop consistency in process controls for oxide thickness control and particularly that of gate oxides. [0019] The present invention in accordance with its various implementations herein, addresses such needs. SUMMARY OF THE INVENTION [0020] In one implementation of the present invention, a method of fabricating a semiconductor device using a process tool in a process for improved consistency control in oxide thickness formation, the method comprising: defining one or more performance variables of the process tool directly associated with oxide thickness formation in the process, conducting one or more experiments to determine at least one performance factor from the one or more performance variables, and modifying the process tool in the process to operate in relation to at least one performance factor, is set forth. [0021] In another implementation, the present invention is an improved method of fabricating a semiconductor for improved oxide thickness control, comprising: defining a process tool in a fabrication process capable of acting on a semiconductor, determining one or more performance variables, evaluating the one or more performance variables affect on yield consistency in the process using the process tool, determining a performance factor, and modifying control of the process tool to operate in relation to the at least one performance factor. [0022] In a further implementation, the present invention is a semiconductor device having one or more oxide gates of a general consistency developed from a process comprising: defining a process tool, determining one or more performance variables, determining a performance factor, and modifying control of the process tool in the fabrication process to operate in relation to the at least one performance factor, with one or more control rules. [0023] In a further implementation, the present invention is a transistor having consistent oxide gates using the method of the present invention in one or more implementations. [0024] In still a further implementation, the present invention is a computer program product for controlling a process having a process tool using the method of the present invention in one or more implementations. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1A depicts an example of a typical wafer, produced by a process tool in a process; [0026] FIG. 1B depicts a typical eight tube furnace bank arrangement; [0027] FIG. 2 depicts a process flow for an implementation of the present invention; [0028] FIG. 3A depicts a particular process flow for a horizontal atmospheric furnace in accordance with an implementation of the present invention; [0029] FIG. 3B depicts an example of a particular process flow 399 for a set of horizontal atmospheric furnaces with a predetermined evaluation schedule for adjustment, in accordance with an implementation of the present invention; [0030] FIG. 3C depicts an example of a particular process flow for a set of horizontal atmospheric furnaces using a predetermined factor, in accordance with an implementation of the present invention; [0031] FIG. 4A depicts results for field oxidation of an experiment set for a horizontal atmospheric furnace, including an associated distribution result, without temperature matching, using a traditional approach; [0032] FIG. 4B depicts results for field oxidation of an experiment set for a horizontal atmospheric furnace, including an associated distribution result, with temperature matching, in accordance with an implementation of the present invention; [0033] FIG. 5A depicts results for field oxidation of an experiment set for a horizontal atmospheric furnace, including a field oxide thickness association, without temperature matching, using a traditional approach; [0034] FIG. 5B depicts results for field oxidation of an experiment set for a horizontal atmospheric furnace, including a field oxide thickness association, with temperature matching, in accordance with an implementation of the present invention. DETAILED DESCRIPTION [0035] The present invention relates generally to semiconductor wafer fabrication and more particularly but not exclusively to advanced process control methodologies for maintaining consistent oxide thickness control. [0036] The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein. [0037] As used herein, the term “tools” and “process tools,” whether singular or plural, are intended to include tools and equipment in the semiconductor fabrication process, without limitation, such as diffusion furnaces, atmospheric diffusion furnaces, low-pressure chemical vapor deposition (LPCVD) poly and nitride systems, and plasma-enhanced chemical vapor deposition PECVD) systems. Further, a tool or process tool, in an implementation of the present invention, may comprise equipment or tooling of a process and an associated controller for controlling the action of the tool. Similarly, a tool may further comprise a metrology tool. Operatively, a wafer is intended to be provided to the process tool where a process operation will be performed on the wafer. The controller of the tool may be used to affect a performance variable and its affect on a wafer. The controller may further use feed-forward or feedback metrology data to affect such performance variables, singly or in groups of more than one or more at a single instance. [0038] FIG. 2 depicts a process flow 200 for an implementation of the present invention. From FIG. 2 , for a semiconductor fabrication process, a process tool is selected at 210 . [0039] With reference to the selection of the process tool at 210 , performance variables of the process tool are determined at 220 and their respective potential fabrication impacts on performance of produced semiconductors (i.e., wafers) are determined by predetermined experimentation at 230 . Experiments at 230 may be actual or modeled, one or more than one, a set, or sets of experiments, and may include physical experiments or virtual experimentation, without limitation. Experiments at 230 are conducted in view of one or more characteristics of the process tool (i.e., input, outputs, variables, operational limitations, etc.) which may affect the thickness and/or consistency of oxide formation. [0040] Once the experiments of 230 are performed, an evaluation of results is conducted to determine performance factors of the process tool at 240 , which may affect the thickness and/or consistency of oxide formation in one implementation. The determined performance factors may be a single variable or may include more than one. The determined performance factor of 240 is the critical performance factor for the process tool of the particular experiments of 230 . [0041] Once the performance factor is determined at 240 , the process tool may be modified directly, by its controller, or by various input, output or other operative means to reflect the findings of the performance factor. For instance, a process tool controller may limit the operative aspects of the process tool for a particular performance characteristics (i.e., such as temperature) from the experimental results obtained. In limiting the process tool accordingly by the present invention, the process tool is operative only within a prescribed spectrum such that its operation is controlled to produce a consistent and predictable thickness of oxide for the semiconductor in its process operation. Thereafter, in a further implementation, additional analysis may be undertaken to further refine the findings and prepare a process operation operative to include optimal tool performance of one or more tools. [0042] FIG. 3A depicts an example of a particular process flow 300 for a horizontal atmospheric furnace, in accordance with an implementation of the present invention. [0043] From FIG. 3A , the Process Tool of a horizontal atmospheric furnace is selected at 310 . In reference to the selection at 310 , performance variables of the horizontal atmospheric furnace are determined at 320 and their respective potential fabrication impacts on performance of produced wafers are determined by predetermined experimentation at 330 . Experiments at 330 may be actual or modeled, and may include physical experiments or virtual experimentation, without limitation. [0044] By way of example, a set of experiments in a particular implementation of the present invention was developed. The set of experiments including using a 100% dry O 2 recipe commonly for each experiment in the set in which after the recipe was run, oxide thicknesses of tube-to-tube comparison were performed. The set of experiments, which may be further associated with FIG. 3A , included matching metrology capabilities (i.e., film measurement metrology and machine parameter metrology) at 340 and the experiments included: (i) measuring profile thermocouple (TC) mV outputs between furnace tubes during fabrication at set intervals of time; (ii) measuring fixed DC mV values input into furnace controllers; and, (iii) assessing dry oxide growth rates for matched furnace tubes within the metrology capability, in relation to hardware and firmware. [0045] From the set of experiments conducted, results of measuring the oxide thicknesses of tube-to-tube comparisons at 350 indicated the following: (i) when measuring profile thermocouple (TC) mV outputs between furnace tubes during fabrication at set intervals of time, no detectable or significantly measurable differences were determined; (ii) when measuring fixed DC mV values input into furnace controllers, no detectable or significantly measurable differences were determined; and, (iii) when assessing dry oxide growth rates for matched furnace tubes within the metrology capability, differing dry oxide growth rates were apparent. Since the differing dry oxide growth rates were measurable, a growth rate performance factor (i.e., apparent growth temperature offset) was identified at 360 as the critical performance factor for the process tool of this particular set of experiments. [0046] At 370 , the performance factor is tested with respect to the process tool of the original experiment set, and for this particular experiment, the controller of the furnace control software was then programmed with a thermocouple (TC) calibration offset in relation to the dry oxide growth rate of a furnace. For instance, if a furnace demonstrated a higher dry oxide growth rate, a positive TC offset would be programmed with the controller of the furnace control software to reduce the water temperature used in the furnace. Since the offset affects a global performance variable for the furnace (or tool) particularly, each recipe undertaken by the furnace having its respective offset would not require any further or unique modification, as set forth at 380 . [0047] In preparing the offset findings for production, a further assessment is undertaken to determine possible ranges of the offset, or banding, at 390 . For production, with respect to the tool of interest, and more particularly for the horizontal atmospheric furnace, it is of interest to provide guard bands on the determined offset to control the furnace and avoid using temperature directly to compensate for other process tool variables. By further experimentation, it was determined for this experiment set that a guard range of temperature operation was determinable. [0048] FIG. 3B depicts an example of a particular process flow 399 for a set of horizontal atmospheric furnaces with a predetermined evaluation schedule for adjustment, in accordance with an implementation of the present invention. [0049] From FIG. 3B , the set of horizontal atmospheric furnaces are predetermined at 391 . For the example of the present implementation, the set of furnaces comprise eight furnace tubes and a controller set having single control capability for each controller of each furnace tube. The performance variables of the furnace set are determined at 392 where performance variables such as time, temperature, pressure, gas flow, and wafer positioning are evaluated for inclusion in experimentation to determine the impact and effect of the performance variables at 393 . Experiments at 393 for the implementation were determined to be actual experiments where trials were run. [0050] One of the experiments of a set of experiments at 393 was defined to include determining the thickness of oxide from yield results of each furnace tube, using a 100% dry O2 recipe commonly for each experiment. The set of experiments, which may be further associated with FIG. 3B , included matching metrology capabilities (i.e., film measurement metrology and machine parameter metrology) in preparation for experiments at 394 a . As part of the experiment set, three experiments were conducted to determine and identify a dominant global factor (i.e., a primary performance factor which commonly affected all recipes of a process tool). The experiment set included: (i) measuring profile thermocouple (TC) mV outputs between furnace tubes during fabrication at predetermined intervals of time; (ii) measuring fixed DC mV values input into furnace controllers of each furnace tube; and, (iii) measuring temperatures between furnace tubes. [0051] From the set of experiments conducted, results were assessed at 394 b . The results of the experiments identified a single common performance factor of differing dry oxide growth rates for yields from the various furnace tubes. Based on these results at 394 b , the dominant global performance factor of apparent growth temperature offset was determined at 394 c in relation to process tools of 391 . [0052] At 395 , the dominant global performance factor was tested with respect to the various furnace tubes, with their associated controllers each being programmed with a thermocouple (TC) calibration offset in relation to the dry oxide growth rate of the respective furnace tube. Additional yields for the furnace tubes were then produced with respect to the implemented dominant global performance factor as an associated offset, with guard bands having been programmed into the controller for all oxidations (wet or dry) between 850 degrees C. and 1200 degrees C. No unique issues or further adjustments to the factor were identified as being required at 396 . Similarly, as no further adjustments were required, the earlier controls set for each furnace tube at 395 were effectively completed for an adjusted furnace tube, ready for production at 397 . [0053] Accordingly, at 398 a , each furnace tube, in view of certain equipment characteristics or TPCs of each tube, was provided with n evaluation date (EVAL). The EVAL was determined uniquely for each furnace tube in relation to its age, performance history, repair history, manufacture, and similar characteristics. The EVAL date was then set forth for each furnace tube, where upon the occurrence of an EVAL date, a second assessment using an implementation of the present invention was conducted per 398 b. [0054] In a further implementation of the present invention, a reference table is used to determine a performance factor. FIG. 3C depicts an example of a particular process flow 389 for a set of horizontal atmospheric furnaces using a predetermined factor, in accordance with an implementation of the present invention. From FIG. 3C , in accordance with data derived from a series of empirical experiments of process tools in a fab environment, a performance factor is defined without experimentation as set forth in Table 1. [0000] TABLE 1 Process Tool Factor LPCVD (Polysilicon) Process Pressure LPCVD (Nitride) Temperature PECVD Silane Gas Flow Atmospheric Tube Temperature [0055] In accordance with Table 1, where the process tool is an atmospheric furnace, the factor determined to be a global factor common to affect all recipes of a process tool is temperature. [0056] From FIG. 3C , a set of horizontal atmospheric furnaces are predetermined at 381 . The performance variables of the furnace sets are determined at 382 in accordance with Table 1, at 383 . From Table 1, the dominant performance factor for the present implementation of FIG. 3C is defined to be temperature. Process tool metrology is determined at 384 . Yields for the furnace tubes are then produced with respect to the implemented dominant global performance factor of temperature as an associated offset, with guard bands having been programmed into the controller for all oxidations (wet or dry) between 850 degrees C. and 1200 degrees C., at 385 . No unique issues or further adjustments to the factor or process tools were identified as being required at 386 . Similarly, as no further adjustments were required, the earlier controls set for each furnace tube at 385 were effectively completed for an adjusted furnace tube, ready for production at 387 . Further, at 388 a , each furnace tube, in view of certain equipment characteristics or TPCs of each tube, was provided with n evaluation date (EVAL). The EVAL was determined uniquely for each furnace tube in relation to its age, performance history, repair history, manufacture, and similar characteristics. Optionally, the EVAL for a process may also be determined in view of the process tool set, the fab line or any one or more characteristics of any of the process tools therein. The EVAL date was then set forth for each furnace tube, where upon the occurrence of an EVAL date, a second assessment using an implementation of the present invention was conducted per 388 b. [0057] Although Table 1 was provided for the example of FIG. 3C , it will be appreciated that the present invention is not so limited as an alternative table, look-up program instructional, or computer code parameter may be employed having differing factors, offsets, relational variables and variants, step functions, and other alternative relationships in result to or in relation to further experiments, testing and similar events as may be predetermined by a user. [0058] FIG. 4A depicts results 401 for field oxidation of an experiment set for a horizontal atmospheric furnace, including an associated distribution result, without temperature matching, using a traditional approach. FIG. 4B depicts results 402 for field oxidation of an experiment set for a horizontal atmospheric furnace, including an associated distribution result, with temperature matching, in accordance with an implementation of the present invention. FIG. 4A shows a wider distribution at 410 using a traditional approach and FIG. 4B shows a narrower distribution at 420 with the offset of the experiment set in accordance with an implementation of the present invention. [0059] FIG. 5A depicts results 501 for field oxidation of an experiment set for a horizontal atmospheric furnace, including a field oxide thickness association, without temperature matching, using a traditional approach. FIG. 5B depicts results 502 for field oxidation of an experiment set for a horizontal atmospheric furnace, including a field oxide thickness association, with temperature matching, in accordance with an implementation of the present invention. FIG. 5A shows a wider distribution at 510 , without temperature matching using a traditional approach and FIG. 5B shows a narrower distribution at 520 with temperature matching. [0060] Using the method of the present invention in accordance with a further particular implementation for a PECVD film, an experimental set involving the deposition of phospho-silicate glass (PSG), boron-phospho-silicate glass (BPSG), undoped silicate glass (USG) and other variants of silicon nitride were deposited and tested to determine the performance factor. In this manner, for this implementation of the present invention, the traditional approach is avoided and a performance factor associated with deposition rate is determined as being common to the processes to be undertaken by the process tool. Tool information was also supplemented using vendor-based information of the tool as well as historical data from experiential testing. Test results indicated that silane gas flow was the performance factor of interest for the specific experimental set. Results of the experimental agree with the understanding that control stability of PECVD gases is generally reasonable, except for silane, as silence mass flow controllers (MFCs) drift due to gas phase reactions inside the typical narrow flow tube. [0061] The experimental set, in accordance with an implementation of the present invention, determined guard limits for silane correction factors. Further, the resulting ability to control oxide thickness also realized significant improvement in dopant (B and P) control. [0062] By way of further example, using the method of the present invention in a further implementation, similar results yielding deposition pressure in relation to polysilicon and temperatures for nitride (Low-pressure chemical vapor deposition (LPCVD) poly and nitride) were also successfully determined. [0063] The present invention is further advantageous over traditional methods as no additional upgrades are required in the functional or operative nature of the fab process to which it impacts, as in general, performance variables are determined within the existing process and modifications within the process and its aspects are determined as a result of the present invention, resulting in less engineering time, improved process controls and improved cycle-times. A further advantage is that the present invention does not require the need to “profile” tooling such as furnaces, contradistinctive to the traditional approach, but instead, the present invention may be operable using a routine dry oxidation recipe. Additionally, further analysis has demonstrated that the present invention also extends changeout cycles of TCs and the need for vendor calibration formalities is reduced. [0064] As used herein, it will be understood by those in the art that in practice, a memory array may be comprised of thousands of the memory cells. [0065] As used herein the terms “performance variables,” “performance variances” and “performance characteristics” are intended to include but not be limited to characteristics of a semiconductor resulting from a process tool which may affect the overall performance of the seminconductor and its associated integrated or electronic circuitry, if any, including film thickness, stress and dopant percentages, oxide thickness, dielectric constants of the floating gate electrode and layers of the ONO layer, physical attributes, footprint, shape, formation details, thickness, conductivity, uniformity, capacitance, band voltage, resistance, and growth impacts dues to temperature and/or pressure during the deposition process, as well as similar characteristics which may affect performance. [0066] As used herein, it is envisioned that the process tool controller may be hardware, software, firmware, or combinations thereof, in its composition and operation, and may therefore further comprise software, instructional code, other applications, and be a computer program product. [0067] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. [0068] Various implementations of a wafer process and methods for fabricating the wafer have been described. Nevertheless, one of ordinary skill in the art will readily recognize that various modifications may be made to the implementations, and any variations would be within the spirit and scope of the present invention. For example, the above-described process flow is described with reference to a particular ordering of process actions. However, the ordering of many of the described process actions may be changed without affecting the scope or operation of the invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the following claims.

The present invention is one or more implementations is a method of fabricating a semiconductor for improved oxide thickness control, defining a process tool, determining and evaluating performance variables, determining a performance impact factor and thereafter modifying control of the process tool in the fabrication process to operate in direct relation to the determined results of the present invention. The present invention sets forth definitive advantages in reducing engineering time, improving process controls and improving cycle-times.

RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Ser. No. 61/984,986, filed Apr. 28, 2014, the entire disclosure of which is herein incorporated by reference. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with U.S. government support under Grant No. N660001-10-1-4062, awarded by the Space and Naval Warfare Systems Center, and under Grant No. HR0011-12-1-0003, awarded by the Defense Advanced Research Projects Agency. The government has certain rights in this invention. FIELD OF THE TECHNOLOGY The present invention relates to tools for experimental research and, in particular, to sensor platforms. BACKGROUND Biomedical research workflows currently suffer from a lack of tools that enable the collection of the experimental context. The multivariate nature of the experimental context makes it difficult to continuously record the evolution of all of the variables over the length of the experiment. As a result, many variables are never recorded, turning the debugging of a failed protocol into a guessing game. This not only makes the discovery of significant experimental variables difficult, but also constitutes the main barrier in training new individuals on these workflows. The lack of contextual data is a key factor in the current inability to apply a data analytics approach to the biomedical experimental workflow. Currently, the only way to create sufficient data to enable such an approach requires the use of expensive and inflexible automation platforms. These platforms require significant adaptation of user workflows that only make such an investment worthwhile if large numbers of samples are used or if experiments are composed of multiple repeated operations. Experimental protocols are nominally descriptive of the steps necessary to perform an experiment but often fail to provide all the accessory information crucial to understanding the experiment's context. Currently, experimental protocols are generally described in text documents that are optimized for human readability and comprehension. Their format does not allow easy machine readability, making it very difficult to programmatically extract the context of an experiment. While experimental description schemas have been proposed in the past [e.g. Systems Biology Markup Language, ExptML: A Markup Language for Science], they are optimized for machine readability, making it very hard for experimenters—who often have little experience with programming—to either read or produce them. SUMMARY A framework of hardware and software tools can enable context-aware experimentation through the collection, visualization, and analysis of disparate data streams. Together with a distributed sensor network, such a framework can facilitate creation of a comprehensive picture of the experimental context and provide insights to the user, both predictively and within timeframes previously not achievable. In one aspect, the invention is a hardware platform comprised of sensors, a microcontroller, and a mesh-enabled radio transceiver capable of distinguishing the laboratory context in which it is placed. Using temperature, humidity, CO 2 , gyroscope, accelerometer sensors, and signal strength from the mesh network radio, a sensor platform according to the invention is able to derive the experimental context it is in. Exemplary form factors for this platform include, but are not limited to, sample tube and biopebble. In another aspect of the invention, a software architecture is able to leverage the platform's sensed information to determine which experimental step a given user is on. In one implementation, the framework includes a protocol descriptor language that allows the description of experimental workflows and steps. In one aspect of the invention, a platform for context-aware experimentation includes a housing configured to hold at least some electronic components comprising the platform, one or more sensors located within the housing and configured to obtain data pertaining to at least one parameter related to an on-going experiment, a communications subsystem located within the housing and configured for transmitting data obtained by the sensors, and at least one microcontroller located within the housing and configured for receiving data from the sensors and providing it to the communications subsystem for transmission. The housing may be a tube, which may be configured to hold a sample and may have a tube cap. The housing may be a waterproof package, which may have an opening to admit at least part of a sample. The sensors may include a temperature sensor, optical density sensor, absorbance sensor, accelerometer, gyroscope, pH sensor, humidity sensor, CO 2 sensor, and/or conductivity sensor. The microcontroller may be configured to control the sensors. The platform may include a power source, which may be wireless charging circuitry. In another aspect, the platform may include a communications mesh network located outside the housing and configured for relaying the sensor data from the communications subsystem to a computer processor for analysis. The platform may include a computer processor located outside the housing, the computer processor specially configured for receiving and analyzing the data obtained by the sensors. The computer processor may analyze the received data to determine the experimental context in which the sensors are operating. The computer processor may determine which experimental step in a protocol a particular user is performing, and may remind the user of required timings and other parameters for the steps in the protocol. BRIEF DESCRIPTION OF THE DRAWINGS Other aspects, advantages and novel features of the invention will become more apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein: FIG. 1A is an exemplary implementation of a sensor platform according to one aspect of the invention; FIG. 1B is the exemplary sensor platform implementation of FIG. 1A in a case, according to another aspect of the invention; FIG. 2 is a schematic for an exemplary implementation of a printed circuit board for a sensor platform according to one aspect of the invention; FIG. 3 is a graph of sample temperature data obtained by an exemplary implementation of a temperature sensor platform according to one aspect of the invention when placed in −20° C. freezer; FIG. 4 is a flowchart depicting the operation of an exemplary motion-activated sensor platform, according to one aspect of the invention; FIG. 5 is an exemplary implementation of a tube-type temperature sensor platform according to an aspect of the invention; FIGS. 6A and 6B are top and side view diagrams, respectively, of the cap of an exemplary implementation of a tube-type optical sensor platform according to an aspect of the invention; FIG. 7 is an exemplary implementation of a tube-type optical sensor platform according to an aspect of the invention; FIG. 8 is an exemplary implementation of a biopebble-type multi-sensor platform according to an aspect of the invention; FIG. 9 is a flowchart depicting an exemplary implementation of the process of determining the experimental step a user is performing using a sensor platform according to the invention; FIG. 10 is a screenshot of an exemplary implementation of a protocol follower interface useable with a sensor platform according to the invention; FIG. 11 is a screenshot of an exemplary visualization of richly contextualized experimental steps as seen on a wearable visualization device, based on use of a sensor platform according to the invention; and FIG. 12 is a screenshot of an exemplary text message notifying the user of the timing requirements of important experimental steps, triggered by data received from a sensor platform according to the invention. DETAILED DESCRIPTION A context-aware sensor platform according to one aspect of the invention is comprised generally of one or more sensors, a microcontroller and a mesh-enabled radio transceiver capable of distinguishing the laboratory context in which it is placed. Using environmentally-aware sensors such as, but not limited to, temperature, humidity, CO 2 , gyroscopes, accelerometers, and signal strength from the mesh network radio or other communications network, the sensor platform can be used to derive the experimental context in which it is operating. Additionally, a software architecture able to leverage the platform's sensed information can be used to determine which experimental step in a protocol a particular user is performing. In one embodiment of a system employing the platform of the invention, a distributed network of sensors is used to gather contextual information about the experiment being carried out. Experimental data streams of interest may include, but are not limited to, temperature, humidity, carbon monoxide and dioxide, luminosity, serial communication, optical density (OD), pH, and power consumption. These sensors are connected wirelessly to a communication mechanism, which can be accomplished using any of the many means known in the art including, but not limited to, using off the shelf hardware and systems, including, but not limited to, 802.15.4 radios, and traditional WiFi (802.11). Exemplary form factors for this platform include, but are not limited to, sample tube-based and biopebble-based. Exemplary Tube-based Sensor Platforms. A tube-based sensor platform according to one implementation of the invention is designed to fit within the body of sample tubes commonly used in biological experiments, such as, but not limited to, Eppendorf tubes and 15 mL and 50 mL Falcon tubes. The electronics typically comprise sensors such as, but not limited, to, temperature, humidity, CO 2 , gyroscopes, and accelerometers, as well as a low power mesh-enabled radio transmitter. The platform is able to automatically sense and/or identify which operations from the protocol are being carried out by utilizing a wireless connection to protocol context information. FIGS. 1A and 1B are views of an exemplary implementation of a tube-based sensor platform, with FIG. 1A depicting platform 100 and FIG. 1 B depicting platform 100 of FIG. 1A within outer tube casing 110 . In FIG. 1A , sensor 120 is connected to microcontroller 130 , which communicates the data obtained by sensor 120 via communications chip 140 . It will be clear to one of skill in the art that this is an exemplary implementation only, and that many other configurations of individual parts performing the same or similar functions would be suitable for use in and with the invention, and that the circuit may be used with any type of suitable sensor and corresponding interface. FIG. 2 is a schematic for an exemplary implementation of a printed circuit board for a sensor platform such as the one shown in FIGS. 1A-B . Shown in FIG. 2 are temperature sensor 220 (DS18B20), MicroUSB 230 , ATTiny85 240 , battery charging integrated circuit 250 , and headers for XBee 260 . It will be clear to one of skill in the art that this is an exemplary implementation only, and that many other individual parts performing the same or similar functions would be suitable for use in and with the invention. The temperature sensing platform in an illustrative embodiment makes use of embedded temperature and humidity sensors to derive actions and context from the experimental setup. For example, for samples placed on ice, it is able to distinguish between ice and water mixture, only ice, and dry ice by calculating the derivative of temperature over time and comparing it to pre-calibrated curves embedded in the microcontroller. Similarly, it is able to determine similar information regarding, for example but not limited to, samples placed on hot plate, samples placed in an incubator, samples placed in a freezer, and samples placed in a refrigerator. FIG. 3 is a graph of sample temperature data 310 obtained by an exemplary implementation of a temperature sensor platform according to one aspect of the invention when placed in −20° C. freezer, comparing temperature (degrees C.) 320 over time 330 measured at the platform sensor versus baseline 340 . Using the RSSI reporting of nodes in the mesh network, one embodiment of the system is also able to determine which freezer the sensor was placed in. This feature requires having multiple neighboring nodes and having at least some of their locations be known. Some embodiments employ motion-activated sensing. This feature uses accelerometer and gyroscope data to automatically discover when the device is being moved and hence there might be data of interest to capture. This method conserves battery power by putting the various components in power saving mode when motion hasn't been detected for a long time. Motion activated sensing can also be used to modify the rate at which sampling from the different sensors occurs. When present, an on-board gyroscope and accelerometer may particularly be used to determine the rotational speed of the sample tube sensor. This is used to determine rotations per minute (RPM), a variable used when centrifuging or agitating samples. By estimating the RPM of the samples, the system is able to distinguish between agitation RPMs (usually low, in the 100s) and centrifuging RPM usually much higher in the 1000s. FIG. 4 is a flowchart depicting the operation of an exemplary motion-activated temperature sensor platform, according to one aspect of the invention. As seen in FIG. 4 , when motion is sensed 405 , the microcontroller is awakened 410 and determined 415 the type of movement detected. If rotational 420 , RPM is estimated 420 . If the movement is continued and not rotational 430 , a wait is instituted 435 for a timeout period. If the movement is brief 440 , no motion-specific action is taken. Next, temperature and humidity are estimated 445 , RSSI of nearby nodes is estimated 450 , estimated information is reported 455 through the mesh network, and the device returns to low power mode 460 . In some embodiments, the sample tube sensor platform is outfitted with a contactless (inductive) charging coil. This allows the user to charge the sensor platform by placing it in a special charging tube rack. The coil has a placement that minimizes the distance to the charging tube rack in order to ensure efficient charging. In one illustrative embodiment, a temperature sensor is embedded in a sample tube. This design allows experimenters to carry an extra tube and treat it like any other sample, thus creating a proxy for quantifying the variables acting upon the actual samples. In a preferred embodiment, the device has electronics that enable the sensing of temperature, 3-axis movement and acceleration, light, conductivity, and humidity. FIG. 5 is an exemplary implementation of a tube-type temperature sensor platform according to this aspect of the invention. Seen in FIG. 5 are sample tube 510 , temperature sensor 520 , microcontroller 530 , communication chip 540 , wireless communication antenna 550 , and optional cap 560 . Absorbance readings at specific wavelengths can be achieved with the tube sensor platform by including an emission light source and a photo sensor at a fixed distance from each-other. When present, the platform preferably senses the presence of the added sensor and performs calibration in air before being operational. The electronics may further be coated for hydrophobicity, allowing the sensor to be submerged in a solution to be measured. When plugged in and reporting optical absorbance data, the sensor platform may also record movement information and transmit all information together. This enables the user and the rest of the software platform (off the sensor) to determine the validity of the measurements. In one illustrative embodiment, an optical density tube sensor provides a new form factor for optical density detection. The embedded electronics design allows the sensor to be embedded within culture tubes, thus facilitating a more scalable approach to continuously monitoring growth curves in biological experiments. Parts of the sensing electronics are made to be both modular for disposal of immersed portions and autoclavable for disinfection. Schematic drawings for an exemplary embodiment of an optical density tube-based sensor are shown in FIGS. 6A-B and 7 . FIGS. 6A and 6B are top and side view diagrams, respectively, of the cap of an exemplary implementation of a tube-type optical sensor platform such as the one shown in FIG. 7 . Different layers of the cap 600 have different functionality including communications 610 , battery 620 , and processing 630 . Also seen in FIGS. 6A and 6B are battery connection 640 , photo emitter connection 650 , photosensor connection 660 , and processor 670 . FIG. 7 is an exemplary implementation of a tube-type optical sensor platform usable with the cap of FIGS. 6A-B . Seen in FIG. 7 are tube 710 , growth medium 720 for/with cell cultures, photoemitter 750 , photosensor 760 , light path 770 , photo emitter connection 650 ( FIG. 6A ), and photosensor connection 660 ( FIG. 6A ). Exemplary BioPebble-Embedded Sensor Platform. The BioPebble sensor platform is a collection of sensors packed in a small waterproof footprint. The novel form factor of the pebble allows it to be dropped directly inside of the solution to be measured. The enclosure is both waterproof and chemically inert. The BioPebble has an embedded coil or antenna that enables short range communication and power transfer. A preferred embodiment of the pebble is electronically passive, extremely low power, and powered wirelessly from an external device. The pebble has embedded sensors that may include, for example, but are not limited to, temperature, conductivity, pH, and optical density at various wavelengths. FIG. 8 is an exemplary implementation of a biopebble-type multi-sensor platform. Shown in FIG. 8 are biopebble enclosure 810 , electronic board 820 , which is inside enclosure 810 and supports sensor 830 , processing unit 840 , RFID coil or antenna 850 , photo emitter 860 , photodetector 870 , and light path 880 , plus enclosure opening 890 that permits liquid to reach photodetector 870 . A complete context-aware experimentation system is preferably aware of which user is present in the lab and interacting with different parts of the system, which is typically accomplished using RFID readers and assorted tags or other identifying technologies, such as, but not limited to, video cameras. Software has been designed to determine which experimental step the user is performing. Using information provided by the sensor platform, the software evaluates statistically the likelihood of a user being at a given step of a described experiment. The logic for determining the step a user is performing using a sensor platform according to the invention is shown in FIG. 9 , which is a flowchart depicting an exemplary implementation of the process. As shown in FIG. 9 , a determination is made as to whether the sensors are variant 905 . If not 910 , a check is made for user input 915 . If none 920 , the system returns to check if sensors are variant 905 . If there is user input 925 , or sensors are variant 930 , data is obtained 940 from the sensor platform, and a check is made for a user-started protocol 945 . If the user has not 950 started a protocol, step information is obtained 955 from the user. If the user has 960 started a protocol, step information is obtained 965 from the protocol system. Compliance criteria for the step are obtained 970 , variance from the compliance criteria is determined 975 , and a determination is made of whether or not the step is “on step” 980 . Finally, step information is obtained 985 from the user, and compliance criteria for the step are recalculated 990 , which two processes provide a feedback learning mechanism 995 for the system. A protocol descriptor language has been developed that permits the incorporation of high-resolution contextual information in a way that is highly readable by the experimenter. This allows the system to display this contextual information in a “just-in-time” fashion. This protocol descriptor language aims to strike a balance between machine readability and human compatibility. The protocol descriptor language lists out the steps for carrying out the experiment. Required fields include an ordered or indexed list of steps and their respective duration. The descriptor language also includes optional fields that greatly enhance its function. These include, but need not be limited to, a field for programming the behavior of the system at the end of each step, such as gathering data, modifying sensing intervals, or modifying the experimental setup. An exemplary protocol is set forth in Table 1. TABLE 1 <protocol>  <id></id>  <name>λred Recombination</name>  <description>Transform plasmid into E. coli cells</description>  <created></created>  <relationship></relationship>  <steps>  <step>   <number>1</number>   <name>Grow overnight culture</name>   <description>Grow from fresh monoclonal culture/colony/glycerol stock</description>   <intensity></intensity>   <duration>12h10m45s</duration>   <data>Optional</data>  </step>  <step>   <number>2</number>   <name>Innoculate growth cultures</name>   <description>Innoculate 30µL into 30mL</description>   <intensity>1</intensity>   <duration>10m</duration>   <data>Optional</data>  </step>  <step>   <number>3</number>   <name>Incubate growth cultures</name>   <description>Incubate growth cultures with shaking at 34°C until OD600=0.4</description>   <intensity>1</intensity>   <duration>45m</duration>   <data>Optional</data>  </step>  <step>   <number>4</number>   <name>Heat shock the culture</name>   <description>Immediately heat shock the culture in a 42°C water bath with shaking for 15 minutes</description>   <intensity>5</intensity>   <duration>15m</duration>   <data></data>  </step>  <step>   <number>5</number>   <name>Ice transformed cells</name>   <description>Immediately put transformed cells on {ice} and move to the cold room</description>   <intensity>5</intensity>   <duration>15m</duration>   <data>Optional</data>  </step>  <step>   <number>6</number>   <name>Move cells to Eppendorf tubes</name>   <description>Move 1mL of cells into eppendorf tubes</description>   <intensity>5</intensity>   <duration>5m</duration>   <data>Optional</data>  </step>  <step>   <number>7</number>   <name>Wash cells 1/2</name>   <description>Wash cells in 1mL of {cold} ultrapure distilled   water</description>   <intensity>2</intensity>   <duration>5m</duration>   <data>Optional</data>  </step>  <step>   <number>8</number>   <name>Spin cells down</name>   <description>Spin cells at 16.1rcf for 20 seconds</description>   <intensity>2</intensity>   <duration>45s</duration>   <data>Optional</data>  </step>  <step>   <number>9</number>   <name>Wash cells 2/2</name>   <description>Wash cells in 1mL of {cold} ultrapure distilled   water</description>   <intensity>2</intensity>   <duration>5m</duration>   <data>Optional</data>  </step>  <step>   <number>10</number>   <name>Spin cells down</name>   <description>Spin cells at 16.1rcf for 20 seconds</description>   <intensity>2</intensity>   <duration>45s</duration>   <data>Optional</data>  </step>  </steps> </protocol> While the example given in Table 1 uses XML, the protocol descriptor language is agnostic of the lower layer format. Versions of the descriptor language based on JSON have also been implemented. The protocol descriptor language not only describes the different steps necessary to carrying out the experimental operations, but also has provisions for requesting data and actuating the distributed sensor network. The protocol descriptor language also allows storage of contextual data. This enables each file to become an instantiation of that protocol as it was run that day. This enables portability and shareability of the protocol that enables the comparison of multiple protocols downstream using analysis tools. Visualization and analysis platform. Web-based interfaces for the display of time-varying experimental information, such as protocol steps and contextual sensory information, have been developed. Exemplary implementations of the visualizations have been created using Node.js and the d3 visualization library. When using the protocol descriptor language, relative time (e.g.: 15 minutes) is used, since the duration of steps is dependent on the others. The software calculates these offsets and produces the chart shown in FIG. 10 . FIG. 10 is a screenshot of an exemplary implementation of a protocol follower interface useable with a sensor platform according to the invention. It highlights the intensity 1010 of each step 1020 using colors to enable the experimenter to plan their time accordingly, such as avoiding breaks or distractions near steps 1020 that require critical timing. In FIG. 10 , “Intensity” is an indicator of (a) the criticality of a step, (b) the precision of timing required for a step, (c) the amount of attention required from the human experimenter, or (d) the difficulty of a step. Steps 1020 are displayed in order, and also shown on a timeline 1030 . In alternative implementations of this interface, the “intensity” parameter may be replaced with two or more parameters such as, but not limited to, criticality, precision of timing, amount of attention required, or difficulty. These visualizations enable the display of implicit information, as well as sensor contextual information, “just-in-time” to the user. In order to achieve this goal, the visualization system was extended to a range of devices that are wearable, such as, but not limited to, Google Glass™ and Pebble Watch. FIG. 11 is a screenshot of an exemplary visualization of richly contextualized experimental steps as seen on a wearable visualization device (Google Glass™), based on use of a sensor platform according to the invention. The different screenshots show the ability to embed sensor data in real time and make decisions as to the progress of the protocol based on the criteria set out in the protocol description file. FIG. 12 is a screenshot of an exemplary text message notifying the user of the timing requirements of important experimental steps, and is triggered by data received from a sensor platform according to the invention. This assists the user in performing steps that, for example, if missed, might significantly delay or affect the result of the experiment. The framework provided by the various aspects of the invention permits aggregation and analysis of multivariate sensor data to determine multidimensional states and take appropriate action. These actions include, but are not limited to, notifying the user ( FIGS. 11 and 12 ), modifying the data collection behavior of the sensor network, or even modifying the experimental variables (such as, for example, but not limited to, temperature or agitation rate). While several illustrative embodiments are disclosed, many other implementations of the invention will occur to one of ordinary skill in the art and are all within the scope of the invention. Furthermore, each of the various embodiments described above may be combined with other described embodiments in order to provide multiple features. Furthermore, while the foregoing describes a number of separate embodiments of the apparatus and method of the present invention, what has been described herein is merely illustrative of the application of the principles of the present invention. Other arrangements, methods, modifications, and substitutions by one of ordinary skill in the art are therefore also considered to be within the scope of the present invention, which is not to be limited except by the claims that follow.

A platform for context-aware experimentation includes a housing for one or more sensors for obtaining data pertaining to an on-going experiment, a communications subsystem for transmitting data obtained by the sensors, and a microcontroller for receiving data from the sensors, providing it to the communications subsystem, and possibly controlling the sensors. The housing may be a tube, which may be configured to hold a sample and may have a cap, or a waterproof package, which may have an opening to admit at least part of a sample. The platform may include a power source. The platform may include a computer processor, located outside the housing, for analyzing the data obtained by the sensors, determining the experimental context in which the sensors are operating and/or which experimental step in a protocol is being performed, and/or reminding users of required parameters for the steps in the protocol.

CROSS-REFERENCE TO RELATED APPLICATION This is a continuation of copending international application PCT/DE99/00762, filed Mar. 17, 1999, which designated the United States. BACKGROUND OF THE INVENTION Field of the Invention The invention relates to a memory cell configuration in which a plurality of memory cells are present in the region of a main area of a semiconductor substrate, in which the memory cells each contain at least one MOS transistor having a source, gate and drain, in which the memory cells are configured in memory cell rows which run essentially parallel, in which adjacent memory cell rows are insulated by an isolation trench, in which adjacent memory cell rows each contain at least one bit line, and where the bit lines of two adjacent memory cell rows face one another. The invention furthermore relates to a method for fabricating this memory cell configuration. Memory cells are used in wide areas of technology. The memory cells may involve both read-only memories, which are referred to as ROMs, and programmable memories, which are referred to as PROMs (programmable ROMs). Memory cell configurations on semiconductor substrates are distinguished by the fact that they allow random access to the information stored in them. They contain a multiplicity of transistors. During the reading operation, the logic states 1 or 0 are assigned to the presence or absence of a current flow through the transistor. The storage of the information is usually effected by using MOS transistors whose channel regions have a doping which corresponds to the desired blocking property. A memory cell configuration of the generic type is shown in Yoshida (5,306,941). In this memory cell configuration, bit lines are configured in the edge region of memory cell webs, and the bit lines of adjacent memory cell webs face one another. In this case, the bit lines are isolated from one another in each case by an isolation trench filled with an insulating material. This document furthermore discloses a method for fabricating a memory cell configuration, in which memory cell webs are formed by etching isolation trenches into a semiconductor substrate. The etching of the isolation trenches is followed by diffusion of a dopant, bit lines being formed by the diffusion. This memory cell configuration of the generic type is suitable for feature sizes of at least 0.5 μm and for a ROM read-only memory. Electrical programming is not possible in this case. A further memory cell configuration is disclosed in DE 195 10 042 A1. This memory cell configuration contains MOS transistors configured in rows. The MOS transistors are connected in series in each row. In order to increase the storage density, adjacent rows are in each case configured alternately at the bottom of strip-type longitudinal trenches and between adjacent strip-type longitudinal trenches at the surface of the substrate. Interconnected source/drain regions are designed as a contiguously doped region. Row-by-row driving enables this memory cell configuration to be read. This memory cell configuration is distinguished by the fact that the area requirement that is necessary for the memory cells has been reduced from 4 F 2 to 2 F 2 where F is the minimum feature size of the photolithographic process used for the fabrication. What is disadvantageous, however, is that a further increase in the number of memory cells per unit area is not possible in this case. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a memory cell configuration and a method of producing the configuration which overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type in such a way the greatest possible number of memory cells is configured in the smallest possible space. Preferably, the memory cell configuration shall also be electrically programmable. In the case of a device of the generic type, this object is achieved by virtue of the fact that the isolation trench penetrates more deeply into the semiconductor substrate than the bit lines, and in that at least one partial region of the source and/or of the drain is situated underneath the isolation trench. The invention thus provides for the memory cell configuration to be configured in such a way that it contains memory cell webs between which there are isolation trenches which penetrate deeply into the semiconductor substrate and thus enable effective insulation of mutually opposite bit lines. An electrical connection between the sources and/or the drains of different memory cell webs is preferably effected by a partial region of the sources and/or of the drains extending from one memory cell web to a further memory cell well. In this case, the sources and/or drains of different transistors are preferably located in a common well. The memory cell configuration is made electrically programmable by the provision of a gate dielectric with traps for electrical charge carriers, for example a triple layer having a first SiO 2 layer, layer, an Si 3 N 4 layer and a second SiO 2 layer, or the like. With the foregoing and other objects in view there is provided, in accordance with the invention, a memory cell configuration, that includes a semiconductor substrate with a plurality of memory cells each including at least one MOS transistor having a source, a gate, and a drain. The plurality of memory cells are configured in substantially parallel memory cell rows. Each of the memory cell rows include at least one bit line configured such that a bit line of one of the memory cell rows faces a bit line of an adjacent one of the memory cell rows. The semiconductor substrate includes isolation trenches insulating adjacent ones of the memory cell rows. The isolation trenches penetrate more deeply into the substrate than the at least one bit line. The at least one MOS transistor includes a region configured to be at least partially underneath the isolation trench, and the region is selected from the group consisting of the source and the drain. In accordance with an added feature of the invention, the sources of adjacent ones of the MOS transistors are designed as a continuously doped region. In accordance with an additional feature of the invention the drains of adjacent ones of the MOS transistors are designed as a continuously doped region. In accordance with another feature of the invention, the isolation trenches penetrate from 0.1 μm to 0.5 μm more deeply into the semiconductor substrate than the at least one bit line. In accordance with a further feature of the invention, the at least one bit line of each of the memory cell rows has a height of from 0.1 μm to 0.3 μm. In accordance with a further added feature of the invention, there is provided a web with mutually opposite side walls configured between each two adjacent ones of the isolation trenches. Each web includes two of the memory cell rows. The at least one bit line of each of the memory cell rows adjoin one of the side walls of the web. Adjacent ones of the memory cells that are perpendicular to a course of the bit lines have a common region selected from the group consisting of a common source region and a common drain region. With the foregoing and other objects in view there is also provided, in accordance with the invention, a method for fabricating a memory cell configuration, which includes steps of: etching isolation trenches into a semiconductor substrate and thereby forming webs between the isolation trenches; producing bit lines after channel regions have been produced; and subsequent to producing the bit lines, performing an etching step resulting in the isolation trenches penetrating more deeply into the semiconductor substrate. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a memory cell configuration and method for fabricating it, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross section through a semiconductor substrate after a first etching operation; FIG. 2 shows the semiconductor substrate illustrated in FIG. 1 after the implantation of a first dopant; FIG. 3 shows the semiconductor substrate after the implantation of a second dopant; FIG. 4 shows the semiconductor substrate after a further etching operation; FIG. 5 shows a circuit diagram for an electrical connection of individual regions of the semiconductor substrate illustrated in FIG. 4; FIG. 6 shows a detail from a section perpendicular to the section shown in FIGS. 1 to 4 , through the upper region of the semiconductor substrate after the deposition of a dielectric layer, the deposition and patterning of a semiconductor layer and the deposition of a further insulating material; FIG. 7 shows the detail from the upper region of the semiconductor substrate after the performance of anisotropic etching for the purpose of forming spacers; FIG. 8 shows the detail from the upper region of the semiconductor substrate after a further etching operation; FIG. 9 shows the detail from the upper region of the semiconductor substrate after the growth of a dielectric layer; FIG. 10 shows the detail from the upper region of the semiconductor substrate after the application and partial etching away of an electrode layer; FIG. 11 shows a plan view of the finished memory cell configuration; and FIG. 12 shows the electrical circuit diagram of a detail from the cell array. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a mask 15 which is applied to a semiconductor substrate 10 that is made, for example, of n-doped monocrystalline silicon with a basic dopant concentration of, preferably, from 1×10 16 cm −3 to 1×10 17 cm −3 , for example 2×10 16 cm −3 . The mask 15 may be composed for example of silicon oxide formed according to a TEOS (Si(OC 2 H 5 ) 4 ) method. In a TEOS method, tetraethyl orthosilicate Si(OC 2 H 5 ) 4 is converted into silicon oxide SiO 2 at a temperature of approximately 700 degrees Celsius and a pressure in the region of 40 Pa. After the application of the mask 15 , an etching process is carried out, for example a multistage process with a first etching step with a gas mixture comprising CF 4 and O 2 or CHF 3 and O 2 and a second etching step with an HBr-containing gas, with the result that isolation trenches 20 are formed in the semiconductor substrate 10 . There are webs 30 between the isolation trenches 20 , the distance between the centers of adjacent webs 30 being 2F. In this case, F is the minimum feature size that can be fabricated, and is preferably in the range of from 0.1 μm to 0.5 μm. This processing state of the semiconductor substrate is illustrated in FIG. 1 . A first dopant 22 is subsequently implanted, with the result that side regions 25 of the webs 30 and lower bottom regions 28 of the isolation trenches 20 are p-doped. The side regions 25 of the webs 30 and the bottom regions 28 of the isolation trenches 20 form channel regions in the finished memory cell configuration. In order to produce p-type doping, boron, for example, is implanted at an implantation energy preferably of the order of magnitude of from 10 to 20 keV. The implantation dose is equal to the product of a desired concentration and the thickness of a layer to be doped. For example, the implantation dose is 4×10 12 cm −2 , given a preferred layer thickness of about 0.2 μm and an advantageous concentration of 2×10 17 cm −3 . After the implantation and drive-in, the concentration of the dopant in the side regions 25 and in the lower bottom regions 28 is approximately 2×10 17 cm −3 . As a result of the dopant drive-in, a bottom region 28 , with two side regions 25 connected to it, forms a region in which a continuous channel can form in the finished memory cell configuration. This processing state of the semiconductor substrate is illustrated in FIG. 2 . A further dopant 35 is subsequently implanted, with the result that side walls 40 of the webs 30 and upper bottom regions 50 of the isolation trenches 20 are heavily doped by the opposite conductivity type to that of the side regions 25 and of the bottom region 28 . In order to produce n + -type doping, phosphorus or arsenic, for example, is implanted at an implantation energy preferably of the order of magnitude of from 40 to 80 keV, and with a dose in the region around 2×10 15 cm −2 . After this implantation, the concentration of the dopant in the side walls 40 and in the upper bottom regions 50 is approximately 2×10 20 cm −3 . This processing state of the semiconductor substrate is illustrated in FIG. 3 . In order to provide insulation between the individual webs 30 , a further etching process is subsequently performed. As a result of this, the isolation trenches 20 are etched more deeply and the doped upper bottom regions 50 of the isolation trenches 20 are removed. As a result of this process, bit lines 60 that are spacially separate from one another are formed from the side walls 40 of the webs 30 , mutual insulation between the bit lines being ensured by virtue of the fact that the isolation trenches 20 penetrate as far as possible into the substrate. Parts of the bit lines 60 form drains of MOS transistors in the finished memory cell configuration. The bit lines 60 have a height of approximately 200 nm. The depth of the isolation trenches 20 is greater than the height of the bit lines 60 . An effective path length 1 for a possible current path through the semiconductor substrate 10 is thereby enlarged. This processing state of the semiconductor substrate is illustrated in FIG. 4 . A low-resistance connection between the sources 29 is effected for example via a common well (not shown). A connection may, for example, also be effected via the semiconductor substrate or an electrically conductive layer. The width of the bit lines 60 is approximately 50 nm. Given a cross-sectional area of (200×10 −9 m)×(50×10 −9 m)=1×10 −14 m 2 , the bit lines thus have a resistance of the order of magnitude of a few 100 kΩ per mm length of the bit line, a typical value being 500 kΩ/mm. Cell arrays with an edge length of about 1 mm can be realized as a result of this. A typical threshold voltage of a memory cell configuration of this type is approximately 0.6 V. A circuit diagram for an electrical connection of the bit lines 60 and of word lines WL is illustrated in FIG. 5 . Through a siliciding process (not shown), the resistance of the bit lines 60 can be considerably reduced, preferably by a factor of 10 or more. In the case of such a siliciding process, the bit lines 60 are converted into a suitable silicide, i.e. into a metal-silicon compound. In the present case, it is particularly expedient to produce silicides such as MoSi 2 , WSi 2 , TaSi 2 , TiSi 2 , PtSi, Pd 2 Si by siliconization. Siliconization is a process of selective silicide formation. It is preferably performed by the silicide-forming metal being sputtered on alone and then being brought to a silicide reaction with the bit lines as silicon support. The application of the silicide-forming metal is followed by heat treatment at temperatures in the range of from 600 to 1000° C., thereby resulting in the formation of the metal silicide. The mask 15 is subsequently removed. After the removal of the mask 15 , the isolation trenches 20 are filled with an insulating material, for example with SiO 2 formed using a TEOS method. This can be done by converting tetraethyl orthosilicate: Si(OC 2 H 5 ) 4 into silicon oxide SiO 2 at a temperature of approximately 700° C. and a pressure in the region of 40 Pa. The filling of the isolation trenches 20 with the insulating material is followed by a planarization operation, preferably a process of chemical mechanical planarization. A suitable dielectric layer is then applied to the webs 30 and the isolation trenches 20 . The dielectric layer may preferably be formed by a multiple layer. It is particularly expedient if the dielectric layer is a triple layer, having a first dielectric layer 90 made of silicon oxide SiO 2 having a thickness of approximately 3 nm, a middle dielectric layer 100 made of silicon nitride having a thickness of approximately 7 to 8 nm, and an upper dielectric layer 110 made of silicon oxide having a thickness of about 4 nm. The first dielectric layer 90 is formed to a desired layer thickness for example by heat treatment in an O 2 -containing atmosphere. In this case, the silicon of the webs 30 is converted into silicon oxide SiO 2 . This layer may subsequently be patterned by anisotropic etching using CHF 3 , for example. The second dielectric layer 100 is preferably applied according to a CVD (Chemical vapor Deposition) method, in particular according to an LPCVD (Low Pressure CVD) method. A particularly suitable variant for forming the second dielectric layer 100 according to the LPCVD method may be performed by converting dichlorosilane (SiH 2 Cl 2 ) into silicon nitride (Si 3 N 4 ) with addition of ammonia (NH 3 ) at a temperature in the region of about 750° C. in a plasma at a pressure of between 10 Pa and 100 Pa, preferably 30 Pa. The upper dielectric layer 110 is subsequently deposited by thermal oxidation, preferably in an H 2 O-containing atmosphere at a temperature of around 900° C. and for a period of about 2 hours, or according to one of the known layer-producing methods, for example an HTO method. Deposition using an HTO method may preferably be done by converting dichlorosilane SiH 2 Cl 2 into silicon oxide SiO 2 in an N 2 O-containing atmosphere at a temperature of approximately 900° C. and a pressure in the region of 40 Pa. A semiconductor layer 120 , for example made of heavily doped polycrystalline silicon, is grown onto the upper dielectric layer 110 . A preferred doping of the polycrystalline silicon is at least 10 20 cm −3 , dopings above 10 21 cm −3 being particularly suitable. By way of example, the semiconductor layer 120 is n + -doped by diffusion or implantation of phosphorus or arsenic. Implantation may be effected for example with an energy of 80 keV and a dose of 1×10 16 cm −2 . A resist mask is subsequently applied to the semiconductor layer 120 . This is followed by an etching process, for example a multistage process with a first etching step with a gas mixture comprising CF 4 and O 2 or CHF 3 and O 2 and a second etching step with an HBr-containing gas. Isolation trenches 130 are thereby etched into the semiconductor layer 120 . Webs 140 are produced between the isolation trenches 130 as a result of the remaining material of the semiconductor layer 120 , the webs serving as word lines in the completed memory cell configuration. An insulation layer 150 is subsequently deposited onto the webs 140 and the isolation trenches 130 according to a suitable method that is as far as possible conformal. It is particularly expedient for the insulation layer 150 to be formed according to a TEOS method. This can be done by converting tetraethyl orthosilicate Si(OC 2 H 5 ) 4 into silicon oxide SiO 2 at a temperature of approximately 700° C. and a pressure in the region of 40 Pa. That detail of the semiconductor substrate which contains the dielectric layers 90 , 100 and 110 and also the webs 140 is illustrated in FIG. 6 . In this case, FIG. 6 shows a section which runs perpendicularly to the section shown in FIGS. 1 to 4 through one of the webs 30 . The insulation layer 150 is subsequently etched anisotropically, the etching removal of this etching operation corresponding to the thickness of the insulation layer 150 on planar regions. Spacers 160 therefore remain on the side walls of the webs 140 , the spacers also being referred to as TEOS spacers. This state of the semiconductor substrate is illustrated in FIG. 7 . An etching process is subsequently performed, the nitride-containing dielectric layer 100 being removed by the use of a suitable agent, for example phosphoric acid with a concentration in the region of 80% and a temperature of around 150° C. The multistage etching process stops at the oxidecontaining lower dielectric layer 90 . The thin dielectric layer 90 is removed in the region of the isolation trenches 130 by means of a further etching operation, for example using a hydrofluoric acid-containing solution (HF-dip). This state of the semiconductor substrate is illustrated in FIG. 8 . A new triple layer is subsequently grown. To that end, a lower dielectric layer 180 , a middle dielectric layer 190 and an upper dielectric layer 200 are formed. The lower dielectric layer 180 is preferably composed of silicon oxide SiO 2 , which is formed to a desired layer thickness using a heat-treatment method, for example. In this case, in the surface region of the webs 140 and of the semiconductor material 120 , silicon is converted into silicon oxide SiO 2 in an oxygen-containing atmosphere at a temperature of approximately 800 to 900° C. The middle dielectric layer 190 is preferably formed by a nitride layer which has been produced by means of an LPCVD method at approximately 700° C. The topmost dielectric layer 200 is preferably composed of the same material as the lower dielectric layer 180 , that is to say once again preferably of SiO 2 . In the final state, the thickness of the lower dielectric layer 180 is 3 nm, for example, the thickness of the middle dielectric layer 190 is approximately 7 to 8 nm and the thickness of the upper dielectric layer 200 is 4 nm. Such a sequence of the thicknesses of the layers is particularly expedient for storing captured charges as long as possible. This state of the semiconductor substrate is illustrated in FIG. 9 . An electrode layer 210 is subsequently formed over the whole area. The electrode layer 210 is composed for example of a doped semiconductor material, preferably n-doped polycrystalline silicon, metal silicide and/or a metal. However, the semiconductor material of the electrode layer 210 may also be p-doped. The electrode layer 210 is formed to a thickness which suffices to fill the isolation trenches 130 between the webs 140 forming the word line. The electrode layer 210 is therefore deposited to a thickness of approximately 0.2 μm to 0.6 μm, preferably 0.4 μm. The electrode layer 210 is subsequently patterned. The electrode layer 210 is patterned in a method which has a number of steps. Firstly, the electrode layer 210 is removed by a planarization process, for example a CMP (Chemical Mechanical Planarization) step. In this case, the middle dielectric layer 190 acts as a stop layer. The dielectric layer 170 is subsequently removed above the webs by the removal of its partial layers 180 , 190 and 200 . This is followed by further etching back or a process of chemical mechanical planarization (CMP) (FIG. 10 ). In the memory cell configuration, memory cells are realized by MOS transistors each formed from part of one of the bit lines 60 , which acts as drain, the adjoining side region 25 , which acts as a channel region, one of the sources 29 and the dielectric layer 90 , 100 , 110 , which acts as a gate dielectric, and one of the webs 140 , which acts as a gate electrode, or the triple layer 180 , 190 , 200 , which acts as a gate dielectric, and part of the patterned electrode layer 210 , which acts as a gate electrode. Since the webs 140 and the patterned electrode layer 210 are fabricated in a self-aligned manner with respect to one another, the memory cell configuration can be fabricated with a distance between the centers of adjacent gate electrodes along one of the webs 30 of a minimum feature size F that can be fabricated. The distance between the centers of adjacent webs 30 is a minimum of 2F given the use of a mask 15 which is fabricated with the aid of photolithographic process steps. Since the webs 30 each have two adjacent memory cells perpendicular to the course of the bit lines 60 , the space requirement per memory cell is F 2 . If the mask 15 is formed with the aid of a spacer technique, then a distance between the centers of adjacent webs 30 of F is achieved. This results in a space requirement per memory cell of 0.5×F 2 . A plan view of the finished memory cell configuration is illustrated in FIG. 11 . This illustration shows the configuration of the bit lines 60 and of first word lines WL 1 and second word lines WL 2 . The first word lines WL 1 and the second word lines WL 2 are formed by the webs 140 and by the patterned electrode layer 210 (see FIG. 10 ), respectively. It can be seen here that, of the two bit lines 60 that are present on a web 30 , one bit line 60 in each case is connected to a contact 220 in the upper region of the cell array. The respective other bit line 60 of the web 30 is connected to the lower edge of the cell array in a manner that is not illustrated. FIG. 12 illustrates the electrical circuit diagram of a detail from the cell array. Interconnection between the bit lines 60 , 60 ′, 60 ″ and word lines WL 1 and WL 2 can be seen here. In order to clarify the method of operation of the electrical circuit, those voltages which are necessary to write to a memory cell 230 are illustrated by way of example. The memory cell 230 is written to by the tunneling of electrical charge. A gate voltage of, preferably, from 9 V to 10 V is applied to the memory cell 230 via the associated word line WL 2 . The common sources of all the memory cells are at a common, elevated potential of 5 V, for example. A drain voltage of 0 V is applied to the memory cell 230 via the bit line 60 ″. Either a gate voltage 0 or a positive drain voltage of 5 V, for example, is applied to the other cells. This prevents cells that have already been written to from being erased. A memory cell is read preferably in such a way that the common sources of the memory cells are at 0 V, that the bit line associated with the cell is at a positive potential, and that the word line associated with the cell is at a potential of 3 V, for example. All of the memory cells are erased simultaneously preferably by the common sources of the cells being at 0 V, by all the bit lines 60 , 60 ′, 60 ″ being at the potential 0 V, and by a negative gate voltage of −10 V, for example, being applied via the word lines WL 1 and WL 2 . The invention is not restricted to the exemplary embodiments described. In particular, the n-type and p-type dopings can be interchanged.

The invention relates to a memory cell configuration in which a plurality of memory cells are present in the region of a main area of a semiconductor substrate ( 10 ), and in which the memory cells each contain at least one MOS transistor having a source ( 29 ), gate (WL 1 and WL 2 ) and drain ( 60 ). The memory cells are configured in memory cell rows which run essentially parallel, in which adjacent memory cell rows are insulated by an isolation trench ( 20 ), in which adjacent memory cell rows each contain at least one bit line ( 60 ), and where the bit lines ( 60 ) of two adjacent memory cell rows face one another. The memory cell configuration is constructed in such a way that the isolation trench ( 20 ) penetrates more deeply into the semiconductor substrate ( 10 ) than the bit lines ( 60 ), and at least one of the source ( 29 ) and/or of the drain is at least partially situated underneath the isolation trench ( 20 ). The invention furthermore relates to a method for fabricating this memory cell configuration.

BACKGROUND [0001] The huge volume of image and video data available on the networks (e.g., the Internet), scientific databases, and newspaper archives, along with recent advances in efficient (approximate) image matching schemes have opened the door for a number of large scale matching applications. The general field of content based image retrieval (CBIR) uses many different input modalities to search for similar images in a database. [0002] In the realm of freeform hand sketches using interactive displays and a standard drawing interface, if a novice user is asked to sketch a face, the result will typically look rough and unrefined. Similarly, if asked to draw a bicycle, for example, most of users would have a difficult time depicting how the frame and wheels relate to each other. [0003] One solution is to search for an image of the object to be drawn, and to either trace the object or use the object in some other way, such as for a reference. However, aside from the difficulty of finding an image of what is to be drawn, simply tracing object edges eliminates much of the essence of drawing (there is very little freedom in tracing strokes). Conversely, drawing on blank paper with only the image in the mind's eye gives the drawer more freedom. Without significant training it is difficult to get the relative proportions of objects correct. Thus, freehand drawing remains a frustrating endeavor. SUMMARY [0004] The following presents a simplified summary in order to provide a basic understanding of some novel embodiments described herein. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. [0005] The disclosed architecture guides the freeform drawing of objects by a user to enable the user to produce improved drawings without significant training. As the user draws, the architecture dynamically updates a relevant shadow image underlying the user's strokes. The shadow images are suggestive of object contours that guide the user during the drawing process. The architecture automatically blends relevant edge images from a large database to construct the shadow. The shadows can either be used or ignored by the drawer. [0006] The architecture preserves the essence of drawing (freedom and expressiveness) and at the same time uses the shadow images as visual references to guide the drawer. Furthermore, shadows obtained from real images can enlighten the artist with the gist of many images simultaneously. The creation becomes a mix of both human intuition and computer intelligence. The computer, in essence, is a partner in the drawing process, providing guidance like a teacher, instead of actually producing the final artwork. The user's own creative styles remain consistent in the drawings, while the overall shapes and spacing are more realistic. [0007] The architecture includes a user interface and two computational processes. An offline step builds a database of images from images collected from the Internet. Each image is converted to an edge drawing using an existing long edge detector technique, and then stored. Numerous overlapping windows in each edge image are analyzed into edge descriptors, which are further coded as sketches with distinct hash keys (e.g., using min-hash), and then stored. [0008] As the user draws, the architecture dynamically analyzes the strokes using a similar encoding to determine hash keys for overlapping windows for fast matching with the database of images. A top ranked set (e.g., one hundred) of matching database edge images are further aligned to the drawing. A set of spatially varying weights are used to blend the edge images into a shadow image. A scoring method is employed to select the optimum image for display. In the user interface, the strokes are overlaid on top of an evolving shadow image to provide guidance for potential future strokes. [0009] To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings. These aspects are indicative of the various ways in which the principles disclosed herein can be practiced and all aspects and equivalents thereof are intended to be within the scope of the claimed subject matter. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 illustrates a system in accordance with the disclosed architecture. [0011] FIG. 2 illustrates an alternative system that shows an analysis component. [0012] FIG. 3 illustrates a flowchart of an exemplary database creation process. [0013] FIG. 4 illustrates a flowchart of an exemplary image matching algorithm. [0014] FIG. 5 illustrates a flow diagram for an online processing pipeline for image matching in realtime guidance of freehand drawing. [0015] FIG. 6 illustrates a rendering pipeline for the user interface. [0016] FIG. 7 illustrates a computer-implemented method in accordance with the disclosed architecture. [0017] FIG. 8 illustrates further aspects of the method of FIG. 7 . [0018] FIG. 9 illustrates a block diagram of a computing system that executes realtime user guidance for freehand drawing in accordance with the disclosed architecture. DETAILED DESCRIPTION [0019] The disclosed architecture is an interactive system that dynamically adapts to the user's sketching and provides realtime feedback. The architecture employs a framework of content based image retrieval (CBIR) as well as a technique of partial spatial matching, and enables multiple matching images based on different sub-regions of the image. In addition, a verification stage and methods for determining blending weights are employed. [0020] As the user draws, a shadow image underlying the user strokes is dynamically updated. The shadows are suggestive of object contours that guide the user during the ongoing drawing process. Relevant edge images are obtained from a large database of images and automatically blended to construct the shadow image. [0021] As described herein, the architecture also provides the capability of an image (visual object) retrieval system that searches and returns candidate images for processing. In other words, a set of images is produced for selection and processing that is similar to the user sketch (or drawing). [0022] Reference is now made to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the novel embodiments can be practiced without these specific details. In other instances, well known structures and devices are shown in block diagram form in order to facilitate a description thereof. The intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claimed subject matter. [0023] FIG. 1 illustrates a system 100 in accordance with the disclosed architecture. The system 100 includes an input component 102 that receives a freeform user stroke 104 (e.g., by pen, touch, mouse, etc.) in association with an interactive surface (e.g., a touch screen, pen-based display, standard non-touch display, etc.). The stroke 104 is input to a drawing process that includes an evolving drawing 106 . A search component 108 searches and retrieves matching visual objects 110 from a datasource 112 in response to input of the user stroke 104 . The visual objects include images, other user-generated hand sketches, art work, photos, web content, video content, and so on. The matching visual objects 110 have object portions which match a part of the evolving drawing 106 . [0024] The system 100 can further include a user interface (UI) component 114 (e.g., a drawing program UI) that presents a dynamically changing composite image 116 of the matching visual objects 110 proximate the user stroke 104 during the drawing process to guide the drawing process. [0025] FIG. 2 illustrates an alternative system 200 that shows an analysis component 202 . The analysis component performs all the analysis capabilities for visual object matching including, but not limited to, candidate matching, alignment, and weighting. For example, the analysis component 202 performs verification of candidate visual objects by alignment of the candidate visual objects to the evolving drawing to obtain matching scores and computation of weights for the candidate visual objects based on the scores. The analysis component 202 computes a score for a candidate visual object based on similarity between an edge orientation of the candidate visual object and the user stroke. The analysis component 202 computes global and spatially varying weights to blend corresponding edge images of candidate visual objects into the composite image. The analysis component 202 performs spatial matching to obtain multiple matching visual objects that include different sub-regions which match parts of the evolving drawing. [0026] Following is a detailed description of the disclosed architecture for realtime guidance for freehand drawing. [0027] The architecture includes the construction of an inverted file structure that indexes a database of visual objects (e.g., images) and associated edge maps; a query method that, given user strokes, dynamically retrieves matching visual objects, aligns the objects to the evolving drawing and weights the objects based on a matching score; and, the user interface for drawing, which displays a shadow of weighted edge maps proximate (e.g., beneath) the user's drawing to guide the drawing process. [0028] With respect to database creation, the visual objects in the database are selected so that the objects depicted, as well as object appearance and pose, are likely to be similar to those drawn by the user. Note that although the term “image” or “images” is used during this description, it is to be understood that an image is one form of visual object, and the description herein applies to all types of visual objects, including images. A large database of hand drawn images can be used. Alternatively, a set of natural images collected from the Internet via categorical image queries such as “t-shirt”, “bicycle”, “car”, etc., as well as from category specific databases can be employed. Although such images have many extraneous backgrounds, objects, framing lines, etc., on average, the images will contain edges a user may want to draw. [0029] Included herein is a set of flow charts representative of exemplary methodologies for performing novel aspects of the disclosed architecture. While, for purposes of simplicity of explanation, the one or more methodologies shown herein, for example, in the form of a flow chart or flow diagram, are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation. [0030] FIG. 3 illustrates a flowchart of an exemplary database creation process. At 300 , database creation of visual objects is initiated. At 302 , each visual object is scaled to a predetermined pixel resolution. At 304 , edges from the visual object are extracted. At 306 , local edge descriptors are computed. At 308 , set of concatenated hashes are computed from the edge descriptors. At 310 , the sets of concatenated hashes are stored in a database. At 312 , the above steps are repeated for all visual objects. At 314 , the resulting database is stored as an inverted file. [0031] More specifically, the images are scaled to fit a predefined pixel resolution (e.g., 300×300). Each image is then processed in three stages and added to an inverted file structure. First, edges are extracted from the image. Next, local edge descriptors are computed. Finally, sets of concatenated hashes (called sketches) are computed from the edge descriptors and added to the database. The database is stored as an inverted file, in other words, indexed by sketch value, which in turn points to the original image, its edges, and the position of the edge descriptor used to compute the sketch. [0032] With respect to edge extraction, given a natural image (a form of visual object), it is desired to find the edges most likely to be drawn by a user while ignoring others. The method of edge detection locally normalizes the magnitudes of the edges, and then sums the normalized magnitudes, weighted by local curvature, along the length of the edge. The result is an edge response that is related to the length of the edge and its degree of curvature, rather than the magnitude of the intensity gradients. The edge images E can be stored using run length encoding. [0033] With respect to patch descriptors, for each edge image, edge positions are determined by finding maxima in the responses perpendicular to the edge direction. The edge's orientation is found using a standard second order operator [−1, 2, −1] applied to the final edges in both horizontal and vertical directions. (The operator is a discrete differential operator used in image processing for edge detection.) Given an image I in the database with corresponding edges E and orientations θ, a set of edge descriptors d i εD is computed. Since the goal is to match an edge image E to incomplete and evolving drawings, the descriptors are computed locally over predetermined patch dimension (e.g., 60×60 patches). The patches used to compute neighboring descriptors can overlap by fifty percent, resulting in eighty-one descriptors over the fixed grid (e.g., 9×9) of patches. [0034] The descriptors can be computed using the BiCE (binary coherent edge) descriptor algorithm, which encodes a histogram of edge positions and orientations. Since the edges drawn by a user are typically less dense than in natural images, a low dimensional version of BiCE can be employed. [0035] A three dimensional histogram can be defined with four discrete edge orientations, eighteen positions perpendicular to the edge, and six positions tangent to the edge. In this example, and using a conventional notation, set n x′ =18, n y′ =6, n θ =4, and n l =1. The buckets of the histogram can be binarized by setting the top twenty percent to one and the rest to zero. The final descriptor d, has four-hundred thirty-two binary bits, with eighty-six ones and three-hundred forty-six zeros. [0036] A feature of the BiCE descriptor is its binary encoding: it can be viewed as a set representation where the ones indicate edge presence. This makes it amenable to min-hash, which is an effective hashing technique for retrieval and clustering. Min-hash has the property that the probability of two sets having the same hash value (“colliding”) is equal to their Jaccard similarity. The Jaccard similarity sim(d i , d j ) between two sets, d i and d j , is the cardinality of the intersection divided by the cardinality of the union: [0000] sim  ( d i , d j ) = #  ( d i ⋂ d j ) #  ( d i ⋂ d j ) . ( 1 ) [0037] A min-hash function randomly permutes the set of indices (the ones and zeros). All sets (BiCE descriptors) are permuted using the same min-hash function. The min-hash value for a given permuted set is its smallest index containing a one after the permutation. A single min-hash can be non-discriminative and introduce many false positive retrievals, especially if the descriptor is non-sparse. To increase precision, k independent random min-hash functions can be computed and applied to all BiCE descriptors. [0038] The resulting k min-hash values are concatenated for each descriptor into k-tuples, called sketches. The probability of two sketches colliding is thus reduced exponentially to sim (d i , d j ) k . To increase recall, this process is repeated n times using n different sets of k min-hash functions, resulting in n sketches per descriptor. To maintain high recall while reducing false positives, tradeoffs are made between the number of sketches stored for each descriptor and the size of the sketch, k. In one implementation, n=20 sketches of size k=3 are stored for each descriptor. [0039] An inverted file structure is stored for each of the n min-hash sketches. Each unique sketch is allocated as a new entry in the structure. The image index and patch location of the descriptor instance that produced the sketch are recorded. [0040] With respect to image matching, the disclosed hashing scheme allows for efficient image queries, since only images with matching sketches need to be considered. [0041] A realtime matching pipeline between the edge images in the database and the user's drawing is now described. FIG. 4 illustrates a flowchart of an exemplary image matching algorithm. At 400 , image matching is initiated. At 402 , a user stroke is received as input to an evolving drawing. At 404 , a set of candidate matching visual objects is obtained from an inverted file structure. At 406 , each candidate match is aligned with the user's drawing. At 408 , Scores from the alignments of candidate objects are generated. At 410 , the scores are used to compute a set of spatially varying weights for each edge image. At 412 , the output is a shadow image resulting from the weighted average of the edge images. At 414 , the shadow image is displayed to the user. [0042] With respect to candidate matches, the user's drawing is recorded as a set of vectorized multi-segment strokes. An edge image {tilde over (E)} is created from these strokes by drawing lines (e.g., with a width of one pixel between the stroke points). The rendered lines have the same style as the edges extracted from the natural images in the database (the edge image {tilde over (E)} used for matching does not need to use the stylized strokes that are seen by the user). The BiCE descriptors and corresponding sketches are computed as described above, using a higher resolution grid (e.g., 18×18=324 patches) with seventy-five percent overlap between neighboring patches. A higher resolution grid is used to increase the accuracy of the predicted position and to increase invariance to translations in the drawing. In one implementation, the user's drawing occupies an area of 480×480 pixels, resulting in 96×96 pixel patches with twenty-four pixel offsets between neighboring patches. Descriptors and sketches can be computed for each of the three-hundred twenty-four patches. [0043] Using the inverse lookup table, each sketch from the user's drawing is matched to the sketches stored in the database. A matching sketch casts one vote for the corresponding database image and patch offset pair. The matches are aggregated in a histogram H storing the number of matching sketches for each image at each grid offset. To reduce the size of H, votes are only stored if the database patch offset is within four patch grid points of the patch being considered in the user's drawing. This corresponds to relative shifts of less than ninety-six pixels between the user's drawing and the database images. The resulting histogram has size m×9×9, where m is the number of images in the database. After adding all the matches for each sketch to the histogram, the optimum matching offset is found for each image, and the top one-hundred images are added to the candidate set C. n=20 sketches are computed for each descriptor, resulting in a maximum possible twenty votes per sketch in the histogram. To reduce the bias from any single descriptor, each descriptor can be limited to at most four votes in the histogram. [0044] Given a large database, computing the candidate set as described above can be computationally expensive. However, user strokes change gradually over time to increase performance, thus, at each time step, only votes resulting from sketches derived from patches that have changed, are updated. This can be accomplished by subtracting the votes added from the previous sketches from H, followed by adding in the votes from the new sketches. At each time frame, any candidate image from the previous time frame that contributed to the shadow image can also be added to the candidate set, if not already present. [0045] With respect to image alignment, the candidate image set of candidates C contains a set of images with approximate offsets d x and d y defined by the optimum matching offset, as described above. The approximation arises from the discretization of the offsets in the grid of patches. These offsets can be refined using a 1D (one-dimensional) variation of the Generalized Hough transform. Using the standard Generalized Hough transform for 2D (two-dimensional) translations, a 2D histogram T over possible offsets x and y is created using: [0000] T  ( x , y ) = ∑ p  E ~  ( p x , p y )  E  ( p x + d x + x , p y + d y + y ) ( 2 ) [0000] where {tilde over (E)}(p x ,p y ) is the value of {tilde over (E)} at pixel p in location (p x , p y ), and similarly for the edge image E. The optimum offset can be determined by finding the maximum value of T(x,y). This approach can be computationally expensive due to the need to sum over the image for every possible combination of x and y offsets. Alternatively, compute the x and y dimensions separately using two histograms: [0000] T x  ( x ) = ∑ p  sin  ( θ ~  ( p x , p y ) )  E ~  ( p x , p y )   sin  ( θ  ( p x + d x + x , p y + d y ) )  E  ( p x + d x + x , p y + d y ) ( 3 ) [0000] and similarly for T y using the cosine of the angles. The sine of the edge angles provides higher weights to the more informative vertical edges when determining the horizontal offsets, and similarly for T y and cosine with horizontal edges. Once the histograms T x and T y are created, the histograms are slightly blurred with σ h =2. The final sub-pixel offsets d′ x and d′ y are determined by adding a quadratic interpolation of the resulting peak response in T x and T y to d x and d y . For additional accuracy, two iterations can be run. To reduce computation, the search range of x and y can be limited to twice the distance between the grid points. In addition, equation (3) is computed on reduced resolution images (e.g., size 160×160). If desired, another one-dimensional histogram may be similarly computed over scale to provide scale alignment between the user drawing and the line images. The aligned edge image is denoted as E′ i . [0046] With respect to image weighting, there now exists a set of candidate images, C, and associated aligned edge images E′ i , aligned using offsets d′ i . The intent is now to blend these aligned edge images into a shadow image S that will help guide the user as the user draws. To do so, blending weight images W i are constructed. [0000] S = ∑ i  W i  E i ′ [0047] The blending weight can be set high where there is a good match between the drawing and the candidate's aligned edges, and low, where there is not a good match. The weight image can be constructed from two terms: a global matching term, v i and a spatially varying matching term, V i , normalized as follows over all images in the candidate set: [0000] W i = v i  V i ∑ i  v i  V i + ε ( 5 ) [0000] The parameter ε is included in the normalization to avoid a noisy shadow just as the drawing begins and all match scores are low. The values of v i and V i are defined based on the global and spatially varying matching scores respectively, u i and U i (described below), based on edge matches at discrete orientations (e.g., eight). [0048] The overall weight, v i , and ε are defined by a non-linear function, Ψ, and the average of the highest matching scores u* (e.g., five), [0000] v i = Ψ  ( u i ) ∑ j  Ψ  ( u j ) , ( 6 ) [0000] where [0000] Ψ  ( u i ) = max ( 0 , ( u i - γ   u * u * - γ   u * ) ) κ ( 7 ) [0000] In one implementation, a value of 0.5 is assigned to y, which means the value of Ψ (u i ) is greater than zero only if the score is greater than half the highest scores. κ=2 sets the rate of weight decay as quadratic. In Equation (5), ε=Ψ (u ε ) is added to the denominator to force all of the weights towards zero when all the scores are low (e.g., when the drawing has just started), resulting in the shadows not being seen by the user. U ε is set to correspond to the score after a single stroke is drawn (e.g., of approximately two-hundred pixels). The locally varying weight V i is set to the spatially varying matching score image U i as described next. [0049] Note that the weighting technique described above is just one possible technique for computing the weights. Accordingly, it is to be understood that other weighting techniques can be employed as well. [0050] Following is a description of the global matching score u and the spatially varying matching image U. A goal is for a candidate image's score to increase if an edge exists with a similar orientation to a user's stroke. To compute the matching scores, each candidate edge image is decomposed into new images θ t (e.g., eight), where t=1 . . . 8 and similarly, the drawing edges into eight images {tilde over (θ)} t . Each of the eight images captures only strokes nearly parallel to one of eight evenly spaced orientations. In other words new image θ 1 includes only the horizontal edges, θ 5 depicts vertical edges, and the other six each capture one other orientation. Edge orientation at each pixel is measured by the ratio of second order operators. If an edge's orientation falls inbetween two of the eight discrete orientations, its contribution is linearly divided between the two oriented edge images. To provide some invariance to position, the oriented edge images can be Gaussian blurred with a blur kernel (σ s ) with standard deviation σ s =1.25φ, where φ is the relative distance between grid points. [0051] It is also desirable that images that contain multiple edges near a stroke receive the same score contribution as those with a single edge. This is accomplished by enforcing the sum of the blurred oriented edge images at each pixel location to be no more than the maximum possible contribution from a single edge crossing that pixel. [0052] Both the matching positive image θ + and negative image θ − are computed as the sum of the products of oriented edge images. The positive matches are the products of the images with same orientations, while the negative matches are defined by the products of orthogonally oriented edge images. [0000] ϑ + = ∑ t = 1 , 8  ϑ t * ϑ ~ t ( 8 ) ϑ - = ∑ t = 1 , 8  ϑ t * ϑ ~ ( t + 4 )  %8 ( 9 ) [0053] Finally, the global matching score u i is defined as the sum of the differences between the positive and negative matches over all pixels, [0000] u i = ∑ p  ϑ i +  ( p ) - ϑ i -  ( p ) ( 10 ) [0000] and the spatially varying score image is a Gaussian blurred version of the positive match image, [0000] U i =g (θ i + ,4φ)  (11) [0054] An offset is added to U i to ensure non-zero values. To reduce computation, the image scores and weights are computed on reduced resolution images (e.g., 40×40 pixels). [0055] As a general summary, a shadow image is computed in realtime by comparing the user-drawn strokes to the candidate images obtained from the database. Global and spatially varying weights are computed to blend the corresponding edge images to create the shadow image used in the drawing interface. These weights are determined by comparing local orientations of edges between the developing drawing and the database edge images. [0056] With respect to the user interface, in one implementation, the user can use a screen/tablet to draw or erase strokes using a stylus. The user sees the evolving drawing formed with pen strokes superimposed on a continuously updating shadow S. The drawing area (e.g., 480×480 pixels) and the line strokes can be rendered using a dark blue marker style. To provide some color contrast, the shadow can be rendered in a sepia tone. [0057] To further make the shadow visible to the user, while not distracting from the user's actual drawing, the shadow image can be filtered to remove noisy and faint edges, [0000] {tilde over (S)}=S *( g ( S,σ r )−ε)  (12) [0000] where σ r =16. Multiplying by a blurred shadow image strengthens edges that agree in position, and weakens others. ε=1 is used to additionally suppress faint edges. In addition, a nominal amount of blur can be added with a standard deviation of 1.25 to soften the shadows. Finally, the shadow S′ can be weighted to show a higher contrast near the user's cursor position p c : [0000] S ′( p )=λ{tilde over ( S )}( p )+(1−λ)ω{tilde over ( S )}( p )  (13) [0000] where ω is a Gaussian weighted distance between p and p c with a standard deviation of 120 pixels. Contrast control parameter λ may be set by the user and controls the contrast of the shadows. [0058] Put another way, a system is provided that comprises an input component that receives a freeform user stroke in association with an interactive surface, the stroke input to a drawing process that includes an evolving drawing, a database of visual objects, the database stored as an inverted file of indexed sketch values that map to original visual objects and associated object edge images, a search component that performs a search of the inverted file in response to the user stroke using a hashing technique to retrieve matching visual objects, the search component includes an analysis component that analyzes the database of visual objects for candidate objects and processes the candidate objects to return the matching visual objects, and a user interface component that presents a dynamically changing composite image of the matching visual objects proximate the user stroke during the drawing process to guide the drawing process. [0059] The analysis component performs verification of candidate visual objects by, alignment of the candidate visual objects to the evolving drawing to obtain matching scores for the candidate visual objects based on similarity between an edge orientation of the candidate visual object and the user stroke, and computation of weights for the candidate visual objects based on the scores. [0060] The visual objects of the database are indexed by concatenated hashes which are derived from an edge extraction process and patch descriptors. The analysis component computes global and spatially varying scores to blend corresponding edge images of candidate visual objects into the composite image, the scores computed based on comparison of local orientation edges between the evolving drawing and database edge images. The analysis component increases a score for a candidate visual object if an edge exists with a similar orientation to the user stroke. [0061] In yet another embodiment, a system is provided that comprises a source of visual objects, the source includes a database where the visual objects are stored as an inverted file of indexed values (e.g., sketch) that map to original visual objects and associated object edge images, and a search component that performs a search of the inverted file using a hashing technique to retrieve matching visual objects, the search component includes an analysis component that analyzes the source of visual objects for candidate objects and processes the candidate objects to return matching visual objects, the analysis component computes global and spatially varying weights for blending of corresponding edge images of candidate visual objects into a composite image presented as a shadow image for drawing guidance during a drawing process. The search component and the analysis component dynamically update the shadow image in response to strokes input to the drawing process. [0062] The analysis component performs verification of candidate visual objects by, alignment of the candidate visual objects to an evolving drawing to obtain matching scores for the candidate visual objects based on similarity between an edge orientation of the candidate visual object and an input stroke, and computation of weights for the candidate visual objects based on the scores. The visual objects of the database can be indexed by concatenated hashes which are derived from an edge extraction process and patch descriptors. The analysis component computes the weights based on comparison of local orientation edges between an evolving drawing and database edge images. The analysis component increases a score for a candidate visual object if an edge exists with a similar orientation to an input stroke. [0063] FIG. 5 illustrates a flow diagram 500 for an online processing pipeline for image matching in realtime guidance of freehand drawing. At 502 , user strokes are received on a user drawing. The user drawing is recorded as a set of vectorized multi-segmented strokes. At 504 , patch descriptors are determined based on predetermined sub-region patches with a percentage overlap. For each sub-region, matches are aggregated in a histogram 506 . Thereafter, a verification process 508 performs fine alignment 510 , spatial scoring 512 , and outputs the resulting shadow image 514 (composite image). [0064] FIG. 6 illustrates a rendering pipeline 600 for the user interface. At 602 , user strokes are received and rendered. In this example, a bicycle is sketched in the drawing 604 . At 606 , weighting is performed based on pen position (for a pen-based interactive surface). The pen position 608 is represented in the drawing 604 . At 610 , a shadow image 612 is created. At 614 , the shadow image 612 is presented relative to the pen position 608 . In other words, the shadow image 612 can be presented under (and perhaps slightly offset from) the drawing 604 . [0065] FIG. 7 illustrates a computer-implemented method in accordance with the disclosed architecture. At 700 , a user stroke is received as input to an evolving drawing during a drawing process. At 702 , visual objects are obtained to find candidate visual objects. At 704 , the candidate visual objects are processed to find matching visual objects. At 706 , relevant matching visual objects are dynamically presented as shadow visual objects proximate the drawing [0066] FIG. 8 illustrates further aspects of the method of FIG. 7 . Note that the flow indicates that each block can represent a step that can be included, separately or in combination with other blocks, as additional aspects of the method represented by the flow chart of FIG. 7 . At 800 , the matching visual objects are aligned to the evolving drawing. At 802 , the matching visual objects are weighted based on the alignment. At 804 , the shadow visual objects are presented as weighted edge maps underlying the drawing and visually perceived to guide the user in the drawing process. At 806 , the visual objects are obtained from other drawings and/or a database, the database is stored as an inverted file of indexed concatenated hashes searchable by a min-hash technology. At 808 , the candidate visual objects are aligned to the drawing to generate associated scores. At 810 , a set of spatially varying weights is computed for each edge of the candidate matching object based on alignment scores. At 812 , the shadow visual objects are filtered to remove noisy and faint edges. [0067] As used in this application, the terms “component” and “system” are intended to refer to a computer-related entity, either hardware, a combination of software and tangible hardware, software, or software in execution. For example, a component can be, but is not limited to, tangible components such as a processor, chip memory, mass storage devices (e.g., optical drives, solid state drives, and/or magnetic storage media drives), and computers, and software components such as a process running on a processor, an object, an executable, a data structure (stored in volatile or non-volatile storage media), a module, a thread of execution, and/or a program. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers. The word “exemplary” may be used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. [0068] Referring now to FIG. 9 , there is illustrated a block diagram of a computing system 900 that executes realtime user guidance for freehand drawing in accordance with the disclosed architecture. However, it is appreciated that the some or all aspects of the disclosed methods and/or systems can be implemented as a system-on-a-chip, where analog, digital, mixed signals, and other functions are fabricated on a single chip substrate. In order to provide additional context for various aspects thereof, FIG. 9 and the following description are intended to provide a brief, general description of the suitable computing system 900 in which the various aspects can be implemented. While the description above is in the general context of computer-executable instructions that can run on one or more computers, those skilled in the art will recognize that a novel embodiment also can be implemented in combination with other program modules and/or as a combination of hardware and software. [0069] The computing system 900 for implementing various aspects includes the computer 902 having processing unit(s) 904 , a computer-readable storage such as a system memory 906 , and a system bus 908 . The processing unit(s) 904 can be any of various commercially available processors such as single-processor, multi-processor, single-core units and multi-core units. Moreover, those skilled in the art will appreciate that the novel methods can be practiced with other computer system configurations, including minicomputers, mainframe computers, as well as personal computers (e.g., desktop, laptop, etc.), hand-held computing devices, microprocessor-based or programmable consumer electronics, and the like, each of which can be operatively coupled to one or more associated devices. [0070] The system memory 906 can include computer-readable storage (physical storage media) such as a volatile (VOL) memory 910 (e.g., random access memory (RAM)) and non-volatile memory (NON-VOL) 912 (e.g., ROM, EPROM, EEPROM, etc.). A basic input/output system (BIOS) can be stored in the non-volatile memory 912 , and includes the basic routines that facilitate the communication of data and signals between components within the computer 902 , such as during startup. The volatile memory 910 can also include a high-speed RAM such as static RAM for caching data. [0071] The system bus 908 provides an interface for system components including, but not limited to, the system memory 906 to the processing unit(s) 904 . The system bus 908 can be any of several types of bus structure that can further interconnect to a memory bus (with or without a memory controller), and a peripheral bus (e.g., PCI, PCIe, AGP, LPC, etc.), using any of a variety of commercially available bus architectures. [0072] The computer 902 further includes machine readable storage subsystem(s) 914 and storage interface(s) 916 for interfacing the storage subsystem(s) 914 to the system bus 908 and other desired computer components. The storage subsystem(s) 914 (physical storage media) can include one or more of a hard disk drive (HDD), a magnetic floppy disk drive (FDD), and/or optical disk storage drive (e.g., a CD-ROM drive DVD drive), for example. The storage interface(s) 916 can include interface technologies such as EIDE, ATA, SATA, and IEEE 1394, for example. [0073] One or more programs and data can be stored in the memory subsystem 906 , a machine readable and removable memory subsystem 918 (e.g., flash drive form factor technology), and/or the storage subsystem(s) 914 (e.g., optical, magnetic, solid state), including an operating system 920 , one or more application programs 922 , other program modules 924 , and program data 926 . [0074] The operating system 920 , one or more application programs 922 , other program modules 924 , and/or program data 926 can include the entities and components of the system 100 of FIG. 1 , the entities and components of the system 200 of FIG. 2 , the entities, components, and flow of the diagram 500 of FIG. 5 , the entities and components of the rendering pipeline 600 of FIG. 6 , and the methods represented by the flowcharts of FIGS. 3 , 4 , 7 , and 8 , for example. [0075] Generally, programs include routines, methods, data structures, other software components, etc., that perform particular tasks or implement particular abstract data types. All or portions of the operating system 920 , applications 922 , modules 924 , and/or data 926 can also be cached in memory such as the volatile memory 910 , for example. It is to be appreciated that the disclosed architecture can be implemented with various commercially available operating systems or combinations of operating systems (e.g., as virtual machines). [0076] The storage subsystem(s) 914 and memory subsystems ( 906 and 918 ) serve as computer readable media for volatile and non-volatile storage of data, data structures, computer-executable instructions, and so forth. Such instructions, when executed by a computer or other machine, can cause the computer or other machine to perform one or more acts of a method. The instructions to perform the acts can be stored on one medium, or could be stored across multiple media, so that the instructions appear collectively on the one or more computer-readable storage media, regardless of whether all of the instructions are on the same media. [0077] Computer readable media can be any available media that can be accessed by the computer 902 and includes volatile and non-volatile internal and/or external media that is removable or non-removable. For the computer 902 , the media accommodate the storage of data in any suitable digital format. It should be appreciated by those skilled in the art that other types of computer readable media can be employed such as zip drives, magnetic tape, flash memory cards, flash drives, cartridges, and the like, for storing computer executable instructions for performing the novel methods of the disclosed architecture. [0078] A user can interact with the computer 902 , programs, and data using external user input devices 928 such as a keyboard and a mouse. Other external user input devices 928 can include a microphone, an IR (infrared) remote control, a joystick, a game pad, camera recognition systems, a stylus pen, touch screen, gesture systems (e.g., eye movement, head movement, etc.), and/or the like. The user can interact with the computer 902 , programs, and data using onboard user input devices 930 such a touchpad, microphone, keyboard, etc., where the computer 902 is a portable computer, for example. These and other input devices are connected to the processing unit(s) 904 through input/output (I/O) device interface(s) 932 via the system bus 908 , but can be connected by other interfaces such as a parallel port, IEEE 1394 serial port, a game port, a USB port, an IR interface, short-range wireless (e.g., Bluetooth) and other personal area network (PAN) technologies, etc. The I/O device interface(s) 932 also facilitate the use of output peripherals 934 such as printers, audio devices, camera devices, and so on, such as a sound card and/or onboard audio processing capability. [0079] One or more graphics interface(s) 936 (also commonly referred to as a graphics processing unit (GPU)) provide graphics and video signals between the computer 902 and external display(s) 938 (e.g., LCD, plasma) and/or onboard displays 940 (e.g., for portable computer). The graphics interface(s) 936 can also be manufactured as part of the computer system board. [0080] The computer 902 can operate in a networked environment (e.g., IP-based) using logical connections via a wired/wireless communications subsystem 942 to one or more networks and/or other computers. The other computers can include workstations, servers, routers, personal computers, microprocessor-based entertainment appliances, peer devices or other common network nodes, and typically include many or all of the elements described relative to the computer 902 . The logical connections can include wired/wireless connectivity to a local area network (LAN), a wide area network (WAN), hotspot, and so on. LAN and WAN networking environments are commonplace in offices and companies and facilitate enterprise-wide computer networks, such as intranets, all of which may connect to a global communications network such as the Internet. [0081] When used in a networking environment the computer 902 connects to the network via a wired/wireless communication subsystem 942 (e.g., a network interface adapter, onboard transceiver subsystem, etc.) to communicate with wired/wireless networks, wired/wireless printers, wired/wireless input devices 944 , and so on. The computer 902 can include a modem or other means for establishing communications over the network. In a networked environment, programs and data relative to the computer 902 can be stored in the remote memory/storage device, as is associated with a distributed system. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers can be used. [0082] The computer 902 is operable to communicate with wired/wireless devices or entities using the radio technologies such as the IEEE 802.xx family of standards, such as wireless devices operatively disposed in wireless communication (e.g., IEEE 802.11 over-the-air modulation techniques) with, for example, a printer, scanner, desktop and/or portable computer, personal digital assistant (PDA), communications satellite, any piece of equipment or location associated with a wirelessly detectable tag (e.g., a kiosk, news stand, restroom), and telephone. This includes at least Wi-Fi (or Wireless Fidelity) for hotspots, WiMax, and Bluetooth™ wireless technologies. Thus, the communications can be a predefined structure as with a conventional network or simply an ad hoc communication between at least two devices. Wi-Fi networks use radio technologies called IEEE 802.11x (a, b, g, etc.) to provide secure, reliable, fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wire networks (which use IEEE 802.3-related media and functions). [0083] The illustrated and described aspects can be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules can be located in local and/or remote storage and/or memory system. [0084] What has been described above includes examples of the disclosed architecture. It is, of course, not possible to describe every conceivable combination of components and/or methodologies, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. Accordingly, the novel architecture is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

Architecture that guides the freeform drawing of objects by a user to enable the user to produce improved drawings without significant training. As the user draws, the architecture dynamically updates a relevant shadow image proximate (e.g., underlying) the user's strokes. The strokes overlay an evolving shadow image, which shadow image is suggestive of object contours that guide the user during the drawing process. Relevant edge images selected from a large database are automatically blended to construct the shadow image. As the user draws, the strokes are dynamically analyzed using an encoding of overlapping windows for fast matching with the database of images. A top ranked set of matching database edge images are aligned to the drawing, a set of spatially varying weights blend the edge images into the shadow image, and a scoring technique is employed to select the optimum shadow image for display.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of, and claims benefit under 35 USC 120 to, international application PCT/EP2009/006171, filed Aug. 26, 2009, which claims benefit of German Application No. 10 2008 046 699.9, filed Sep. 10, 2008 and U.S. Ser. No. 61/095,689, filed Sep. 10, 2008. International application PCT/EP2009/006171 is hereby incorporated by reference in its entirety. FIELD [0002] The disclosure relates to an imaging optical system with a plurality of mirrors, which image an object field in an object plane into an image field in an image plane. BACKGROUND [0003] Imaging optical systems of this type are known from EP 1 093 021 A2 and WO 2006/069725 A1. Further imaging optical systems are known from US 2007/0035814 A1, U.S. Pat. No. 7,186,983 B2, US 2007/0233112 A1 and WO 2006/037 651 A1. An imaging optical system is known from U.S. Pat. No. 6,172,825 B1, in which the position of an entry pupil plane of the imaging optical systems is produced from the position for an aperture diaphragm or stop AS. SUMMARY [0004] The disclosure provides illumination system including an imaging optical system in which the transmission losses of the illumination system are relatively low. [0005] In some embodiments, an imaging optical system has a beam path, an object plane, an image plane and an entry pupil. The imaging optical system also has a connecting axis, which is perpendicular to the object plane and runs through the geometric centre point of the mirror which is most closely adjacent to the object field. The mirror which is most closely adjacent to the object field is arranged at a spacing from the object field which is greater than a spacing of an entry pupil plane of the imaging optical system from the object field. The pupil plane lies in the beam path of the imaging light up-stream of the object field. [0006] The imaging optical system includes a plurality of mirrors that image an object field in an object plane into an image field in the image plane along the beam path. A connecting axis is perpendicular to the object plane and runs through the geometric centre point of the mirror which is most closely adjacent to the object field. The distance between the object field and the mirror which is most closely adjacent to the object field is greater than the distance between the object field and the entry pupil plane. The entry pupil plane lies in the beam path up-stream of the object field. [0007] In certain embodiments, an imaging optical system with a plurality of mirrors, which image an object field in an object plane into an image field in an image plane, where: an entry pupil plane lies in the beam path of the imaging light upstream of the object field, the imaging light is reflected on the object plane, a connecting axis is perpendicular to the object plane and runs through the geometric center point of the entry pupil, an intersection point of the connecting axis with the entry pupil plane is closer to the object plane than a first intersection point in the beam path of the imaging light downstream of the object field, of a main beam of a central object field point with the connecting axis, at least one of the mirrors has a through-opening for imaging light to pass through. [0013] In an imaging optical system of this type, when using a reflecting object to be imaged, an optical component may be arranged in the beam path upstream of the object field on the connecting axis. As a result, the number of components used to illuminate the object field, of an optical illumination system arranged in the beam path upstream of the imaging optical system can be reduced, so the total losses of illumination light are reduced. The disclosure also provides to develop an imaging optical system of the type mentioned at the outset in such a way that deformations of a mirror adjacent to a field have effects, which are as small as possible, on the imaging behaviour of the imaging optical system. [0014] This can be achieved according to the disclosure by an imaging optical system of the type mentioned at the outset, the imaging optical system, spaced apart from a first mirror, which is most closely adjacent to one of the two fields and is called the neighboring mirror, having a deformable further mirror, which is arranged in a plane, which is optically conjugated to an arrangement plane of the neighboring mirror in the imaging optical system. Examples of planes optically conjugated with respect to one another of an imaging optical system are the field planes of the imaging optical system or the pupil planes of the imaging optical system. All planes, which correspond to one another with regard to the bundle form and the angle distribution of the imaging beams, are planes which are optically conjugated with respect to one another. [0015] According to the disclosure, it was recognized that a deformable mirror in an optically conjugated plane with respect to the neighboring mirror, the deformation of which brings about undesired changes in the properties of the imaging optical system, leads to good compensation of changes in the imaging properties caused because of the deformation. In this case, deformations of the neighboring mirror, which may have various causes, can be compensated. Deformations of the neighboring mirror because of its inherent weight, in other words gravitative deformations, may be compensated. Deformations of the neighboring mirror can also be compensated by the further mirror arranged in the optically conjugated plane, these being produced by oscillations of the neighboring mirror. In this case, the deformable mirror may be equipped with actuating elements, which allow a deformation which is synchronised with the oscillations of the neighboring mirror. The deformable mirror may, for example, be actuatable at a bandwidth corresponding to the bandwidth of the oscillation of the neighboring mirror. An example of actuating elements which can be used for this in the deformable mirror is described in U.S. Pat. No. 7,443,619 B2. The actuating elements disclosed there, which are used for the deformation of the reflection surface of a mirror, may be operated at a bandwidth, which is so high that compensation of deformations induced by oscillation in the neighboring mirror is thereby possible. In particular, Lorentz actuators may be used. Thermal deformations of the neighboring mirror may also be compensated with the aid of the deformable mirror arranged in the optically conjugated plane. [0016] A further object of the present disclosure is to develop an imaging optical system of the type mentioned at the outset in such a way that a spacing, which is as small as possible, of a reflection surface of a field-adjacent mirror from the adjacent field is possible. [0017] This object is achieved according to the disclosure by an imaging optical system of the type mentioned at the outset, wherein a support body of a mirror, which is most closely adjacent to one of the two fields, which is also called a neighboring mirror, is made of a material, the modulus of elasticity of which is at least twice as great as the modulus of elasticity of the material of the support body of at least one of the other mirrors. [0018] According to the disclosure, it was recognized that it is certainly possible to use a material with a very high modulus of elasticity in the material selection for the neighboring mirror. This allows the neighboring mirror to be equipped with a very thin support body, which can be brought correspondingly closely to the field. Because of the high modulus of elasticity of the material of the support body of the neighboring mirror, the latter, despite the optionally very thin support body, has adequate stability. The support bodies of the other mirrors, which may be thicker, in other words less thin, may, on the other hand, be made of a material with a lower modulus of elasticity. The material selection for these other mirrors may therefore take place from other points of view. These other mirrors may all be manufactured from the same material; this is however not imperative. The modulus of elasticity of the neighboring mirror may be at least twice as great as the greatest modulus of elasticity of the material of the support bodies of all the other mirrors. The comparative material, with which the material of the neighboring mirror is compared with respect to the modulus of elasticity, is then the material of the other mirror with the greatest modulus of elasticity. When using the imaging optical system as a projection lens system for transmitting a structure arranged in the object field into the image field, the neighboring mirror is most closely adjacent to the image field of the imaging optical system. Another application of the imaging optical system is a microscope lens system. In this case, the neighboring mirror is most closely adjacent to the object field of the imaging optical system. Generally, the neighboring mirror is most closely adjacent to the field on the high-aperture side of the imaging optical system. No other mirror of the imaging optical system thus has a smaller spacing from this field. [0019] The features of the imaging optical systems according to the disclosure described above may also be implemented in combination. [0020] The neighboring mirror may be manufactured from a material with a modulus of elasticity which is at least 150 GPa. A modulus of elasticity of this type allows a very thin design of the support body of the neighboring mirror. The support body of the neighboring mirror is preferably made of a material with a modulus of elasticity which is at least 200 GPa, more preferably at least 250 GPa, more preferably 300 GPa, more preferably 350 GPa and still more preferably 400 GPa. [0021] The support body of the neighboring mirror may also be manufactured from silicon carbide. This material, for example, allows production of a very thin support body via a forming method by a graphite forming body. The support body can then be still further processed using known surface processing methods, if this becomes desirable to achieve the optical imaging quality. Alternative materials for the support body of the neighboring mirror are SiSiC, CSiC and SiN. [0022] The imaging optical system, spaced apart from the neighboring mirror, may have a deformable mirror. With the aid of a deformable mirror of this type, a compensation of thermal deformations of the neighboring mirror is possible, which may, for example, come from a thermal loading of the neighboring mirror by residual absorption of the imaging light. [0023] The deformable mirror may be arranged in an optical plane which is conjugated with respect to the arrangement plane of the neighboring mirror in the imaging optical system. This simplifies the compensation of thermal deformations of the neighboring mirror by a compensating deformation of the deformable mirror, as measured deformations of the neighboring mirror can easily be converted into compensating deformations of the deformable mirror. In this case, it is sufficient to make a single mirror of the imaging optical system deformable to compensate thermal deformations of the neighboring mirror. Alternatively, it is naturally also possible to make a plurality of mirrors of the imaging optical system deformable in a targeted manner. [0024] The mirrors, which the imaging optical system has in addition to the neighboring mirror, may be constructed from a material with a thermal expansion coefficient, which is at most 1×10 −7 m/m/K. Examples of materials of this type are Zerodur® and ULE®. A thermal load on mirrors made of these materials practically does not lead to any or only very slight deformation of the reflection surfaces thereof. [0025] If the imaging optical system has precisely six mirrors, this allows a simultaneously compact and, with regard to its imaging errors, well corrected imaging optical system. [0026] A reflection surface of at least one mirror of the imaging optical system may be designed as a surface which can be described by a rotationally symmetrical asphere. As a result, good imaging error correction is made possible. [0027] A reflection surface of at least one mirror of the imaging optical system may be designed as a freeform surface which cannot be described by a rotationally symmetrical function. The use of freeform surfaces instead of reflection surfaces having a rotationally symmetrical axis provides new degrees of design freedom, which leads to imaging optical systems with feature combinations which could not be realised with rotationally symmetrical reflection surfaces. Freeform surfaces suitable for use in imaging optical systems according to the disclosure are known from US 2007/0058269 A1 and US 2008/0170310 A1. At least one of the mirrors of the imaging optical system may have a through-opening for imaging light to pass through. This allows the design of the imaging optical system with a very large numerical aperture. When using the imaging optical system as a projection lens systems, a very high structure resolution at the given wavelength of the imaging light may thus be achieved. [0028] The advantages of a projection exposure system with an imaging optical system according to the disclosure, a light source for the illumination and imaging light and with an illumination optical system for guiding the illumination light to the object field of the imaging optical system, and in particular the advantages of a projection exposure system, in which a pupil facet mirror of the optical illumination system is arranged in an entry pupil plane of the imaging optical system, correspond to those, which were stated above in relation to the imaging optical system according to the disclosure. In an arrangement of the pupil facet mirror in the entry pupil plane of the imaging optical system, the pupil facet mirror can direct the illumination and imaging light directly to the object field. Optical components lying in between, between the pupil facet mirror and the object field are not then necessary and this increases the transmission of the projection exposure system. This is advantageous, in particular, when the illumination and imaging light can generally only be guided with losses, which is the case, for example, in EUV wavelengths in the range between 5 nm and 30 nm. If the imaging optical system according to the disclosure is designed such that, on a connecting axis, which is perpendicular to the object plane and runs through the geometric center point of the mirror, which is most closely adjacent to the object field, the mirror most closely adjacent to the object field is arranged at a spacing, which is greater than a spacing of an entry pupil plane located in the beam path of the imaging light upstream of the object field, of the imaging optical system from the object field, when using a reflecting object to be imaged, the pupil facet mirror arranged in the entry pupil plane can be accommodated on the connecting axis and therefore compactly between other components of the imaging optical system. The same applies when the imaging optical system according to the disclosure is designed such that an intersection point of a connecting axis, which is perpendicular to the object plane and runs through the geometric center point of the entry pupil, with the entry pupil plane, lies closer to the object plane than a first intersection point lying in the beam bath of the imaging light after the object field of a main beam, of a central object field point with the connecting axis. It is to be noted here that because of the fact that the beam path of the illumination or imaging light is reflected on the object plane, the entry pupil plane, although it lies in the beam path upstream of the object plane, comes to rest on the side of the object plane facing the image plane and generally between the object plane and the image plane. [0029] The light source of the projection exposure system may be wideband and, for example, have a bandwidth, which is greater than 1 nm, which is greater than 10 nm or which is greater than 100 nm. In addition, the projection exposure system may be designed such that it can be operated by light sources of different wavelengths. An optical illumination system with a pupil facet mirror is, for example, known from US2007/0223112 A1. [0030] Corresponding advantages, as stated above, apply to a method for producing a microstructured component having the following method steps: providing a reticle and a wafer, projecting a structure on the reticle onto a light-sensitive layer of the wafer with the aid of the projection exposure system according to the disclosure, producing a microstructure on the wafer, and the microstructured or nanostructured component produced thereby. BRIEF DESCRIPTION OF THE DRAWINGS [0034] Embodiments will be described in more detail below with the aid of the drawings, in which: [0035] FIG. 1 schematically shows a projection exposure system for microlithography; [0036] FIG. 2 shows a meridianal section which contains imaging beam paths of field points spaced apart from one another, through an embodiment of an optical projection system of the projection exposure system according to FIG. 1 ; and [0037] FIG. 3 schematically shows a beam path supplemented by an illumination system of the projection exposure system in a projection exposure system with a further embodiment of an optical projection system. DETAILED DESCRIPTION [0038] A projection exposure system 1 for microlithography has a light source 2 for illumination light. The light source 2 is an EUV light source, which generates light in a wavelength range of between 5 nm and 30 nm. Other EUV wavelengths are also possible. Generally any wavelengths, for example visible wavelengths are even possible for the illumination light guided in the projection exposure system 1 . A beam path of the illumination light 3 is shown very schematically in FIG. 1 . [0039] An optical illumination system 6 is used to guide the illumination light 3 to an object field 4 in an object plane 5 . The object field 4 in an image field 8 in an image plane 9 is imaged at a predetermined reduction scale by an optical projection system 7 . The optical projection system 7 reduces by a factor of 8. [0040] Other imaging scales are also possible, for example 4×, 5×, 6× or else imaging scales, which are greater than 8×. For illumination light with EUV wavelengths, an imaging scale of 8× is suitable in particular, as the angle of incidence on the object side can thus be kept small on a reflection mask. Illumination angles on the object side of less than 6° can be realised for an image-side aperture of the optical projection system 7 of NA=0.5, with an imaging scale of 8×. The image plane 9 is arranged in the optical projection system 7 parallel to the object plane 5 . A section coinciding with the object field 4 , of a reflecting mask 10 , which is also called a reticle, is imaged here. Because of the reflecting effect of the reticle 10 , the illumination light 3 is reflected on the object plane 5 . The imaging takes place on the surface of a substrate 11 in the form of a wafer, which is carried by a substrate holder 12 . FIG. 1 schematically shows between the reticle 10 and the optical projection system 7 , a beam bundle 13 of the illumination light 3 running into the latter and, between the optical projection system 7 and the substrate 11 , a beam bundle 14 of the illumination light 3 running out of the optical projection system 7 . The image field-side numerical aperture NA of the optical projection system 7 according to FIG. 2 is 0.50. [0041] To facilitate the description of the projection exposure system 1 , a Cartesian xyz coordinate system is given in the drawing, from which the respective position relationship of the components shown in the figures emerges. In FIG. 1 , the x-direction runs perpendicularly to the plane of the drawing into the latter, and the y-direction runs to the right and the z-direction runs downwardly. [0042] The projection exposure system 1 is of the scanner type. Both the reticle 10 and the substrate 11 are scanned during operation of the projection exposure system 1 in the y-direction. [0043] FIG. 2 shows the optical design of the optical projection system 7 . The beam path is shown, in each case, of three individual beams 15 , which emanate from five object field points lying one above the other in FIG. 2 and spaced apart from one another in the y-direction, the three individual beams 15 , which belong to one of these five object field points, being associated in each case with three different illumination directions for the five object field points. These three illumination directions are depicted by the upper coma beam, the lower coma beam and the main beam of each of the five object field points. [0044] Proceeding from the object plane 5 , the individual beams 15 are firstly reflected by a first mirror M 1 and then by further mirrors, which are designated below, in the order of the beam path, mirror M 2 , M 3 , M 4 , M 5 and M 6 . In each case, the mathematical parent surfaces used to calculate the form of the reflection surfaces of the mirrors M 1 to M 6 are shown. In the actual optical projection system 7 , the reflection surfaces of the mirrors M 1 to M 6 are actually only present where they are impinged upon by the individual beams 15 . [0045] The optical projection system 7 according to FIG. 2 thus has six reflecting mirrors. These mirrors bear a highly reflective coating for the wavelength of the illumination light 3 , if this is desirable because of the wavelength, for example in the EUV. In particular, the mirrors M 1 to M 6 have multi-reflection coatings to optimise their reflection for the impinging illumination light 3 . The reflection is, in particular, when EUV illumination light 3 is used, all the better, the closer the reflection angle, in other words the angle of impingement of the individual beams 15 on the surfaces of the mirrors M 1 to M 6 , to the perpendicular incidence. The optical projection system 7 overall has small reflection angles for all the individual beams 15 . [0046] Radiations with very different wavelengths from one another can also be guided in the optical illumination system 6 and the optical projection system 7 , as these optical systems have substantially achromatic properties. It is thus possible, for example, to guide an adjustment laser or an auto focusing system in these optical systems, a wavelength which is very different from the working wavelength thereof being simultaneously worked with for the illumination light. Thus, an adjusting laser may work at 632.8 nm, at 248 nm or at 193 nm, while illumination light in the range between 5 and 30 nm is simultaneously worked with. [0047] The mirror M 3 has a convex basic shape. In other words, the mirror M 3 can be described by a convex best adapted surface. In the following description, mirrors of this type are designated, in a simplified manner, convex. Mirrors which can be described by a concavely best adapted surface, are designated, in a simplified manner, concave. The convex mirror M 3 ensures a good Petzval correction in the optical projection system 7 . [0048] An overall length of the optical projection system 7 , in other words the spacing between the object plane 5 and the image plane 9 , is 1521 mm in the optical projection system 7 . The individual beams 15 belonging to a specific illumination direction of the five object field points combine in a pupil plane 16 of the optical projection system 7 . The pupil plane 16 is arranged adjacent to the mirror M 3 in the beam path thereafter. [0049] The mirrors M 1 to M 4 image the object plane 5 in an intermediate image plane 17 . The intermediate image-side numerical aperture of the optical projection system 7 is about 0.2. The mirrors M 1 to M 4 form a first part imaging optical system of the optical projection system 7 with a reducing imaging scale of about 3.2×. The following mirrors M 5 and M 6 form a further part imaging optical system of the optical projection system 7 with a reducing imaging scale of about 2.5×. Formed in the beam path of the illumination light 3 between the mirrors M 4 and M 5 upstream of the intermediate image plane 7 and adjacent thereto is a through-opening 18 in the mirror M 6 , through which the illumination or imaging light 3 passes upon the reflection from the fourth mirror M 4 to the fifth mirror M 5 . The fifth mirror M 5 in turn has a central through-opening 19 , through which the beam bundle 14 passes between the sixth mirror M 6 and the image plane 9 . [0050] In the beam path between the fifth mirror M 5 and the sixth mirror M 6 is a further pupil plane 20 of the optical projection system 7 , which is optically conjugated to the first pupil plane 16 . At the site of the further pupil plane 20 there exists a diaphragm plane which is physically accessible from the outside. An aperture diaphragm may be arranged in this diaphragm plane. [0051] The optical projection system 7 , in one of the pupil planes 16 , 20 , has an obscuration diaphragm or stop arranged in a centered manner. As a result, the part beams of the projection beam path associated with the central through-openings 18 , 19 in the mirrors M 6 , M 5 are obscured. Therefore, the design of the optical projection system 7 is also called a design with a central pupil obscuration. [0052] A distinguished individual beam 15 , which connects a central object field point with a centrally illuminated point in the entry pupil of the optical projection system 7 is also called a main beam of a central field points. The main beam of the central field point, from the reflection at the sixth mirror M 6 , with the image plane 9 , approximately encloses a right angle, in other words, runs approximately parallel to the z-axis of the projection exposure system 1 . This angle is greater than 85°. [0053] The image field 8 has the shape of a ring field segment, in other words is delimited by two part circles running parallel to one another and two side edges also running parallel to one another. These side edges run in the y-direction. Parallel to the x-direction, the image field 8 has an extent of 13 mm. Parallel to the y-direction, the image field 8 has an extent of 1 mm. The radius R of the through-opening 19 satisfies the following relation for a vignetting-free guidance. [0000] R ≥ 1 2 · D + d w · NA [0054] D is the diagonal here of the image field 8 . d w is a free working spacing of the mirror M 5 from the image plane 9 . This free working spacing is defined as the spacing between the image plane 9 and the section located closest thereto of a used reflection surface of the closest mirror of the optical projection system 7 , in other words, in the embodiment according to FIG. 2 of the mirror M 5 , NA is the image-side numerical aperture. The free working spacing d w in the optical projection system 7 is 39 mm. [0055] The fifth mirror M 5 is the mirror which is most closely adjacent to the object field 5 in the image plane 9 . The fifth mirror M 5 is therefore also called the neighboring mirror below. The neighboring mirror M 5 has a support body 21 which is indicated by dashed lines in FIG. 2 , on which the reflection surface of the neighboring mirror M 5 is formed. The support body 21 is made of silicon carbide. This material has a modulus of elasticity (Young's modulus) of 400 GPa. The other mirrors M 1 to M 4 and M 6 of the optical projection system 7 are made of Zerodur®. This material has a modulus of elasticity of 90 GPa. [0056] The modulus of elasticity of the support body 21 of the neighboring mirror M 5 is thus more than twice as great as the modulus of elasticity of the material for the support body 22 of the other mirrors M 1 to M 4 and M 6 . [0057] The support body 21 has a maximum thickness of 35 mm, so a free working spacing of 4 mm remains between a rear of the mirror M 5 remote from the reflection surface of the mirror M 5 , and the image plane. A maximum diameter of the reflection surface used of the mirror M 5 in the optical projection system 7 is 285 mm. A ratio between this maximum diameter and the thickness of the support body 21 of the mirror M 5 is therefore 285/35=8.14. Other ratios of this type, which will also be called aspect ratios below are possible in the range between 6 and 20. [0058] The support body 21 of the neighboring mirror M 5 may also be made from a different material with a modulus of elasticity which is at least 150 GPa. Examples of materials of this type are reaction-bound silicon-infiltrated silicon carbide (SiSiC) with a modulus of elasticity of 395 GPa, carbon fibre-reinforced silicon carbide (CSiC) with a modulus of elasticity of 235 GPa and silicon nitride (SiN) with a modulus of elasticity of 294 GPa. Zerodur®, has, in the room temperature range of interest, a thermal expansion coefficient of less than 50×10 −9 m/m/K. The support bodies 22 of the mirrors M 1 to M 4 and M 6 may also be constructed from a different material with a thermal expansion coefficient, which is at most 1×10 −7 m/m/K. A further example of a material of this type is ULE® with a thermal expansion coefficient, which, in the room temperature range of interest, is also less than 50×10 −9 m/m/K, and which has a modulus of elasticity of 69 GPa. [0059] The thermal expansion coefficient of the material of the support body 21 of the neighboring mirror M 5 is significantly greater than the thermal expansion coefficient of the support bodies 22 of the other mirrors of the optical projection system 7 . SiC, for example, has a thermal expansion coefficient in the room temperature range of interest of 2.6×10 −6 m/m/K. The thermal expansion coefficients of the other material variants for the support body 21 of the neighboring mirror M 5 vary in a range between 1×10 −6 m/m/K and 2.6×10 −6 m/m/K. [0060] The neighboring mirror M 5 is in an arrangement plane in the imaging beam path of the optical projection system 7 , which is optically conjugated to an arrangement plane, in which the third mirror M 3 lies. The mirror M 4 lying in between in the imaging beams path thus acts such that it approximately images these two arrangement planes of the mirrors M 3 and M 5 in one another. [0061] The third mirror M 3 is designed as a deformable mirror. The reflection surface of the third mirror M 3 is, in one embodiment of the deformable mirror, connected at the rear to a plurality of actuators 23 acting perpendicularly to the reflection surface, which are connected by signal lines or a signal bus 24 to a control device 25 . By individual activation of the actuators 23 by the control device 25 , the form of the reflection surface of the mirror M 3 can be input. [0062] As the mirror M 3 is arranged in a position optically conjugated to the position of the neighboring mirror M 5 , deformations of the reflection surface of the neighboring mirror M 5 caused, for example, because of a thermal expansion of the support body 21 of the neighboring mirror M 5 can be compensated by deformations in the opposite direction of the reflection surface of the third mirror M 3 , input by the control mechanism 25 . A deformation of the reflection surface of the neighboring mirror M 5 may be detected optically, for example. Corresponding detection methods are known. The result of this detection of deformation can then be used as an input signal for the control device 25 to determine control values for the individual actuators 23 . [0063] In this manner, thermal drifts, in particular caused by the different thermal expansion coefficients of the materials of the support body 21 , on the one hand, and of the support bodies 22 , on the other hand, can be compensated by a deformation of the reflection surface of the third mirror M 3 . A targeted deformation of the reflection surface of the third mirror M 3 can naturally also be used to correct or compensate further imaging errors, for example for Petzval correction. [0064] The reflection surface of the third mirror M 3 may be designed as a closed reflection surface, sections of this closed reflection surface in each case being mechanically connected to an individual actuator 23 . It is alternatively possible to equip the third mirror M 3 with a reflection surface made of a plurality of mirror sections which can be moved separately from one another, for example as a multi-mirror array or a facet mirror. Each of these mirror sections can then be tilted or displaced individually by their own actuator 23 , so a deformation of the reflection surface of the third mirror M 3 formed by the totality of the mirror sections is thus brought about. A deformation of the mirror surface of a mirror, which has a highly reflective coating is also possible by the use of an electronically activatable piezo-electric layer, which may, for example, be arranged between the mirror substrate and the highly reflective coating. [0065] It is possible to use as actuators to deform the third mirror M 3 or to deform one of the mirror sections of the third mirror M 3 , actuators which are described, for example, in U.S. Pat. No. 7,443,619. Lorentz actuators, in particular, can be used. The actuating elements of the third mirror M 3 can be activated at a high band width. This makes it possible to also compensate deformation imaging influences caused by oscillations or vibrations of the neighboring mirror M 5 via the deformable mirror M 3 . The deformations of the deformable mirror M 3 are then synchronised with the oscillation deformations of the neighboring mirror M 5 . This can be realised by a corresponding sensory scanning or sampling of the oscillations of the mirror M 5 and activation derived therefrom of the actuating elements for the deformable mirror M 3 . [0066] The reflection surfaces of the mirrors M 1 to M 6 have rotationally symmetrical aspherical basic shapes, which can be described by known asphere equations. Alternatively, it is possible to design at least individual ones of the mirrors M 1 to M 6 as freeform surfaces which cannot be described by a rotationally symmetrical function. Freeform surfaces of this type for reflection surfaces of mirrors of optical projection systems of projection exposure systems for microlithography are known from US 2007/0058269 A1 and US 2008/0170310 A1. [0067] The support body 21 of the neighboring mirror M 5 can be produced by a CVD (chemical vapour deposition) method. Here, silicon carbide from the gas phase is deposited on a forming body made of graphite. The forming body in this case has a shape corresponding to the desired reflection surface. After the separation of the support body 21 from the forming body, another coating of the support body 21 can be carried out to improve the processability and the reflectivity of the reflection surface of the support body 21 . [0068] As an alternative to a configuration made of a material with a modulus of elasticity, which is at least twice as great as that of one of the other mirrors, the neighboring mirror M 5 may also be made of Zerodur® or of ULE® (Ultra Low Expansion) glass. A titanium silicate glass may be used here, for example. Deformations of the neighboring mirror M 5 and the effects thereof on the imaging properties of the imaging optical system 7 may be compensated via the deformable third mirror M 3 . [0069] FIG. 3 schematically shows a further embodiment of a projection exposure system 1 . Components, which correspond to those which were described above with reference to FIGS. 1 and 2 , have the same reference numerals and are not discussed again in detail. [0070] A collector 26 for collecting the usable emission of the light source 2 is arranged down-stream of the light source 2 . Arranged downstream of the collector 26 is in turn a spectral filter 27 , which is operated in grazing incidence. A field facet mirror 28 is arranged downstream of the spectral filter 27 . A pupil facet mirror 29 is arranged downstream of the field facet mirror 28 . The concept of facet mirrors 28 , 29 of this type as components of the optical illumination system 6 is basically known, for example, from U.S. Pat. No. 7,186,983 B2. [0071] The pupil facet mirror 29 is arranged in the region of an entry pupil plane 30 of an optical projection system 31 , which can be used as an alternative to the optical projection system 7 in the projection exposure system 1 . The illumination light 3 is directed by the pupil facet mirror 29 directly to the reflective reticle 10 . No further component influencing or deflecting the illumination light 3 , for example a mirror with a grazing incidence is present between the pupil facet mirror 29 and the reticle 10 . [0072] The optical projection system 31 is only described below where it qualitatively differs from the optical projection system 7 according to FIGS. 1 and 2 . [0073] In the optical projection system 31 , the first pupil plane 16 after the object plane 5 lies between the second mirror M 2 and the third mirror M 3 . At this point, an aperture diaphragm, for example, may be arranged to limit the illumination light beam bundle. [0074] The pupil facet mirror 29 and the second mirror M 2 of the optical projection system 31 are arranged on a connecting axis 32 . This connecting axis is defined as the axis passing through the geometric center point of the mirror most closely adjacent to the object plane 5 and perpendicular to the object plane 5 . In the embodiment according to FIG. 3 , the mirror M 2 is the mirror which is most closely adjacent to the object plane 5 . The second mirror M 2 is therefore the mirror, which is most closely adjacent to the object field 4 along the connecting axis 32 , of the optical projection system 31 . The second mirror M 2 is arranged along the connecting axis 32 at a spacing A from the object plane 5 , which is greater than a spacing B of the entry pupil plane 30 from the object plane 5 . The spacing A is 704 mm. The spacing B is 472 mm. The pupil facet mirror 29 and the second mirror M 2 of the optical projection system 31 are arranged back to back. Therefore, the optical projection system 31 provides construction space for accommodating the pupil facet mirror 29 on the connecting axis 32 . The pupil facet mirror 29 can thus be arranged in such a way that the illumination light 3 from the pupil facet mirror 29 is reflected directly to the reflecting reticle 10 . [0075] The connecting axis 32 is also perpendicular to the image plane 9 . The connecting axis 32 also runs through the geometric center point of the mirror M 5 , which is most closely adjacent to the image field 8 . An intersection point C of the connecting axis 32 with the entry pupil plane 30 lies closer to the object plane 5 than a first intersection point D in the beam path of the illumination and imaging light 3 of a main beam 33 of a central object field point with the connecting axis 32 . Because of the reflecting action of the reticle 10 , the entry pupil plane, despite the fact that it is arranged in the beam path upstream of the object plane 5 , lies between the object plane 5 and the image plane 9 . Because of the fact that the spacing of the intersection point C from the object plane 5 is smaller than the spacing of the intersection point D from the object plane 5 , the possibility is produced of moving the pupil facet mirror 29 into the construction space of the optical projection system 31 , without an illumination beam path of the illumination light 3 being obstructed by components of the optical projection system 31 and without an imaging beam path of the illumination light 3 being obstructed by the pupil facet mirror 29 . [0076] In contrast to the optical projection system 7 , in the optical projection system 31 , the spacing of the mirror M 3 from the object plane 5 is less than the spacing of the mirror M 1 from the object plane 5 . [0077] The optical projection system 31 has an image-side numerical aperture NA of 0.4. The object field 4 , in the optical projection system 31 , has an extent of 2 mm in the y-direction and 26 mm in the x-direction. The reduced imaging scale of the optical projection system 31 is 4×. [0078] The optical data of the optical projection system 31 are reproduced below with the aid of two tables in the Code V®-format. [0079] The first table in the “radius” column in each case shows the radius of curvature of the mirrors M 1 to M 6 . The third column (thickness) describes the spacing, proceeding from the object plane 5 , in each case from the following surface in the z-direction. [0080] The second table describes the precise surface form of the reflection surfaces of the mirrors M 1 to M 6 , the constants K and A to G being inserted in the following equation for the arrow height z: [0000] z  ( h ) == ch 2 1 + SQRT  { 1 - ( 1 + K )  c 2  h 2 } ++  A   h 4 + Bh 6 + Ch 8 + Dh 10 + Eh 12 + Fh 14 + Gh 16 [0081] h is the spacing here from an optical axis of the optical projection system 31 . Thus h 2 =x 2 =y 2 applies. For c, the reciprocal value of “radius” is used. [0000] Surface Radius Thickness Operating mode Object Infinite 1008.515 plane M1 −589.188 −304.940 REFL M2 −241.133 226.892 REFL M3 −1530.294 −188.411 REFL M4 557.639 1651.258 REFL M5 1500.000 −509.557 REFL Stop Infinite −745.289 M6 1483.965 1284.846 REFL Image plane Infinite 0.000 Surface K A B C M1 −1.907467E−01 −4.201365E−14 −1.850017E−17 −2.806339E−22 M2 −5.642091E−01 1.123646E−08 −1.729255E−13 4.634573E−18 M3 −1.457717E−02 6.326755E−09 1.214295E−13 7.108126E−18 M4 3.218346E−03 3.917441E−09 1.354421E−13 −2.254336E−17 M5 1.035722E+00 4.337345E−10 9.699608E−16 5.753846E−21 M6 1.041374E−01 −7.896075E−13 −1.157231E−19 −3.023015E−25 Surface D E F G M1 4.451266E−27 −5.566664E−32 3.449801E−37 −8.987817E−43 M2 2.211189E−21 −1.041819E−24 1.928886E−28 −1.341001E−32 M3 −2.395752E−21 8.896309E−31 2.012774E−28 −3.680072E−32 M4 2.671995E−21 −1.455349E−25 3.081018E−32 2.302996E−34 M5 −2.106085E−25 1.011811E−29 −2.375920E−34 2.279074E−39 M6 1.895127E−30 −6.992363E−36 1.347813E−41 −1.055593E−47 [0082] An overall length of the optical projection system 31 , in other words the spacing between the object plane 5 and the image plane 9 , in the optical projection system 31 is 2423 mm. The free working spacing d w of the mirror M 5 from the image plane 9 is 30 mm in the optical projection system 31 . The support body 21 has a maximum thickness of 26 mm, so that a free working spacing of 4 mm remains between a rear of the mirror 5 remote from the reflection surface of the mirror M 5 and the image plane 9 . A maximum diameter of the reflection surface used of the mirror M 5 in the optical projection system 31 is 300 mm. A ratio between this maximum diameter and the thickness of the support body 21 of the mirror M 5 is therefore 300/26=11.5. [0083] To produce a microstructured or nanostructured component, in particular a semiconductor component for microelectronics, in other words, for example, a microchip, the procedure is as follows: firstly, the reticle 10 and the wafer 11 are provided. Then, a structure present on the reticle 10 is projected onto a light-sensitive layer of the wafer 11 with the aid of the projection exposure system 1 . By developing the light-sensitive layer, a microstructure or nanostructure is then produced on the wafer 11 . [0084] Corresponding designs of the optical projection system 7 , like that according to FIG. 2 , may also be used in applications other than projection exposure, for example as a microscope lens system. In this case, the object field 4 and the image field 8 exchange their roles. The mirror M 5 , in other words, the neighboring mirror, in the case of application of the optical projection system 7 as a microscope lens system, is then most closely adjacent to the object field 8 .

An imaging optical system includes a plurality of mirrors configured to image an object field in an object plane of the imaging optical system into an image field in an image plane of the imaging optical system. An illumination system includes such an imaging optical system. The transmission losses of the illumination system are relatively low.

FIELD OF THE INVENTION The present invention relates to compositions and processes for providing corrosion protection for metal substrates, particularly substrates comprised of aluminum or aluminum alloys, using treatment solutions comprising chitosan which has been reacted with selected acids. BACKGROUND OF THE INVENTION Many metals are susceptible to corrosion. In this regard, atmospheric corrosion is of particular concern. Corrosion may affect the performance and/or appearance of the metals affected, and the products produced therefrom. In addition, when polymer coatings such as paints, adhesives or sealants are applied to the metal, corrosion of the underlying metal may cause loss of adhesion between the polymer coating and the base metal. Aluminum and aluminum alloys frequently require corrosion protection and improvements in adhesion between the base aluminum (or aluminum alloys) and subsequent polymer coatings. Aluminum alloys, in particular, can be susceptible to corrosion since the alloying elements used to improve the aluminum's mechanical properties may decrease corrosion resistance. Specifications for testing the effectiveness of the corrosion inhibition and adhesion promotion of various treatments have been established. Examples of such specifications include ASTM standard D3359-87, ASTM standard B117 and Military specification MIL-C-5541D. Prior art techniques for improving corrosion resistance of metals widely employ the use of chromate conversion coatings to passivate the surface. Such chromate treatments are undesirable however, because the chromium used is highly toxic, carcinogenic, and environmentally undesirable. Various attempts have been made to reduce the toxicity of these chromium treatments, including the use of trivalent chromium in place of the more toxic hexavalent chromium, but these attempts have proven less than completely successful. Phosphate conversion coatings are also used, but generally provide substantially less corrosion protection than is typically desired. More recently the use of treatment compositions comprising silicates and/or silanes has been proposed. However, these treatments have also fallen short of corrosion protection expectations in many cases. As a result, there remains a real need for non-toxic treatment solutions which are safe to handle and provide the level of corrosion protection typically demanded in a variety of applications. The composition and process of the current invention are meant to address the foregoing needs. Thus it is an object of this invention to provide an improved method of inhibiting corrosion of metals, especially aluminum and aluminum alloys, which is simple to employ, cost effective and environmentally friendly. It is a further object of this invention to provide a treatment for metals which improves the adhesion of subsequent organic coatings to the metal while at the same time improving the corrosion resistance of the metal. SUMMARY OF THE INVENTION The foregoing objectives can be accomplished by treating a metal, particularly aluminum or aluminum alloys, with a treatment composition which comprises an aqueous solution of chitosan which has been reacted with an acid selected from the group consisting of phosphonic acids, carboxylic acids and mixtures of the foregoing. The treatment composition is applied directly to a clean metal surface by immersion, spray, flood or other means of direct contact. The treatment solution is preferably applied to the metal at a temperature of from 70° F. to 150° F. Preferably the treatment solution is acidic enough to solubilize the acid modified chitosan. Preferably, the metal surface is cleaned, deoxidized, and/or etched prior to treatment with the chitosan based treatment solution. A variety of known cleaners, deoxidizers and/or etchants may be employed for this purpose, with the appropriate choice being made with the specific metal surface to be prepared in mind. Once the chitosan treatment is applied to the metal surface the treated surface should be allowed to dry. Drying may occur at room temperature or upon baking the surfaces at temperatures which preferably do not exceed about 200° C. The compositions and processes of this invention are particularly suitable for treating aluminum and aluminum alloys. The inventor has found that treating aluminum or aluminum alloys with the acid modified chitosan solution of this invention provides both increased corrosion resistance and enhanced adhesion of subsequent organic coatings to the treatment surfaces. DETAILED DESCRIPTION OF THE INVENTION Chitosan is the product of deacetylation of chitin. Generally chitosan is an amorphous solid which is soluble in aqueous solutions with pH less than about 6. Chitosan is of nearly identical structure to chitin, except that it is de-acetylated. The chemical structure of chitosan is as follows: where n represents the number of repeating units in the polymer chain. Because chitosan is more easily solubilized than chitin, chitosan is preferred for use in the process of the invention. Chitosan is also a low cost polymer, since its source, chitin, comes from the shells of marine crustaceans such as shrimp, crabs and lobsters. The inventor herein has discovered that although aqueous solutions of chitosan, itself, do not adequately function as corrosion prevention treatments for metallic surfaces, certain modified chitosans do provide desirable levels of corrosion protection for metals. Specifically the inventor herein has discovered that aqueous solutions of chitosan which has been reacted with an acid selected from the group consisting of phosphonic acids, carboxylic acids and mixtures thereof provide an excellent corrosion protection treatment for metals. Polyphosphonic acids (i.e. phosphonic acids having two or more phosphonic acid groups) and polycarboxylic acids (i.e. carboxylic acids having two or more carboxylic acid groups) are particularly preferred in creating the modified chitosan of this invention and polyphosphonic acids are most preferred. Without being bound by theory, it is believed that when the phosphonic and/or carboxylic acids are reacted with the chitosan, they tend to form amide bonds with the glucosamine ring structure, thereby bridging between chitosan strands. The resulting modified chitosan structure is more hydrophobic in nature than the unmodified chitosan structure, thereby reducing the permeability of the modified chitosan matrix. It is believed that this reduction in permeability of the modified chitosan matrix provides better corrosion protection for the treated metal. As noted, the modified chitosan is created by reacting chitosan with an acid selected from the group consisting of phosphonic acids, carboxylic acids and mixtures of the foregoing, with polyphosphonic acids and polycarboxylic acids preferred, and with polyphosphonic acids being most preferred. Preferably, the foregoing acids are reacted with the chitosan at elevated temperatures. One method of preparing the treatment solution of this invention is as follows: 1) Adjust the pH of distilled water to less than 1 with a mineral acid such as hydrochloric acid. 2) Dissolve chitosan in the acidified distilled water with stirring and heat. 3) Create a concentrated solution of an acid selected from the group consisting of phosphonic acids, carboxylic acids and mixtures thereof, in distilled water. 4) Add the concentrated solution from step 3 to the chitosan solution from step 2 with stirring and heat. Preferably the combined solution is heated to at least 150-190° F. and held there for about one hour then allow to cool. 5) Preferably filter the resulting treatment solution. The acids used to react with and modify the chitosan should be selected from the group consisting of phosphonic acids, carboxylic acids and mixtures thereof. The inventor has found polyphosphonic acids and polycarboxylic acids (i.e. acids containing two or more phosphonic and/or carboxylic acid groups per molecule), to be particularly preferred, with polyphosphonic acids being most preferred. The weight ratio of reactant acid to chitosan should be kept in the range of between 10%/90% to 90%/10% and is preferably from 20% to 80%. It is also particularly preferred for the reactant acids to have mercapto or other similar sulfur bearing groups in addition to the phosphonic and/or carboxylic acid groups. Examples of suitable phosphonic acids include aminotri(methylenephosphonic) acid and amino di(methylene phosphonic) acid. Examples of suitable carboxylic acids include mercapto-succinic acid, sebacic acid, and adipic acid. Polyacids which are either insoluble or very slightly soluble in water are preferred, since they are believed to synergistically increase the hydrophobic nature of the coating produced. Chitosan and the modified chitosans of this invention are only very sparingly soluble in water but their solubility increases in acidified water. As a result, the modified chitosans of this invention should be dissolved into an aqueous solution which preferably has pH adjusted to less than about 1, preferably with a mineral acid such as hydrochloric acid. The concentration of the modified chitosan in the treatment solution should range from about 1 to 20 grams per liter and is preferably from about 5 to 10 grams per liter. In addition to the water, the mineral acid and the modified chitosan, the treatment solution may also contain other additives such as solvents, surfactants, thickeners and other similar additives. Solvents and/or surfactants may be used to enhance the cleaning properties of the treatment solution and to improve the overall contact between the treatment solution and the metal surface being treated, thereby increasing the uniformity of the coating created. In this regard, 2-butoxyethanol is a preferred solvent. Solvents such as 2-butoxyethanol may also be used to solubilize or disperse the reactant acids in the aqueous solution. Before application of the treatment solution to the metal surface, it is preferred to clean, deoxidize and/or etch the metal surface so that the uniformity and adhesion of the subsequently formed corrosion protection coating is enhanced. A variety of known cleaners, deoxidizers and/or etchants may be employed for this purpose, with appropriate choice being made with the specific metal surface to be prepared in mind. For aluminum and aluminum alloy surfaces the inventor has found Isoprep 49L and Isoprep 184, available from MacDermid, Incorporated of Waterbury, Conn., to be a particularly effective pre-treatment for cleaning and deoxidizing the surfaces prior to treatment with the process of this invention. The treatment solution of this invention is applied directly to a clean metal surface by immersion, spray, flood or other means of direct contact. The solution is preferably applied to the metal at a temperature of from 70° F. to 150° F. Contact time between the treatment solution and the metal can range from 30 seconds to 5 minutes and is dependent upon the temperature of the treatment solution and the method of application. Once the treatment solution is applied to the metal surface, the treated surface should be allowed to dry. Drying may occur at room temperature, or upon baking at temperatures which preferably do not exceed about 200° C. The compositions and processes of this invention may be utilized on a variety of ferrous and non-ferrous metal surfaces, however, they are particularly suited to treating aluminum and aluminum alloys. The inventor has found that treating aluminum and aluminum alloys with the treatment solution of this invention provides both increased corrosion resistance and enhanced adhesion of subsequent organic coatings, such as paints, to the treated surfaces. The following examples. further illustrate the composition and process of the invention, but should not be taken as limiting in any manner. EXAMPLE I A treatment composition in accordance with this invention was prepared with the following composition: Component Concentration (% by weight) Hydrochloric Acid 0.50 Chitosan 0.35 Aminotri(methylenephosphonic) acid 0.15 Water 99.00 The foregoing treatment composition was prepared using the following procedure: 1) Place 100 ml of distilled water in a 250 ml beaker along with a stirbar. Begin stirring and add 1.0 gram HCL. 2) Add 0.7 g of chitosan and heat to 190° F. Allow to stir for 3 hours while covered with a watchglass. 3) In a separate beaker with stirbar, place 100 ml of distilled water and 0.3 grams of Aminotri(methylenephosphonic) acid and stir until well mixed. 4) Add the contents of the second beaker to that of the first. Cover with a watchglass, heat to 190° F. and stir. Hold at temperature for one hour and then allow to cool to room temperature. Add back water to bring to original volume. 5) Once cooled, filter with a Buchner funnel using number 4 filter paper. An aluminum substrate was sequentially pre-treated, in accordance with the manufacturer's instructions, with MacDermid Isoprep 49L and Isoprep 184 in order to clean and deoxidize the surface. The surface was then rinsed with water. The aluminum substrate was then immersed in the treatment solution of 75° F. for one minute. The substrate was removed from the treatment solution and dried at 175° C. for 30 minutes. The treated aluminum substrate was then exposed to salt spray exposure. The aluminum substrate remained for 360 hours before corrosion was apparent. EXAMPLE II A treatment composition in accordance with this invention was prepared with the following composition: Component Concentration (% by weight) Hydrochloric Acid 0.50 Chitosan 0.35 Mercaptosuccinic Acid 0.15 Water 99.00 The foregoing treatment composition was prepared using the following procedure: 1) Place 100 ml of distilled water in a 250 ml beaker along with a stirbar. Begin stirring and add 1.0 gram HCL. 2) Add 0.7 g of chitosan and heat to 190° F. Allow to stir for 3 hours while covered with a watchglass. 3) In a separate beaker with stirbar, place 100 ml of distilled water and 0.3 grams of mercaptosuccinic acid and stir until well mixed. 4) Add the contents of the second beaker to that of the first. Cover with a watchglass, heat to 190° F. and stir. Hold at temperature for one hour and allow to cool to room temperature. Add back water to bring to original volume. 5) Once cooled, filter with a Buchner funnel using number 4 filter paper. An aluminum substrate was sequentially pre-treated, in accordance with the manufacturer's instructions, with MacDermid Isoprep 49L and Isoprep 184 in order to clean and deoxidize the surface. The surface was then rinsed with water. The aluminum substrate was then immersed in the treatment solution at 75° F. for 1 minute. The substrate was then removed from the treatment solution and dried at 175° C. for 30 minutes. The treated aluminum substrate was then exposed to salt spray exposure. The aluminum substrate remained for 456 hours before corrosion was apparent. EXAMPLE III A treatment composition in accordance with this invention was prepared with the following composition: Component Concentration (% by weight) Hydrochloric Acid 0.50 Chitosan 0.35 Sebacic acid acid 0.15 2-butoxyethanol 7.50 Water 91.50 The foregoing treatment composition was prepared using the following procedure: 1) Place 100 ml of distilled water in a 250 ml beaker along with a stirbar. Begin stirring and add 1.0 gram HCL. 2) Add 0.7 g of chitosan and heat to 190° F. Allow to stir for 3 hours while covered with a watchglass. 3) In a separate beaker with stirbar, place 100 ml of distilled water and 15 grams of 2-butoxyethanol and allow to mix well. Add 0.3 grams of sebacic acid acid and stir until well mixed. 4) Add the contents of the second beaker to that of the first. Cover with a watchglass, heat to 190° F. and stir. Hold at temperature for one hour and allow to cool to room temperature. Add back water to bring to original volume. 5) Once cooled, filter with a Buchner funnel using number 4 filter paper. An aluminum substrate was sequentially pre-treated, in accordance with the manufacturer's instructions with MacDermid Isoprep 49L and Isoprep 184 in order to clean and deoxidize the surface. The surface was then rinsed with water. The aluminum substrate was then immersed in the treatment solution at 75° F. for 1 minute. The substrate was then removed from the treatment solution and dried at 175° F. for 30 minutes. The treated aluminum substrate was then exposed to salt spray exposure. The aluminum substrate remained for 384 hours before corrosion was apparent. EXAMPLE IV A treatment composition in accordance with this invention was prepared with the following composition: Component Concentration (% by weight) Hydrochloric Acid 0.50 Chitosan 0.35 Adipic acid 0.15 2-butoxyethanol 7.50 Water 91.50 The foregoing treatment composition was prepared using the following procedure: 1) Place 100 ml of distilled water in a 250 ml beaker along with a stirbar. Begin stirring and add 1.0 gram HCL. 2) Add 0.7 g of chitosan and heat to 190° F. Allow to stir for 3 hours while covered with a watchglass. 3) In a separate beaker with stirbar, place 100 ml of distilled water and 15 grams of 2-butoxyethanol and allow to mix well. Add 0.3 grams of adipic acid and stir until well mixed. 4) Add the contents of the second beaker to that of the first. Cover with a watchglass, heat to 190° F. and stir. Hold at temperature for one hour and allow to cool to room temperature. Add back water to bring to original volume. 5) Once cooled, filter with a Buchner funnel using number 4 filter paper. An aluminum substrate was sequentially pre-treated, in accordance with the manufacture's instructions, with MacDermid Isoprep 49L and Isoprep 184 in order to clean and deoxidize the surface. The surface was then rinsed with water. The aluminum substrate was then immersed in the treatment solution at 75° F. for 1 minute. The substrate was then removed from the treatment solution and dried at 175° F. for 30 minutes. The treated aluminum substrate was then exposed to salt spray exposure. The aluminum substrate remained for 288 hours before corrosion was apparent.

A composition and process for inhibiting the corrosion of metallic substrates is revealed. The process utilizes an aqueous treatment solution comprising chitosan which has been reacted with an acid selected from the group consisting of phosphonic acids, carboxylic acids and mixtures thereof. The composition and process are particularly useful in providing corrosion protection for aluminum and aluminum alloys.

FIELD OF TECHNOLOGY [0001] The present disclosure relates to smart-home networking and messaging BACKGROUND [0002] Multimedia messages or service messages of various types employed in communication services such as SMS (Short Message Service), MMS (Multimedia Message Service), e-mail (electronic mail), IM (Instant Messaging), and others are typically transmitted on the downlink and uplink between a communication server in the service center and a terminal embodied in the mobile radio network as a mobile telephone (cell phone) and in the circuit-switched and/or packet-switched fixed network as a communication terminal that can be used for this purpose in a “Smart Home” scenario. [0003] As a successor to the very widely disseminated Short Message Service (SMS), mobile radio operators have developed and introduced the Multimedia Message Service (MMS). This is characterized in that images, sound, and text files are transmitted in unison, delivered directly to the recipient, and visualized by the terminal. A prerequisite is for the recipient to have an MMS-enabled terminal. If that is not the case the recipient will be notified accordingly via another route (SMS, telephone call, e-mail, etc.) and at the same time be offered a link to a “URL (Unified Resource Locator)” via which he or she will be able to retrieve the message at a later time using a “WEB browser”. [0004] According to the prior art, a special gateway, in particular an “F-MMS gateway”, and a terminal designed for the service, in particular an MMS-enabled terminal, is required for delivering service messages, in particular “multimedia messages”, to a terminal (for example a DECT telephone) that is not directly connected to the mobile radio system. However, such terminals for fixed networks are only being introduced into, and available on the market gradually. For a swift launch of the various services, in particular the MMS service, in a fixed network it is therefore necessary also to enable users to receive such service messages using any terminals. [0005] According to the prior art a terminal designed for the service, in particular an MMS-enabled terminal, is again necessary for producing service messages, in particular MMS messages. Alongside this, “WEB clients” are also employed on the personal computer for producing messages of said type. So that the above-described reception of service messages, in particular MMS messages, on any terminals can be employed to practical advantage, a concept is also required for producing and sending service messages, in particular MMS messages, on terminals that are not suitable for this purpose. [0006] To enable the individual communication subscribers offered the communication services cited at the beginning to have uniform access to the services and so that data transmitted therein can be administered, it is known that providers of such communication services operate special internet portals such as, for example, “WEB.DE” (http://web.de), and offer them for use. The “WEB.DE” offering comprises a large, editorially maintained directory of German-language internet pages and services relating to navigation, information, communication, discussion, and entertainment. “WEB.DE” moreover also offers what is termed the “Unified Messaging” service which includes, inter alia, an e-mail service, an SMS service, an organizer service (calendar, appointment, and address management), and a telefax service, and further offers the possibility of conducting telephone calls. SUMMARY [0007] Accordingly, a method, terminal, and server for transmitting service messages in a fixed and/or mobile network is disclosed, wherein various types of service messages such as, for example, multimedia messages (MMS messages), short messages (SMS messages), e-mail messages, facsimile messages, “voice mail” messages, “Instant Messaging” messages etc. that are available or provided in a service center or generated in the terminal are transmitted between the service center and terminal without the terminal's having to be embodied as a “client” with reference to transmitting and processing the service message. [0008] Different multimedia messages may be transmitted from a service center directly or indirectly, via an intermediate server, to a server embodied as a “message server” which edits the message in accordance with the present disclosure, and forwards them therefrom in edited form for output on a fixed/mobile network-specific terminal to the terminal and, in the opposite direction, to transmit multimedia message content from the terminal to the server, which produces a multimedia message from said content then forwards said message again directly or indirectly to the service center. [0009] The technical features include: (i) Delivering the multimedia message (service message) to the terminal and processing multimedia content, although the terminal itself does not have a special “client” for understanding and processing the message. (ii) Provisioning a server which edits the multimedia messages and communicates with the terminal over a packet-switched connection. (iii) A mechanism which allows a terminal subscriber (for example a person using the terminal) to define, as the sender/recipient, the extent to which he/she wishes to be informed about the receipt of new service messages and to produce the content of notifications about new service messages on a need-oriented basis. (iv) A concept that allows service messages to be produced on and sent from a terminal which itself does not have a special “client” for producing a service message. [0014] The components include the following functions and characteristics: [0015] Server [0016] Registering, authenticating, authorizing, and administering registered terminal subscribers (senders/recipients). [0017] Accepting incoming service messages using, for example, an SMTP protocol. [0018] Analyzing and structuring incoming messages (from whom, which media, semantic analysis of audio, images, and video—identifying characteristic features to simplify and speed up later locating, filtering, and converting); describing by means of structure information in, for example, MPEG-7 format. [0019] Archiving received messages in personal directories. [0020] Delivering notifications to the terminal about the arrival of new messages in the form of “PUSH” via TCP/IP; alternatively as an SIP notification or, as the case may be, message. [0021] Editing the service message in a form harmonized with the terminal and the terminal subscriber's personal preferences; XSLT transformation based on stored style sheets and, depending on terminal features and personal preferences, a presentation of the message generated from the elements of the received message; producing a presentation in a format that is suitable for the terminal, for example HTML, for a “WEB browser” (alternatively also SMIL, WML, XML, etc.). [0022] Provisioning of control functions such as, for instance, the deletion of messages, implemented using, for example, JavaScripts. [0023] Administering statuses of logged-on terminal subscribers with reference to the retrieval of service messages. This will allow several users of one and the same terminal, for example a set-top box used in conjunction with a television set, to retrieve and manage their personal messages individually. [0024] Accepting message elements from the terminal for sending as an MMS. [0025] Composing an MMS and sending it via SMTP to the MMSC. [0026] Terminal [0027] Can be any terminal and in a specific embodiment is, for example, a set-top box used in conjunction with a television set. [0028] Makes an application available for the purpose of outputting, for example visualizing presentations/media, for example a “WEB browser”. [0029] Implements a communication component, called a notification recipient or “listener”, which accepts the notifications from the server. [0030] It is alternatively also possible for an “SIP client” to be implemented in the terminal. [0031] The “listener” visualizes the notifications, which can contain both text and images, audio, and video components. Visualizing in the form of text, audio data, images, window size, window position, and commands is controlled via an “Application Programming Interface (API)”. The notification recipient can alternatively also forward the received content to the “WEB browser” for visualizing. [0032] The “listener” makes a “Unified Resource Locator (URL)” available to the “WEB browser” via which URL said browser can retrieve the actual message edited for the terminal. [0033] The notification recipient allows an application, for example the browser, to be called up directly from the notification for retrieving the entire message. [0034] The terminal can, as either a “plug-in” or an autonomous application, implement an application for sending messages. Said application conveys the produced/selected information (text, image, audio, video) to the server along with the structure information [for example a form of address, closing phrase, meaning/function of text elements (for example main text, comment, footnote, etc.), and references] which is determined automatically during editing and described in, for example, MPEG-7 format. [0035] Notification: [0036] A particular feature is that the type and scope of the notification (the way the notification message appears) can be individually set by the terminal subscriber. For this purpose he/she informs the server of the required mode during log-on: [0037] Insertion of a window in which are displayed the semantically most important message elements of the received information or, as the case may be, parts of said elements. In the case of a set-top box used in conjunction with a television set the window is inserted over the current TV picture. Both the size of the window and its position on the television screen can vary and should not completely cover the TV screen. The content is extracted from the received service message by the server. [0038] Insertion of information in a status line, with in particular the sender and addressee being displayed. What type of message the service message is constitutes a useful addition if the notification system is used for different service messages. [0039] A result of the status-line solution is that there will be no notification, which is to say that the subscriber will not be disturbed or, as the case may be, interrupted. [0040] The server uses the stored structure information to extract the relevant message elements for the mode that has been set and sends said message elements to the notification recipient in accordance with the mode that has been set. [0041] The components hardware configuration is mostly based on known technologies; special features include component design and combination in a way allowing new functions or, as the case may be, functionalities to be realized in a novel manifestation: [0042] The use of terminals [for example a set-top box, Personal Digital Assistant (PDA), etc.] not designed for a specific communication service for any asynchronous multimedia communication services (SMS, MMS, e-mail, Instant Messaging, chat, etc.). [0043] The delivery of notifications (for example MMS, SMS) does not require a separate circuit-switched connection (for example POTS, ISDN). [0044] Individualized message receipt/delivery can also be realized via a non-personal telephone number/address. [0045] Implementing of a message archive that can administer any messages from any services and display them on any terminals, which do not require a specific “client”. [0046] Retrieval of messages from any terminal, adapted to the terminal's features and to personal preferences. [0047] Uniform access to any asynchronous communication services; no need to implement a separate “client” etc. for each service (SMS, MMS, e-mail, IM, chat). [0048] Description of “transmitting an MMS message” scenario: [0049] A terminal subscriber (subscriber B) purchases a new set-top box and wants to use the “MMS-on-TV” service. To be able to use the service the terminal subscriber first has to register with the server or, as the case may be, server operator. When this is done, an “account” is set up on the server for him/her under which he/she can then log on and retrieve messages. His/her telephone number to which MMS messages would normally be forwarded is also passed on to the “Multimedia Message Service Center (MMSC)” for configuring same. [0050] Subscriber B is at home and watching TV and wants, while doing so, to be notified of the arrival of new messages. His/her set-top box is connected to the “internet” over an existing TCP/IP connection via his/her “Internet Service Provider (ISP)”. The connection can be provided via a modem (POTS, ISDN, for example), xDSL, CableModem, PowerLine, or WLAN, etc. [0051] Subscriber B launches the “WEB browser” via the set-top box's menu and calls up the pre-configured start page for logging on to the server. He/she logs on there using his/her personal password, thereby automatically storing the IP address under which he/she will henceforth be accessible and wants to receive messages. He/she also informs the server of which terminal he/she wishes henceforth to use for receiving and retrieving messages (the set-top box). He/she finally indicates how he/she wishes to be notified of the arrival of new messages (not at all, via a short notice, fully via an Instant Message, etc.) [0052] The server administers this configuration in a database (see table below). Telephone IP address Account Account Notify Device number of the STB name password mode profile 08927134322 123.45.67.8 John Doe Dhsk&7wel! Full TV Jane Doe Hksd792HKS Status PDA [0053] The notification recipient program, which, for example, opens a TCP port and listens for events (for example TCP packets) directed at said port, is launched at the same time. [0054] From a mobile telephone (cell phone) or an MMS-enabled fixed-network telephone, another subscriber (subscriber A) then sends an MMS message to subscriber B, who is known in a fixed network and registered there through his/her telephone number. [0055] The MMS message arrives at the operator's “MMSC”, which is configured in such a way that all messages addressed to registered destination telephone numbers (among which is subscriber B's telephone number) will be forwarded to the server. Present-day systems forward an MMS message in the mobile radio network to the destination mobile telephone or to an F-MMSC gateway or an e-mail/WEB portal. [0056] The forwarding mechanism is based on the SMTP protocol, behind which is a standardized mail protocol. [0057] An SMTP server accepts the message on the server and forwards it for message analysis. [0058] The message is here disassembled into its various components (for example images, text, audio, video, presentation scripts, and other data) and the structure analyzed. From the information contained the structural analysis attempts to identify the semantic meaning of individual components (for example comment, form of address, closing phrase, descriptive metadata such as, for example, camera parameters, etc.), but also the cross-referencing between elements (references, for example text refers to an image). This analysis also includes analyzing the media, in particular video data. For example video clips are disassembled into semantically relevant scenes, which are in turn represented by means of individual key images. When the message is retrieved, video clips can thus also be displayed in the form of short video compilations or of individual key images. The same applies to audio clips. The structure information is described and stored in, for example, MPEG-7 format. [0059] The analysis module identifies the recipient using the information contained in the MMS message, either from the telephone number, where applicable with a number extension, and/or from the form of address (greeting), and/or by means of an explicit address entry in the MMS-specific structure information (Note: The MMS message can itself also contain structure information/metadata). The message and its elements are stored in the recipient's personal message archive, with each message being assigned its own subdirectory. For example: Root → user 1 → message1 → message2 → user 2 → message1 [0060] Because subscriber B is logged on and has set the notification mode to “Full” (see table), a message compositor will produce a notification. For this purpose said compositor receives the most important text components (image, audio, where applicable video) from the analysis module as well as a “Unified Resource Identifier (URI)” under which the entire message can be retrieved. [0061] The message compositor sends the notification, for example as a TCP packet, to the IP address of the set-top box with the port of the notification recipient. [0062] The notification recipient accepts the packet and, since the notification mode is “Full”, opens a “top-level” window on the television screen in which the message components contained are displayed. The notification simultaneously contains details of actions to be initiated when specific keys are actuated. [0063] By pressing the remote control key “OK”, subscriber B can hence go immediately to message retrieval. [0064] The notification recipient for this purpose launches the “WEB browser” and gives it the “URL/URI” from the notification. [0065] The “WEB browser” issues an “http request” with the “URL/URI” contained in the notification. [0066] From the “URL/URI” the server recognizes who wants to retrieve which message. Because subscriber B has specified a set-top box as the terminal, the XSLT transformer produces an HTML presentation of the message from the style-sheet-based configuration profile designed for a television set and from the structure information of the message, with the media elements being “inserted” into the presentation and adjusted to the format. [0067] Said matching of the media elements to the presentation format is performed by a media adapter which scales and rotates images, matches color spaces, and converts formats (the set-top box requires only one decoder for a single format) etc. Modality changes such as, for example, text-to-speech and video-to-still images, etc. can also be realized here. [0068] An image composed of, for example, 4 quadrants is assembled on the set-top box. [0069] An overview of the messages contained in the message archive is produced in the top left quadrant which overview displays which messages have been read or, as the case may be, are unread, and which message is being read. The subscriber can scroll through the list and select messages. This selection function is implemented in JavaScript form and triggers the compilation of a new HTML presentation on the server. The currently opened message is visualized, for example, having a colored background. [0070] The television program in progress is shown scaled in the top right quadrant. [0071] The text portion of the message containing the links to the media is shown in the bottom left quadrant. [0072] The bottom right quadrant shows the currently selected image. [0073] Subscriber B can change between the quadrants using the “right” and “left” cursor keys, with the selected quadrant again being, for example, color-highlighted. [0074] The “up” and “down” cursor keys are used to scroll within a window. [0075] Subscriber B is furthermore able to use supporting functions such as Full-image display Delete messages Send messages (Reply, Forward, Compose new message) Change the notification mode [0080] These functions are controlled by means of JavaScripts, with new HTML pages being generated accordingly by the server. [0081] Subscriber B can by selecting an application open an editor for producing a message. He/she is presented with a pre-specified structure via a mask. Images, video, and audio can be inserted alongside a text. The media can be “grabbed” from an archive on the set-top box, from a memory card inserted into the box, from the server, or from the program in progress. [0082] The editor conveys the media elements together with the structure information pre-specified by the mask (in, for example, MPEG-7) to the server (using, for example, the http protocol), which generates a valid MMS message therefrom. This is then forwarded to the “MMSC” for sending. BRIEF DESCRIPTION OF THE DRAWINGS [0083] The various objects, advantages and novel features of the present disclosure will be more readily apprehended from the following Detailed Description when read in conjunction with the enclosed drawings, in which: [0084] FIG. 1 shows a first scenario for transmitting different service messages between service centers and terminals located in a “Smart Home” scenario based on a “one-server concept”; [0085] FIG. 2 shows a second scenario for transmitting different service messages between service centers and terminals located in a “Smart Home” scenario based on a “two-server concept”; [0086] FIG. 3 shows, proceeding from FIG. 2 , a modified “two-server concept” wherein a server and a terminal in the “Smart Home” scenario form a structural and functional unit; [0087] FIGS. 4 a and 4 b are a first flowchart for transmitting a service message according to the “one-server concept” shown in FIG. 1 ; [0088] FIGS. 5 a and 5 b are a second flowchart for transmitting a service message according to the “two-server concept” shown in FIG. 2 ; [0089] FIG. 6 is a change-of-state diagram with a top-down approach for transmitting a service message on the downlink (service center→terminal) according to the flow shown in FIGS. 4 a and 4 b for the “one-server concept” ( FIG. 1 ); [0090] FIG. 7 is a change-of-state diagram with a top-down approach for transmitting a service message on the uplink (terminal→service center) according to the flow shown in FIGS. 4 a and 4 b for the “one-server concept” ( FIG. 1 ); [0091] FIG. 8 is a change-of-state diagram with a top-down approach for transmitting a service message on the downlink (service center→terminal) according to the flow shown in FIGS. 5 a and 5 b for the “two-server concept” ( FIG. 2 ); [0092] FIG. 9 is a change-of-state diagram with a top-down approach for transmitting a service message on the uplink (terminal→service center) according to the flow shown in FIGS. 5 a and 5 b for the “two-server concept” ( FIG. 2 ); [0093] FIG. 10 shows the basic structure of the server in FIG. 1 and of the second server in FIGS. 2 and 3 for transmitting a service message on the downlink (service center→terminal); [0094] FIG. 11 shows the basic structure of the server in FIG. 1 and of the second server in FIGS. 2 and 3 for transmitting a service message on the uplink (terminal→service center); [0095] FIG. 12 shows the basic structure of the terminal (set-top box, television set, and remote control) in FIGS. 1 to 3 for transmitting a service message in accordance with a first transmission protocol HTTP-over-TCP/IP; and [0096] FIG. 13 shows the basic structure of the terminal (set-top box, television set, and remote control) in FIGS. 1 to 3 for transmitting a service message in accordance with a second transmission protocol SIP, HTTP-over-TCP/IP. DETAILED DESCRIPTION [0097] FIG. 1 shows a first embodiment for transmitting different service messages SN between service centers SZ 1 . . . SZ 5 and terminals EG located in a “Smart Home” scenario SHU. Of the service centers SZ 1 . . . SZ 5 a first service center SZ 1 is embodied for transmitting the “Multimedia Message Service (MMS)” as a “Multimedia Message Service Center (MMSC)”, a second service center SZ 2 is embodied for handling the “Short Message Service (SMS)” as a “Short Message Service Center (SMSC)”, a third service center SZ 3 is embodied for handling the “e-mail” Service as an “Electronic Mail Service Center (EMail SC)”, a fourth service center SZ 4 is embodied for handling the “Voice Mail/Phone Call/Fax” service as a “Voice Mail/Phone Call/Fax Service Center (Voice Mail/Phone Call/Fax SC”, and a fifth service center is embodied for handling the “Instant Messaging” service” as an “Instant Messaging Service Center (IMSC)”. [0098] Of the service centers SZ 1 . . . SZ 5 , the first service center SZ 1 , the second service center SZ 2 , and the third service center SZ 3 are each connected via a first packet-switched connection V 1 to a server SV. A server/service center-specific transmission protocol SMTP, MM 1 . . . MM 7 -over-TCP/IP is handled via said first connection V 1 between the respective service center SZ 1 . . . SZ 3 and the server SV. The transmission protocol is preferably a “Simple Mail Transfer Protocol (SMTP)” or MMS-specific protocol specified by the “3GPP” standardizing body based on MMS interfaces MM 1 . . . MM 7 which in either case is handled in the course of a “Transmission Control Protocol/Internet Protocol (TCP/IP)”. Although the packet-switched connection is basically present again between the server SV and the respective service center SZ 4 , SZ 5 when service messages are transmitted according to the “Voice Mail/Phone Call/Fax” service and the “Instant Messaging” service, additional measures or, as the case may be, components are required to be able to control the respectively cited service with the aid of the server SV. [0099] Various protocols are used for the “Instant Messaging” service all of which have in common that it is assumed that the terminal EG is ready to receive and the IM messages can be delivered immediately. The IM message is generally not stored or may be the responsibility of the “client” installed on the terminal EG. A preferred implementation of the “Instant Messaging” service is based on the server SV being configured as a “Session Initiation Protocol (SIP)” server having an SIP-based User Authentication and on the SIMPLE protocol based on the “Session Initiation Protocol” being used. Arriving IM messages are routed to the server SV, which terminates the SIP session, via an SIP redirector SIP-U embodied as an “SIP redirect server”. If the terminal EG has an “IM client” based on the SIMPLE protocol, the terminal subscriber will also be able to use the “Instant Messaging” service directly. [0100] In the case of the “Voice Mail/Phone Call/Fax” service, regular telephone calls conducted over, for instance, a circuit-switched network ISDN, PSTN (Integrated Services Digital Network, Public Switched Telephone Network) will, if a call is not answered, be switched to a converter KON, embodied as a “gateway”, which will accept the call and convert it into an “SIP call”. For that purpose the converter has a POTS (Plain Old Telephone Service) interface and an SIP interface. Said “SIP call” is terminated by the server SV in the form of an SIP-based answering machine which stores the voice mail as a message in the archive and notifies the terminal subscriber of the voice mail's arrival. Fax messages are also accepted and forwarded to the server SV in an analogous manner. [0101] The server SV at which the service messages SN transmitted by the service centers SZ 1 . . . SZ 5 arrive has, for processing said service messages SN, an editing unit ABE that is connected to a service message memory SNS. Besides the service message memory SNS the editing unit ABE is also assigned a user database NDB that is also used by an “SIP proxy” SIP-P. The service message memory SNS and/or the user database NDB are/is either located outside the server SV or form/forms a constituent part thereof. [0102] The “SIP proxy” SIP-P is preferably located in a “client-server architecture” between the “client” and server. In FIG. 1 the “client” is the terminal EG in the “Smart Home” scenario SHU, while the server is formed from the SIP redirector SIP-U in conjunction with the server SV or from the SIP redirector SIP-U in conjunction with the service center SZ 5 . [0103] The server SV is assigned via a second packet-switched connection V 2 to a packet-switched network PVN embodied preferably as the internet. Via the second connection V 2 the packet-switched network PVN is furthermore assigned an “Internet Service Provider” ISP and a router RT in the “Smart Home” scenario SHU as a coupling module for coupling the terminal EG to the packet-switched network PVN. The data or, as the case may be, information transmitted over the second packet-switched connection V 2 between the router RT, the “Internet Service Provider” ISP, and the server SV is transmitted in accordance with a server-/terminal-specific transmission protocol HTTP, SIP-over-TCP/IP. The cited transmission protocol is preferably a “HyperText Transfer Protocol (HTTP)” or “Session Initiation Protocol (SIP)” handled in each case in the course of the “Transmission Control Protocol/Internet Protocol (TCP/IP)”. [0104] In the “Smart Home” scenario SHU a cordless base station BS embodied as an “Access Point (AP)” is connected between the router RT and the respective terminal EG. The base station BS has a connection to an ISDN/PSTN-specific circuit-switched network and a connection to the “SIP proxy” SIP-P. Via a DECT/WLAN air interface, the base station BS is furthermore assigned a conventional cordless mobile unit MT for circuit-switched cordless telephony. Besides the mobile unit MT, the base station BS is also assigned a multiplicity of potential terminals EG. For example a set-top box STB connected to a television set FA via SCART or S-video interface, a personal computer PC, a “Personal Digital Assistant” PDA, and a smart telephone STF are embodied in the “Smart Home” scenario SHU as a terminal EG. While the set-top box STB, the “Personal Digital Assistant” PDA, and the smart telephone STF are each connected to the base station BS via a short-range radio interface embodied preferably according to the IEEE 802.11 standard (WLAN standard) or Bluetooth standard, the personal computer PC is connected to the base station BS via a USB port. [0105] FIG. 2 illustrates a second embodiment for transmitting different service messages SN between service centers SZ 1 . . . SZ 5 and terminals EG located in a “Smart Home” scenario SHU. Again, of the service centers SZ 1 . . . SZ 5 a first service center SZ 1 is embodied for transmitting the “Multimedia Message Service (MMS)” as a “Multimedia Message Service Center (MMSC)”, a second service center SZ 2 is embodied for handling the “Short Message Service (SMS)” as a “Short Message Service Center (SMSC)”, a third service center SZ 3 is embodied for handling the “e-mail” service as an “Electronic Mail Service Center (EMail SC)”, a fourth service center SZ 4 is embodied for handling the “Voice Mail/Phone Call/Fax” service as a “Voice Mail/Phone Call/Fax Service Center (Voice Mail/Phone Call/Fax SC”, and a fifth service center is embodied for handling the “Instant Messaging” service” as an “Instant Messaging Service Center (IMSC)”. [0106] Of the service centers SZ 1 . . . SZ 5 the first service center SZ 1 , the second service center SZ 2 , and the third service center SZ 3 are again each connected via a first packet-switched connection V 1 to a first server SV 1 . A server/service center-specific transmission protocol SMTP, MM 1 . . . MM 7 -over-TCP/IP is again handled via said first connection V 1 between the respective service center SZ 1 . . . SZ 3 and the first server SV 1 . The transmission protocol is again preferably a “Simple Mail Transfer Protocol (SMTP)” or MMS-specific protocol specified by the “3GPP” standardizing body based on MMS interfaces MM 1 . . . MM 7 which in either case is handled in the course of a “Transmission Control Protocol/Internet Protocol (TCP/IP)”. Although the packet-switched connection is basically present again between the first server SV 1 and the respective service center SZ 4 , SZ 5 when service messages are transmitted according to the “Voice Mail/Phone Call/Fax” service and the “Instant Messaging” service, additional measures or, as the case may be, components are required to be able to control the respectively cited service with the aid of the first server SV 1 . [0107] Various protocols are used for the “Instant Messaging” service all of which have in common that it is assumed that the terminal EG is ready to receive and the IM messages can be delivered immediately. The IM message is as a rule not stored or, as the case may be, said function is the responsibility of the “client” installed on the terminal EG. A preferred implementation of the “Instant Messaging” service is based on the first server SV 1 being configured as a “Session Initiation Protocol (SIP)” server having an SIP-based User Authentication and on the SIMPLE protocol based on the “Session Initiation Protocol” being used. Arriving IM messages are routed to the first server SV 1 , which terminates the SIP session, via an SIP redirector SIP-U embodied as an “SIP redirect server”. If the terminal EG has an “IM client” based on the SIMPLE protocol, the terminal subscriber will also be able to use the “Instant Messaging” service directly. [0108] In the case of the “Voice Mail/Phone Call/Fax” service, regular telephone calls conducted over, for instance, a circuit-switched network ISDN, PSTN (Integrated Services Digital Network, Public Switched Telephone Network) will, if a call is not answered, be switched to a converter KON, embodied as a “gateway”, which will accept the call and convert it into an “SIP call”. For that purpose the converter has a POTS (Plain Old Telephone Service) interface and an SIP interface. Said “SIP call” is terminated by the first server SV in the form of an SIP-based answering machine which stores the voice mail as a message in the archive and notifies the terminal subscriber of the voice mail's arrival. Fax messages are also accepted and forwarded to the first server SV in an analogous manner. [0109] In contrast to the server SV in FIG. 1 , the server SV at which the service messages SN transmitted by the service centers SZ 1 . . . SZ 5 arrive is conventionally designed for processing said service messages SN. It therefore does not have an editing unit ABE. Furthermore, the first server SV 1 is only assigned a user database NDB and not a service message memory. Besides this, the user database NDB forms a constituent part of the first server SV 1 . There is, moreover, a further user database NDB′ which is used by an “SIP proxy” SIP-P. [0110] The “SIP proxy” SIP-P is located in a “client-server architecture” between the “client” and server. In FIG. 2 the “client” is again the terminal EG in the “Smart Home” scenario SHU, while the server is formed from the SIP redirector SIP-U in conjunction with the first server SV 1 or from the SIP redirector SIP-U in conjunction with the service center SZ 5 . [0111] The first server SV 1 is again assigned via a second packet-switched connection V 2 to a packet-switched network PVN embodied preferably as the internet. Via the second connection V 2 the packet-switched network PVN is again furthermore assigned an “Internet Service Provider” ISP and a router RT in the “Smart Home” scenario SHU as a coupling module for coupling the terminal EG to the packet-switched network PVN. The data or, as the case may be, information transmitted over the second packet-switched connection V 2 between the router RT, the “Internet Service Provider” ISP, and the server SV is transmitted in accordance with a server-/terminal-specific transmission protocol HTTP, SIP-over-TCP/IP. The cited transmission protocol is preferably a “HyperText Transfer Protocol (HTTP)” or “Session Initiation Protocol (SIP)” handled in each case in the course of the “Transmission Control Protocol/Internet Protocol (TCP/IP)”. [0112] In contrast to FIG. 1 , a second server SV 2 , for example a home server, is located in the “Smart Home” scenario SHU between the router RT and the respective terminal EG (two-server concept in contrast to the one-server concept in FIG. 1 ). Like the server in FIG. 1 , the second server SV 2 again has an editing unit ABE that is connected to a service message memory SNS located in the second server SV 2 . In contrast to the server in FIG. 1 , the second server SV 2 is not, though, assigned a user database NDB. Connected downstream of the second server SV 2 via a third connection V 3 is a set-top box STB embodied as an “Access Point (AP)”. The set-top box STB has, for example, a USB link to a cordless base station BS that is in turn connected to an ISDN-/PSTN-specific circuit-switched network. The set-top box STB further has a connection to the “SIP proxy” SIP-P. Via a DECT/WLAN air interface said base station BS is furthermore connected to a conventional cordless mobile unit MT for circuit-switched cordless telephony and to a fax machine FG. [0113] Finally, the set-top box STB is connected to a plurality of potential terminals EG, that is to say a “Personal Digital Assistant” PDA and a smart telephone STF. The connection between the set-top box STB and the cited terminals is again based preferably on a short-range radio interface embodied according to the IEEE 802.11 standard (WLAN standard) or Bluetooth standard. The set-top box STB is additionally connected to a television set FA via a SCART or S-Video interface, with the set-top box STB and television set FA forming a further terminal EG. [0114] FIG. 3 shows a third scenario for transmitting different service messages SN between service centers SZ 1 . . . SZ 5 and terminals EG located in a “Smart Home” scenario SHU which differs from the second scenario according to FIG. 2 only in that the second server SV 2 , with all its functionalities, is a constituent part of the set-top box STB. The integrating of units having different functionalities can be advanced to such an extent, for example, that the router RT is also a constituent part of the set-top box STB. [0115] FIGS. 4 a and 4 b show a first flowchart having a plurality of flow phases AP 1 . . . AP 6 for transmitting a service message SN according to the “one-server concept” shown in FIG. 1 , in which concept the service center SZ 1 . . . SZ 5 is connected via the first connection V 1 to the server SV and in which concept the server SV is connected via the second connection V 2 to the terminal EG and together with the terminal EG forms a communication system KS. [0116] In an initial status AZ the terminal EG is put into operation by a user. In a directly ensuing first flow phase AP 1 a network address NAD containing, for example, a telephone number or e-mail address is transmitted from the terminal EG to the server SV for registering the terminal EG with the server SV. The server SV stores the network address NAD and forwards it to the service center SZ 1 . . . SZ 5 , where the network address NAD is likewise stored. [0117] This is shown in the respective change-of-state diagram in FIGS. 6 and 7 by the transition from a first EG status (terminal status) “Network address NAD, for example telephone number, e-mail address etc.” EGZ 1 to a first SV status (server status) “Storing the network address and communication system address” SVZ 1 and a first SZ status (service center status) “Storing the network address” SZZ 1 . [0118] On receiving the network address NAD, server SV responds by transmitting an access authorization ZGB to the terminal EG. [0119] The terminal EG logs on to the server SV in a directly ensuing second flow phase AP 2 . For this purpose said terminal transmits a communication system address KSAD containing, for example, an IP address, device information GIF comprising, for example, type or features, and control information STIF, comprising, for example, a password or the type and scope of a notification message, to the server SV. The server SV stores the communication system address KSAD and the device and control information GIF, STIF and transmits a service message generating template SNEV to the terminal EG which template is presented, for example, in different formats such as “HyperText Markup Language (HTML)”, “EXtensible Markup Language (XML)”, “WAP (Wireless Application Protocol) Markup Language (WML)” or “Synchronized Multimedia Integration Language (SMIL)”. [0120] This is also shown or, as the case may be, indicated, substantially excepting obvious individual storage operations, in the change-of-state diagrams in FIGS. 6 and 7 by the transitions from a second EG status “Communication system address KSAD, for example an IP address etc.” EGZ 2 to the first SV status “Storing the network address and communication system address” SVZ 1 , from a third EG status “Device information GIF, for example type and features etc.” EGZ 3 to the server SV or, as the case may be, to a second SV status “Producing a service message generating template SNEV, for example HML, XML, WML, SMIL, etc.” SVZ 2 , from a fourth EG status “Control information STIF, for example a password, the type and scope of the notification message etc.” EGZ 4 to the server SV, and from the second SV status “Producing a service message generating template SNEV, for example HML, XML, WML, SMIL, etc.” SVZ 2 to the terminal EG. [0121] In a third flow phase AP 3 the server SV uses the received information GIF, STIF to generate a configuration profile which is stored by the server SV. [0122] How the configuration profile is generated is shown, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 6 by the transitions from a third SV status “Communication template KFV, for example XSLT (style sheet)” SVZ 3 (EXtensible Style Sheet Language Transformation) to a fourth SV status “Parameterizing” SVZ 4 , and from the fourth SV status “Parameterizing” SVZ 4 , taking account of the device and control information GIF, STIF (transitions of the EG statuses EGZ 3 , EGZ 4 to the server SV) transmitted from the terminal EG to the server SV, to a fifth SV status “Communication profile KFP, for example XSLT (style sheet)” SVZ 5 . [0123] The configuration profile KFP is consequently the result of parameterizing the configuration template KFV by means of the device and control information GIF, STIF. [0124] In a first follow-on status FZ 1 a service message SN arrives in the service center SZ 1 . . . SZ 5 for the user of the terminal EG. In a fourth flow phase AP 4 the service center SZ 1 . . . SZ 5 thereupon transmits the service message SN to the server SV for example in accordance with the server/service center-specific transmission protocol SMTP, MM 1 . . . MM 7 . The received service message SN is analyzed and stored in the server SV. The server SV then transmits a notification message MN to the terminal EG informing the terminal EG that a service message SN intended for the terminal EG is in the server SV and can be collected. For this purpose the notification message MN contains a “Unified Resource Location (URL)”. [0125] This is also shown, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 6 by the transitions from a second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to the server SV, from the second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to a sixth SV status “Analyzing and disassembling the service message” SVZ 6 , from the sixth SV status “Analyzing and disassembling the service message” SVZ 6 to a seventh SV status “Structure information SIF, for example MPEG-7” SVZ 7 , from the second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to an eighth SV status “Producing a notification” SVZ 8 , from the first SV status “Storing the network address and communication system address” SVZ 1 to the eighth SV status “Producing a notification” SVZ 8 , and from the eighth SV status “Producing a notification” SVZ 8 to a fifth EG status “Notification message MN” EGZ 5 . [0126] The service message stored in the server SV is disassembled into its individual components during analyzing and disassembling in the sixth SV status SVZ 6 and the structure of the message and/or the semantic meaning of the individual components analyzed. The results of said analysis are then compiled into structure information SIF, preferably in MPEG-7 format, and stored. In parallel with the above-described analysis, a notification is generated in the eighth SV status SVZ 8 concerning the service message's arrival in the server SV, where applicable (as an additional option) also taking account of individual message content, after which the notification message MN is transmitted with the “Unified Resource Location (URL)” to the relevant terminal EG in accordance with the network address and communication system address NAD, KSAD stored in the server. [0127] In a directly ensuing fifth flow phase AP 5 the terminal EG transmits a retrieval request AAF to the server SV to collect the service message SN stored in the server SV. On receiving said retrieval request AAF the server SV edits the stored service message SN for outputting and presenting the message content on the terminal EG and, for this purpose, produces a presentation message PN that is presented, for example, in different formats such as “HyperText Markup Language (HTML)”, “EXtensible Markup Language (XML)”, “WAP (Wireless Application Protocol) Markup Language (WML)” or “Synchronized Multimedia Integration Language (SMIL)” and which it transmits to the terminal EG in accordance with the server-/terminal-specific transmission protocol HTTP, SIP. After receiving the presentation message PN the terminal EG presents said presentation message PN acoustically, graphically, and/or optically. [0128] This is also shown or, as the case may be, indicated, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 6 by the transitions from the fifth EG status “Notification message MN” EGZ 5 to a sixth EG status “Retrieval request AAF” EGZ 6 , from the sixth EG status “Retrieval request AAF” EGZ 6 to a ninth SV status “Generating a presentation” SVZ 9 , from the seventh SV status “Structure information SIF, for example MPEG-7” SVZ 7 to the ninth SV status “Generating the presentation” SVZ 9 , from the fifth SV status “Configuration profile KFP, for example XSLT (style sheet)” SVZ 5 to the ninth SV status “Generating the presentation” SVZ 9 , from the ninth SV status “Generating a presentation” SVZ 9 , taking account of the service message SN transmitted from the service center SZ 1 . . . SZ 5 to the server SV (transition of the SZ status SZZ 2 to the server SV), to a seventh EG status “Presentation message PN, for example HTML, XML, WML, SMIL etc.” EGZ 7 , and from the seventh EG status “Presentation message PN, for example HTML, XML, WML, SMIL etc.” EGZ 7 to an eighth EG status “Presenting the presentation message, for example acoustically, graphically, and/or optically” EGZ 8 . When the terminal EG has transmitted the retrieval request AAF to the server SV for collecting the service message SN, a presentation is generated in the ninth SV status SVZ 9 from the stored service message SN by means of the configuration profile KFP and the structure information SIF, after which the presentation message PN is transmitted to the terminal EG, where said message is presented acoustically, graphically, and/or optically. [0129] In a second follow-on status FZ 2 the user of the terminal EG wishes to send someone (for example a distant mobile radio subscriber) a service message SN. In a sixth flow phase AP 6 the user of the terminal EG first generates the content of said service message then inserts the generated content into the service message generating template SNEV received from the server SV during the log-on phase. If the service message generating template SNEV is not available to the user at this time, which may certainly be the case if, as a possible alternative to the case shown in FIGS. 4 a and 4 b , the service message generating template SNEV has not been transmitted during the second flow phase AP 2 (log-on phase) of the terminal, then the service message generating template SNEV must be requested separately from the terminal EG. The completed service message generating template SNEV will be conveyed to the server SV when the user has inserted the generated content into the service message generating template SNEV. In the sixth flow phase AP 6 the server SV generates the service message SN from the conveyed service message generating template SNEV and transmits said message to the service center SZ 1 . . . SZ 5 for the purpose of conveying the message to the distant mobile radio subscriber. [0130] This is also shown or, as the case may be, indicated, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 7 by the transitions from a ninth EG status “Message content generated by the user of the terminal” EGZ 9 to a tenth EG status “Transferring the message content to the service message generating template, for example HTML, XML, WML, SMIL etc.” EGZ 10 , from the tenth EG status “Transferring the message content to the service message generating template, for example HTML, XML, WML, SMIL etc.” EGZ 10 , taking account of the service message generating template SNEV transmitted from the server SV to the terminal EG (transition of the SV status SVZ 2 to the terminal) to an eleventh EG status “Completed service message generating template” EGZ 11 , from the eleventh EG status “Completed service message generating template” EGZ 11 to a tenth SV status “Producing the service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SVZ 10 , and from the tenth SV status “Producing the service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SVZ 10 to a third SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 3 . [0131] FIGS. 5 a and 5 b show a second flowchart having a plurality of flow phases AP 1 ′. . . AP 7 ′ for transmitting a service message SN according to the “two-server concept” shown in FIG. 2 , in which concept the service center SZ 1 . . . SZ 5 is connected via the first connection V 1 to the first server SV 1 and in which concept the first server SV 1 is connected via the second connection V 2 to the second server SV 2 and together with the second server SV 2 forms a first communication system KS 1 , and in which concept the second server SV 2 is connected via the third connection V 3 to the terminal EG and together with the terminal EG forms a second communication system KS 2 . [0132] In an initial status AZ′ the second server SV 2 and the terminal EG are put into operation by a user. In a directly ensuing first flow phase AP 1 ′ a network address NAD containing, for example, a telephone number or e-mail address is transmitted from the second server SV 2 to the first server SV 1 for registering the second server SV 2 with the first server SV 1 . The first server SV 1 stores the network address NAD and forwards it to the service center SZ 1 . . . SZ 5 , where the network address NAD is likewise stored. [0133] This is shown in the respective change-of-state diagram in FIGS. 8 and 9 by the transition from a first SV 2 status (server-2 status) “Network address NAD, for example telephone number, e-mail address etc.” SV 2 Z 1 to a first SV 1 status (server- 1 status) “Storing the network address and first communication system address” SV 1 Z 1 and a first SZ status (service center status) “Storing the network address” SZZ 1 . [0134] On receiving the network address NAD, the first server SV 1 responds by transmitting an access authorization ZGB to the second server SV 2 . [0135] The second server SV 2 logs on to the first server SV 1 in a directly ensuing second flow phase AP 2 ′. For this purpose the second server transmits a first communication system address KSAD 1 containing, for example, an IP address to the first server SV 1 . The first server SV stores the first communication system address KSAD 1 . [0136] This is shown in the respective change-of-state diagram in FIGS. 8 and 9 by the transition from a second SV 2 status “First communication system address KSAD 1 , for example IP address etc.” SV 2 Z 2 to the first SV 1 status “Storing the network address and first communication system address” SV 1 Z 1 . [0137] The terminal EG logs on to the second server SV 2 in a then ensuring third flow phase AP 3 ′. For this purpose said terminal transmits a second communication system address KSAD 2 containing, for example, an IP address, device information GIF comprising, for example, type or features, and control information STIF, comprising, for example, a password or the type and scope of a notification message, to the second server SV 2 . The second server SV 2 stores the second communication system address KSAD 2 and the device and control information GIF, STIF and transmits a service message generating template SNEV to the terminal EG which template is presented, for example, in different formats such as HyperText Markup Language (HTML)”, “EXtensible Markup Language (XML)”, “WAP (Wireless Application Protocol) Markup Language (WML)” or “Synchronized Multimedia Integration Language (SMIL)”. [0138] This is also shown, substantially excepting obvious individual storage operations, in the change-of-state diagrams in FIGS. 8 and 9 by the transitions from a twelfth EG status “Second communication system address KSAD 2 , for example IP address etc.” EGZ 12 to a third SV 2 status “Storing the second communication system address” SV 2 Z 3 , from the third EG status “Device information GIF, for example type and features etc.” EGZ 3 to the second server SV 2 or, as the case may be, to a fourth SV 2 status “Producing a service message generating template SNEV, for example HML, XML, WML, SMIL, etc.” SV 2 Z 4 , from the fourth EG status “Control information STIF, for example a password, the type and scope of the notification message etc.” EGZ 4 to the second server SV 2 , and from the fourth SV 2 status “Producing a service message generating template SNEV, for example HML, XML, WML, SMIL, etc.” SV 2 Z 4 to the terminal EG. [0139] In a fourth flow phase AP 4 ′ the second server SV 2 uses the received information GIF, STIF to generate a configuration profile which is stored by the second server SV 2 . [0140] How the configuration profile is generated is shown, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 8 by the transitions from a fifth SV 2 status “Communication template KFV, for example XSLT (style sheet)” SV 2 Z 5 (EXtensible Style Sheet Language Transformation) to a sixth SV 2 status “Parameterizing” SV 2 Z 6 , and from the sixth SV 2 status “Parameterizing” SV 2 Z 6 , taking account of the device and control information GIF, STIF (transitions of the EG statuses EGZ 3 , EGZ 4 to the second server SV 2 ) transmitted from the terminal EG to the second server SV 2 , to a seventh SV 2 status “Communication profile KFP, for example XSLT (style sheet)” SV 2 Z 7 . [0141] The configuration profile KFP is consequently the result of parameterizing the configuration template KFV by means of the device and control information GIF, STIF. [0142] In a first follow-on status FZ 1 ′ a service message SN arrives in the service center SZ 1 . . . SZ 5 for the user of the terminal EG. In a fifth flow phase AP 5 ′ the service center SZ 1 . . . SZ 5 thereupon transmits the service message SN to the first server SV 1 for example in accordance with the server/service center-specific transmission protocol SMTP, MM 1 . . . MM 7 , which server forwards said message to the second server SV 2 . The received service message SN is analyzed and stored in the second server SV 2 . The second server SV then transmits a notification message MN to the terminal EG informing the terminal EG that a service message SN intended for the terminal EG is in the second server SV 2 and can be collected. For this purpose the notification message MN contains a “Unified Resource Locator (URL)”. [0143] This is also shown, substantially excepting obvious individual storage and forwarding operations, in the change-of-state diagram in the change-of-state diagram in FIG. 8 by the transitions from a second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to the second server SV 2 , from the second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to an eighth SV 2 status “Analyzing and disassembling the service message” SV 2 Z 8 , from the eighth SV 2 status “Analyzing and disassembling the service message” SV 2 Z 8 to a ninth SV 2 status “Structure information SIF, for example MPEG-7” SV 2 Z 9 , from the second SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 2 to a tenth SV 2 status “Generating a notification” SV 2 Z 10 , from the third SV 2 status “Storing the second communication system address” SVZ 1 to the tenth SV 2 status “Generating a notification” SV 2 Z 10 , and from the tenth SV 2 status “Generating a notification” SV 2 Z 10 to the fifth EG status “Notification message MN” EGZ 5 . [0144] The service message stored in the second server SV 2 is disassembled into its individual components during analyzing and disassembling in the eighth SV 2 status SV 2 Z 8 and the structure of the message and/or the semantic meaning of the individual components analyzed. The results of said analysis are then compiled into structure information SIF, preferably in MPEG-7 format, and stored. In parallel with the above-described analysis, a notification is generated in the tenth SV 2 status SV 2 Z 10 concerning the service message's arrival in the second server SV 2 , where applicable (as an additional option) also taking account of individual message content, after which the notification message MN is transmitted with the “Unified Resource Location (URL)” to the relevant terminal EG in accordance with the network address and second communication system address NAD, KSAD 2 stored in the second server. [0145] In a directly ensuing sixth flow phase AP 6 ′ the terminal EG transmits a retrieval request AAF to the second server SV 2 to collect the service message SN stored in the second server SV 2 . On receiving said retrieval request AAF the second server SV 2 edits the stored service message SN for outputting and presenting the message content on the terminal EG and, for this purpose, produces a presentation message PN that is presented, for example, in different formats such as “HyperText Markup Language (HTML)”, “EXtensible Markup Language (XML)”, “WAP (Wireless Application Protocol) Markup Language (WML)” or “Synchronized Multimedia Integration Language (SMIL)” and which it transmits to the terminal EG in accordance with the server-/terminal-specific transmission protocol HTTP, SIP. After receiving the presentation message PN the terminal EG presents said presentation message PN acoustically, graphically, and/or optically. [0146] This is also shown or, as the case may be, indicated, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 8 by the transitions from the fifth EG status “Notification message MN” EGZ 5 to the sixth EG status “Retrieval request AAF” EGZ 6 , from the sixth EG status “Retrieval request AAF” EGZ 6 to an eleventh SV 2 status “Generating a presentation” SV 2 Z 11 , from the ninth SV 2 status “Structure information SIF, for example MPEG-7” SV 2 Z 9 to the eleventh SV 2 status “Generating the presentation” SV 2 Z 11 , from the seventh SV 2 status “Configuration profile KFP, for example XSLT (style sheet)” SV 2 Z 7 to the eleventh SV 2 status “Generating the presentation” SV 2 Z 11 , from the eleventh SV 2 status “Generating a presentation” SV 2 Z 11 , taking account of the service message SN transmitted from the service center SZ 1 . . . SZ 5 to the second server SV 2 (transition of the SZ status SZZ 2 to the second server SV 2 ) to the seventh EG status “Presentation message PN, for example HTML, XML, WML, SMIL etc.” EGZ 7 , and from the seventh EG status “Presentation message PN, for example HTML, XML, WML, SMIL etc.” EGZ 7 to the eighth EG status “Presenting the presentation message, for example acoustically, graphically, and/or optically” EGZ 8 . When the terminal EG has transmitted the retrieval request AAF to the second server SV 2 for collecting the service message SN, a presentation is generated in the eleventh SV 2 status SV 2 Z 11 from the stored service message SN by means of the configuration profile KFP and the structure information SIF, after which the presentation message PN is transmitted to the terminal EG, where said message is presented acoustically, graphically, and/or optically. [0147] In a second follow-on status FZ 2 ′ the user of the terminal EG wishes to send someone (for example a distant mobile radio subscriber) a service message SN. In a seventh flow phase AP 7 ′ the user of the terminal EG first generates the content of said service message then inserts the generated content into the service message generating template SNEV received from the second server SV 2 during the log-on phase. If the service message generating template SNEV is not available to the user at this time, which may certainly be the case if, as a possible alternative to the case shown in FIGS. 5 a and 5 b , the service message generating template SNEV has not been transmitted during the third flow phase AP 3 ′ (log-on phase) of the terminal, then the service message generating template SNEV must be requested separately from the terminal EG. The completed service message generating template SNEV will be conveyed to the second server SV 2 when the user has inserted the generated content into the service message generating template SNEV. In the seventh flow phase AP 7 ′ the second server SV 2 generates the service message SN from the conveyed service message generating template SNEV and transmits said message to the service center SZ 1 . . . SZ 5 for the purpose of conveying the message to the distant mobile radio subscriber. [0148] This is also shown or, as the case may be, indicated, substantially excepting obvious individual storage operations, in the change-of-state diagram in FIG. 9 by the transitions from the ninth EG status “Message content generated by the user of the terminal” EGZ 9 to the tenth EG status “Transferring the message content to the service message generating template, for example HTML, XML, WML, SMIL etc.” EGZ 10 , from the tenth EG status “Transferring the message content to the service message generating template, for example HTML, XML, WML, SMIL etc.” EGZ 10 , taking account of the service message generating template SNEV transmitted from the second server SV 2 to the terminal EG (transition of the SV 2 status SV 2 Z 4 to the terminal) to the eleventh EG status “Completed service message generating template” EGZ 11 , from the eleventh EG status “Completed service message generating template” EGZ 11 to a twelfth SV 2 status “Producing the service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SV 2 Z 12 , and from the twelfth SV 2 status “Producing the service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SV 2 Z 12 to the third SZ status “Service message SN, for example SMS, MMS, e-mail, fax, voice mail, Instant Messaging etc.” SZZ 3 . [0149] FIG. 10 shows the basic structure of the server SV in FIG. 1 and of the second server SV 2 in FIGS. 2 and 3 for transmitting a service message SN on the downlink (service center→terminal). Besides the editing unit ABE already mentioned in the description of FIGS. 1 to 3 , the service message memory SNS located in the server SV, SV 2 and assigned to the editing unit ABE, and the user database NDB likewise located in the server SV, SV 2 and assigned to the editing unit ABE, the server SV, SV 2 accordingly also contains a server/service center interface (SS interface) SS-S and a server/terminal interface (SE interface) SE-S, SE-S′. The server SV, SV 2 is connected via the SS interface SS-S to the service center SZ 1 . . . SZ 5 and via the SE interface SE-S, SE-S′ to the terminal EG. While the SS interface SS-S is designed for transmitting the service message SN in accordance with the transmission protocol SMTP, MM 1 . . . MM 7 -over-TCP/IP, the SE interface SE-S is embodied for transmitting the presentation message PN, the notification message MN, and other information or, as the case may be, messages in accordance with the transmission protocol HTTP-over-TCP/IP. As an alternative to the SE interface SE-S it is, however, also possible to use the SE interface SE-S′ (this is indicated in FIG. 10 by the dot-and-dash lining), with the SE interface SE-S′ being embodied for transmitting the presentation message PN, the notification message MN, and other information or, as the case may be, messages in accordance with the transmission protocol SIP-over-TCP/IP. [0150] The editing unit ABE contains a service message analyzing module SNAM and a notification message generating module MNEM, with the latter having an I connection (INPUT connection) to the service message analyzing module SNAM. Both the service message analyzing module SNAM and the notification message generating module MNEM moreover also have an I connection to the SS interface SS-S. The service message analyzing module SNAM also has an O connection (OUTPUT connection) to the service message memory SNS, while the notification message generating module MNEM also has an I connection to the user database NDB and an O connection to the SE interface SE-S, SE-S′. The transmitting and processing operations belonging to the flow phase AP 4 , AP 5 ′ in FIGS. 4 a and 5 b are performed in the functional unit formed from the service message analyzing module SNAM, the service message memory SNS, the notification message generating module MNEM, the user database NDB, the SE interface SE-S, and the SS interface SS-S according to the representations shown in FIGS. 4 a , 5 b , 6 , and 8 . [0151] The editing unit ABE furthermore has a configuration module KFM, a “style sheet” archive SSA, a “WEB server” module WSM, and a media adaption module MAM, with the configuration module KFM having an I connection to the service message memory SNS and “style sheet” archive SSA and an I/O connection (INPUT/OUTPUT connection) to the user database NDB and the “WEB server” module WSM, with the “WEB server” module WSM having, alongside the I/O connection to the configuration module KFM, in each case a further I/O connection to the user database NDB, the SE interface SE-S, and the media adaption module MAM, and an O connection to the SS interface SS-S, and with the media adaption module MAM having, alongside the I/O connection to the “WEB server” module WSM, an I connection to the user database NDB. [0152] The transmitting and processing operations belonging to the flow phases AP 1 , AP 1 ′, AP 2 , AP 2 ′, AP 3 ′ in FIGS. 4 a and 5 a are performed in the functional unit formed from the “WEB server” module WSM, the user database NDB, the SE interface SE-S, and the SS interface SS-S according to the representations shown in FIGS. 4 a , 5 a and 6 to 9 . [0153] The transmitting and processing operations belonging to the flow phases AP 3 , AP 5 , AP 4 ′, AP 6 ′ in FIGS. 4 a , 4 b , 5 a , and 5 b are performed in the functional unit formed from the configuration module KFM, the service message memory SNS, the “style sheet” archive SSA, the “WEB server” module WSM, the user database NDB, the media adaption module MAM, and the SE interface SE-S, SE-S′ according to the representations shown in FIGS. 4 a , 4 b , 5 a , 5 b , 6 , and 8 . [0154] FIG. 11 shows the basic structure of the server SV in FIG. 1 and of the second server SV 2 in FIGS. 2 and 3 for transmitting a service message SN on the uplink (terminal→service center). Besides the editing unit ABE already mentioned in the description of FIGS. 1 to 3 , the service message memory SNS located in the server SV, SV 2 and assigned to the editing unit ABE, and the user database NDB likewise located in the server SV, SV 2 and assigned to the editing unit ABE, the server SV, SV 2 accordingly also contains a server/service center interface (SS interface) SS-S and a server/terminal interface (SE interface) SE-S, SE-S′. The server SV, SV 2 is connected via the SS interface SS-S to the service center SZ 1 . . . SZ 5 and via the SE interface SE-S, SE-S′ to the terminal EG. While the SS interface SS-S is designed for transmitting the service message SN in accordance with the transmission protocol SMTP, MM 1 . . . MM 7 -over-TCP/IP, the SE interface SE-S is embodied for transmitting the presentation message PN, the notification message MN, and other information or, as the case may be, messages in accordance with the transmission protocol HTTP-over-TCP/IP. As an alternative to the SE interface SE-S it is, however, also possible to use the SE interface SE-S′ (this is indicated in FIG. 11 by the dot-and-dash lining), with the SE interface SE-S′ being embodied for transmitting the presentation message PN, the notification message MN, and other information or, as the case may be, messages in accordance with the transmission protocol SIP-over-TCP/IP. [0155] Besides the “WEB server” module WSM and the user database NDB, the editing unit ABE contains a service message generating module SNEM, a template producing module VEM, and a template archive VA, with the “WEB server” module WSM having, alongside the I/O connection to the user database NDB and the SE interface SE-S, an O connection to the service message generating module SNEM and an I/O connection to the template producing module VEM, with the template producing module VEM having, alongside the I/O connection to the “WEB server” module WSM, an I connection to the user database NDB and the template archive VA, and with the service message generating module SNEM having, alongside the connection to the “WEB server” module WSM, an O connection to the SS interface SS-S. [0156] The transmitting and processing operations belonging to the flow phases AP 6 , AP 7 ′ in FIGS. 4 b and 5 b are performed in the functional unit formed from the “WEB server” module WSM, the user database NDB, the template archive VA, the service message generating module SNEM, the template producing module VEM, the SE interface SE-S, and the SS interface SS-S according to the representations shown in FIGS. 4 b , 5 b , 7 , and 9 . [0157] FIG. 12 shows the basic structure of the terminal EG embodied as a set-top box STB in conjunction with a television set FA, FBS and with a remote control instrument FBI. The central element of the terminal EG is the set-top box STB consisting substantially of a processing unit VAE, a buffer memory PSP, a wireless interface DL-S, and a server/terminal interface (SE interface) SE-S. The set-top box STB is connected to the server SV, SV 2 according to FIGS. 10 and 11 via the SE interface SE-S, which is again designed for the transmission protocol HTTP-over-TCP/IP. [0158] The wireless interface DL-S sets up the wireless connection, preferably embodied as an infrared or radio link, to the remote control instrument FBE, which can be embodied as, for example, a computer keyboard or a television remote control unit. [0159] The buffer memory PSP serves to buffer the output data transmitted via a SCART or S-video interface to the television set FA having a television screen FBS. [0160] The processing unit VAE of the set-top box STB contains a “WEB browser” module WBM and a message receiver module MEM embodied as a “listener” or, as the case may be, notification recipient. Both the “WEB browser” module WBM and the message receiver module MEM have in each case I/O connections to the buffer memory PSP, the SE interface SE-S, and the wireless interface DL-S. The “WEB browser” module WBM furthermore has an I connection to the message receiver module MEM. [0161] For displaying the output data on the television screen this is subdivided into four quadrants Q 1 . . . Q 4 . The content of a message archive is displayed in a first quadrant Q 1 (top left on the screen). The television program in progress is displayed in a second quadrant Q 2 (top right on the screen), while the respective message text or, as the case may be, current media element, for example an image or video, is displayed in a third quadrant Q 3 (bottom left on the screen) and a fourth quadrant Q 4 (bottom right on the screen). [0162] The remote control instrument FBI has an OK key, for example for selecting a message, and in each case two vertical cursor keys (“top/up” and “bottom/down” arrow keys) and horizontal cursor keys (“left” and “right” arrow keys). The vertical cursor keys make it possible to navigate in the message archive while the horizontal keys are used to change between the individual quadrants Q 1 . . . Q 4 . The OK key and cursor keys of the remote control instrument FBI can alternatively be embodied as softkeys. [0163] FIG. 13 shows the basic structure of the terminal EG embodied as a set-top box STB in conjunction with a television set FA, FBS and with a remote control instrument FBI wherein the data and messages requiring to be transmitted to the terminal can be transmitted with the aid of an SIP protocol. The central element of the terminal EG is again the set-top box STB consisting substantially of a processing unit VAE′ modified owing to the SIP protocol, the buffer memory PSP, the wireless interface DL-S, and a modified server/terminal interface (SE interface) SE-S′. The set-top box STB is connected to the server SV, SV 2 according to FIGS. 10 and 11 via the SE interface SE-S′ which, in contrast to the SE interface shown in FIG. 12 , is designed for the transmission protocol SIP-over-TCP/IP. [0164] The wireless interface DL-S again sets up the wireless connection, preferably embodied as an infrared or radio link, to the remote control instrument FBE, which can be embodied as, for example, a computer keyboard or a television remote control unit. [0165] The buffer memory PSP again serves to buffer the output data transmitted via a SCART or S-video interface to the television set FA having a television screen FBS. [0166] The processing unit VAE of the set-top box STB again contains a “WEB browser” module WBM and a modified message receiver module MEM′ embodied as a “listener” or, as the case may be, notification recipient. Both the “WEB browser” module WBM and the message receiver module MEM′ again have in each case I/O connections to the buffer memory PSP, the SE interface SE-S, and the wireless interface DL-S. The “WEB browser” module WBM furthermore has an I connection to the message receiver module MEM′. [0167] For displaying the output data on the television screen this is again subdivided into four quadrants Q 1 . . . Q 4 . The content of a message archive is displayed in a first quadrant Q 1 (top left on the screen). The television program in progress is displayed in a second quadrant Q 2 (top right on the screen), while the respective message text or, as the case may be, current media element, for example an image or video, is displayed in a third quadrant Q 3 (bottom left on the screen) and a fourth quadrant Q 4 (bottom right on the screen). [0168] The remote control instrument FBI again has an OK key, for example for selecting a message, and in each case two vertical cursor keys (“top/up” and “bottom/down” arrow keys) and horizontal cursor keys (“left” and “right” arrow keys). The vertical cursor keys make it possible to navigate in the message archive while the horizontal keys are used to change between the individual quadrants Q 1 . . . Q 4 . The OK key and cursor keys of the remote control instrument FBI can alternatively be embodied as softkeys. [0169] While the invention has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

According to the disclosure, various service messages, such as multimedia messages, short messages, Email messges, fax messages, “Voice Mail” messages, “Instant Messaging” messages etc., available or provided in a service center, or generated in a terminal are transmitted between the service center and a terminal, without the terminal having to be embodied as a client with relation to the transmission and processing of the service message, whereby the service message is directly or indirectly transmitted from the service center to a server, embodied as message server, preparing the message using an intermediate server and sent from the above in prepared form, for output on a network specific terminal to the terminal and multimedia message content is transmitted in the reverse direction from the terminal to the server which generates multimedia messages from the content and then sends the above directly or indirectly to the service center.

This is a division of the application Ser. No. 405,749, filed Sept. 11, 1989 now U.S. Pat. No. 5,012,457. BACKGROUND The present invention relates to aquatic alarms and sound systems and, more particularly to apparatus for producing high-fidelity sound underwater, and for reliably signalling unauthorized activity in or near a body of water such as a swimming pool or spa. Traditionally, underwater speakers have been used primarily for public plunges and aquatic athletic events. They have been either temporary installations using pulley methods for lowering the speaker into the water, or permanent installations that project outwardly from the concrete side-walls of a swimming pool. In the latter case, in-field repair or replacement has been extremely difficult, if not impossible. Conventional underwater speakers have relatively poor fidelity in that they introduce unwanted distortion, and they have limited frequency response in that they typically can only reproduce high frequencies. Consequently, underwater speakers are not normally used for producing music. This poor performance is related to an alignment spider that is typically connected to a diaphragm of the speaker for preventing contact between an attached voice coil and a permanent magnet that is closely spaced thereto. Intrusion alarms for swimming pools and the like are known. Typically they produce an alarm signal in response to wave motion that is generated when, for example, a child falls into the pool. Such alarms are often ineffective in that a child can enter the pool and drown without producing sufficient wave motions to trip the alarm, or the alarm is not triggered by the initial entry but only after the child is in distress--possibly too late for help to arrive in time. Also, existing alarm systems do not distinguish between normal recreational activity and situations requiring assistance or intervention. Moreover, wave motion sensors are subject to damage from normal recreational activity, and from weathering. Thus there is a need for an underwater speaker system that is effective for producing High-fidelity sound, particularly at low frequencies, that is convenient to install, easy to service, and does not interfere with normal aquatic activities. There is a further need for a pool intrusion alarm that is effective for monitoring a body of water, signalling unauthorized entry, whether or not such activity is accompanied by significant wave activity, and that is not subject to damage from normal pool activity or weathering. SUMMARY The present invention meets this need by providing an underwater transducer system that is particularly effective for reproducing a high-fidelity audio signal underwater, and for detecting and monitoring low levels of sound activity in the water. In one aspect of the invention, the system includes a housing, means for positioning the housing in a body of water, a diaphragm in the housing, an outer edge thereof connected to the housing with the diaphragm directly contacting the water, a coil assembly having at least one turn of a conductor on a coil axis, a pair of coil terminals at opposite ends of the conductor, the coil assembly being movable within the housing and rigidly connected to the center of the diaphragm by means of a tubular member of the coil assembly engaging a cylindrical outside surface of a boss portion that is formed in the diaphragm, and a magnetic field intersecting the conductor for correlating sound waves in the water with a voltage between the coil terminals. This system is particularly effective in producing high-fidelity sound underwater because the means for centering the coil permits the use of a very large coil and field magnet combination, yet does not require a conventional centering spider which would detract from the sound output and introduce distortion. Preferably the tubular member has an end registration surface perpendicular to the coil axis and that engages an outwardly radiating portion of the diaphragm proximate the boss portion for further facilitating the centering of the coil assembly with the diaphragm. The system can further include an adhesive material, which can be an epoxy resin, for rigidly holding the tubular member on the boss portion. The means for producing the field can be a field magnet having an annular slot for movably receiving the coil assembly, the system preferably including a cylindrical strip of lubricative plastic for preventing contact between the coil assembly and the magnet. Also, the coil assembly is preferably provided with a first connector element on a free end of a flexible member that is attached to the tubular member for removably connecting the coil terminals to a pair of transducer conductors extending from the housing, thereby facilitating field maintenance as well as initial assembly of the system. In another aspect of the invention, the diaphragm can include a rigid armature member and flexible ring member connected to an outer periphery of the armature member to form the outer edge of the diaphragm, the system further including flexible submerged plate member, means for moving an armature connection point of the plate member in a direction normal to the plate member in response to movement of the armature member, and means for connecting the plate member to the housing at locations spaced about the armature connection point for causing the plate member to flex, thereby to producing the correlation between the voltage between the coil terminals and the sound in the water. The body of water can be in contact with a wall structure to which the housing is adapted for mounting. In one aspect, the housing can be mounted in a fixture recess of the wall structure. In another aspect, the housing can be suspended by an elongated cord member from a coping that forms an upper extremity of the wall structure, the system also including a control unit that is located to one side of the water, the cord member connecting the control unit to the housing, and a hanger member for engaging the coping, the hanger member being connected to the cord member. A preferred configuration of the hanger member has a passage for grippingly receiving cord in a metallic material that is formed with uniform cross section. It is further preferred, when the coping has a lip portion extending horizontally from the wall structure to a lip extremity, that the hanger member be field-formable about the lip portion for positioning a vertically extending portion of the cord member below the lip portion, between the wall structure and the lip extremity. It is further preferred that the cord member be provided with a cover member that extends from proximate the hanger member toward the control unit for preventing those passing between the hanger member and the control unit from being tripped by the cord member. In another aspect of the invention, the system can be provided with a source of illumination, and conduit means for conducting the illumination to within the coil assembly, thence through the diaphragm for illuminating the water. The source of illumination can be external to the housing, the conduit means including a flexible optical conduit that extends from the source of illumination, along the coil axis, to a point of termination proximate the diaphragm, and an optical element that protrudes the diaphragm, the element being sealingly mounted to the diaphragm, for receiving illumination from the conduit and transmitting same into the water. Preferably a head portion of the optical element substantially fills the boss portion of the diaphragm for spreading the illumination to an exit diameter that approximates a coil diameter of the coil assembly. More preferably, the optical element has a first mirrored surface centered on the head portion for reflecting the illumination radially outwardly and rearwardly within the head portion and toward the conduit, and a second mirrored surface in the head portion for reflecting the reflected illumination forwardly and into the water. Moreover, the system can also include means for modulating the brightness of the illumination source in relation to the movement of the coil. In another aspect, the system can include an audio signal source and speaker connection means for driving the coil terminals in response to the signal source, producing the sound waves in the water in response to the signal source. The system can further include power amplifier means, and means for connecting the power amplifier means between the signal source and the coil terminals. In another aspect of the invention, the system is provided with signal amplifier means, signal output means, and microphone connection means for connecting the signal amplifier means between the signal output means and the coil terminals for signalling activity in the water to a location outside the water. Preferably the system further includes threshold means for producing an alarm signal in response to a predetermined output from the signal amplifier means. The threshold means can have an adjustment for setting an alarm threshold magnitude. Preferably the threshold means includes discriminator means for filtering a signal amplifier output, whereby a predetermined signal pattern associated with a crisis condition produces the alarm signal at a relatively low signal energy level, and a signal pattern associated with normal pool activity does not produce the alarm signal, even at a higher signal energy level. Thus the present invention is effective for remotely signalling an alarm condition based on sounds that are generated in the body of water, in response to either unauthorized entry or to signal patterns indicative of an emergency condition. Preferably the discriminator means can includes a band-pass filter having a first corner frequency of approximately 20 Hz and a second corner frequency of approximately 100 Hz. The discriminator means also produces a prefered frequency gain rolloff of at least approximately 24 dB per octave outside of the first and second corner frequencies. The alarm signal can be operatively connected to a housing indicator on the housing, the housing indicator being visible underwater for locally signaling occurrence of the alarm condition. Persons nearby would thus be prompted to take remedial action, if necessary, and report to those remotely monitoring the alarm condition. Preferably, the threshold means further includes latch means for holding the alarm signal following an alarm condition. In a further and important aspect of the invention, the system can also include a radio transmitter operatively responsive to the threshold means for producing an alarm transmission, and a radio receiver for producing a system alarm signal in response to the alarm transmission. Preferably the threshold means also includes oscillator means for producing and transmitting an alarm tone when the alarm signal is present. In a further aspect, the system includes a combination of the audio signal source and speaker connection means, and the signal amplifier means, signal output means, and microphone connection means, and switching means for inhibiting the microphone connection means in a first mode wherein the sound waves are produced in the water in response to the audio signal source, and for inhibiting the speaker connection means in a second mode wherein the signal output means is responsive to the sound waves in the water for remotely signalling activity in the water. This combination can further include the power amplifier means connected between the audio signal source and the coil terminals in the first mode, and/or the threshold means for producing the alarm signal. Preferably the second mode of the switching means is operative in a monitor submode wherein the signal amplifier means drives the signal output means for continuously monitoring sound activity in the water, and alarm submode wherein the threshold means drives the signal output means for signalling occurrence of the alarm condition. In a further aspect, the system includes the housing and means for positioning in the water, aquatic transducer means in the housing and including the diaphragm, the means for connecting the diaphragm to the housing, a coil member having at least one turn of a conductive material and forming the pair of coil terminals, and means for connecting the coil member to the diaphragm for correlating a voltage between the coil terminals and sound waves in the water, together with the signal amplifier means, the signal output means, the microphone connection means, the audio signal source, the speaker connection means, and the switching means for providing the first mode for producing the sound waves in response to the audio signal source and the second mode for signalling the activity in the water to a location outside the water. In an other aspect, the system includes the housing for mounting in the fixture recess, the aquatic transducer means, the source of illumination, the conduit means for conducting the illumination, the audio signal source, the signal amplifier means, the speaker connection means, and the means for modulating the brightness of the illumination source in response to the audio signal source. In another and important aspect of the invention, the system is capable of signalling an approach by an intruder to proximate a surveillance region such as the vicinity of a body of water, and includes one or more transducer units for producing an alarm signal in response to an alarm condition, having radio transmitter means for producing an alarm transmission in response to the alarm signal, and radio receiver means for producing a system alarm signal upon occurrence of the alarm transmission from any one transducer unit. At least one of the transducer units can have a base that is mountable on a movable member such as a gate that is opened for access to the surveillance region, the unit producing the alarm signal in response to movement of the movable member. A still further aspect of the invention provides a method for making an underwater transducer, including the steps of: (a) providing a housing for positioning in a body of water, the housing having a cavity therein; (b) forming a diaphragm with a peripheral edge and a centrally located boss portion, the boss portion having a cylindrical outside surface; (c) providing a coil assembly having at least one turn of a conductor on a coil axis, and a tubular extension at one end of the assembly and having a cylindrical inside surface concentric with the coil axis; (d) affixing the coil assembly to the diaphragm with the coil axis concentric with the boss portion, the inside surface of the tubular extension engaging the outside surface of the boss portion; (e) mounting a field magnet within the housing, the magnet having an annular slot for receiving the coil assembly; and (f) mounting the peripheral edge of the diaphragm to the housing, the diaphragm covering the cavity, the coil assembly extending into the annular slot of the field magnet. The method preferably includes the further step of locating a cylindrical strip of a lubricative plastic material within the annular slot for preventing contact between the coil assembly and the magnet. DRAWINGS These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: FIG. 1 is a pictorial schematic diagram of an underwater transducer system according to the present invention; FIG. 2 is a fragmentary sectional elevational view of of the system of FIG. 1 within region 2 of FIG. 1; FIG. 3 is a sectional elevational view of the system of FIG. 1 within region 3 of FIG. 1; FIG. 4 is a sectional elevational detail view of the system of FIG. 1 on line 4--4 of FIG. 3; FIG. 5 is a sectional elevational detail view of the system of FIG. 1 on line 5--5 of FIG. 3; FIG. 6 is a fragmentary sectional elevational view of as in FIG. 2 showing an alternative configuration of the system of FIG. 1; FIG. 7 is a fragmentary sectional elevational view showing an alternative configuration of a portion of the system shown in FIG. 6; FIG. 8 is fragmentary sectional elevational view as in FIG. 6, showing another alternative configuration of the system of FIG. 1; FIG. 9 is a fragmentary elevational view of an auxiliary transducer for the system of FIG. 1; FIG. 10 is a schematic circuit diagram of an electronic discriminator portion of the system of FIG. 1; and FIG. 11 is a functional block diagram showing another alternative configuration of the system of FIG. 1. DESCRIPTION The present invention is directed to an aquatic transducer system for producing high-fidelity sound underwater, for monitoring aquatic activity, and for detecting and signalling unauthorised or emergency conditions. With reference to the drawings, most particularly FIGS. 1 and 2, a transducer system 10 according to the present invention includes a transducer unit 12 that is located below a liquid surface 14 of a body of water such as a swimming pool 16, and a control unit 20 that is operatively connected to the transducer unit 12. The transducer unit 12 includes a housing 22 having a cavity 24 therein, the cavity 24 being covered at one side of the housing 22 by a semi-flexible diaphragm 26, and edge mounding means 28 for sealingly connecting the diaphragm 26 at a peripheral edge thereof to the housing 22. As shown in FIG. 2, the housing 22 is formed from a suitable plastic material for excluding water from the cavity 24. A coil assembly 30, including a tubular member 32 having a conductive coil 34 affixed thereto on a coil axis 36, is connected to the diaphragm 26 with the coil axis 36 concentric with the edge mounting means 28, the coil assembly 30 being movable along the coil axis 36 with corresponding flexure of the diaphragm 26. A permanent magnet field assembly 38 having an annular slot or cylindrical gap 40 is fixedly mounted within the cavity 24 with the gap 40 also concentric with the mounting means 28, such that the coil axis 36 is also at least approximately concentric with the gap 40, the coil 34 being axially movable therein. In order to facilitate production of the transducer unit 12 with the coil axis 36 concentric with the gap 40, the diaphragm 36 is formed with a centrally located cylindrical boss portion 42 therein, the tubular member 32 being located relative to the diaphragm 36 by a close fit with the boss portion 42. A forward extremity of the tubular member 32 is formed perpendicular to the coil axis 36 for contacting the diaphragm 36 at locations immediately proximate the boss portion 42, further facilitating proper alignment of the tubular member 32. The tubular member 32 is affixed to the boss portion 42 by a suitable epoxy bond 44. The edge mounting means 28 includes a gasket member 46 that is formed from a flexible material having C-shaped cross-section for receiving a peripheral edge 46 of the diaphragm 36, and a clamp assembly 48 for compressing the gasket member against an outwardly extending, conical flange portion 50 of the housing 22. The clamp assembly 48 includes a ring member 52 that is formed with a tapered C-shaped cross-section, and a clamp screw 54 for drawing together opposite ends of the ring member 52. A cylindrical strip 56 of a lubricative plastic material such as Teflon® is located within the gap 40 for maintaining the coil assembly concentric with the gap 40 by insuring that the coil assembly 30 does not directly contact the field assembly 38. The coil assembly 30 is prevented from making such direct contact by the tubular member 32 coming into sliding contact with the strip 56, the lubricative properties of the plastic material preventing excessive distortion in the axial movement of the coil assembly instead of contacting the field assembly 38, for maintaining a high-fidelity correlation between sound waves in the water and a voltage across the coil 34. The field assembly 38 includes a body member 58, and a belt member 60 rigidly affixed thereto, the body member 58 having a cylindrical outside body surface 62 concentric with the gap 40, the belt member 60 extending outwardly from the body surface 62 and forming a locating shoulder 64 that is oriented perpendicular to both the body surface 62 and the gap 40. The field assembly 38 is mounted in the housing 22 by locating engagment of the body surface 62 and the shoulder 64 with corresponding portions of the cavity 24 for concentrically positioning the gap 40 relative to the coil axis 40. A plurality of retainer members, one of which is designated 66 in FIG. 2, is affixed to the housing 22 within the cavity 24 by a plurality of screw fasteners 68, for holding the field assembly 38 with the shoulder 64 in contact with the corresponding portion of the cavity 24. With further reference to FIGS. 3-5, the transducer unit 12 is suspended from a coping portion 70 of the swimming pool 16, the coping portion 70 being formed at an upper extremity of a side wall 72 of the pool 16. A transducer cord 74 that connects the transducer unit 12 to the control unit 20 extends over the coping portion 70, the cord 74 engaging a hanger member 76 that hooks onto the coping portion 70 for supporting the transducer unit 12 by the cord 74. The hanger member 76 is preferably made from a relatively soft metallic material for field-forming to conform to a lateral profile of the coping portion 70, so that the hanger member 76 can formed to closely follow such profile without the use of special tooling. Accordingly, the hanger member 76 is relatively elongated, having uniform cross-section, incorporating a snap-in groove 78 for gripping the cord 74. Typically, the coping portion 70 forms an extension of a deck surface 80, having a raised lip 82 that extends horizontally a short distance over the liquid surface 14 to a lip extremity as shown in FIG. 3. As further shown in FIG. 3, the hanger member 76 is formed for resting on the lip 82, extending from the deck surface 80 in close conformity with the lip 82, downwardly proximate the lip extremity 84 to a lower terminus 86 of the groove 78, the terminus 86 being located horizontally more closely to the side wall 72 than the lip extremity 84 for supporting proximate the side wall 72 a depending portion 88 of the cord 74. Preferably the hanger member 76 is formed with a reverse curvature for avoiding a sharp bend in the cord at the as indicated at 90 in FIG. 3, thereby avoiding damage to the cord 74 that might otherwise result from loading by the transducer unit 72. A cover member 92 is provided for a portion of the transducer cord 74 that extends on the deck surface 80 between the hanger member 76 and the control unit 20, the cover member 92 protecting the cord 74 from wear and other damage resulting from traffic about the swimming pool 16, as well as for preventing those passing by from being tripped by the cord member. The cover member 92 can be formed from a suitable length of conventional flexible plastic power line floor covering strip. The depending portion 88 of the transducer cord 74 is connected to the transducer unit 12 for support thereof by means of a stress relief clamp 94 that is fixed on the housing 22, the cord 74 forming a loop 96 between the clamp 94 and a sealed feedthrough 98, the cord 74 passing into the cavity 24 by means of the feedthrough 98. The cord 74 includes a pair of transducer conductors, one such being designated transducer conductor 100 in FIG. 2. A shield conductor 102 of the cord 74 functions as the other transducer conductor. Conductor extensions of the transducer conductor 100 and the shield conductor 102 are operatively connected to the coil 34 through a polarized connector 104 having a first connector member 106 at a free end of a flexible member 108 that extends in a generally radial direction from the tube member 32 of the coil assembly 30, and a mating second connector member 110 that is electrically connected to the conductors 100 and 102 of the transducer cord 74. The first connector member 106, being electrically connected to the coil 34 through the flexible member 108, functions as a pair of coil terminals of the coil 34. The flexible member 108 between the tubular member 32 and the connector 104 serves to isolate the mass of the connector 104 from the coil assembly 30, for enhancing the high-fidelity correlation of the movement of the coil 34 with sound waves in the pool 16. A transducer alarm indicator 112 is mounted to the housing 22 for external visual exposure. One side of the indicator 112 is electrically connected to the control unit 20 through an indicator conductor 114 that forms a part of the transducer cord 74 for indicating occurrence of an alarm condition described below. The opposite side of the indicator 112 is connected through an indicator ground lead 116 to the shield conductor 102 of the transducer cord 74 for providing a return electrical path. The indicator conductor 114 and the ground lead 116 protrude the retainer 66 and an indicator sleeve 118 that sealingly holds the indicator 112 in position exposed to view from outside of the transducer unit 12, the sleeve 118 in turn being retained in the housing 22 by the retainer 66. The suspension of the transducer unit 12 by the transducer cord 74 locates the housing 22 proximate the side wall 72 of the pool 16 by virtue of the close proximity of the depending portion 88 of the cord 74 to the side wall 72 from the hangar member 76 as described above. Further, the housing 22 is semi-rigidly affixed to the side wall 72 by a suction ring 120 that sealingly protrudes from a back side 122 of the housing 22. The control unit 20 includes an audio source 124 and a power amplifier 126 for driving, through the transducer conductor 100 of the transducer cord 74, the transducer unit 12 as an underwater speaker. Typically, the audio source 124 provides AM, FM and tape signals which are selectively input to the power amplifier 126 through a source selector 128 as shown in FIG. 1. The power amplifier 126 includes a main volume control 130 for adjusting the level of sound that is produced underwater by the transducer 12. The control unit 20 also includes a monitor speaker 132 for monitoring the output of the power amplifier 126, the monitor speaker 132 being connected to the amplifier output through a monitor attenuator 134 for adjusting the volume output of the monitor speaker 132 relative to the output of the power amplifier 126. A mode output switch 136, further described below, is connected in series between the output of the power amplifier 126 and the transducer conductor 100 for effecting a speaker mode in which a speaker connection of the coil 34 to the power amplifier 126 is completed as described above; and a microphone mode for making a microphone connection whereby the transducer unit 12 is operative as a microphone for picking up sounds that are produced by activity in the swimming pool 16. In the speaker mode, the transducer 12 is particularly effective for producing sound underwater that is a high-fidelity reproduction of the output of the power amplifier 126, because the coil assembly 30 is properly centered relative to the gap 40 of the field assembly 38 without requiring a conventional centering spider that would otherwise diminish and distort the axial movements of the diaphragm 26. Also, the lubricative strip 56 within the gap 40 insures that the coil assembly 30 cannot come into direct contact with the field assembly 38, and any contact between the tubular member 32 of the coil assembly with the strip 56 produces only minimal distortion. Further, the diaphragm 26 is generously sized, preferably having an active peripheral diameter D of at least 8 inches and, more importantly, the coil assembly 30 and the field assembly 38 are very large in relation to the size of the diaphragm 26, the coil 34 having a diameter d that is at least 20% of the diaphragm active peripheral diameter D, the coil 34 also having an active length L within the gap 40 that is at least approximately 10% of the diameter D for allowing a multiplicity of turns of the coil 34 to occupy a very thin annular region, permitting a narrow spacing of the gap 40, thus facilitating a very high field strength of the field assembly 38 within the gap 40 and consequent high efficiency of the transducer unit 12. Another important feature of the present invention is that diaphragm 26 is easily field replaceable. In particular, the diaphragm 26 may be removed from the transducer unit 12 by loosening the clamp screw 54 for removing the clamp assembly 48, thus allowing the diaphragm 26, together with the gasket member 46, to be separated from the flange portion 50 of the housing 22. Next, the coil assembly 30 is withdrawn sufficiently from the gap 40 to provide access to the connector 104 for separation of the first connector member 106 from the second connector member 110, thereby completing the disassembly of the diaphragm 26 from the transducer unit 12. Replacement by a new diaphragm 26 and attached coil assembly 30 is also easily accomplished by reversing the steps for disassembly. Moreover, initial assembly of the transducer unit 12 is facilitated in the same manner by the combination of the removable clamp assembly 48 and the polarized connector 104, which also facilitates proper polarization of multi-transducer systems. As introduced above and with further reference to FIG. 10, the control unit 20 also provides a microphone mode, described herein. The mode output switch 136 is operative in response to a mode signal, designated mode signal A in FIG. 1, for connecting the transducer conductor 100 by a microphone path 137 to the input of a signal amplifier 138, the signal amplifier 138 being operatively connected for driving an alarm discriminator 140 that described below and, through a submode switch 142 that is also described below, an output amplifier 144 for driving a remote speaker 146, the connection of the signal amplifier 138 to the submode switch 142 being also tied to a monitor input, designated 148 in FIG. 1, of the source selector 128 for driving the monitor speaker 132 in response to the sounds in the swimming pool 16 that are picked up by the transducer unit 12. The submode switch 142 is operative in response to a submode signal, designated submode signal B in FIG. 1, for effecting a monitor submode in which the connection between the output of the signal amplifier 138 and the input of the output amplifier 144 together with the monitor input 148 to the source selector 128 is completed; and an alarm submode for operatively connecting an alarm signal 150 to the monitor input 148 and the output amplifier 144. In the alarm submode, there is a need for detecting disturbances likely to be associated with a distress situation, while ignoring normal activity. For example, when an object weighing from about 10 to about 100 pounds falls into the pool, there is a reasonable possibility that a baby or child is in distress. On the other hand, the continuous occurrence of a relatively high-frequency (100 Hz or higher) sound is indicative of rain, not distress. For generating the alarm signal 150 according to the present invention, a discriminator output 152 of the alarm discriminator 140 drives a threshold detector 154 for producing a detector output 156, the detector output 156 being connected to a latch circuit 158 having the alarm signal 150 as an output thereof. As shown in FIG. 10, the alarm discriminator 140 is implemented as a bandpass filter circuit including a differential preamplifier stage 300 that has a low-pass corner frequency of approximately 100 Hz, the preamplifier stage 300 incorporating the signal amplifier 138. An adjustable gain buffer amplifier 302 that is responsive to the differential amplifier 300 feeds a bandpass filter 304 having cut-off frequencies of 20 Hz and 100 Hz, including a two-stage low-pass section 306 having a corner frequency of 106 Hz and a series-connected two-stage high-pass section 308 having a corner frequency of 23.5 Hz. Each of the filter sections 306 and 308 is connected for achieving a frequency gain rolloff of 24 dB per octave. The connection of the differential amplifier 300 to the buffer amplifier is made through a notch filter 310, the notch filter 310 having shunt-connected a 60 Hz section 312 and a 120 Hz section 314 for partially removing 60 Hz and 120 Hz noise components. The threshold detector 154 is responsive to the discriminator output 152, and to an adjustable reference signal 160 for producing the detector output 156 in response to an adjustably predetermined alarm threshold level of the discriminator output 152. As further shown in FIG. 10, the threshold detector 154 is implemented with an operational amplifier 316 having positive feedback for combining the function of the latch 158. Accordingly, the alarm signal 150 is maintained in an inactive state until the detector output 156 becomes active, the latch circuit 158 driving the alarm signal 150 to an active level thereafter. When the alarm submode is terminated in response to operator intervention, as described below, the latch circuit 158 is reset in response to a reset connection to the submode signal B, restoring the alarm signal 150 to its inactive state. The alarm signal 150 is operatively connected to an alarm indicator 162 on the control unit 20 and, through the indicator conductor 114, the transducer alarm indicator 112. As shown in FIG. 1, an alarm oscillator 164 is interposed between the alarm signal 150 and the submode switch 142 for producing an alarm burst signal 166, the alarm burst signal 166 being connected through the submode switch 142, in the alarm submode, to the monitor input 148 and the output amplifier 144 for audibly driving the monitor speaker 132 and the remote speaker 146 from commencement of an alarm condition until the latch circuit 158 is reset by operator intervention as described above. Also, and as shown in FIG. 10, the alarm signal 150 is connected through a driver transistor 318 to an alarm horn 320, the alarm horn 320 incorporating a piezoelectric transducer and a counterpart of the alarm oscillator 164 for producing an audible alarm indication without requiring the connection through the submode switch 142. Also, the alarm indicator 162 (and/or the transducer alarm indicator 112) can be implemented as a flashing light emitting diode by the use of a commercially available flashing LED module. For controlling the mode signal A and the submode signal B, a mode logic circuit 168 is responsive to operator actuation of an alarm switch 170, a music switch 172, and a monitor switch 174. The mode logic circuit 168, shown as a functional block in FIG. 1, can be constructed from conventional logic circuitry for performing operations described herein, using methods which are known to those skilled in using such logic circuitry. With the source selector 128 set to one of the AM, FM, or tape inputs from the audio source 124, operation of the music switch 172 effects the speaker mode for producing the speaker connection by the mode switch 136 in response to the mode signal A, and simultaneous activation of a speaker mode indicator 176 that is associated with the music switch 172. Subsequent operation of either the alarm switch 170 or the monitor switch 174 extinguishes the speaker mode indicator 176, effecting the microphone mode for switching the mode switch 136 to the microphone connection in response to the mode signal A. Also, in case of operation of the alarm switch 170, an alarm mode indicator 178 that is associated therewith is activated by the logic circuit 168, which also effects the alarm submode by switching the submode switch 142 to the alarm connection and enabling the latch circuit 158 in response to the submode signal B. In case of termination of the speaker mode by operation of the monitor switch 174, a monitor mode indicator 180 that is associated therewith is activated by the logic circuit 168, which also effects the monitor submode of the microphone mode by maintaining the monitor connection of the submode switch 142 and a reset condition of the latch circuit 158 in response to the submode signal B. Electrical power for the logic circuit 168, the power amplifier 126, the signal amplifier 138, the output amplifier 144, and the other components of the control unit 20 is provided by appropriate connections (not shown) to a conventional power supply 182 which is powered from AC mains and/or batteries. With further reference to FIG. 6, an alternative configuration of the transducer system 10 has the transducer unit 12 mounted in a fixture cavity 184 that is formed in the side wall 72 of the pool 16, the fixture cavity 184 typically being configured for receiving a conventional underwater lamp assembly (not shown). The fixture cavity 184 has a mounting ring 186 associated therewith, and a power conduit 188 for feeding electrical power to the cavity 184. In this configuration, an important feature of the present invention is the inclusion of illumination means 190 in the transducer unit 12 for transmitting light from an illumination source 192 through the diaphragm 26 and into the water of the swimming pool 16. As shown in FIG. 6, the illumination source 192 includes a lamp 194, a light modulator 196, and a fiber-optic conduit 198, which are conventional components of a commercially available product. The conduit 198 passes downwardly below the deck surface 80, through a junction cavity 200 to which the power conduit 188 is connected, and through the power conduit 188 into the fixture cavity 184. According to the present invention, the conduit 198 protrudes the housing 22, continuing along the coil axis 36 to a point of termination 202 that is proximate the diaphragm 26. In FIG. 6, the housing 22 is shown as being formed from a sheet of a metallic material such as corrosion resistant steel. As shown in FIG. 6, the retainer 66 for the field assembly 38 is formed as a single slotted ring that is threadedly engaged by the fasteners 68, the fasteners 68 sealingly protruding the housing 22 from the outside thereof. The housing 22 is supported within the fixture cavity 184 by a plurality of mounting tabs 204 that are rigidly attached to the ring member 52 of the clamp assembly 48 the mounting tabs extending axially outwardly for attachment to the inside of a bezel member 206 by corresponding mounting screws 208. The bezel member 206 is secured to the mounting ring 186 by a plurality of set screws 210 that engage an annular inside enlargement 212 of the mounting ring 186. The field assembly 38 is provided with a field passage 214 for receiving the conduit 198, the conduit 198 being centered on the coil axis of 36 by a sleeve member 216, the sleeve member 216 being formed of a flexible material such as neoprene and having a tapered head portion 218 that extends external to the housing 22 for sealed clamping engagement by a clamping ring 220 that threadingly engages a cylindrical extension 222 of the housing 22 for fixably locating the axial position of the termination 202 and for excluding water from the cavity 24. An important feature of the present invention is an optical element 224 that is sealingly mounted to the diaphragm 26 within the boss portion 42 for transmitting light from the conduit 198 through the diaphragm 26, the element 224 having a head portion 226 that substantially fills the boss portion 42 for spreading the illumination to an exit diameter e that is approximately equal to the coil diameter d of the coil assembly 30. The optical element 224 protrudes the diaphragm 226, being sealingly mounted thereto by appropriate washers, such as the washers 228 and 230, and a clamp nut 232. In a preferred form of the optical element 224, the head portion 226 incorporates a pair of mirrored surfaces, designated first mirrored surface 234 and second mirrored surface 236 in FIG. 6. The combination of the head portion 226 with the mirrored surfaces 234 and 236 uniformly spreads the incoming light from the conduit 198 within the head portion 126 for efficiently transmitting the light from the optical element 124 into the water of the pool 16, thereby uniformly illuminating the pool 16 in response to the illumination source 192. Moreover, the output of the output amplifier 144 of the control unit 20 can drive a modulator input 238 of the illumination source 192 for controlling the light modulator 196, thereby varying the illumination of the pool 16 in response to the audio source 124. With further reference to FIG. 7, it has been discovered that the diaphragm 26 can be advantageously configured as a disk diaphragm 240, the diaphragm 240 having an annular groove 242 for axially receiving an end portion of the tubular member 32, the tubular member 32 being centered by engagement with a boss portion 244 of the diaphragm 240 that is formed by the groove 242. The diaphragm 240, being configured as a flat disk, can be inexpensively molded or machined from a readily available plastic material such as Plexiglas®, such that the transducer unit 12 has enhanced durability and is easier to clean. So configured, the diaphragm preferably has a thickness of about 0.125 inch, the outside diameter D being approximately 7.5 inches. As further shown in FIG. 7, the optical element 224 protrudes the diaphragm 224 and is sealingly fastened thereto by the washers 228 and 230, and the clamp nut 232, in the manner shown in FIG. 6. With further reference to FIG. 8, it has also been discovered that a particularly effective configuration of the transducer unit 12 incorporates a diaphragm 246 that is confugured with overhanging, cantilevered edge portions 248, the coil assembly 30 and the field assembly 38 being enclosed in a housing 250 that is spaced away from the diaphragm 246. An armature 252 that is axially movable within the housing 250, being sealingly connected thereto by a flexible sealant 254, has the coil assembly rigidly attached thereto as described above, the armature 252 being connected to the diaphragm 246 by a cap screw 256 that threadingly engages the armature 252, a head portion 258 of the capscrew 256 bearing against a central point of the armature 246. The diaphragm 246 is connected to the housing 250 by a plurality of stand-off fasteners 260 that are located in a circular pattern about the cap screw 256. With further reference to FIGS. 9 and 11, the transducer system 10 can incorporate one or more auxiliary transducers 330, such as a deck transducer 332 for detecting the close approach of intruders to the pool 16 prior to any entry of the pool 16 by such intruders This is an important feature of the present invention that greatly enhances the safety of the pool 16 in that an alarm condition can be sensed and responded to without waiting for an actual emergency such as the falling of a baby into the pool 16. As shown in FIG. 9, the deck transducer 332 includes a conventional permanent magnent speaker-microphone 334 that is mounted in a deck transducer housing 336, the housing 336 positioning the microphone 334 in a downward orientation and approximately flush with an underside of the housing 336. The housing 336 is equipped with a plurality of housing feet 338 for spacing the underside of the housing 336 above the deck surface 80 by a spacing S of approximately 0.125 inch. Accordingly, the deck transducer 332 is particularly responsive to low-frequency vibrations of the deck surface 80, and is also responsive to atmospheric sounds that are carried in the space below the housing 336. As shown in FIG. 11, the deck transducer 332 is connected through a deck alarm circuit 340 that incorporates counterparts of the discriminator 140 and the threshold detector 154 to a radio transmitter 342, the transmitter 342 sending an alarm transmission to a radio receiver 344 of a central station 346 of the transducer system 10. The deck alarm circuit 340 incorporates circuitry corresponding to the band-pass filter 304, but with the frequency response of the low-pass section 306 extended upwardly for responding to mid-range frequencies. Preferably the deck alarm circuit 340 has a band-pass frequency response of from about 20 Hz to about 400 Hz. The deck transducer 332 is provided with a top-mounted solar cell array 348 for charging a battery (not shown) that is included with the deck alarm circuit 340 for powering both the circuit 340 and the transmitter 342. The radio transmitter 342 and receiver 344 provide for convenient location of the deck transducer 332 on the deck surface 80 nearby the pool 16, without the need for running wires that would otherwise connect the deck transducer 332 into the transducer system 10. Similarly, and as also shown in FIG. 11, the transducer unit 12 is connected to an underwater module 150 that is provided with another of the radio transmitters 342 for obviating a need for wiring between the transducer unit 12 and the central station 146 The underwater module 150, which has another of the solar cell arrays 148, can be located on the deck surface 80 proximate the pool 16. As shown in FIG. 11, the underwater module 150 includes the mode switch 136 for selectively coupling a music source 152 to the transducer unit 12 in a manner similar to the above description of the control unit 20. The underwater module 150 also incorporates the alarm discriminator 140 and the threshold detector 154 in an underwater alarm circuit 154. For enhanced reliability of the transducer system 10, especially under varient environmental conditions, additional counterparts of the auxiliary transducer are provided as further shown in FIG. 11 and described herein. The pool 16 is depicted as being accessible through a gate 356, the gate 356 being provided with an acceleration sensor 358 that incorporates a mercury switch or the like, the sensor 358 being operatively connected for activating another of the radio transmitters 342. Also, the system 10 is provided with an optical scanner unit 360 and a microwave scanner unit 362, the scanner units 360 and 362 each being operatively connected for activating corresponding counterparts of the radio transmitter 342. The radio receiver 344 of the central station 346 is responsive to each of the transmitters 342 for setting a system alarm signal 345 when any one of the auxiliary transducers 330 or the transducer unit 12 activates the associated radio transmitter 342 in response to a corresponding activation of its alarm signal 150. In this configuration of the system 10, the deck alarm circuit 340, the underwater alarm circuit 354, the acceleration sensor 358, and each of the scanner units 360 and 362 activates the associated radio transmitter 342 for a short period of time for conserving battery power to the transmitters 342. In an exemplary configuration of the system 10, the transmitters 342 are activated for about three seconds upon occurrence of an alarm condition. The transmitters 342 are operative at a carrier frequency on the order of 10 MHz, the actual carrier frequency being determined by approporately selecting an oscillator crystal in a manner known to those skilled in the art. Prototype circuits of the transmitters 342 have been fabricated for testing in an experimental version of the transducer system 10, the carrier frequency being 10.126 MHz, the circuits being similar to those that are commonly used by hobbiests. When activated, each of the transmitter circuits draws approximately 47 milliamps of current at 9 V, with essentially no current drain when inactive. As further shown in FIG. 11, the transducer system 10 includes a closed circuit television camera 364 that is mounted for surveillance in the vicinity of the pool 16. The camera 364 is operatively connected to a TV monitor 366 that is located within the central station 346. Electrical power is carried to the camera 364 by a camera cable 368 that also transmits conventional video signals to the monitor 366. According to the present invention, occurrence of the system alarm signal 345 at the central station 346 results in activation of the camera 364, thereby producing an image at the monitor 366. The activation of the camera 364 can be for a predetermined period of time, such as for a period of 10 minutes. As also shown in FIG. 11, the TV camera 364 is equipped with a camera microphone 370 that is connected through the camera cable 368 to a monitor speaker (not shown) of the TV monitor 366 for audio surveillance of the vicinity of the pool 16. Further, the camera microphone 370 is operative as a speaker in a two-way communication between an operator at the monitor 366 and an intruder within range of the camera microphone 370, the monitor 366 being also equipped with a monitor speaker (not shown) that is operable as a microphone. A closed circuit TV system that is suitable for use as the camera 364 and the monitor 366 in the present invention is available commercially. As further shown in FIG. 11, the system 10 also includes a portable remote station 372 for passive alert in response to the alarm transmission of any of the radio transmitters 342. Although not necessarily required, the central station 346 is provided with one of the radio transmitters 342 (which can be more powerful than the others) for relaying the alarm transmission to the remote station 372. Typically the transmitter 342 of the central station 346 is operative at the same carrier frequency as that of the other transmitters, but this is not necessary. A user within audio or visual range of the remote station, in response to an audio or visual indication of the alarm condition as reproduced by the remote station 372, would either move to the central station for viewing the monitor 366, or take other remedial action such as moving directly to the vicinity of the pool 16. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, the latch circuit 158 can be implemented such that it is "cocked" upon occurrence of a first activation of the detector output 156, the alarm signal 150 being activated only if the detector output 156 is also active after a fixed interval such as two seconds after the first activation, thereby excluding false activations of the detector output 156 from activating the alarm signal 150. Also, the latch circuit 158 can be implemented for automatic reset after a predetermined alarm interval, such as for momentary activation of the transmitter 342. Further, the camera microphone 370 can be provided with a counterpart of the deck alarm circuit for activating the system alarm 345 in response to sounds that are picked up by the camera microphone 370. Also, monitor 366 can be operatively connected to a video recorder for recording on tape the video from the camera 364 during and immediately following occurrences of the system alarm 345. Moreover, the transducer unit 12 can incorporate a deflector for shielding the unit 12 from harmful contact by a pool sweep mechanism, the transducer unit 12, together with its transducer cord 74 being isolated by spring suspension within the deflector for preventing false alarm signals that would otherwise be produced by objects contacting the deflector. The deflector can form a slot or other opening for permitting fluid communication between the diaphragm 26 and outside of the deflector, the opening being covered by a screen. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions contained herein.

An underwater transducer system reproduces high-fidelity audio signals underwater, and detects and monitors low levels of sound activity, both adjacent to a body of water such as a swimming pool, and in the water. The system includes an underwater housing for a diaphragm that directly contacts the water, a coil assembly movable within the housing and rigidly connected to the center of the diaphragm by a tubular member of the coil assembly engaging a cylindrical boss portion of the diaphragm. The housing can be suspended by an elongated cord member from a wall coping, or mounted within a wall fixture structure. The system can have a source of illumination, a conduit from the source terminating in the housing on the coil axis proximate the diaphragm, and an optical element sealingly protrudes the diaphragm for transmitting light-amplified illumination into the water. A head portion of the optical element that substantially fills the boss portion of the diaphragm incorporates a pair of mirrored surfaces for spreading the illumination and transmitting it into the water. A control unit located to one side of the water provides a speaker mode and a microphone mode of operating the transducer, the microphone mode having a monitor mode and an alarm mode for detecting an alarm condition based on discrimination of an alarm sound condition occurring in the pool. The control unit can also interface a closed circuit TV for visually monitoring the pool. Also disclosed is a method for making the underwater transducer.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of U.S. application Ser. No. 10/287,664, filed Nov. 5, 2002, which is a continuation of U.S. application Ser. No. 09/986,605, filed Nov. 9, 2001, now U.S. Pat. No. 6,560,066, which is a continuation of U.S. application Ser. No. 09/769,362, filed Jan. 26, 2001, now U.S. Pat. No. 6,369,977. BACKGROUND OF THE INVENTION [0002] The present invention relates to a magnetic disk device and, more particularly, to a magnetic disk drive which has a high reliability and is capable of reducing windage vibrations of a magnetic head due to turbulent air currents produced by a rotating magnetic disk. [0003] [0003]FIG. 6 shows a known magnetic disk device 600 disclosed in JP-A No. 2000-156068. The magnetic disk device 600 drives a magnetic disk 11 by way of a spindle motor 12 . A magnetic head for writing information to and reading information from the magnetic disk 11 is supported on the extremity of a suspension 21 . A carriage arm 25 supports the suspension 21 . The carriage arm 25 has a base end fixed to a pivot shaft 20 . A voice coil motor 28 drives the carriage arm 25 for turning. This prior art magnetic disk device 600 is provided with a filter 60 placed on an air passage 61 formed by cutting a portion of a shroud 41 . SUMMARY OF THE INVENTION [0004] The air passage 61 formed by cutting a portion of the shroud 41 as shown in FIG. 6 often enhances the hydrodynamic vibrations of the magnetic disk 11 generally called disk fluttering [0005] Accordingly, it is an object of the present invention to provide a magnetic disk device which has a high reliability and is capable of reducing windage vibrations of a magnetic head caused by air currents produced by a rotating magnetic disk. [0006] With the foregoing object in view, according to a first aspect of the present invention, a magnetic disk device comprises a magnetic disk for recording information, a spindle motor for driving the magnetic disk for rotation, a magnetic head for writing information to and reading information from the magnetic disk, a carriage arm supporting the magnetic head, a voice coil motor for moving the carriage arm, a shroud forming a peripheral wall, a structure forming an air passage extending through a clearance between the voice coil motor and the shroud between a position on the upper side of the carriage arm with respect to the direction of rotation of the magnetic disk and a position on the lower side of the carriage arm with respect to the direction of rotation of the magnetic disk, and a filter placed in the air passage to clean air flowing through the air passage. [0007] According to a second aspect of the present invention, a magnetic disk device comprises a magnetic disk for recording information, a spindle motor for driving the magnetic disk for rotation, a magnetic head for writing information to and reading information from the magnetic disk, a carriage arm supporting the magnetic head, a voice coil motor for moving the carriage arm, a loading/unloading mechanism for retracting the carriage arm from a position on the magnetic disk, a shroud forming a peripheral wall, and a structure forming an air passage extending through a clearance between the voice coil motor and the shroud between a position on the upper side of the carriage arm with respect to the direction of rotation of the magnetic disk and a position on the lower side of the carriage arm with respect to the direction of rotation of the magnetic disk. [0008] According to a third aspect of the present invention, a magnetic disk device comprises a magnetic disk for recording information, a spindle motor for driving the magnetic disk for rotation, a magnetic head for writing information to and reading information from the magnetic disk, a carriage arm supporting the magnetic head, a voice coil motor for moving the carriage arm, a loading/unloading mechanism for retracting the carriage arm from a position on the magnetic disk, and a shroud forming a peripheral wall; wherein the rotating direction of the magnetic disk is the same as a direction from the free end of the carriage arm toward the base end of the same. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The invention disclosed herein will be understood better with reference to the following drawings of which: [0010] [0010]FIG. 1 is a schematic plan view of a magnetic disk device representing a first embodiment according to the present invention; [0011] [0011]FIG. 2 is a schematic plan view of a magnetic disk device representing a second embodiment according to the present invention; [0012] [0012]FIG. 3 is a schematic plan view of a magnetic disk device representing a third embodiment according to the present invention; [0013] [0013]FIG. 4 is a schematic plan view of a magnetic disk device representing a fourth embodiment according to the present invention; [0014] [0014]FIG. 5 is a graph showing the results of experiments on pressure variation; and [0015] [0015]FIG. 6 is a plan view of a prior art magnetic disk device. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] Preferred embodiments of the present invention will be described by way of example with reference to the accompanying drawings. [0017] First Embodiment [0018] Referring to FIG. 1, which shows a magnetic disk device 100 representing a first embodiment according to the present invention, a magnetic disk 11 is driven for rotation by a spindle motor 12 . A magnetic head for writing information to and reading information from the magnetic disk 11 is supported on the extremity of a suspension 21 supported on a carriage arm 25 . The carriage arm 25 is capable of turning on a pivot shaft 26 . A voice coil motor 28 drives the carriage arm 25 for turning. The rotating direction of the magnetic disk 11 is the same as a direction from the base end of the suspension 21 toward the extremity of the same. A connector 10 connects input and output signal lines, not shown, extending from the magnetic head supported on the suspension 21 to a control circuit, not shown, which is included in the magnetic disk device 100 . A loading/unloading mechanism 31 in the form of a lumped loading system is disposed so that a tab 32 slides onto the loading/unloading mechanism 31 when the carriage arm 25 is turned to a position outside the magnetic disk 11 . [0019] A shroud 41 has a wall surrounding the magnetic disk 11 . The shroud 41 and a land 39 form return channels 45 a , 45 b and 45 c , i.e., air passages, through which air currents produced when the magnetic disk 11 is rotated flow. A filter 60 for removing dust is placed in the return channel 45 c . The return channel 45 c is connected to an air passage 50 defined by an extension 42 . Air currents produced when the magnetic disk 11 is rotated flow into the return channel 45 a , flow through the return channels 45 b and 45 c and the air passage 50 , and flow outside through an exit 49 formed at a position below the loading/unloading mechanism 31 with respect to the direction of flow of the air currents. The air currents flow also through a space immediately above the loading/unloading mechanism 31 into the air passage 50 and flow outside through the exit 49 b. [0020] In the magnetic disk device 100 , spaces on the upper and the lower side of the loading/unloading mechanism 31 are connected by the air passage 50 , and a screen 42 b screens a principal section of the air passage 50 from the magnetic disk 11 so that air flows smoothly downstream to prevent the production of turbulent air currents around the loading/unloading mechanism. Thus, enhancement of windage vibrations of the magnetic head due to turbulent air currents can be prevented and the reliability of the magnetic disk device can be enhanced. [0021] The fluttering amplitude of the magnetic disk 11 on the magnetic disk device 100 provided with the filter 60 in the return channel 45 b or 45 c was smaller by about 27% than that of a magnetic disk on a conventional magnetic disk device provided with an air passage specially for a filter. [0022] The effect of placing the filter in the return channel in reducing the fluttering amplitude of the magnetic disk 11 is effective not only in magnetic disk devices provided with a loading/unloading mechanism, but also in magnetic disk devices of a CSS (contact start stop) system in which a magnetic head is in sliding contact at the start and stop of rotation of the magnetic disk. [0023] The filter 60 may be placed in the return channel 45 a or 45 b . Experiments proved that flutter reduction when the filter 60 is placed at the inlet of the return channel 45 a was greater by about 10% than those when the filter 60 was placed at other positions. The effect of air on cooling the voice coil motor 28 can be enhanced by placing the filter 60 in the return channel 45 b between the voice coil motor 28 and the shroud 41 . [0024] Second Embodiment [0025] A magnetic disk device 200 representing a second embodiment according to the present invention will be described with reference to FIG. 2, in which parts like or corresponding to those of the magnetic disk device 100 in the first embodiment will be denoted by the same reference numerals and a respect of the description thereof will be omitted. [0026] The magnetic disk device 200 is provided with a screen 43 to produce smooth air currents around a loading/unloading mechanism 31 . The screen 43 covers a region on one side of the loading/unloading mechanism 31 spaced from the magnetic disk 11 , i.e., on the opposite side of the mechanism 31 from the magnetic disk 11 , and extends into a region on the lower side of the loading/unloading mechanism 31 with respect to the rotating direction of the magnetic disk 11 . A portion 44 of a shroud 41 is shaped so that the width of the air passage 50 decreases gradually. [0027] The air passage 50 is defined by a portion of the screen 43 on the lower side of the loading/unloading mechanism 31 with respect to the direction of air flow, and the shroud 41 . Air flows through an entrance 49 a into the air passage 50 and flows outside the air passage 50 through an exit 49 b . The screen 43 is shaped so as to guide air so that air flows smoothly and screens a principal section of the air passage 50 from the magnetic disk 11 . The exit 49 b is located on a line passing through the center of the magnetic disk 11 and at an angle θ about the center of the magnetic disk 11 measured in the rotating direction of the magnetic disk 11 from a line passing through the center of the magnetic disk 11 and the loading/unloading mechanism 31 (head stroke position). Preferably, the angle θ is in the range of 10° to 30°, more preferably, in the range of 15° to 25°. Turbulent flow of air is produced unavoidably in the vicinity of the exit 49 b , and, if the angle θ is below 10°, the exit 49 b will be excessively near to the loading/unloading mechanism 31 and turbulent flow of air produced at the exit 49 b will adversely affect the function of the loading/unloading mechanism 31 . Consequently, the turbulence control effect of the magnetic disk device will be unsatisfactory. When the angle θ is greater than 30°, the shroud 41 is excessively short and the exciting force that causes the magnetic disk 11 to flutter increases. [0028] In the magnetic disk device 200 in the second embodiment, the screen 43 covers the region on one side of the loading/unloading mechanism 31 spaced from the magnetic disk 11 and extends into the region on the lower side of the loading/unloading mechanism 31 with respect to the rotating direction of the magnetic disk 11 . Therefore, the production of turbulent flow of air by the irregular shape of the loading/unloading mechanism 31 can be prevented and air is able to flow smoothly. [0029] Since the air currents produced by the rotating magnetic disk 11 flow in a direction opposite the rotating direction of the magnetic disk 11 with respect to the loading/unloading mechanism 31 , the collision of the air currents against the loading/unloading mechanism 31 and the resultant turbulent flow of air can be prevented. Thus, it is possible to prevent the deterioration of the reliability of the magnetic disk device 200 caused by the enhancement of windage vibrations of the magnetic head by the loading/unloading mechanism 31 , the enhancement of exciting force that causes the magnetic disk 11 to flutter, and the unstable loading and unloading operations due to the adverse effect of turbulent flow on the suspension 21 and the carriage arm 25 . [0030] Third Embodiment [0031] A magnetic disk device 300 representing a third embodiment according to the present invention will be described with reference to FIG. 3, in which parts like or corresponding to those of the magnetic disk devices 100 and 200 in the first and the second embodiment will be denoted by the same reference numerals, and a repeated description thereof will be omitted. [0032] The magnetic disk device 300 is basically the same in construction as the magnetic disk device 200 in the second embodiment. The magnetic disk device 300 is provided with a screen 43 a that extends from the upper side to the lower side of a loading/unloading mechanism 31 to guide air currents more smoothly from the upper side of the loading/unloading mechanism 31 into an air passage 50 . A filter 60 is placed in a passage between an extension 42 and the screen 43 a. [0033] In the magnetic disk device 300 in the third embodiment, the stability of air currents flowing from the upper side toward the lower side of the loading/unloading mechanism 31 can be enhanced because the screen 43 a extends from the upper side to the lower side of the loading/unloading mechanism 31 . Experiments show that the screen 43 a increases flutter reducing effect by about 10%. The filter 60 , similarly to that of the first or the second embodiment, may be disposed in the return channel 45 a or 45 b. [0034] Fourth Embodiment [0035] A magnetic disk device 400 representing a fourth embodiment according to the present invention will be described with reference to FIG. 4, in which parts like or corresponding to those of the magnetic disk devices 100 , 200 and 300 in the first, the second and the third embodiment will be denoted by the same reference numerals, and a repeated description thereof will be omitted. [0036] This magnetic disk device 400 drives a magnetic disk 11 by way of a spindle motor 12 . The magnetic disk 11 is rotated in a direction opposite the direction in which the magnetic disks 11 in the first to the third embodiments are rotated; that is, the magnetic disk 11 is rotated in a direction from a loading/unloading mechanism 31 toward a suspension 21 , in a direction from the extremity toward the base end of the suspension 21 or in a direction from a magnetic head toward a carriage arm 25 supporting the suspension 21 . [0037] In a magnetic disk device of a CSS system, the magnetic disk cannot be turned in the reverse direction because troubles, such as buckling, occur in the gimbals and the suspension of the magnetic disk device when the magnetic disk is rotated in the reverse direction. The magnetic disk device provided with the loading/unloading mechanism 31 is free from such troubles even if the magnetic disk is rotated in the reverse direction. [0038] A shroud 41 and a land 39 define return channels 45 a , 45 b and 45 c through which air currents produced by a rotating magnetic disk 11 flow. A filter 60 is placed in the return channel 45 c to filter out dust from the air. An extension 42 connects the return channel 45 c to an air passage 50 . The filter 60 , similarly to that of the first or the second embodiment, may be placed in the return channel 45 a or 45 b. [0039] The air passage 50 is defined by a screen 43 b disposed on the upper side of the loading/unloading mechanism 31 . Air flows through an entrance 49 a on the upper side of the loading/unloading mechanism 31 into the air passage 50 and flows out of the air passage 50 through an exit 49 b on the lower side of the loading/unloading mechanism 31 . The screen 43 b is shaped so as to guide air so that air flows smoothly, and screens a principal section of the air passage 50 from the magnetic disk 11 . The screen 43 b is extended on the upper side of the loading/unloading mechanism 31 with respect to the direction of air flow. Air currents produced by the rotating magnetic disk 11 flow through the entrance 49 a into the air passage 50 , flow out of the air passage 50 through the exit 49 b and flow through the return channels 45 c , 45 b and 45 a. [0040] [0040]FIG. 5 shows measured ranges of pressure variation at positions at angles 90°, 180° and 270° in the rotating direction of the magnetic disk 11 from a reference line at an angular position of 0° corresponding to the position of the carriage arm 25 . As obvious from FIG. 5, the range of pressure variation decreases with the angle from the reference line. When the magnetic disk 11 is rotated in the direction indicated by the arrow in FIG. 4, the range of pressure variation is the widest in a region between the carriage arm 25 and the exit of the return channel 45 a , extending under an open section of the shroud 41 , i.e., a section between the entrance 49 a of the passage defined by the shroud 41 and the magnetic disk 11 and a position where the passage defined by the land 39 and the magnetic disk 11 is narrowed. The range of pressure variation is the narrowest in a region around the entrance 49 a on the upper side of the open section of the shroud 41 . [0041] Since the head 11 of the magnetic disk device 400 in the fourth embodiment is located at an angular position corresponding to the region around the entrance 49 a on the upper side of the open section of the shroud 41 , where the range of pressure variation is the narrowest, the windage vibrations of the head 11 can be prevented, thereby to enhance the reliability of the magnetic disk device 400 . [0042] The mode of variation of the range of pressure variation in a magnetic disk device not provided with any return channels is the same as that shown in FIG. 5. The effect of the magnetic disk device 400 in the fourth embodiment can be attained also in a magnetic disk device not provided with any return channels. [0043] As apparent from the foregoing description, the magnetic disk device according to the present invention is capable of reducing windage vibrations of the head caused by air currents generated by the rotating magnetic disk, which enhances the reliability of the magnetic disk device. [0044] Although the invention has been described in its preferred embodiments with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.

A magnetic disk device having a magnetic disk for recording information, a spindle motor for driving the magnetic disk for rotation, a magnetic head for reading information from the magnetic disk, a carriage arm for supporting the magnetic disk, a voice coil motor for moving the carriage arm, a loading/unloading mechanism for retracting the carriage arm from a position on the magnetic disk, and a shroud for forming a peripheral wall. The magnetic device includes an air passage positioned between the loading/unloading mechanism and the shroud.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application may relate to subject matter disclosed in one or more of U.S. patent application Ser. Nos. (P40761) entitled “Method of Making Stabilized Polymers, Polymer Compositions, and Articles Containing Such Polymers”, (P40957) entitled “Method of Making Silanol and Silanediol Stabilized Polymers, Polymer Compostions, and Articles Containing Such Polymers”, and (P41148) entitled “Method of Making Polymers, Polymer Compositions, and Articles Containing Such Polymers”. Each of the aforementioned applications is filed of even date herewith and assigned to an entity common hereto and shares an inventor common hereto. Further, the entirety of each and every one of the aforementioned applications is incorporated herein by reference for all purposes. TECHNICAL FIELD [0002] The field of art to which this invention pertains is conjugated diolefin polymers, methods of producing the same, and compositions and articles containing such polymers. BACKGROUND [0003] Many attempts have been made to increase the dispersibility of fillers in polymer compositions. A common method for doing this is to modify the polymer with a functional group that interacts with the filler. Note, for example, U.S. Pat. No. 6,369,167, Patent Application Publication No. 2009/0163668, and U.S. Pat. No. 6,255,404, the disclosures of which are incorporated by reference. Silica fillers, in particular, impart desirable properties to polymers, especially those adapted to tire use. However, the use of silica fillers in polymers can also result in special problems relating to dispersibility and processability. Modifications to polymers to improve silica interaction with the polymer can have adverse effects on the polymer's interaction with carbon black, which also imparts desirable polymer properties to polymers, especially adapted to tire use. Therefore, functional group modification of polymers must produce satisfactory interaction with a variety of fillers. However, this functional group termination may also result in an increase in the Mooney viscosity of the treated polymers (hereinafter the use of Mooney viscosity will refer to conventional Mooney ML 1+4/100 viscosity measures unless otherwise indicated). Note, for example, U.S. Pat. Nos. 5,659,056; 6,255,404; and 7,342,070, the disclosures of which are incorporated by reference. And Mooney viscosity creep with aging has become even more pronounced with the movement from batch to continuous polymerization. Note also, for example, U.S. Pat. Nos. 3,244,644 and 4,185,042, the disclosures of which are incorporated by reference. [0004] As described above, the polymers are typically terminated using a number of different functional compounds including silane containing compounds to yield silane end-capped polymers. However, upon subsequent desolventization of the alkoxysilane terminated polymers through the use of either steam or heated water, an even larger increase in Mooney viscosity often occurs during the hydrolysis of alkoxysilane end groups thereby leading to coupling of the polymer via formation of Si—O—Si bonds between two end groups. Accordingly, it has been found that many of the processes tried in the past do not actually prevent an increase in Mooney viscosity, but only slow the rate of the hydrolysis reaction and, therefore, the rate of coupling of the polymer. Over a period of time, the slow hydrolysis of the end groups will occur, thereby continuing the problem of increased Mooney viscosity and coupling of the alkoxysilane terminated polymers with aging. Aging of polymers result in issues with rubber consistency, ease of mixing, etc. [0005] Thus, while attempts have been made in the art to improve polymer interaction with various fillers, and improve processability of the polymers, a way to slow down the rate of the hydrolysis reaction and coupling of the alkoxysilane terminated polymers is still needed. BRIEF SUMMARY OF THE INVENTION [0006] Improved processability of polymers, a way to slow down the rate of the hydrolysis reaction and coupling of siloxane end groups of polymers, along with improved filler interaction, is accomplished with the present invention by polymerizing conjugated diolefins in solvents such as hydrocarbon solvents in the presence of an initiator, followed by reaction of the living polymer with functionalizing agents such as trialkylsiloxy or triarylsiloxy iminosilanes. The polymer may then be desolvatized. The resulting polymer not only has good filler interaction and processability, but has improved Mooney viscosity stability, even over long periods of time, for example, during storage. [0007] Aspects of the invention include desolvatizing by drum drying, direct drying, or steam desolvatizing; the use of iminosilane functionalizing agents such as [0000] [0000] wherein R 1 to R 6 are C 1 to C 20 alkyl or aryl groups, optionally containing heteroatoms or functional groups, and x being equal to or greater than 1, and n being between 1 and 3; polymer functionalizing agents having the above formula; the use of iminosilane terminal functionalizing agents such as 3-(1-methylethylidene)aminopropyltris(trimethylsiloxy) silane; the use of an initiator such as n-butyl lithium; and the use of hydrocarbon solvents such as one or more hexanes. [0008] Aspects of the invention include the use of a conjugated diolefin such as 1,3-butadiene; the use of an aromatic vinyl compound in the initial polymerizing step; the use of an aromatic vinyl compound such as styrene in the polymerization step; drying the polymer after desolvatizing; the addition of a silica filler to the polymer; and the optional addition of a carbon black filler to the polymer. [0009] Aspects of the invention include the polymers produced by the processes recited above; a conjugated diolefin polymer containing alkylsiloxy or arylsiloxy iminosilane terminal end groups, having a stable Mooney viscosity; rubber compositions containing a filler and the polymer produced by the process described above; and tires containing the rubber of the present invention. [0010] These and other objects, aspects, embodiments and features of the invention will become more fully apparent when read in conjunction with the following detailed description. DETAILED DESCRIPTION OF THE INVENTION [0011] The particulars shown herein are by way of example and for purposes of illustrative discussion of the various embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. [0012] The present invention will now be described by reference to more detailed embodiments, with occasional reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. [0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety. [0014] Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches. [0015] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. [0016] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. [0017] Attempts to address some of the above issues are described, for example, in U.S. Pat. No. 5,659,056 which describes a process to treat the polymer prior to desolventization with a C 1 to C 12 aliphatic or C 6 to C 12 cycloaliphatic or aromatic carboxylic acid viscosity stabilizing agent soluble in the solvent used to prepare the polymer. U.S. Pat. No. 6,255,404 describes a method for stabilizing the Mooney viscosity of alkoxysilane terminated polymer having at least one hydrolyzable substituent on the silane end group with an alkyl trialkoxysilane viscosity stabilizing agent. U.S. Pat. No. 7,342,070 teaches improving polymer properties by bonding a primary amino group and an alkoxysilyl group to the polymer chain. [0018] Polymers that can be stabilized in accordance with the process of the present invention can be any conjugated diolefins known in the art including polybutadiene, polyisoprene, and the like, and copolymers thereof with monovinyl aromatics such as styrene, alpha methyl styrene and the like, and trienes such as myrcene. Thus, the polymers include diene homopolymers and copolymers thereof with aromatic vinyl compounds. Exemplary diene homopolymers are those prepared from diolefin monomers having from about 4 to about 12 carbon atoms. Exemplary vinyl aromatic polymers are those prepared from monomers having from about 8 to about 20 carbon atoms. [0019] Preferred polymers include diene homopolymers such as polybutadiene and polyisoprene and copolymers such as styrene butadiene rubber (SBR). Polymers and copolymers can comprise from 100 to about 20 percent by weight of diene units and from 0 to about 80 percent by weight of monovinyl aromatic hydrocarbon or triene units, totaling 100 percent. The copolymers may be random copolymers or block copolymers. Block copolymers include, but are not limited to, poly(styrene-butadiene-styrene), which are thermoplastic polymers. The polymers utilized and treated in accordance with the process of the present invention display utility in a number of applications, including, for example, use in the manufacture of tires. [0020] The polymers employed in the practice of this invention can be prepared by employing any polymerization techniques. These techniques include, but are not limited to, cationic and anionic techniques, transition metal or coordination catalyst techniques, emulsion techniques, etc. Similarly, any organic alkali metals and/or the organic alkali earth metals may be used in the polymerization process of the present invention, including alkyllithiums such as n-butyllithium, s-butyllithium and t-butyllithium, alkylenedilithiums such as 1,4-dilithiobutane, phenyllithium, stilbenelithium, lithiumnaphthalene, sodiumnaphthalene, potassiumnaphthalene, n-butylmagnesium, n-hexylmagnesium, ethoxycalcium, calcium stearate, t-butoxystrontium, ethoxybarium, isopropoxybarium, ethylmercaptobarium, t-butoxybarium, phenoxybarium, diethylaminobarium, and barium stearate. Polymerization of the monomers may be conducted in the presence of an organolithium anionic initiator catalyst composition. The organolithium initiator employed may be any anionic organolithium initiators useful in the polymerization of 1,3-diene monomers. In general, the organolithium compounds include hydrocarbon containing lithium compounds of the formula R(Li) x wherein R represents hydrocarbon groups containing from one to about 20 carbon atoms, and preferably from about 2 to about 8 carbon atoms, and x is an integer from 1 to 2. Although the hydrocarbon group is preferably an aliphatic group, the hydrocarbon group may also be cycloaliphatic or aromatic. The aliphatic groups may be primary, secondary, or tertiary groups although the primary and secondary groups are preferred. Examples of aliphatic hydrocarbyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-amyl, sec-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, n-nonyl, n-dodecyl, and octa-decyl. The aliphatic groups may contain some unsaturation such as allyl, 2-butenyl, and the like. Cycloalkyl groups are exemplified by cyclohexyl, methylcyclohexyl, ethylcyclohexyl, cycloheptyl, cyclopentylmethyl, and methylcyclopentylethyl. Examples of aromatic hydrocarbyl groups include phenyl, tolyl, phenylethyl, benzyl, naphthyl, phenyl cyclohexyl, and the like. [0021] Specific examples of organolithium compounds which are useful as anionic initiators in the polymerization of conjugated dienes in accordance with the process of the present invention include, but are not limited to, n-butyl lithium, s-butyl lithium, n-propyl lithium, isobutyl lithium, tertiary butyl lithium, amyl-lithium, and cyclohexyl lithium. Mixtures of different lithium initiator compounds also can be employed preferably containing one or more lithium compounds such as R(Li) x , R and x as defined above. Other lithium catalysts which can be employed alone or in combination with the hydrocarbyl lithium initiators are tributyl tin lithium, lithium dialkyl amines, lithium dialkyl phosphines, lithium akyl aryl phosphines and lithium diaryl phosphines. The preferred organolithium initiator is n-butyl lithium and in situ produced lithium hexamethylenimide initiator. [0022] The amount of initiator required to effect the desired polymerization can be varied over a wide range depending upon a number of factors such as the desired polymer molecular weight, the desired 1,2- and 1,4-content of the conjugated diene, and the desired physical properties for the polymer produced. In general, the amount of initiator utilized may vary from as little as 0.2 millimole of lithium per 100 grams of monomers up to about 100 millimoles of lithium per 100 grams of monomers, depending upon the desired polymer molecular weight (typically 1,000 to 100,000,000 number average molecular weight). [0023] The polymerizations of the present invention may be conducted in an inert solvent and would consequently be solution polymerizations. The term “inert solvent” means that the solvent does not enter into the structure of the resulting polymer, does not adversely affect the properties of the resulting polymer, and does not adversely affect the activity of the catalyst employed. Suitable inert solvents include hydrocarbon solvents which may be contain aliphatic, aromatic or cycloaliphatic hydrocarbons such as hexane, pentane, toluene, benzene, cyclohexane and the like. Ethers such as tetrahydrofuran and tertiary amines such as triethylamine and tributylamine may also be used as solvents, but these will modify the polymerization as to styrene distribution, vinyl content and rate of reaction. The preferred solvents are aliphatic hydrocarbons and of these solvents, hexane is particularly preferred, including blends and mixtures of hexanes, e.g., linear and branched, including such things as cyclohexane alone or mixed with other forms of hexane. [0024] Polymerization conditions such as temperature, pressure and time are well known in the art for polymerizing the monomers as described with the anionic initiator as described. For example, for illustrative purposes only, the temperature employed in the polymerization is generally not critical and may range from about −60° C. to about 150° C. Preferred polymerization temperatures may range from about 25° C. to about 130° C. for a polymerization time of a few minutes to up to 24 hours or more, and employing pressures generally sufficient to maintain polymerization admixtures substantially in the liquid phase, preferably at or near atmospheric pressure, depending on the temperature and other reaction parameters. Polymerization of any of the above-identified monomers in the presence of an organolithium initiator results in the formation of a “living” polymer. The lithium proceeds to move down the growing chain as polymerization continues. Throughout formation or propagation of the polymer, the polymeric structure may be anionic and living. In other words, a carbon anion is present. A new batch of monomer subsequently added to the reaction can add to the living ends of the existing chains and increase the degree of polymerization. A living polymer, therefore, may include a polymeric segment having an anionic reactive end. Reference to anionically polymerized polymers or anionically polymerized living polymers refers to those polymers prepared by anionic polymerization techniques. [0025] In order to promote randomization in copolymerization and to control vinyl content, one or more modifiers may optionally be added to the polymerization ingredients. Amounts range from between 0 and about 90 or more equivalents per equivalent of lithium. Compounds useful as modifiers are typically organic and include those having an oxygen or nitrogen heteroatom and a non-bonded pair of electrons. Examples include dialkyl ethers of mono and oligo alkylene glycols; crown ethers; tertiary amines such as tetramethyethylene diamine (TMEDA); tetrahydrofuran (THF), THF oligomers linear and cyclic oligomeric oxolanyl alkanes and the like. Particular examples of these modifiers include potassium t-amylate and 2,2′-di(tetrahydrofuryl) propane. These modifiers are further described in U.S. Pat. No. 4,429,091, the disclosure of which in incorporated by reference. [0026] Polymerization is begun by charging a blend of the monomer(s) and solvent to a suitable reaction vessel, followed by the addition of the modifier(s) and the initiator solution previously described. The procedure is carried out under anhydrous, anaerobic conditions. The reactants may be heated to a temperature of from about 23° C. to about 120° C., and are typically agitated for about 0.15 to about 24 hours. [0027] After polymerization is complete, the product is removed from the heat and terminated with the functional reagents of the present invention as is conventionally done in the art, although termination could also be done without removal of heat. Prior to terminating the polymerization reaction with the functional end groups, a coupling agent may be added to the polymerization reaction to increase the Mooney viscosity to a desired range. Tin coupling agents such as tin tetrachloride (SnCl 4 ) are well known in the art and may be added in varying amounts, typically in amounts of 0 to about 0.9 mole equivalents functionality per each mole equivalent of anionic initiator depending upon the desired Mooney viscosity of the polymer. [0028] The functional reagents reacted with the polymer are trialkyl or triarylsiloxy iminosilanes having the formula [0000] [0000] wherein R 1 to R 6 are C 1 to C 20 alkyl or aryl groups, optionally containing heteroatoms or functional groups, and x is equal to or greater than 1, and n is between 1 and 3. Typical heteroatoms may include N, O, and Si, and typical functional groups may include Cl, F, and Br. 3-(1-methylethylidene)aminopropyltris(trimethylsiloxy)silane is especially preferred as the iminosilane. [0029] Optionally, upon termination, the functional terminated polymer could be quenched, if necessary, and dried. Quenching may be conducted by contacting the siloxane terminated polymer with a quenching agent for about 0.05 to about 2 hours at temperatures of from about 30° C. to about 120° C. to insure complete reaction. Suitable well known quenching agents include alcohols, water, carboxylic acids such 2-ethylhexanoic acid (EHA), acetic acid and the like. Alternative to, or in combination with, the step of quenching, the siloxy silane terminated polymer may be drum dried as is well known in the art. The use of steam or high heat to remove solvent is also well known in the art. [0030] An antioxidant such as 2,6-di-t-butyl-4-methylphenol or butylated hydoxy toluene (BHT) may be added in solvent (hexane) solution, as is well known in the art. The antioxidant reduces the likelihood that Mooney viscosity instability is due to oxidative coupling. [0031] The functionalizing agent is typically present in a molar ratio of about 0.25 to 2, and preferably about 0.5 to 1 based on moles of polymer. [0032] While polymers produced with a final Mooney viscosity less than 150 are workable, less than 120 is preferred, and less than 100 more preferred. Ideally, 40 to 80 is the most preferred target range. Also, control of Mooney creep over time is one of the real advantages of the present invention. Under normal conditions, Mooney Unit (MU) growth of less than 40, preferably less than 20, and most preferably less than 10, over a storage period of up to two years is preferred. [0033] The invention is further illustrated by reference to the following examples. It will be apparent to those skilled in the art that many modifications, both to the materials and methods, may be practiced without departing from the purpose and scope of the invention. [0034] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Examples Synthesis of 3-(1-methylethylidene)aminopropyltris(trimethylsiloxy)silane [MEAPTTSS] [0035] A dry, nitrogen-purged 250 milliliter (mL) 3-neck round bottom flask was charged with 100 grams (g) (0.284 mol) 3-aminopropyltris(trimethylsiloxy)silane, 15.5 g MgSO 4 (0.128 mol), 100 g (150 mL) dry hexanes, and 23 mL (18.1 g, 0.313 mol, 1.10 equivalents) ACS (American Chemical Society) reagent grade acetone and stirred at room temperature under N 2 overnight (for approximately 18 hours). The milky suspension was filtered under nitrogen using a medium filter frit to remove the hydrated magnesium salts. The resulting clear, colorless solution was transferred to a capped bottle and the residual hexanes were removed by sparging with nitrogen. The product was a clear and colorless liquid. Yield 99 g, 89%. 1 H and 13 C NMR (nuclear magnetic resonance) analyses were performed to confirm product structure. 13 C NMR: 163, 55, 29, 24, 18, 0 ppm. 1 H NMR: 3.1 (t), 2.0 (s), 1.8 (s), 1.6 (m), 0.5 (m), 0.1 (s) ppm. [0036] Sample 1: Synthesis of Trialkylsiloxyiminosilane Terminated Styrene-Butadiene Rubber (SBR) [0037] A 100-gallon (379 liter) reactor was charged with the following: 52.7 kilograms (kg) dry hexanes, 82.4 kg of a 21.8 weight percent solution of 1,3-butadiene in hexanes (17.9 kg, 332.7 mol), and 29.8 kg of a 31.0 weight percent solution of styrene in hexanes (9.2 kg, 88.8 mol). The mixture was stirred and heated to 35° C. When the temperature target was reached, 0.48 kg of a 3 weight percent solution of n-BuLi in hexanes (14.4 g, 0.225 mol), 27 g of a 10 weight percent solution of 2,2′-isopropylidene bis(tetrahydrofuran) in hexanes (0.015 mol), and 15.2 g of a 15 weight percent solution of potassium t-amylate in hexanes (0.018 mol) were added. The reaction temperature reached a peak of 69.2° C. within 2 hours, at which time 44.9 g (0.11 mol, 0.50 equiv) of 3-(1-methylethylidene)aminopropyltris(trimethylsiloxy)silane (MEAPTTSS) was added. The reaction was stirred for 30 minutes, and the sample was removed from the reactor. [0038] Comparative Samples 2 and 3: Synthesis of Alkoxysilane Terminated Styrene-Butadiene Rubber (SBR) [0039] A 100-gallon (379 liter) reactor was charged with the following: 52.7 kilograms (kg) dry hexanes, 82.4 kg of a 21.8 weight percent solution of 1,3-butadiene in hexanes (17.9 kg, 332.7 mol), and 29.8 kg of a 31.0 weight percent solution of styrene in hexanes (9.2 kg, 88.8 mol). The mixture was stirred and heated to 35° C. When the temperature target was reached, 0.48 kg of a 3 weight percent solution of n-BuLi in hexanes (14.4 g, 0.225 mol), 27 g of a 10 weight percent solution of 2,2′-isopropylidene bis(tetrahydrofuran) in hexanes (0.015 mol), and 15.2 g of a 15 weight percent solution of potassium t-amylate in hexanes (0.018 mol) were added. The reaction temperature reached a peak of 69.2° C. within 2 hours, at which time 33.4 g (0.11 mol, 0.50 equiv) of 3-(1,3-dimethylbutylidene)aminopropyltriethoxysilane (DMBAPTS) was added. The reaction was stirred for 30 minutes, and half of the sample was removed from the reactor (sample 2) and the other half was moved to a blend tank (sample 3). In the blend tank, 218 g octyltriethoxysilane (OTES) (0.79 mol, 7 equivalents/Li) was added directly to the polymer cement and stirred at room temperature for 30 minutes. The excess OTES added was used as a Mooney viscosity stabilizing agent for the alkoxysilane functionalized rubber. The first portion of the polymer sample (sample 2) did not contain any stabilizing additives. [0040] The three samples were dried via steam desolvatization and dried in an oven. Aging tests were performed in an ambient atmosphere oven at 70° C. over a period of 7 days. Mooney viscosity measurements were made before and after oven aging. Table 1 illustrates the impact of aging on the Mooney viscosity of the samples. [0000] TABLE 1 Sample # 1 2 3 4 5 6 DMBAPTS/Li 0.5 0.5 0.9 0.9 Ratio MEAPTTSS/Li 0.5 0.9 Ratio Stabilizer OTES OTES Stabilizer/Li 0.0 0.0 7.0 0.0 0.0 7.0 Ratio Initial ML 47.1 84.1 68.4 33.9 84.9 67.2 (1 + 4/100° C.) ML after 52.8 132.0 76.5 44.5 154.7 78.5 Aged 7 days @ 70° C. Δ ML +5.7 +47.9 +8.1 +10.6 +69.8 +11.3 (1 + 4/100° C.) DMBAPTS = 3-(1,3-dimethylbutylidene)aminopropyltriethoxysilane MEAPTTSS = 3-(1-methylethylidene)aminopropyltris(trimethylsiloxy)silane OTES = octyltriethoxysilane [0041] As shown in Table 1, the preparation of living polymers synthesized via anionic polymerization, followed by reaction of the polymer with functionalizing agents such as trialkylsiloxy or triarylsiloxy iminosilanes (MEAPTTSS) demonstrate a significant improvement in controlling the Mooney growth of the polymer after aging. Polymers reacted with MEAPTTSS show superior Mooney viscosity stability growth than polymers terminated with DMBAPTS, even after addition of an excess of the stabilizing agent OTES and at different levels of functionalizing agent added. This demonstrates that polymers reacted with MEAPTTSS have inherently superior aging stability. [0042] Comparative Sample 7: Synthesis of Silane Coupled, Non-Functionalized Styrene-Butadiene Rubber (SBR) [0043] A 100-gallon (379 liter) reactor was charged with the following: 48.6 kilograms (kg) dry hexanes, 81.1 kg of a 21.8 weight percent solution of 1,3-butadiene in hexanes (17.7 kg, 315.5 mol), and 30.3 kg of a 31.4 weight percent solution of styrene in hexanes (9.5 kg, 91.7 mol). The mixture was stirred and heated to 35° C. When the temperature target was reached, 0.45 kg of a 3 weight percent solution of n-BuLi in hexanes (13.5 g, 0.211 mol), 32.6 g of a 10 weight percent solution of 2,2′-isopropylidene bis(tetrahydrofuran) in hexanes (0.018 mol), and 14.0 g of a 15 weight percent solution of potassium t-amylate in hexanes (0.017 mol) were added. The reaction temperature reached a peak of 70.9° C. within 1 hour, at which time 53 g (0.031 mol, 0.59 equiv Si—Cl/Li) of a 10 wt % solution of silicon tetrachloride (SiCl 4 ) in hexanes was added. The reaction was stirred for 30 minutes, moved to a blend tank, and dried using steam desolvatization. This polymer was utilized as a non-functional control for compounding comparison studies. [0000] TABLE 2 Polymer Samples Mixed: properties and composition. Sample # 7 8 9 SBR Polymer Characteristics Wt. Percent Styrene 38.7 36.7 37.3 Percent 1,2- Vinyl Units 31.3 27.5 25.3 ML (1+4/100° C.) 75.8 29.5 46.1 Silane added (equiv./Li) MEAPTMSS — 0.50 0.50 SiCl 4 0.15 — — [0000] TABLE 3 Mixing batch components Materials added phr grams MASTERBATCH Polymer (SBR, examples 7-9) 80.0 121.3 Natural rubber 20.0 30.3 Carbon black 5.0 7.6 Silica 50.0 75.8 Silane coupling agent 5.0 7.6 Black Oil 10.0 15.2 Stearic Acid 2.0 3.0 FINAL MIX Masterbatch 172.0 252.0 Sulfur 1.5 2.2 TBBS 2.5 3.7 DPG 1.4 2.1 6PPD 1.0 1.5 Zinc Oxide 2.5 3.7 Key: Natural Rubber: NR20 grade, SIR20 Carbon Black: High structure N343, HAF Silica: HISIL 190G precipitated silica, PPG Silane coupling agent: EVONIC Si75, bis(triethoxysilylpropyl)polysulfide Black Oil: Modified naphthenic oil, ERGON BO300 6PPD: SANTOFLEX 13 antioxidant (N-1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine TBBS: SANTOCURE NS accelerator, N-tert-butyl-2-benzothiazolesulfenamide DPG: Diphenylguanidine (accelerator) phr—parts per hundred based on polymer [0044] Mixing Procedure (Masterbatch): Into a Brabender mixer, 75 wt. % of the HISIL 190G silica, N343 carbon black and stearic acid were added and mixed for 30 seconds with the SBR polymer. At this point, the black oil, Si75 coupling agent, and the remainder of the silica, black, and stearic acid were added into the mixer. The mixture was mixed until the internal temperature reached 170° C. or 6 minutes total time elapsed. The batch was then passed through a mill preheated to 40° C. with a ¼ inch gap four times, folding between passes, and removed. The batch was let rest for 1 hour before the remill step was performed. [0045] Mixing Cycle (Remill): The Brabender mixer was preheated to 90° C., then charge with the masterbatch contents and mixed until temperature reaches 150° C. The material was removed from the mixer, and the batch was then passed through a mill preheated to 40° C. with a ¼ inch gap four times, folding between passes, and removed. The batch was let rest for 1 hour before the final mixing step was performed. [0046] Mixing Cycle (Final): A Brabender mixer was preheated to 70° C., charged with the masterbatch rubber and the curing ingredients, and mixed until the temperature reaches 110° C. The material was removed from the mixer, and the batch was then passed through a mill preheated to 40° C. with a ¼ inch gap four times, folding between passes, and removed. The cured rubber batch material was then sheeted out and compounded for testing. [0000] TABLE 4 Sample Compounding Analyses Example 7 8 9 Compound ML (1+4/100° C.) 85.2 64.8 81.0 Tensile (MPa) 19.9 15.8 16.0 200% Modulus (MPa) 8.4 8.0 8.8 300% Modulus (MPa) 14.8 14.6 16.4 Elongation (%) 374 316 304 RDA Strain Sweep (5% Strain, 10 Hz) 0° C. G′ 6.55 4.82 4.50 G″ 3.19 1.99 1.82 Tan Δ 0.486 0.414 0.403 65° C. G′ 3.32 2.64 2.86 1st Strain G″ 0.40 0.23 0.25 Tan Δ 0.120 0.088 0.086 Delta G′ 2.040 0.413 0.743 Testing is done using ASTM standards techniques: Mooney viscosity: D-1646; Stress/strain: D-412. Tan delta analyses was performed using a Rheometric Scientific RDAII, at 5% strain and 10 Hz. [0047] The data in Table 4 show that the polymer reacted with the trialkylsiloxyiminosilane MEAPTTSS has superior hysteresis properties (Tan Δ) in rubber formulation than non-functionalized polymers, while retaining comparable physical properties (tensile strength, modulus, and elongation at break) without the accompanying Mooney growth issues observed with alkoxysilane terminated SBR polymers. [0048] The stabilized polymers and methods of the present invention can be used separately with other equipment, methods and the like, to produce various elastomeric materials or compounds suitable for use in the production of various articles including pneumatic tires and the like, especially in the tread and sidewall portions of the tires. Thus, the scope of the invention shall include all modifications and variations that may fall within the scope of the attached claims. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Methods of making polymers by polymerizing conjugated diolefin in a hydrocarbon solvent in the presence of an initiator are described. Trialkyl or triaryl siloxy iminosilane functionalizing agents are reacted with the polymer, followed by desolvatizing the polymer. The resulting polymer not only has good filler interaction and processability, but results in a polymer with stable Mooney viscosity. A polymer made by the process of the present invention, including silica, and carbon black fillers, and rubber compositions, and tires containing side walls and treads containing the polymers are also described.

FIELD OF THE INVENTION [0001] The present invention relates generally to improvements to tracking the direction of an item by laser bar code scanners. More particularly, the present invention relates to methods and apparatus for determining the direction of a moving item by utilizing a bar code scanner to sense the dark to light and light to dark video transitions of the item's packaging. BACKGROUND OF THE INVENTION [0002] Bar code scanners typically operate by using a motor and pattern mirrors to scan a light beam across a label surface and measuring the reflected light. The light beam is generated by a laser, usually a laser diode, and associated optics. The reflected light returns along the incident path and is focused onto a photodetector. The photodetector converts this collected light energy into an electrical signal. This electrical signal is processed by analog electronics, converted to a digital signal, and further processed by digital electronics, usually including a processor and associated firmware. [0003] The processor receives a stream of bar code label data including whatever has passed within the range of the laser or light beam, including complete and partial label data. The processor, under control of programming typically stored in firmware, attempts to piece together partial bar code label data or bar code fragments (“partials”) in order to decode a bar code label, ignore multiple reads of the same item, and perform other tasks. The information received can be ambiguous and otherwise difficult to interpret, for a number of reasons. For example, scanners may have difficulty reading a bar code due to its position on the item relative to the light beam. Typically, the firmware attempts to avoid a multiple read problem by requiring a relatively long delay between good reads of bar code label on identical items. This reduces scanning throughput, and is therefore presently a necessary but undesirable solution. [0004] Another approach to eliminating duplicate scans involves utilizing item gates implemented utilizing of a light emitting diode (LED) and photocell pair at the entry and exit of a scan zone. A bar code scanner utilizing this approach would detect an item entering and exiting the scan zone when the light from the entry and exit LEDs were blocked and unblocked by the item. This approach had many failings including inaccurate readings. For example, an item might not block enough of the light from the LEDs to trigger an item gate and, thus, the scan of the item would be rejected and the operator would be required to re-scan the item. Additionally, this solution requires additional hardware utilized only for the specific purpose of addressing the duplicate scan problem, thus, adding to the cost of the bar code scanner. [0005] Another conventional approach to eliminating duplicate scans, as described in Blanford et al., U.S. Pat. No. 6,347,741, assigned to the assignee of the present invention and incorporated herein by reference in its entirety, involves utilizing motor positional information to determine the location of a bar code at any given time to determine if an item has left the scan zone. Despite its advantages, this solution requires that the bar code label be seen more or less continuously through the scan zone which does not happen on many scans due to the location or small size of bar codes currently in use. SUMMARY OF THE INVENTION [0006] Methods, computer readable medium, and apparatus for tracking the direction of a moving item by laser bar code scanners are disclosed. According to one aspect of the invention, the method may suitably include the following steps at a first sample in time. These steps include sensing video transitions reflected off packaging graphics of the moving item by a pair of scan planes, counting the number of video transitions sensed by each scan plane of the pair of scan planes, and determining if the moving item intersects each of the scan planes by comparing the counted number of video transitions for each scan plane of the pair with a predetermined threshold at the first sample. At a second sample in time, the above steps are repeated and the method includes the additional step of evaluating the change in how the item intersects the scan plane pair at the second instance in time in order to set a moving indicator to reflect the direction of the moving item. [0007] Among its several advantages, the present invention samples video transitions reflected off packaging graphics of a moving item sensed at a pair of scan planes at different times, and these samples are used to determine the direction of the moving item. One application of the present invention is providing an improved solution to the problem of double scanning an item. [0008] A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following Detailed Description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 illustrates an exemplary multiple window scanner capable of tracking the direction of an item in accordance with the present invention. [0010] FIGS. 2A and 2B (collectively FIG. 2 ) illustrate details of internal components and circuitry of the scanner shown in FIG. 1 . [0011] FIG. 3 shows further details of the video circuit of FIG. 2 used to collect interval data words to carry video transition information in accordance with the present invention. [0012] FIGS. 4A, 4B , and 4 C (collectively FIG. 4 ) is a flowchart illustrating a method for determining the direction of travel of an object as it passes through a scan volume in accordance with the present invention. [0013] FIG. 5 is a flowchart illustrating a further method employing the results of the method of FIG. 4 to eliminate a duplicate scan in accordance with the present invention. DETAILED DESCRIPTION [0014] FIG. 1 illustrates an exemplary multiple window scanner 100 capable of tracking the direction of an item in accordance with the present invention. The scanner 100 has a horizontal scan window 102 and a vertical scan window 104 . The scanner 100 generates a scanner signal based on light reflected from an object, such as object 106 , passing within the field of view of one or both of the windows 102 and 104 . In this illustrated example, item 106 passes through a first scan plane 110 and a parallel second scan plane 112 both emitted from the vertical scan window 104 . Parallel scan planes 110 and 112 are separated by a distance, 114 , of approximately one inch. The volume of space defined between parallel scan planes 110 and 112 is a scan zone. It should be noted that although only two parallel scan planes are shown for ease of illustration and purposes of discussion, many parallel scan plane pairs may be, and typically will be, emitted from both the vertical scan window 102 and the horizontal scan window 104 . [0015] Each of the scan planes 110 and 112 is produced by the tracing of a scan beam along a path determined by the rotation of a spinner 233 ( FIG. 2 ) within the scanner 100 . As the item 106 passes across scanner 100 from right to left in a normal scanning motion within the field of view of the scanner windows 102 and 104 , the item 106 first intersects the scan plane 110 , then, intersects both scan planes 110 and 112 , then, intersects scan plane 112 , and, finally, no longer intersects either scan plane 110 and 112 . During the time that the item 106 is intersecting either scan plane 110 , 112 , or both, light is being reflected back by item 106 's packaging graphics into the scanner 100 . Packaging graphics are generally located on all sides of an item, and scanner 100 senses changes in reflection from the light or dark areas found on such packaging, and evaluates said changes to recognize the presence and direction of travel of the item without reading a bar code as will be described in further detail below. [0016] Edge information relating to the number of video transitions, transitions from light to dark and dark to light, reflected by item 106 's packaging graphics and into the scanner 100 can be determined in accordance with the teachings of the present invention. As will be addressed in connection with the discussion of FIG. 4 , video transitions of scan plane pairs can be used to determine the direction an item is moving. As item 106 passes through scan planes 112 and 110 video transitions or activity will be seen by scanner 100 at these scan planes. As item 106 leaves the scan zone, the trailing edge of item 106 will pass beyond scan plane 110 , causing a decrease in video transitions from scan plane 110 while continuing to cause video transition from scan plane 112 , indicating that the item is leaving the scan zone in the right-to-left direction of FIG. 1 . It should be noted that when an object 106 passes from right to left in FIG. 1 , this movement will be considered generally as the forward direction by convention. Similarly, when an object 106 passes from left to right in FIG. 1 , this movement will be considered as the backward direction by convention. [0017] Additionally, if a bar code is detected on the item 106 from scan planes 110 , 112 , or any other scan planes, the direction of travel at the time of which the bar code is detected can also be noted. As will be addressed in connection with the discussion of FIG. 4 , this information can be utilized to improve scanner accuracy and scanning throughput. [0018] For example, a scanner, according to the teachings of the invention, can utilize an evaluation of video transitions from package graphics to determine that a first item has passed through the scan zone from the entry side, for example scan plane 110 , through to the exit side, for example scan plane 112 , and that the first item did not re-enter the scan zone from the exit side. If a second item enters the scan zone at the entry side, the scanner can determine that it is a new item and not the same item as the first item by discriminating between forward and backward travel. Consequently, even if the two similar items contain the same bar code label information, the scanner will determine that the second item is a new item and be able to register the second scan without the use of long time-outs to prevent double scans of the same item. Similarly if the first item reenters the scan zone from the exit plane, re-scanning of its already read bar code can be prevented. [0019] FIG. 2 ( FIGS. 2A and 2B collectively) illustrates internal components and circuitry of scanner 100 . The scanner 100 includes an ASIC 212 . ASIC 212 includes a quiescent register 213 , an interval count register 211 , a video circuit 217 , and a microprocessor 219 under the control of code or firmware 215 according to the teachings of the present invention. The video circuit 217 is discussed in greater detail below in connection with FIG. 3 . The operation of microprocessor 219 and the code 215 according to the teachings of the present invention will be discussed in greater detail in connection with FIGS. 4 and 5 . [0020] The quiescent register 213 contains a predetermined threshold value of video transitions. A count of transitions above this predetermined threshold value indicates the presence of an object intersecting first scan plane 110 . Interval count register 211 maintains a count of video transitions or intervals as described below for first scan plane 110 when an object, such as item 106 , intersects first scan plane 110 . Preferably, there is a register pair, referred to as an activity register pair, containing a quiescent register and a count register for each scan plane in the system. However, the teachings of the present invention also contemplate a global quiescent register shared for all scan planes. For ease of illustration, a first activity register pair 211 , 213 is shown for scan plane 110 and a second activity register pair 221 is shown for scan plane 112 . [0021] The illustrated scanner 100 also includes a scale assembly 226 on which an object such as a variable mass product 221 , such as a bag of produce, may be placed for weighing. Scale assembly 226 then supplies weight information to ASIC 212 . [0022] Scanner 100 may also suitably include scale display and communication circuit 218 , first peripheral communication circuit 220 , second peripheral communication circuit 222 , scale communication to host terminal circuit 224 , and scanner/scale communication to host terminal circuit 226 , each of circuits 218 - 226 furnishing signals to ASIC 212 , the signal from each of circuits 218 - 226 first passing through plane conditioner 228 . [0023] ASIC 212 also furnishes a laser control signal to a laser 229 . It also furnishes motor control commands to a motor 230 . The motor 230 includes a motor shaft 231 which is attached to an optical assembly 232 . The assembly 232 may suitably include fixed mirrors or other optical components (not shown in detail), mounted so as to rotate on a spinner 233 . As the motor 230 is driven in response to signals from the ASIC 212 , spinner 233 is moved by motor 230 . As light is emitted from laser 229 , the light is reflected by assembly 232 to an optical basket which directs the light into one or more sets of parallel scanning planes so as to strike the item 106 as the item 106 crosses one or more of the scanning planes. It is presently preferred that the present invention be implemented as an upgrade to an NCR model 7875 bi-optic scanner, but it will be recognized that the present invention may be advantageously utilized as an upgrade for a wide variety of scanners for which it is desired to track the direction of an item including single scan window scanners, or as part of a newly developed scanner product. [0024] When light strikes item 106 , the light is reflected back to optical assembly 232 , collected and passed to an analog video preprocessing circuit 252 , which provides VIDEO 0 signals to ASIC 212 . Scanner 100 also preferably includes capabilities for sound generation, including sound output circuit 248 and speaker 250 . Scanner 100 also includes random access memory (RAM) 244 and read only memory (ROM) 246 for storing code 215 . [0025] A data bus passes between ASIC 212 , RAM memory 244 , ROM memory 246 and sound output circuit 248 . An address and control bus also passes between ASIC 212 , RAM memory 244 , and ROM memory 246 . [0026] Scanner 100 produces tones and generated voice sounds in order to communicate with an operator and to provide operator feedback. Sound output circuit 248 receives signals from ASIC 212 for instructions on what sounds to generate and when, and accesses data from RAM 244 and ROM 246 for the generation of sounds. The sounds are passed to speaker 250 . [0027] FIG. 3 is a diagram illustrating further details of an implementation of the video circuit 217 of FIG. 2 which may be suitably used to count video transitions and read bar codes in accordance with the present invention. Video circuit 217 includes interval width counter 302 , edge detector 304 and prebuffer 308 . The prebuffer 308 includes a flags prebuffer 308 a and an intervals prebuffer shift register 308 b . Video circuit 217 further includes a timestamp (Tstamp) prebuffer shift register 310 , interval sums 314 , a multiplexer 318 , UPC filter 320 and an interval first in first out (FIFO) circuit 322 . [0028] In operation, video circuit 217 receives a video input, which is routed into the edge detector 304 . Edge detector 304 produces a shift clock output which is supplied to the flags prebuffer shift register 308 a and the Tstamp prebuffer shift register 310 . The shift clock output is also supplied to the interval width counter 302 as a reset input. Edge detector 304 causes interval width counter 302 to be started on a video transition, a 12-bit signal INT which represents value and video polarity of the interval. The signal INT is shifted into the intervals prebuffer shift register on the next transition of the video signal, which also resets interval width counter 302 , thus starting the timing of the next video interval. These video intervals represent the time interval of a dark or light portion of a packaging graphic of an item, such as the item 106 . These video intervals will also represent the widths of bars and spaces making up a bar code on the item 106 being scanned. [0029] At the same time, a time stamp signal, which represents a 10-bit timestamp and four least significant bits of a motor revolution counter are shifted into the time stamp prebuffer shift register 310 . Thus, the time duration of each video interval, the polarity and the time relationship to a motor position is captured for each video transition. Since each scan plane is read based on the rotation and position of motor 230 , a scan plane is denoted by its associated time stamp. For example, timestamp values 1-10 may correspond to scan plane 1 , timestamp values 11-20 may correspond to scan plane 2 , and so on for as many scan planes as are utilized in scanner 100 . A scan plane table reflecting this relationship between time stamp values and associated scan plane values preferably is stored in ROM 246 . Furthermore, each interval captured by a scan plane contains an associated time stamp. By separately counting each interval having a time stamp associated with a scan plane, the number of intervals captured for a particular scan can be determined by microprocessor 219 . Separately counting each interval for a particular scan plane is discussed further below in connection with FIG. 4 . [0030] The video intervals are also sent through interval sum circuit 314 and filter circuit 320 , which determine if the video data stream meets predetermined timing relationships to indicate that the video data stream represents valid bar code data. For example, if the time interval between the beginning and end of the video data is too long, the data did not come from a valid scan of a bar code, and will be marked as an invalid bar code time interval. However, for video transition counting, both valid and invalid intervals are forward to interval FIFO 332 . Similarly, if the time interval between a start and stop character of a bar code is too short, the scan will be marked as an invalid bar code time interval. The beginning and end of legitimate bar code data are marked by setting flag bits in the flags prebuffer shift register 308 a to demarcate valid bar code intervals for subsequent decoding. The flag bits are then added to the corresponding interval data word stored in intervals prebuffer shift register 308 b . The flags are used by the microprocessor 219 to determine which intervals are bar code intervals in order to decode a corresponding bar code. The time stamp value corresponding to a time interval is also written into interval FIFO circuit 332 with each 32 bit interval data word. Each interval data word is forwarded to microprocessor 219 for counting and, if the interval data word reflects a bar code interval, decoding as well. [0031] Microprocessor 219 , when executing code 215 , processes each interval data word on an interval by interval basis. With each interval data word received, microprocessor 219 reads the time stamp carried in the interval data word, looks up an associated scan plane from the time stamp in the scan plane table stored in ROM 246 , and increments an interval count register associated with the scan plane such as interval count register 211 for scan plane 110 . Microprocessor 219 processes interval data words for all scan planes in one revolution of motor 230 . At the end of each motor revolution, microprocessor 219 , under the control of code 215 , compares the value of each interval count register with its associated quiescent register to determine if activity exists on the corresponding scan plane. If the value of the interval count register is equal to or greater than the quiescent register value, activity is said to be present on the corresponding scan plane. If the quiescent register value is less than its associated interval count register value, the quiescent register value may be modified to reflect the lowest value of its associated interval count register in order to take into account different characteristics of individual scan planes such as their position and angle with respect to a scan window. [0032] FIG. 4 ( FIGS. 4A, 4B , and 4 C collectively) is a flowchart illustrating a method 400 for determining the direction of movement of an object in accordance with the present invention. At step 405 , the method checks whether a monitor indicator is set. This indicator is used to indicate that a pair of scan planes have sensed activity in a previous revolution of motor 230 . This step 405 is used in order to make at least two samples of activity on a particular scan plane pair. A comparison of at least two samples of activity allow for the method to deduce the direction of a moving object as will be discussed below. If the monitor indicator is not set, a first sample has not yet been established. Thus, method 400 proceeds to step 410 where activity for each scan plane pair is determined. As mentioned above, activity on a particular scan plane is determined by comparing the value of its corresponding interval count register with its associated quiescent register. At step 415 , it is determined whether there is a scan plane pair where activity exists for one scan plane and no activity exists for its corresponding paired scan plane. Such a scan plane pair would indicate that an object has intersected one scan plane but has not yet intersected the corresponding scan plane. If there is such a scan plane pair, the method proceeds to step 420 to select that scan plane pair to be monitored. At step 425 , a monitor indicator is set to watch the activity of the selected pair in the next motor revolution. [0033] Additionally, a position pair indicator is set to indicate whether the first or second scan plane of the select pair has activity. In the present embodiment, the first scan plane is defined as the scan plane, such as scan plane 110 , which would first be intersected when the object is moving in a forward direction. At step 430 , method 400 waits for the next motor revolution before transitioning back to step 405 . Additionally, step 430 will clear interval count registers associated with each scan plane in order for another scan plane pair to sense the direction of the object in a subsequent motor revolution. Returning to step 415 , if there is no scan plane pair where activity exists on one scan plane while no activity exists on the other, method 400 proceeds to step 430 to wait for the next motor revolution before returning to step 405 . Although video transitions are collected at a first scan plane, such as scan plane 110 , before a second scan plan, such as scan plane 112 due to the rotation of the motor, it will be recognized for the purposes of this invention that the first and second scan planes are sampled at the same time such as at the end of a motor revolution. [0034] Returning to step 405 , if the monitor indicator is set, method 400 has already established a pair of scan plane pairs to take a second sample of activity in order to determine direction of the object and proceeds to step 435 . At step 435 , it is determined if there is current activity on both scan planes composing the selected pair. If there is, method 400 proceeds to step 440 where it is determined whether the position indicator indicates that the first scan plane indicated activity in a previous motor revolution as well. If the position indicator does so, method 400 proceeds to step 445 . At step 445 , a determination is made that the object in a previous motor revolution intersected the first scan plane and now currently intersects both the first and second scan plane. Consequently, step 445 sets a moving indicator to indicate an object is moving in the forward direction. Method 400 then proceeds to step 453 where the monitor indicator is cleared. In so doing, the direction of an object may be located by it intersecting a different set of scan plane pairs in a subsequent motor revolution. Method 400 then proceeds to step 430 to wait for the completion of the next motor revolution. At step 430 , method 400 clears the interval count registers corresponding to scan planes are cleared and the method waits for the next motor revolution to complete before transitioning to step 405 . [0035] Returning to step 440 , if the position indicator does not indicate that the first scan plane in a previous motor revolution had activity, the second scan plane according to step 425 in the previous motor revolution must have had activity. This result means that an object in a previous motor revolution intersected the second scan plane and now in the most recent motor revolution intersects both the first and second scan plane. At step 450 , the object is moving in the backward direction. Consequently, step 450 sets the moving indicator to indicate the object is moving in the backward direction. Method 400 then proceeds to step 453 where the monitor indicator is cleared to allow another pair of scan planes to monitor the direction of the object in the next motor revolution as the object continues to move. [0036] Returning to step 435 , if there is no current activity on both scan planes composing the selected pair, method 400 proceeds to step 455 . At this point in method 400 , the object intersected one scan plane from the selected pair in a previous motor revolution and, during the most recent motor revolution, the object intersects with either the first scan plane, the second scan plane, or neither the first or second scan planes. Each of these three scenarios is addressed in the remaining steps. At step 455 , it is determined if there is no activity on either scan plane in the select scan plane pair. Step 455 may be accomplished by comparing the corresponding interval count registers with their associated quiescent register. If there is no activity on either scan plane, method 400 proceeds to step 460 . At step 460 , it is determined if the position indicator indicates that the first scan plane had activity in a previous motor revolution. If it has, the object in a previous motor revolution intersected with a first scan plane and now, in the most recent motor revolution, the object does not intersect in either of the scan planes in the selected scan plane pair. In step 450 , the moving indicator is set to indicate that the object is moving in the backward direction. If the position indicator does not indicate that the first scan plane had activity in a previous motor revolution, step 460 , the second scan plane must have had activity in the previous motor revolution. At this point, the object, in the previous motor revolution, has intersected with the second scan plane and, now, in the most recent motor revolution, does not intersect with either the first or second scan plane. Thus, method 400 proceeds to step 445 to set the moving indicator to indicate that the object is moving in the forward direction. [0037] Returning to step 455 , if there is activity on one of the first or second scan planes, method 400 proceeds to step 465 to determine which scan plane has current activity to the exclusion of the paired scan plane. At step 465 , it is determined if there is current activity on the first scan plane. If there is, method 400 proceeds to step 470 . At step 470 , it is determined if the position indicator indicates that the first scan plane from a previous motor revolution indicates activity. If it does, then in both a previous motor revolution and in the most current motor revolution, there has been activity on the first scan plane and no activity on the second scan plane. This scenario may result if a clerk holds the object still over a scanning window or sets it down on the scanning window. Since movement cannot be determined yet, method 400 proceeds to step 430 to wait for the next motor revolution to analyze the activity register pairs. If the position indicator does not indicate that the first scan plane had activity in a previous motor revolution, an object intersected the second scan plane in the previous motor revolution, and now currently intersects the first scan plane in the present motor revolution. Consequently, method 400 proceeds to step 450 to set the movement indicator to indicate the object is moving in the backward direction. [0038] Returning to step 465 , if there is no activity on the first scan plane and since step 455 has determined that there is activity on one of the scan planes of the selected scan plane pair, there is current activity on the second scan plane and the method 400 proceeds to step 475 . At step 475 , it determined if the position indicator indicates that the first scan plane had activity in a previous motor revolution. If so, the object intersected with the first scan plane in the previous motor revolution and, now, in the current motor revolution, the object intersects with the second scan plane and not the first scan plane. Thus, method 400 proceeds to step 445 to set the moving indicator to indicate that the object is moving in a forward direction. Returning to step 475 , if the position indicator does not indicate that the first scan plane in a previous motor revolution had activity, there was activity on the second scan plane in the previous motor revolution and there is current activity in the present motor revolution on the second scan plane. This scenario can occur if a clerk holds an object still which intersects the second scan plane of the selected scan plane pair. Since no movement can be inferred at this point, method 400 proceeds to step 430 to await the next motor revolution to analyze the selected activity register pairs. [0039] FIG. 5 is a flowchart illustrating a method 500 for utilizing the results of method 400 of FIG. 4 to eliminate a duplicate scan in accordance with the present invention. When processor 219 processes interval words which have been marked as valid bar code intervals as described in connection with the discussion of FIG. 3 , processor 219 performs the steps of method 500 by executing the instructions in code 215 . At step 510 , interval words marked as valid bar code intervals are decoded and the monitor indicator of FIG. 4 is sampled and temporarily stored with the decoded bar code. At step 515 , the decoded bar code is compared with the last decoded bar code. If they are different, method 500 proceeds to step 520 where the decoded bar code is allowed to proceed further in a known overall itemization process. Additionally, at step 520 , a lockout timer is set. The lockout timer defines a window of time outside of which a scan of the same bar code will be allowed. The lockout time may be viewed as a backup feature to ensure that rescanning is detected in case the scan direction cannot be determined such as the step sequence 470 to 430 and the step sequence 475 to 430 . A typical value for a lockout timer is around 1.0 seconds. If the scan direction of either a first or second reading of an item with the same bar code cannot be determined, the lockout timer will reject the second reading of the item with the same bar code as long as the timer has not expired. [0040] If, at step 515 , it is determined that the decoded bar code is the same as the last decoded bar code, method 500 proceeds to step 525 . At step 525 , the current movement indicator is read to see whether it indicates movement in the forward direction. If it does, method 500 proceeds to step 540 . At step 540 , method 500 determines whether the last decoded bar code was also traveling in the forward direction. If it was, method 500 the last decoded bar code and the current decoded bar code are traveling in the same forward direction. Since a rescan typically occurs in the opposite direction of the initial scan, method 500 interprets the currently decoded bar code as an additional item and proceeds to step 520 to allow the decoded bar code to proceed further in the itemization process without waiting for a timer to expire. Consequently, scanning throughput is increased. [0041] Returning to step 540 , if the last decoded bar code was traveling in the backward direction, the direction opposite of the currently decoded bar code, method 500 proceeds to step 535 . At step 535 , method 500 determines whether the lockout timer has expired. If it has, method 500 proceeds to step 520 to allow the currently decoded bar code to proceed further in the itemization process. By way of example, this situation may occur if a clerk holds two of the same item, one in each hand, and scans the first item in the forward direction. The clerk then scans the second item in the backward direction. If the timer has not expired, method 500 proceeds to step 545 and precludes the decoded bar code from proceeding further in the itemization process. [0042] Returning to step 525 , if the decoded bar is traveling in the backward direction, method 400 proceeds to step 530 . At step 530 , method 500 it is determined if the last decoded bar code was traveling in the forward direction. If it is not, method 530 proceeds to step 520 to allow the decoded bar code to proceed further in the itemization process. [0043] If the last decoded bar code was traveling in the forward direction, method 500 proceeds to step 535 . At step 535 , method 500 determines if the lockout timer has expired. If it has not, method 500 proceeds to step 520 to allow the currently decoded bar code to proceed further in the itemization process. By way of example, a clerk may have initially passed the item in the backward direction (step 525 -→step 530 ) which correctly read the bar code. The clerk, recognizing the item was scanned in the backward direction, places that item in a bag. Subsequently, the clerk scans a second and similar item in the forward direction (step 530 -→step 535 ). Since the clerk spent time putting the first item in a bag the lockout timer expires allowing scanner 100 to interpret the bar code of the second item as a second item to be itemized. [0044] If the lockout timer has not timed out, method 500 proceeds to step 545 where the currently decoded bar code is not allowed to continue with the itemization process and the lockout timer is restarted. By way of example, this situation occurs if a clerk scans the item in the backwards direction and unknowingly attempts to re-scan the same item in the forward direction. [0045] It should be noted that the indicators described in FIGS. 4 and 5 may be implemented as flags in RAM 244 or in separate registers in ASIC 212 . Furthermore, although FIG. 5 describes an application of the present technique of tracking the direction of a moving item, the present invention contemplates other scanning applications utilizing the teachings of the present invention. [0046] The foregoing process will be illustrated by the following examples. A clerk may hold two of the same items, one in each hand. The clerk would sequentially scan the two items in the same direction. Since the second item is proceeding in the same direction as the first item, both bar codes associated with these two items will be itemized regardless of how fast the clerk can move his or her hands in the same direction. Second, a clerk may have to scan eight individual cans of beans, for example. The clerk can use both hands and scan two cans at a time in the same direction. Since all scans were performed in the same direction, all eight cans will be properly itemized. Many other examples may be advantageously addressed by the present invention. [0047] While the present invention has been disclosed in the context of various aspects of presently preferred embodiments, it will be recognized that the invention may be suitably applied to other environments consistent with the claims which follow.

Methods, computer readable medium, and apparatus for tracking the direction of a moving item by laser bar code scanners are disclosed. In particular, the method includes the following steps at a first sample in time. Those steps include sensing video transitions reflected off packaging graphics of the moving item by a pair of scan planes, counting the number of video transitions sensed by each scan plane of the pair of scan planes, and determining if the moving item intersects each of the scan planes by comparing the counted number of video transitions for each scan plane of the pair with a predetermined threshold at the first sample. At a second sample in time, the above steps are repeated and the method includes the additional step of evaluating the direction of movement of the moving item from changes observed from the first sample and the second sample.

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is a Continuation of U.S. patent application Ser. No. 12/848,877, which is the National Phase of International Patent Application No. PCT/NL2006/050075, filed Apr. 6, 2006, which claims the benefit of U.S. Provisional Application No. 60/751,632, filed Dec. 20, 2005. The contents of these applications are herein incorporated by reference in their entirety. FIELD OF THE INVENTION The invention relates to gelatin comprising films on which cells can be or are cultivated. In particular the invention relates to such films that are used to treat wounds, such as severe burns or physical or chemical injury of the skin or wounds caused by diseases. The invention also related to methods for producing such films and the use of such films. In a further aspect of the invention human artificial skin grown on such films are provided, and methods of making these. BACKGROUND Films on which cells are cultured are used in the treatment of skin wounds such as for example wounds caused by severe burns or mechanical or chemical injuries or in diseases where extensive loss of skin occurred. In cases of acute extensive skin loss treatment generally involves two phases. In the first phase the requirements for a film material are directed towards short term requirements such as controlling moisture flow through the wound and shielding from infectious agents. In the second stage long term effects are considered such as non-antigenicity, and skin regeneration. Development of such materials is in the direction of multilayer materials of increasing complexity as described in, for example, EP 0 686 402, WO 03/101501. Many patent applications disclose the use of porous collagen or gelatin matrices or sponges that require the formation of collagen fibrils and forming of a porous network, for example by freeze drying, before crosslinking the porous matrices as in for example EP 0 177 573, EP 0 403 650, EP 0 403 650, EP 0 411 124, EP 0 702 081, U.S. Pat. No. 4,016,877 and U.S. Pat. No. 4,294,241. In applications for wound treatment fibroblast and keratinocyte layers are cultured on a collagen or gelatin matrix. In such cultures the fibroblast cells and/or keratinocyte cells are usually actually embedded in the matrix material, due to the porous nature of the collagen or gelatin matrix. EP 0 243 132 describes culturing of fibroblasts on an insoluble collagen film and the subsequent culturing of keratinocytes on top of the fibroblast layer, but has as a drawback that the fibroblast and keratinocyte layers are in contact. WO 80/01350 discloses production of a living tissue by culturing keratinocytes on a collagen layer in which fibroblasts are imbedded, but this also means that the fibroblast layer and the keratinocyte layers are in contact. WO 91/16010 describes a complex material based on a non-porous collagen gel that is stabilized by iodine and which is laminated on top of a porous collagen sponge containing fibroblasts. Keratinocytes are cultured on top of the stabilized collagen gel. The porous collagen sponge is crosslinked to prevent too fast biodegradation. Use of recombinant collagen or gelatin is disclosed in e.g. WO 00/09018 but describes the formation of crosslinked sponges of collagen fibrils. WO 04/78120 also discloses porous structures from recombinant collagen. Films are also used to test for example allergic reactions to topical applications comprising medicines, pharmaceuticals or cosmetics. In spite of the above described materials there remains a need for alternative films for culturing cells that are suitable for treatment of wounds involving the loss of skin. SUMMARY OF THE INVENTION It is an object of the invention to provide a film suitable for making a human artificial skin equivalent and a method for making such a skin equivalent. It is especially an object to provide a film which enables rapid growth of autologous cells on it surfaces and which enhances cell attachment (adhesion) to the film and cell-to-cell binding of the autologous cells. More specifically it is an object to provide a full equivalent of human skin. It is further an object of the invention to provide a method to produce such a film cheap and efficiently with high speed. Thus it is an object of this invention to provide a non-antigenic film suitable for culturing human and/or mammalian cells of which the biodegradability can be regulated, and particularly it is an objective to provide such a film that is permeable to molecules, including polypeptides and proteins, of up to 25 kilo Dalton. It is also an objective of the invention to provide a film which is suitable as a test substrate for medicines, pharmaceuticals or cosmetics. In particular the effect of compounds contacted with living or viable cells present on the film can be tested. Surprisingly it was found that all these objectives were met by a non-porous film comprising on at least one side thereof a layer comprising living or viable cells and wherein the non-porous film comprises a collagenous polypeptide comprising at least one GXY domain having a length of at least 5 consecutive GXY triplets, wherein X and Y each represent any amino acid and wherein at least 20% of the amino acids of said collagenous polypeptide are present in the form of consecutive GXY triplets, characterized in that the film thickness when placed in demineralized water of 37 degrees Celsius for 24 hours is at most 10 times its initial thickness. The non-porous film preferably comprises a collagenous polypeptide comprising at least one GXY domain having a length of at least 5 consecutive GXY triplets, wherein X and Y each represent any amino acid and wherein at least 20% of the amino acids of said collagenous polypeptide are present in the form of consecutive GXY triplets, characterized in that said film is crosslinked by adding between 0.02 millimol and 5.0 millimol of a crosslinking compound per gram collagenous polypeptide. DESCRIPTION OF THE INVENTION When extensive skin loss occurs, wounds are generally treated in two phases. There remains a need for films that can specifically be matched to the requirements of each treatment phase or more specifically, to the desired biodegradation speed while being sufficiently permeable to compounds that are involved in culturing cells on the film, specifically for compounds that promote growth of cells on both sides of the film. The present inventors found that such films can be made which are matched to the requirements of each treatment phase by careful choice of the swelling behavior and permeability. Swelling behavior is the increase of the initial thickness of a non-porous collagenous polypeptide film when placed in a liquid. In the art it is taught that a pore size of at least 1 micron is necessary to provide enough permeability for compounds involved in wound healing such as nutrients and growth factors, especially when fibroblasts and keratinocytes are present within a matrix or in different matrices, see for example EP-0 702 081 and also the reference in column 4, lines 44-49 therein. The present inventors found, however, that films that are non-porous, or have an average pore-size of less than 1 micron, are capable of taking up water and are permeable for compounds involved in wound healing. Although it was recognized in prior art as early as 1976, or even earlier, that crosslinking is necessary to prevent too fast biodegradation, it was not recognized until now that the degree of crosslinking can be advantageously used to adjust swellability and thus biodegradability and permeability. Thus the use of films of this invention for the preparation of a composition for treating wounds is an aspect of this invention. The films of this invention can be used to match any particular treatment, especially first phase or second phase treatment, by providing a non-porous film comprising on at least one side thereof a layer comprising living or viable cells and wherein the non-porous film thickness increases up to 10 times its initial thickness when placed in demineralized water at 37 degrees Celsius. Depending on the desired permeability or biodegradability the film swells at most 8 times, or at most 6 times or at most 4 times its original thickness in water. Preferably the film swells at least 2 times its original thickness in water. In particular, a method was developed to produce non-porous films having a desired degree of cross-linking and therefore also a desired biodegradation speed and permeability in vivo (after contact with skin wounds e.g. during treatment phase one or two). In one embodiment of the invention films with a desired, predetermined degree of cross linking are non-porous films (suitable for cultivating living or cells on at least one side thereof) comprising a collagenous polypeptide that comprises at least one GXY domain having a length of at least 5 consecutive GXY triplets, wherein X and Y each represent any amino acid and wherein at least 20% of the amino acids of said collagenous polypeptide are present in the form of consecutive GXY triplets. In one embodiment the films according to the invention are crosslinked by adding one or more crosslinking compounds in an amount of between about 0.02 and 5.0 millimol per gram collagenous polypeptide, preferably between 0.1 to 1.0 millimol/g. In another embodiment no cross-linking compound is present, but the (equivalent) degree of cross-linking is achieved by radiation. In yet another embodiment cross-linking is achieved by a combination of radiation and addition of one or more cross-linking compounds. A further advantage of the method and films according to the invention is, that the step of forming fibrils, which is necessary when making porous structures is now obsolete. Further, also the step of freeze drying which is involved in obtaining a porous material is now obsolete, (although both steps may still optionally be carried out) thereby reducing the time and energy that is involved in producing artificial skin and making it possible to produce the non-porous film of this invention efficiently and with high speed. The term “non-porous” means that essentially no micropores are formed as in for example EP 0 177 573, EP 0 403 650, EP 0 403 650, EP 0 411 124, EP 0 702 081, U.S. Pat. No. 4,016,877 or U.S. Pat. No. 4,294,241. The term ‘porous’ or ‘macroporous’ can be ambiguous, and one may define a crosslinked collagen or gelatin layer as being ‘porous’ on a nano-scale. In the broadest sense, non-porous means in this case that the average pore-size is less than 1 micron, as determined by scanning electron microscopy (SEM) described in for example by Dagalakis et. al. (Design of an artificial skin Part III Control of pore structure—Journal of Biomedical Materials Research, Vol. 14, 519 (1980)). The non-porous film is however permeable for molecules, including polypeptides or proteins, of up to 5 kilo Dalton, preferably up to 10 kilo Dalton and more preferably up to 25 kilo Dalton. In comparison to a globular protein, permeability of a linear protein such as for example a collagen may be higher, up to between 30 and 40 kilo Dalton. In one embodiment crosslinking of the collagenous polypeptide is achieved by addition of one or more crosslinking agents. These comprise agents that start crosslinking spontaneously upon addition to collagenous polypeptide solution, or after adjusting for example, pH, or by photo initiation or other activation mechanisms. In this particular embodiment a number of millimol crosslinks per gram collagenous polypeptide is defined as being equal to the amount of crosslinking agent that has reacted with the collagenous polypeptide. In another embodiment crosslinking of the collagenous polypeptide is achieved by exposure to radiation such as UV-radiation or electron beam. In this particular embodiment of the invention a number of millimol crosslinks is defined as the amount of crosslinking agent that would need to be added to obtain the same number of crosslinks as are obtained by exposure to radiation. In other words, the exposure to radiation results in an equivalent degree of cross-linking as the addition of between about 0.02 millimol to about 5.0 millimol of crosslinking compound per gram collagenous polymer does. The amount of crosslinking agent to be added to obtain a certain number of crosslinks can be calculated or determined experimentally. In case of exposure to radiation the required exposure time and intensity has to be determined experimentally, but this is within the capability of a skilled person without undue burden. The degree of crosslinking can be determined in several ways. In one method, the degree of swelling of the crosslinked collagenous polypeptide is measured by soaking the film in demineralized water and measuring the increase in thickness (swelling) or the increase in weight resulting from water uptake. A series of radiation exposures is then compared to a series in which varying amounts of crosslinking agent is added. Comparing the results of a swelling test provides a correlation between the two methods of crosslinking. A method for measuring swelling of collagenous films is described for example by Flynn and Levine (Photogr. Sci. Eng., 8, 275 (1964). Suitable crosslinking agents are preferably those that do not elicit toxic or antigenic effects when released during biodegradation. Suitable crosslinking agents are, for example, one or more of glutaraldehyde, water-soluble carbodiimides, bisepoxy compounds, formalin, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-hydroxy-succinimide, glycidyl ethers such as alkylene glycol diglycidyl ethers or polyglycerol polyglycidyl ether, diisocyanates such as hexamethylene diisocyanate, diphenylfosforylazide, D-ribose. Crosslinking techniques are also described by Weadock et. al. in Evaluation of collagen crosslinking techniques (Biomater. Med. Devices Artif. Organs, 1983-1984, 11(4): 293-318). In a preferred embodiment water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide is used. In one embodiment the film is particularly suitable for the first phase treatment and is crosslinked by adding between 0.02 and 1.0 millimol crosslinking compound(s) per gram collagenous polypeptide (or radiation induced crosslinking which is equivalent hereto). Thus, the cross-linking compound(s) may be present in an amount of about 0.02, 0.05, 0.1, 0.25, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 millimol/gram polypeptide. In another embodiment the film is particularly suitable for second phase treatment and is crosslinked by adding between 0.5 and 5.0 millimol crosslinking compound(s) per gram collagenous polypeptide (or radiation induced crosslinking which is equivalent hereto), preferably about 1.0 to 2.5 millimol/g. Thus, the cross-linking compound(s) may be present in an amount of about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2.0, 3.0, 4.0 and 5.0 millimol/gram polypeptide. In yet another embodiment the film can be used as an intermediate between first and second phase treatment and is crosslinked by adding between 0.25 and 2.5 millimol crosslinking compound(s) per gram collagenous polypeptide (or radiation induced crosslinking which is equivalent hereto). Another way to express the amount of crosslinking agent is the molar ratio with lysine residues in the polypeptide. Especially in case of recombinantly produced collagenous polypeptides the number of lysine residues can be increased as desired. Many crosslinking agents bind to lysine residues and/or N-terminal amines. Natural gelatin contains between 25 and 27 lysines per 1000 amino acids. In recombinant collagens or collagenous polypeptides this can be reduced to for example equal to or less than about 20, 15, 10 or 5 lysines per 1000 amino acids or increased to for example equal to or more than about 30, 40 or 50 lysines per 1000 amino acids. For example, a recombinant collagen-like polypeptide monomer is described in EP1 398 324 that contains 8 lysines in a sequence of 204 amino acids, or 39 lysines per 1000 amino acids. Preferably the non-porous films according to the invention comprise between 0.01 and 12.5 millimol crosslinking compound(s) per millimol lysine in the collagenous polypeptide, or between 0.1 and 10 millimol per millimol lysine or between 1 and 5 millimol per millimol lysine, depending on the amount of lysines present in the collagenous polypeptide. Suitable collagenous polypeptides to make the films according to the invention are collagens or gelatins from natural, synthetic or recombinant sources or mixtures thereof. Although strictly speaking there is a difference between collagen and gelatin, these differences are in principle not essential to the invention, although specific requirements may make the selection of collagen or gelatin for a certain application obvious. In this respect “collagen” may also be read as “gelatin” and “collagenous polypeptide” may also be read as “gelatinous polypeptide”. A collagenous or gelatinous polypeptide is thus defined as being a polypeptide in which at least one GXY domain is present of at least a length of 5 consecutive GXY triplets and at least 20% of the amino acids of the collagenous polypeptide are present in the form of consecutive GXY triplets, wherein a GXY triplet consists of G representing glycine and X and Y representing any amino acid. Suitably at least 5% of X and/or Y can represent proline and in particular at least 5%, more in particular between 10 and 33% of the amino acids of the GXY part of the collagenous polypeptide is proline. Collagenous polypeptides which can be obtained from natural gelatin can be for example alkaline processed gelatin, acid processed gelatin, hydrolyzed gelatin or peptized gelatin resulting from enzymatic treatment. Natural sources can be the skin or bones of mammals such as cattle or pigs but also of cold-blooded animals such as fish. The collagenous polypeptide preferably has an average molecular weight of less than 150 kilo Dalton, preferably of less than 100 kilo Dalton. Ranges of between 50 an 100 kilo Dalton are suitable or hydrolyzed collagenous polypeptides of less than 50 kilo Dalton or between 5 and 40 kilo Dalton may be used. Preferably the collagenous polypeptides have an average molecular weight of at least 5 kilo Dalton, preferably at least 10 kilo Dalton and more preferably of at least 30 kilo Dalton. A smaller average molecular weight means that more crosslinking compound(s) should be added to obtain a certain permeability than with larger polypeptides. However, lower molecular weights may be preferred for example in production of the non-porous film where lower molecular weight has a lower viscosity which makes higher concentrations of collagenous polypeptides possible. The method of making recombinant collagenous polypeptides has been described in detail in U.S. Pat. No. 6,150,081 and US 2003/229205 by the same applicant, the content of which is herein incorporated by reference. The methodology is described in the publication ‘High yield secretion of recombinant gelatins by Pichia pastoris ’, M. W. T. Werten et al., Yeast 15, 1087-1096 (1999). Recombinantly produced collagenous polypeptides are preferred because the detrimental effects involved in using gelatin or collagen from animal sources, such as for example BSE, are avoided. Also, better control of parameters such as size distribution, amino acid sequence or the occurrence of specific amino acids is possible. Preferably such recombinant collagenous polypeptides have even lower antigenicity than natural gelatins. In one embodiment the recombinant collagenous polypeptide does not form stable triple helices, specifically not at temperature of more than 5 degrees Celsius, or at temperatures higher than 25 degrees Celsius. Such collagenous polypeptides have preferably an amount of prolines present in GXY triplets that is comparable to collagen originating from mammals or collagens originating from cold-blooded animals such as fish. To prevent stable triple helix formation less than 2 number percent, preferably less than 1 number percent, of the amino acids present in the collagenous polypeptide are hydroxylated. Occurrence of hydroxyprolines can be reduced to be practically zero by expression in micro organisms that do not co-express a prolylhydroxylase or fulfill that function in another way. Practically zero means that the presence of hydroxyprolines in the growth medium of for example yeasts may result in incorporation of some of these amino acids into the collagenous polypeptide. Recombinant collagen-like polypeptides that are not hydroxylated and have the advantage of avoiding the occurrence of anaphylactic shock are described in EP 1 238 675. In a preferred embodiment the non-porous film comprises collagenous polypeptides with excellent cell attachment properties, and which do not display any health related risks, by production of RGD-enriched collagenous polypeptides in which the percentage of RGD motifs related to the total number of amino acids is at least 0.4. If the RGD-enriched collagenous polypeptide comprises 350 amino acids or more, each stretch of 350 amino acids contains at least one RGD motif. Preferably the percentage of RGD motifs is at least 0.6, more preferably at least 0.8, more preferably at least 1.0, more preferably at least 1.2 and most preferably at least 1.5. A percentage RGD motifs of 0.4 corresponds with at least 1 RGD sequence per 250 amino acids. The number of RGD motifs is an integer, thus to meet the feature of 0.4%, a collagenous polypeptide consisting of 251 amino acids should comprise at least 2 RGD sequences. Preferably the RGD-enriched recombinant collagenous polypeptide comprises at least 2 RGD sequence per 250 amino acids, more preferably at least 3 RGD sequences per 250 amino acids, most preferably at least 4 RGD sequences per 250 amino acids. In a further embodiment an RGD-enriched collagenous polypeptide comprises at least 4 RGD motifs, preferably 6, more preferably 8, even more preferably 12 up to and including 16 RGD motifs. The term ‘RGD-enriched collagenous polypeptide’ in the context of this invention means that the collagenous polypeptides have a certain level of RGD motifs, calculated as a percentage of the total number of amino acids per molecule and a more even distribution of RGD sequences in the amino acid chain than a natural gelatin. In humans up to date 26 distinct collagen types have been found on the basis of protein and or DNA sequence information (see K. Gelse et al, Collagens-structure, function and biosynthesis, Advanced Drug Delivery reviews 55 (2003) 1531-1546). Sequences of natural gelatins, both of human and non-human origin, are described in the Swiss-Prot protein database. Here below follows a list of suitable human native sequences, identified by their entry name and primary accession number in the Swiss-Prot database, that may serve as a source of parts of natural sequences comprised in the RGD-enriched collagenous polypeptides comprised in the non-porous films of this invention. CA11_HUMAN (P02452) Collagen alpha 1(I) chain precursor. {GENE: COL1A1 }—Homo sapiens (Human) CA12_HUMAN (P02458) Collagen alpha 1(II) chain precursor [Contains: Chondrocalcin]. {GENE: COL2A1 }—Homo sapiens (Human) CA13_HUMAN (P02461) Collagen alpha 1(III) chain precursor. {GENE: COL3A1 }—Homo sapiens (Human) CA14_HUMAN (P02462) Collagen alpha 1(IV) chain precursor. {GENE: COL4A1 }—Homo sapiens (Human) CA15_HUMAN (P20908) Collagen alpha 1(V) chain precursor. {GENE: COL5A1 }—Homo sapiens (Human) CA16_HUMAN (P12109) Collagen alpha 1(VI) chain precursor. {GENE: COL6A1 }—Homo sapiens (Human) CA17_HUMAN (Q02388) Collagen alpha 1(VII) chain precursor (Long-chain collagen) (LC collagen). {GENE: COL7A1 }—Homo sapiens (Human) CA18_HUMAN (P27658) Collagen alpha 1(VIII) chain precursor (Endothelial collagen). {GENE: COL8A1 }—Homo sapiens (Human) CA19_HUMAN (P20849) Collagen alpha 1(IX) chain precursor. {GENE: COL9A1 }—Homo sapiens (Human) CA1A_HUMAN (Q03692) Collagen alpha 1(X) chain precursor. {GENE: COL10A1 }—Homo sapiens (Human) CA1B_HUMAN (P12107) Collagen alpha 1(XI) chain precursor. {GENE: COL11A1 }—Homo sapiens (Human) CA1C_HUMAN (Q99715) Collagen alpha 1(XII) chain precursor. {GENE: COL12A1 }—Homo sapiens (Human) CA1E_HUMAN (P39059) Collagen alpha 1(XV) chain precursor. {GENE: COL15A1 }—Homo sapiens (Human) CA1F_HUMAN (Q07092) Collagen alpha 1(XVI) chain precursor. {GENE: COL16A1 }—Homo sapiens (Human) CA1G_HUMAN (Q9UMD9) Collagen alpha 1(XVII) chain (Bullous pemphigoid antigen 2) (180 kDa bullous pemphigoid antigen 2). {GENE: COL17A1 OR BPAG2 OR BP180 }—Homo sapiens (Human) CA1H_HUMAN (P39060) Collagen alpha 1(XVIII) chain precursor [Contains: Endostatin]. {GENE: COL18A1 }—Homo sapiens (Human) CA1I_HUMAN (Q14993) Collagen alpha 1(XIX) chain precursor (Collagen alpha 1(Y) chain). {GENE: COL19A1 }—Homo sapiens (Human) CA21_HUMAN (P08123) Collagen alpha 2(I) chain precursor. {GENE: COL1A2 }—Homo sapiens (Human) CA24_HUMAN (P08572) Collagen alpha 2(IV) chain precursor. {GENE: COL4A2}- Homo sapiens (Human) CA25_HUMAN (P05997) Collagen alpha 2(V) chain precursor. {GENE: COL5A2 }—Homo sapiens (Human) CA26_HUMAN (P12110) Collagen alpha 2(VI) chain precursor. {GENE: COL6A2 }—Homo sapiens (Human) CA28_HUMAN (P25067) Collagen alpha 2(VIII) chain precursor (Endothelial collagen). {GENE: COL8A2 }—Homo sapiens (Human) CA29_HUMAN (Q14055) Collagen alpha 2(IX) chain precursor. {GENE: COL9A2 }—Homo sapiens (Human) CA2B_HUMAN (P13942) Collagen alpha 2(XI) chain precursor. {GENE: COL11A2 }—Homo sapiens (Human) CA34_HUMAN (Q01955) Collagen alpha 3(IV) chain precursor (Goodpasture antigen). {GENE: COL4A3 }—Homo sapiens (Human) CA35_HUMAN (P25940) Collagen alpha 3(V) chain precursor. {GENE: COL5A3 }—Homo sapiens (Human) CA36_HUMAN (P12111) Collagen alpha 3(VI) chain precursor. {GENE: COL6A3 }—Homo sapiens (Human) CA39_HUMAN (Q14050) Collagen alpha 3(IX) chain precursor. {GENE: COL9A3 }—Homo sapiens (Human) CA44_HUMAN (P53420) Collagen alpha 4(IV) chain precursor. {GENE: COL4A4 }—Homo sapiens (Human) CA54_HUMAN (P29400) Collagen alpha 5(IV) chain precursor. {GENE: COL4A5 }—Homo sapiens (Human) CA64_HUMAN (Q14031) Collagen alpha 6(IV) chain precursor. {GENE: COL4A6 }—Homo sapiens (Human) EMD2_HUMAN (Q96A83) Collagen alpha 1(XXVI) chain precursor (EMI domain containing protein 2) (Emu2 protein) (Emilin and multimerin-domain containing protein 2). {GENE: EMID2 OR COL26A1 OR EMU2 }—Homo sapiens (Human) Natural gelatins are known to comprise RGD sequences. It is important however that a collagenous polypeptide molecule does not contain too large parts without RGD motifs. Too large parts without RGD sequence reduce the possibility of cell attachment when such a collagenous polypeptide is used for instance in tissue engineering applications such as artificial skin. Apparently not all RGD sequences in a collagenous polypeptide are under all circumstances available for cell attachment. It was found that cell attachment was remarkably improved in collagenous polypeptides according to the invention compared to gelatins having a stretch of amino acids of more than 350 without an RGD sequence. For collagenous polypeptides of less than 350 amino acids it is sufficient to have a percentage of RGD sequences of at least 0.4. Note that for a collagenous polypeptide of 251-350 amino acids this means that at least 2 RGD motifs are present. Thus, either fragments enriched in RGD triplets may be identified in natural collagenous proteins, and/or natural collagenous proteins may be modified generate a polypeptide with a suitable number and distribution of RGD triplets. Nucleic acid sequences encoding suitable polypeptides may then be made and expressed in a suitable host cell or organism. In a preferred embodiment the RGD-enriched collagenous polypeptide is prepared by recombinant DNA technology. Recombinant collagenous polypeptides of this invention are preferably derived from collagenous sequences. Nucleic acid sequences encoding collagens have been generally described in the art. (See, e.g., Fuller and Boedtker (1981) Biochemistry 20: 996-1006; Sandell et al. (1984) J Biol Chem 259: 7826-34; Kohno et al. (1984) J Biol Chem 259: 13668-13673; French et al. (1985) Gene 39: 311-312; Metsaranta et al. (1991) J Biol Chem 266: 16862-16869; Metsaranta et al. (1991) Biochim Biophys Acta 1089: 241-243; Wood et al. (1987) Gene 61: 225-230; Glumoff et al. (1994) Biochim Biophys Acta 1217: 41-48; Shirai et al. (1998) Matrix Biology 17: 85-88; Tromp et al. (1988) Biochem J 253: 919-912; Kuivaniemi et al. (1988) Biochem J 252: 633640; and Ala-Kokko et al. (1989) Biochem J 260: 509-516.). For pharmaceutical and medical uses, recombinant collagenous polypeptides with amino acid sequences closely related to or identical to amino acid sequences of natural human collagens are preferred. Amino acid sequences closely related to human collagens (also referred to as proteins which are “essentially similar” to human collagens) are those sequences which comprise at least about 50, 60, 70, 75, 80, 90, 95, 98, 99% or more amino acid sequence identity over the full length to human collagen proteins, such as for example the proteins listed above. Sequence identity is determined using pairwise alignment, whereby two peptide sequences are optimally aligned using programs such as GAP or ‘needle’ (the equivalent of GAP provided in EmbossWIN v2.10.0) using default parameters. GAP and “needle” uses the Needleman and Wunsch global alignment algorithm to align two sequences over their entire length, maximizing the number of matches and minimizes the number of gaps. Generally, the GAP default parameters are used, with a gap creation penalty=50 (nucleotides)/8 (proteins) and gap extension penalty=3 (nucleotides)/2 (proteins). Also included are herein fragments of human collagen proteins and of essentially similar proteins, such as fragments of at least 30, 50, 100, 150, 200, 250, 300, 350, 400, 500, 600, 800, 900, 1000 or more consecutive amino acids. As described below, such fragments may also be used to make repeats thereof, such that the fragment is repeated 2, 3, 4, 5, 10, 15, 20, 30, 50, 70, 80, 90 100 times or more. Optionally spacers may be present between the repeats. More preferably the amino acid sequence of the collagenous polypeptide is designed by a repetitive use of a selected amino acid sequence of a human collagen. A part of a natural collagen sequence comprising an RGD motif is selected. The percentage of RGD motifs in such a selected sequence depends on the chosen length of the selected sequence, selection of a shorter sequence results in a higher RGD percentage. Repetitive use of a selected amino acid sequence results in a gelatin with a higher molecular weight, which is non-antigenic and with an increased number of RGD motifs (compared to natural gelatins or collagens). Thus in a preferred embodiment the RGD-enriched collagenous polypeptide comprises a part of a native human collagen sequence. Preferably the RGD-enriched collagenous polypeptide consists for at least 80% of one or more parts of one or more native human collagen sequences. Preferably each of such parts of human collagen sequences has a length of at least 30 amino acids, more preferably at least 45 amino acids, most preferably at least 60 amino acids, up to e.g. 240, preferably up to 150, most preferably up to 120 amino acids, each part preferably containing one or more RGD sequences. Preferably the RGD-enriched collagenous polypeptide consists of one or more parts of one or more native human collagen sequences. An example of a suitable source of a collagenous polypeptide for preparing the films according to this invention is human COL1A1-1. A part of 250 amino acids comprising an RGD sequence is given in WO 04/85473. RGD sequences in collagenous polypeptides can adhere to specific receptors on the cell wall called integrins. These integrins differ in their specificity in recognizing cell binding amino acid sequences. Although both natural gelatin and, for example, fibronectin may contain RGD sequences, gelatin can bind cells that will not bind to fibronectin and vice versa. Therefore fibronectin comprising RGD sequences cannot always replace gelatin for cell adhesion purposes. The RGD-enriched collagenous polypeptides can be produced by recombinant methods as disclosed in EP-A-0926543, EP-A-1014176 or WO 01/34646. For the production and purification of collagenous polypeptides that are suited for preparing films of this invention reference is made to the examples in EP-A-0926543 and EP-A-1014176. The preferred method for producing an RGD-enriched collagenous polypeptides is by starting with a natural nucleic acid sequence encoding a part of the collagen protein that includes an RGD amino acid sequence. By repeating this sequence an RGD-enriched collagenous polypeptide is obtained. If X-RGD-Y is a part of the natural collagen amino acid sequence, a (part of a) collagenous polypeptide with three RGD amino acid sequences would have the structure -X-RGD-Y-(GXYG)m-X-RGD-Y-(GXYG)n-X-RGD-Y-, with m and n being integers starting from 0. By varying n the number of RGD sequences on the total amino acids the percentage of RGD motifs can be controlled. A clear advantage of this method is that the amino acid sequence remains most natural and thus has the lowest risk of inducing immunological response in clinical applications. Starting from a natural nucleic acid sequence encoding (part of) a collagenous polypeptide, also point mutations can be applied so as to yield a sequence encoding an RGD sequence. Based on the known codons a point mutation can be performed so that an RGX sequence after mutation will yield an RGD sequence, alternatively also an YGD sequence can be mutated to yield an RGD sequence. Also it is possible to carry out two mutations so that an YGX sequence will give an RGD sequence. Also it may be possible to insert one or more nucleotides or delete one or more nucleotides giving rise to a desired RGD sequence. Further it was found that the properties of the gelatin used to make the film, in terms of the degree of glycosylation, optionally in combination with the number of RGD triplets in the gelatin, can influence the speed of cell growth, the cellular attachment to the film and the cell-to-cell adhesion of the autologous cells, whereby the final thickness and quality (cell density and adhesion strength) of the artificial skin layer can be influenced and improved. Low or no glycosylation of the gelatin used and/or high numbers of RGD triplets in the gelatin used to make the film had a positive effect on the speed of cell (e.g. fibroblast and keratinocyte) growth on the surfaces, and on the cellular adhesion properties. Thus, it was found that by controlling the ratio of glycosylation to the number of RGD triplets, films of good quality can be made. In a further embodiment, the gelatins used to make the film are low in glycosylation and preferably also substantially pure when used for film making. There are various methods for ensuring that glycosylation is low or absent. Glycosylation is a posttranslational modification, whereby carbohydrates are covalently attached to certain amino acids of the protein or polypeptide. Thus both the amino acid sequence and the host cell (and enzymes, especially glycosyltransferases, therein) in which the amino acid sequence is produced determine the glycosylation pattern. There are two types of glycosylation: N-glycosylation begins with linking of GlcNAc (N-actylglucosamine) to the amide group of asparagines (N or Asn) and O-glycosylation commonly links GalNAc (N-acetylgalactosamine) to the hydroxyl group of the amino acid serine (S or Ser) or threonine (T or Thr). Glycosylation can, therefore, be controlled and especially reduced or prevented, by choosing an appropriate expression host, and/or by modifying or choosing sequences which lack consensus sites recognized by the hosts glycosyltransferases. Obviously, chemical synthesis of proteins or polypeptides results in unglycosylated proteins. Also, glycosylated proteins may be treated after production to remove all or most of the carbohydrates or unglycosylated proteins may be separated from glycosylated proteins using known methods. In yeasts N-linked glycosylation of asparagine occurs on the consensus sites Asn-X-Thr or Asn-X-Ser, wherein X is an amino acid. Commonly glycosylation in yeast results in N-linked and O-linked oligosaccharides of mannose. Thus, for expression in yeast the nucleic acid sequence may be modified or selected so that consensus sites are reduced or preferably absent. The Asn codon and/or the Thr codon may be modified, e.g. by mutagenesis or de novo synthesis. Preferably Asn and/or Thr is replaced by another amino acid. Also Asp may be replaced by another amino acid. In one embodiment the polypeptide sequence contains no Ser and/or no Asn. To analyse the degree of post-translational modification or to determine the content of glycosylation mass spectrometry, such as MALDI-TOF-MS (Matrix Assisted Laser Desorption Ionization mass spectrometry) can be carried out as known in the art. Alternatively the amount of glycosylation can be determined using the titration method described by Michel Dubois et al, “Colorimetric Method for Determination of Sugars and Related Substances”, Analytical Chemistry, vol 28, No. 3, March 1956, 350 356. This method can be used to determine simple (mono) sugars, oligosaccharides, polysaccharides, and their derivatives, including the methyl ethers with free or potentially free reducing groups, and thus the method is quantitative. The content of glycosylation of the colleganous polypeptide used is preferably equal to, or less than about 2 (m/m) %, more preferably less than about 1 (m/m) %, most preferably less than about 0.5 (m/m) %, 0.2 (m/m) % or 0.1 (m/m) %. In a preferred embodiment the glycosylation content (or degree of glycosylation) is zero. The content of glycosylation refers to the total carbohydrate weight per unit weight of the collagenous polypeptides as determined by for example MALDI-TOF-MS (Matrix Assisted Laser Desorption Ionization mass spectrometry) or preferably the titration method by Dubois et al. referred to above. The term ‘glycosylation’ refers not only to monosaccharides, but also to poysaccharides such as di-. tri- or tetra saccharides. In another embodiment the number of RGD triplets (defined as the number of RGD triplets per 250 amino acids of collagenous polypeptide) is preferably at least 2, more preferably at least 3, 4, 5, 6, 7, 8 ore more. Such collagenous polypeptides are referred to as “RGD-enriched collagenous polypeptides”. Thus, in one embodiment a method of making a film which has advantageous properties in the manufacture of artificial skin equivalents is provided. In one embodiment a film is made using collegenous polypeptides having low or no glycosylation and/or a high number of RGD triplets. Film made using the above RGD enriched polypeptides and/or polypeptides low in glycosylation (including polypeptides with zero glycosylation) are also provided. Such film are suitably made as described herein. Thus the collagenous polypeptides can be produced by expression of nucleic acid sequence encoding such polypeptide by a suitable micro-organism. The process can suitably be carried out with a fungal cell or a yeast cell. Suitably the host cell is a high expression host cells like Hansenula, Trichoderma, Aspergillus, Penicillium, Saccharomyces, Kluyveromyces, Neurospora or Pichia . Fungal and yeast cells are preferred to bacteria as they are less susceptible to improper expression of repetitive sequences. Most preferably the host will not have a high level of proteases that attack the collagen structure expressed. In this respect Pichia or Hansenula offers an example of a very suitable expression system. Use of Pichia pastoris as an expression system is disclosed in EP-A-0926543 and EP-A-1014176. The micro-organism may be free of active post-translational processing mechanism such as in particular hydroxylation of proline and also hydroxylation of lysine. Alternatively the host system may have an endogenic proline hydroxylation activity by which the collagenous polypeptide is hydroxylated in a highly effective way. The selection of a suitable host cell from known industrial enzyme producing fungal host cells specifically yeast cells on the basis of the required parameters described herein rendering the host cell suitable for expression of collagenous polypeptides which are suitable for use as artificial skin in combination with knowledge regarding the host cells and the sequence to be expressed will be possible by a person skilled in the art. In another embodiment the recombinant collagenous polypeptides have a higher glass transition temperature than natural occurring gelatins. Such sequences are described in WO 05/11740. The film obtainable using the methods described below has advantageous properties when it is used to make human artificial skin equivalents, using autologous human cells, especially fibroblasts and/or keratinocytes. As shown in the examples, the film enables better (optimized, faster) cell growth compared to cell growth on film comprising high glycosylation and/or low numbers of RGD triplets. This may be due to the enhanced cell-to-film and/or cell-to-cell attachment properties, whereby cell spread across the film is improved. A dense, full thickness artificial skin is obtainable by growing cells on at least one, but preferably both sides of the film. The cells are grown until the skin equivalent is preferably at least about 10, 15, 20 μm thick, or more. Preferably the skin equivalent is “full thickness” (at least about 15-20 μm thick in total). Preferably, multiple layers of cells (e.g. fibroblasts and/or keratinocytes) are grown on at least one, more preferably both sides of the film. This includes the formation of a horny layer. The method of making an artificial skin comprises the steps of producing a film comprising an RGD enriched collagenous polypeptide and/or a polypeptide having a low degree of glycosylation (e.g. no glycosylation); contacting the film on one or both sides with live or viable human cells, especially autologous human cells (e.g. fibroblasts and/or keratinocytes); incubating the film comprising the cells for a suitable period of time, under suitable conditions for cell growth and optionally repeating the steps of contacting and incubating one or more times. Cells that can be grown on at least one side of the non-porous film of the invention can be any living, genetically modified or malignant living cell. Preferably normal (healthy) cells, such as those that occur in the human dermis or epidermis, are cultured on the non-porous film. Preferred are human (or mammalian) cells that occur in skin tissue such as fibroblasts, keratinocytes, melanocytes, Langerhans'cells, and the like. In a preferred embodiment the cells are obtained from the subject to be treated (they are “autologous cells”). In one embodiment the invention provides a non-porous film comprising on one side fibroblasts. In another embodiment the invention provides a non-porous film comprising on one side keratinocytes. Preferably the keratinocytes are exposed to air during culturing so that a horny layer (stratum corneum) is formed at the air-culture interface. In a preferred embodiment a layer comprising fibroblasts on one side of the non-porous film while a layer comprising keratinocytes on the opposite side is provided to avoid that the fibroblasts interfere with keratinocyte growth and differentiation. By exposing the keratinocyte culture to air the formation of horny tissue, hence a stratum corneum, occurs. Thus a full human skin-equivalent is provided comprising a non-porous film according to the present invention comprising on one side thereof a layer comprising fibroblasts and on the opposite side of the layer comprising fibroblasts a layer comprising keratinocytes. In particular the layer comprising keratinocytes comprises at the surface that is not in contact with the non-porous film horny tissue. After culturing, such a material is suitable for use as artificial skin or as a test substrate for medicines or pharmaceutical or cosmetic compounds, for instance for assessing the permeability of medicines or pharmaceutical or cosmetic compounds through the artificial skin, and/or the influence on cells on either side of the non-porous collagenous polypeptide of the artificial skin or testing properties such of for example UV absorbing compounds. In case of the embodiment having on both sides of the non-porous film cells, in particular fibroblasts and keratinocytes, the non-porous crosslinked gelatin film resembles the basal membrane found in natural skin, thereby providing a full human skin equivalent closely resembling natural skin. This may be of benefit for example in particular for effects of test substrates on skin and also for the treatment of wounds. Culturing or growing viable or living cells on one or both sides of the film can be done using cell culture methods known in the art and as described in the Examples. Nutrients and other components may either be added together with the cells or separately, and the films comprising the cells are incubated for a sufficient period of time and under suitable conditions for cells growth and/or cells divisions to occur. The non-porous crosslinked gelatin film is particularly suited for the culturing of cells on both sides as the gelatin film has the required physical stability, or mechanical strength, for optimal handling during culturing, in particular in the step of turning the film upside down for culturing the second layer of cells. The non-porous film may further comprise one or more bioactive compounds such as hormones, growth promoters, antibiotics, immune-suppressors, and the like. Further the non-porous film may comprise one or more compounds that can aid in the wound healing process. A “bioactive compound” is any compound (either a natural compound or a synthetic compound) which exerts a biological effect on other cells. Such compounds are widely available in the art. The compound may be incorporated into the film during its manufacture or, alternatively, it may be added subsequently to one or both sides of the film. The non-porous film can also be used in cases where skin loss is less extensive but needs to be replaced still, for example in cases of chronic open wounds or in the case of bedsores that occur with for example paralysis. In another embodiment a method for manufacturing a film according to the invention is provided. This method comprising the steps of: a) providing a collagenous polypeptide solution of between 2 and 30 weight percent in an aqueous solution, b) adding a suitable amount of (one or more) crosslinking compound(s) to said aqueous solution, preferably between about 0.02 and 5.0 millimol of (one or more) crosslinking compound(s) per gram collagenous polypeptide (or any other suitable amount as described herein above) c) coating said collagenous polypeptide solution onto a substrate that was, optionally, first subjected to an adhesion improving treatment of at most 30 watt·minute per square meter d) drying said coated substrate, and optionally e) separating the dried non-porous film from the substrate. Also provided is a method for producing a non-porous film suitable for culturing living or viable cells on at least one side thereof comprising the steps of: a) providing a collagenous polypeptide solution of between 2 and 30 weight percent in an aqueous solution, b) coating said collagenous polypeptide solution onto a substrate that was, optionally, first subjected to an adhesion improving treatment of at most 30 watt·minute per square meter c) drying said coated substrate, d) subjecting said dried coated substrate to radiation (as described herein above) to form crosslinks between said collagenous polypeptides, and optionally e) separating the dried non-porous film from the substrate. The non-porous film of this invention can be produced efficiently and with high speed by coating the collagenous polypeptide solution onto a suitable substrate. The coating solution is prepared by dissolving between about 2 and 30 weight percent of (one or more) collagenous polypeptide(s) in an aqueous solvent. Preferably the concentration of the collagenous polypeptide is between about 5 and 20 weight percent, more preferably between about 10 and 15 weight percent. In case recombinant collagenous polypeptides are used that cannot form stable triple helixes at room temperature or lower temperature, higher concentrations can be used than with natural gelatin or collagen. The aqueous solution contains at least 50 weight percent water, preferably at least 60 weight percent. An additional solvent may be added to reduce the surface tension of the coating solution in order to improve coatability. Suitable solvents are those that have lower surface tension than water and that in principle can be removed completely by drying. Suitable solvents are for example lower alkyl alcohols such as ethanol, ketones such as acetone, lower alkyl acetates such as ethylacetate and the like. Preferred additional solvents are lower alkyl alcohols such as methanol, ethanol, (iso)propanol. Preferably ethanol is used. Lower alkyl means that the alkyl chain has from 1 to about 6 carbon atoms. The coating solution is then coated onto a solid substrate. As a coating equipment any method known in the art can be used such as slide bead coating, curtain coating, bar coating, cast coating and the like. Suitable substrates are substrates having a resin surface such as a polyolefin layer. Preferably the resin layer comprises a polyethylene (PE) or polypropylene (PP), which can be a high density, a low density, a linear low density, a metallocene PE or PP or a mixture thereof. The substrate can also be a paper base coated with a resin layer. Before coating, the resin surface is optionally subjected to an adhesion promoting treatment such as a flame treatment, a corona treatment or a plasma treatment is necessary of at least 1.5 watt·minute per square meter, preferably at least 2.5 watt·minute per square meter, and at most 30 watt·minute per square meter, preferably at most 25, 20, 15, 10 or 5 watt·minute per square meter. Purpose of the adhesion promoting treatment is to provide enough adhesion so that the material can be coated, dried and subjected to processes such as rolling up or cutting without release of the non-porous film. On the other hand the adhesion should be weak enough to facilitate easy separation from the substrate prior to use for growing or culturing cells. Just before coating the coating solution onto a substrate, a crosslinking compound(s) may be added. Depending on the desired degree of biodegradability the amount of crosslinking compound(s) added can be between, for example, 0.02 and 0.5 millimol crosslinking compound(s) per gram collagenous polypeptide, between 0.05 and 1 between 0.1 and 2.0, between 0.25 and 2.5, or between 1.0 and 5.0 millimol crosslinking compound(s) per gram collagenous polypeptide. Adding ‘just before coating’ or ‘immediately prior to coating’ means that after addition of crosslinking compound the coating solution is coated onto a substrate before the viscosity increase is too high. The reaction speed of crosslinking and thus the increase of viscosity depends, amongst other factors, on concentrations of both crosslinking compound and collagenous polypeptide. In practical situations the coating liquid is coated within at most about two hours after addition, preferably within at most about 60 minutes, more preferably within at most about 30 minutes after addition of the crosslinking compound to the solution. Drying can be done by any method known in the art. Preferably the drying conditions, such as humidity and temperature, are controlled so that too fast drying, resulting in cracking or breaking of the film, is prevented. Before inoculating or contacting the film with one or more cells, the film may optionally be sterilized, for example by exposure to gamma radiation. This can be done before or after peeling (separating) the film from the substrate. Alternatively the whole process is carried out under sterile conditions and by using sterile components, so that the film is sterile prior to being contacted with live or viable cells. The desired cells may also be contacted with one of the surfaces while the film is still attached to the substrate. In another embodiment the collagenous polypeptides in the film are crosslinked after coating, by exposure to radiation, such as UV-radiation or electron beam. This can replace the addition of crosslinking compound or can be used in combination therewith. A film obtainable by any of the methods described herein is also an embodiment of the invention. The film according to the invention may then be contacted with live or viable cells on one and/or both sides of the film. This can be done using known methods, for example inoculating the surface with a cell suspension by pouring or pipetting the (liquid or semi-solid) suspension onto the surface or by or dipping or laying the film surface into/onto the cell suspension. The cells may further be distributed on the film's surface by streaking or other methods. Further, nutrients and or other components may be supplied to the cells and the films are incubated for sufficient time and under suitable conditions to allow cell growth and/or cell division(s). DESCRIPTION OF THE FIGURES FIG. 1 : Effect of crosslinking on initial thickness and swelling of a non-porous film. The graph shows the EDC/lysine ratio (tetramer example 1, 72.6 kDa) vs dry thickness (μm) and swelling (μm, H 2 O 37° C.). FIG. 2 : Effect of crosslinking on degradation speed of a non-porous film. The graph shows the degradation speed of EDC cross-linked tetramer (72.6 kDa) to a bacterial collagenase solution with 10 CDU/mg gelatin. FIG. 3 : Diffusion cell for testing permeability of a non-porous film, wherein 1=donor compound, 2=receptor compartment, 3=receptor input, 4=compound and receptor output for analysis, 5=⅛″ OD× 1/32″ wall tubing. FIG. 4 : Effect of crosslinking on permeability and degradation of a non-porous film. The graph shows the permeability for lysozyme (14.3 kDa, 1st fraction) and degradation (weight remaining) after 25 h of EDC cross-linked tetramer (72.6 kDa) to a collagenase solution with 10 CDU/mg gelatin. EXAMPLES Preparation of a Non-Porous Film or Film of this Invention A natural gelatin or a recombinantly produced collagenous polypeptide, as described for example in EP-A-1398324, of a molecular weight up to 100 kilo Dalton is dissolved in demineralized water at a temperature of 40° C. After the polypeptide is dissolved the temperature is increased to 60 degrees Celsius for 30 minutes to fully uncurl the gelatin or collagen strands, after which the temperature is decreased again to 40 degrees Celsius. To improve wetability 15˜30% (weight/weight) 96% pure EtOH is added to obtain final collagenous polypeptide concentrations of 10˜25% (weight/weight). Depending on the cross-linking compound the pH is adjusted with 1M NaOH or 1M HCl to 5˜6 when using glutaraldehyde (GTA: 25% solution (weight/weight)) and to 7˜8 when using N-Ethyl-N′-(3-Dimethyl aminopropyl)carbodiimide.HCl (EDC: 25% solution (weight/weight)). The crosslinking compound is added to the gelatin solution just before coating, that is, before viscosity due to crosslinking becomes too high. The collagenous polypeptide solution is thoroughly mixed with the crosslinking compound solution and directly after mixing coated on a polyethylene substrate. Wet coating thickness of 100˜400 μm is applied which after drying results in dry membrane thickness of 10˜100 μm. Drying may be done for example at ambient conditions for at least 24 h. After drying, films are cut and irradiated with gamma rays at a doses of at least 25 kGy to realize sterile gelatin films Culture of Keratinocytes and Fibroblasts: Keratinocytes and fibroblasts were isolated from normal human skin obtained from breast surgery. Keratinocytes were grown in keratinocyte medium using 3 parts of Dulbecco's modified eagles medium (DMEM) and 1 part of Ham's F12 medium supplemented with 5% serum (fetal calf) and various other additives e.g 100 microgram streptomycin/ml and 100 I.U. penicillin/ml. For establishment of human skin equivalents keratinocytes of passage 2 were used. Fibroblasts were grown in DMEM, supplemented with 5% calf serum. For fabrication of skin equivalents fibroblasts of passage 2-9 were used. Keratinocytes and fibroblasts were grown to confluence in plastic tissue culture dishes. Preparation Method of Human Skin Equivalents: The collagenous polypeptide films were washed during 24 hours in buffered saline solution at room temperature. After 1 and 2 hours, the buffered saline solution was refreshed. After washing, fibroblasts were seeded onto the films and either a. incubated for 3 days in fibroblast medium with 5% serum, 1 nanogram/ml Epidermal Growth Factor (EGF) and various other additives. b. incubated for 3 days in fibroblast medium with 1% serum, 1 nanogram/ml EGF and various other additives. During this culture period—at day two—keratinocytes were seeded onto the backside of the collagenous polypeptide films. Human skin equivalents are grown onto metal grid supports. After 3 days, the combined keratinocyte/fibroblast cultures were lifted to the air-liquid interface and cultured in DMEM/Ham's F12 medium supplemented with 1 nanogram/ml EGF, in the absence of serum. Cells were grown for an additional 10 days to confluence. Example 1 Preparation of Nonporous Film from a Recombinantly Produced Tetramer of 72.6 Kilo Dalton as Described in EP-A-1398324 Totally 11.4 g of the tetramer was dissolved in 34.2 g demineralized water at 40 degrees Celsius. After dissolving, the temperature was increased to 60 degrees Celsius for 30 minutes and then decreased again to 40 degrees Celsius. Additional 11.4 g EtOH (96% pure) was added. pH of the solution was adjusted with 1M NaOH to 7.5. 25% EDC (N-Ethyl-N′-(3-Dimethyl aminopropyl)carbodiimide.HCl) solution was prepared by dissolving 1 g EDC in 3 g demineralized water. Additions of the crosslinking compound solution to the collagenous polypeptide solutions were done according table 1. After addition the mixtures were stirred thoroughly and the mixtures were applied on non-treated photographic base-paper with a polyethylene top layer. With a spirally wound ‘Large K Hand Coater Bar’ No. 125 a wet film deposit of 125 1.1M was coated on A4 sized substrates. The coated films were left to dry at room temperature for at least 24 h. Dry thickness was measured using a Lorentzen & Wettre micrometer type 221. Swelling can be measured with a method as described by Flynn and Levine (Photogr. Sci. Eng., 8, 275 (1964). Physical strength was determined qualitatively by manually handling a film. The designation ‘−’ means too weak, ‘+’ no tear during normal handling, ‘+/−’ means that in about 50 percent of the tests the film tore and ‘++’ means no tear even after applying more force than necessary. Brittleness was also tested qualitatively in a similar manner by bending the film. Results of dry thickness, water swelling (vertical) and physical properties are also listed in table 1: TABLE 1 EDC/Lysine Dry ratio thickness Swelling Physical Solution (mol/mol) (micron) (micron) strength brittleness I 0.4 25 159 +/−  + II 0.5 24 138 + + III 0.6 22 133 +/++ + IV 1.0 23 64 ++ + V 2.0 21 54 − − See FIG. 1 for the graphic processing of the swelling data. The obtained films were cut to circular membranes with a diameter of 27 millimeter and were sterilized by means of gamma irradiation with a doses of at least 25 kGy. Preparation Method of Full Human Skin Equivalent: A gelatin membrane was placed in a petridish (using a pair of tweezers); Phosphate buffered saline solution was added to the petridish for washing the membrane (at RT). After 2 hrs. the PBS solution was removed by a pipette and fresh PBS solution was added to the membrane; After 1 day PBS solution was removed (by pipette) and fibroblast culture medium was added for an additional washing step; After 2 hrs culture medium solution was removed by pipette and fibroblasts were seed on the membrane; The cells were allowed to attach to the membrane for ˜1 h; The fibroblast culturing medium was added in such an amount that the membrane was not air-exposed since fibroblasts have to grow under wet conditions; Culturing took place for 1 week, 2 times per week culture medium was refreshed (removal by pipette); Membrane with fibroblasts was turned upside down using a Millipore filter (TETP02500, 8 μm). The membrane was lifted via a pair of tweezers and put upside down on a metal grid; The medium was changed to keratinocyte medium as described above; Keratinocytes were seeded on the backside of the gelatin membrane in a metal ring (to prevent dispersion of the cells). After adherence of the keratinocytes the metal ring was removed and the culture continued for another 7 days; After 7 days, the cultures were exposed to the air interface and cultured for another 14 days; culture medium was refreshed 2 times per week); no extra handlings were needed since the amount of medium was reduced so that the keratinocytes remained above the liquid surface. Evaluation of Full Human Skin Equivalent: skin equivalents were harvested and fixed in 4% paraformaldehyde, dehydrated and embedded in paraffine; then the embedded tissue was cut into slices and stained with haematoxyline/eosine; Stained slices were visualized by light microscope; Clearly several layers (multilayer) of keratinovcytes were visible having on the air-exposed side thereof horny tissue (stratum corneum); fibroblasts were separated from the keratinocytes by the gelatin membrane. Example 2 In Vitro Degradation of the Cross-Linked Membranes Bacterial collagenase (activity of >125 CDU/mg (One Collagen Digestion Unit liberates peptides from collagen equivalent in ninhydrin color to 1.0 μmole of leucine in 5 hr at pH 7.4 at 37° C. in the presence of calcium ions)) from Clostridium histolyticum (Sigma-Aldrich, EC 3.4.24.3) was selected as an enzyme for the degradation studies because of its specificity for collagen. These collagenase preparations contain at least six different collagenases which are capable of cleaving peptide bonds within the triple helical structure and have a specificity for the Pro-X-Gly-Pro-Y region, splitting between X and Gly. In a typical degradation experiment, a 10 milligram sample of cross-linked collagenous polypeptide with either GTA or EDC is immersed in 0.5 ml of a 0.1 M Tris-HCl buffer solution (pH 7.4) containing 0.005M CaCl 2 and 0.05 mg/ml sodium azide and incubated at 37° C. After one hour, 0.5 ml collagenase solution in Tris-HCl buffer (37° C.) was added to give the desired final concentration and absolute amount of collagenase (100 CDU/ml or 10 CDU/mg collagenous polypeptide). The degradation was discontinued at the desired time interval by the addition of 0.1 ml 0.25M EDTA (Titriplex III) and cooling of the system. The weight-loss of the cross-linked collagenous polypeptide samples during the degradation was determined by a gravimetrical method. Samples were dried overnight under vacuum over KOH and were weighted. Thereafter the samples were degraded as described above. After a pre-determined degradation period, EDTA was added and the tubes were centrifuged at 600 G for 10 minutes and the remaining solution was discarded. The resulting pellet was washed with distilled water and centrifuged. This washing procedure was conducted three times in total. After the final washing step, the remaining pellet was freeze dried and weighted to determine the weight-loss of the collagenous polypeptide samples. See FIG. 2 for the graphical presentation of the data. Example 3 Permeability and Degradation Level Vs. Cross-Link Density To determine the permeability of the prepared membranes a diffusion experiment was initiated. 193 mg of Lysozyme, a globular protein of 14.3 kDa, was dissolved in 5 ml physiological salt solution to obtain a lysozyme concentration of 38.6 mg/ml (donor solution). The EDC cross-linked gelatin membranes with a cross-linking density of 0.4, 0.6, 1.0 and 1.5 EDC/lysine (mol/mol) were mounted in the diffusion cells (see FIG. 3 ) and 300 μl of the donor solution was put on top of the mounted membranes. The receptor fluid (also physiological salt solution) flow is 1 ml/hr. During the whole experiment the temperature of the system was kept at 37° C. The first fraction of 5 ml and the diluted donor solution were analyzed by means of GPC at a wavelength of 280 nm. The results were compared to the degradation level (weight remaining %) after 25 h. See FIG. 4 for the graphical presentation of the data which show that both parameters, permeability and degradation, can be controlled by the cross-linking density. Example 4 Effect of RGD Triplets and/or Glycosylation of the Collagenous Polypeptide on Cell Growth Method: To test glycosylation and/or RGD triplet numbers on human cell growth, various polypeptides were made. Results: Glycosylation (m/m)% Nr. of RGD triplets Cell growth 7-9 0 Very bad 1-2 0 bad 1-2 1 moderate ≦1-2   5 Very good

The invention relates to collagenous polypeptide films on which cells are cultivated. In particular the invention relates to such films that are used to treat wounds such as severe burns or physical or chemical injury. The invention also related to methods for producing such films.

This application is a divisional application of U.S. patent application Ser. No. 08/850,171, filed May 2, 1997, now abandoned. FIELD OF THE INVENTION The present invention relates to the detection of specific nucleic acid sequences in a target test sample. In particular, the present invention relates to the automated detection of specific nucleic acid sequences which are either unamplified or amplified nucleic acid sequences (amplicons). In addition, the present invention relates to the use of automated amplification, methods and compositions for monitoring successful amplification, improved methods for reducing the chance for contamination, and the use of unified reaction buffers and unit dose aliquots of reaction components for amplification. Finally, the present invention also relates to unique constructs and methods for the conventional or automated detection of one, or more than one different nucleic acid sequences in a single assay. THE BACKGROUND OF THE INVENTION The development of techniques for the manipulation of nucleic acids, the amplification of such nucleic acids when necessary, and the subsequent detection of specific sequences of nucleic acids or amplicons has generated extremely sensitive and nucleic acid sequence specific assays for the diagnosis of disease and/or identification of pathogenic organisms in a test sample. Amplification of Nucleic Acids When necessary, enzymatic amplification of nucleic acid sequences will enhance the ability to detect such nucleic acid sequences. Generally, the currently known amplification schemes can be broadly grouped into two classes based on whether, the enzymatic amplification reactions are driven by continuous cycling of the temperature between the denaturation temperature, the primer annealing temperature, and the amplicon (product of enzymatic amplification of nucleic acid) synthesis temperature, or whether the temperature is kept constant throughout the enzymatic amplification process (isothermal amplification). Typical cycling nucleic acid amplification technologies (thermocycling) are polymerase chain reaction (PCR), and ligase chain reaction (LCR). Specific protocols for such reactions are discussed in, for example, Short Protocols in Molecular Biolog , 2 nd Edition, A Compendium of Methods from Current Protocols in Molecular Biology , (Eds. Ausubel et al., John Wiley & Sons, New York, 1992) chapter 15. Reactions which are isothermal include: transcription-mediated amplification (TMA), nucleic acid sequence-based amplification (NASBA), and strand displacement amplification (SDA). U.S. Patent documents which discuss nucleic acid amplification include U.S. Pat. Nos. 4,683,195; 4,683,202; 5,130,238; 4,876,187; 5,030,557; 5,399,491; 5,409,818; 5,485,184; 5,409,818; 5,554,517; 5,437,990 and 5,554,516 (each of which are hereby incorporated by reference in their entirety). It is well known that methods such as those described in these patents permit the amplification and detection of nucleic acids without requiring cloning, and are responsible for the most sensitive assays for nucleic acid sequences. However, it is equally well recognized that along with the sensitivity of detection possible with nucleic acid amplification, the ease of contamination by minute amounts of unwanted exogenous nucleic acid sequences is extremely great. Contamination by unwanted exogenous DNA or RNA nucleic acids is equally likely. The utility of amplification reactions will be enhanced by methods to control the introduction of unwanted exogenous nucleic acids and other contaminants. Prior to the discovery of thermostable enzymes, methods that used thermocycling were made extremely difficult by the requirement for the addition of fresh enzyme after each denaturation step, since initially the elevated temperatures required for denaturation also inactivated the polymerases. Once thermostable enzymes were discovered, cycling nucleic acid amplification became a far more simplified procedure where the addition of enzyme was only needed at the beginning of the reaction. Thus reaction tubes did not need to be opened and new enzyme did not need to be added during the reaction, allowed for an improvement in efficiency and accuracy as the risk of contamination was reduced, and the cost of enzymes was also reduced. An example of a thermostable enzyme is the polymerase isolated from the organism Thermophilus aquaticus. In general, isothermal amplification can require the combined activity of multiple enzyme activities for which no optimal thermostable variants have been described. The initial step of an amplification reaction will usually require denaturation of the nucleic acid target, for example in the TMA reaction, the initial denaturation step is usually ≧65° C., but can be typically ≧95° C., and is used when required to remove the secondary structure of the target nucleic acid. The reaction mixture is then cooled to a lower temperature which allows for primer annealing, and is the optimal reaction temperature for the combined activities of the amplification enzymes. For example, in TMA the enzymes are generally a T7 RNA polymerase and a reverse transcriptase (which includes endogenous RNase H activity). The temperature of the reaction is kept constant through out the subsequent isothermal amplification cycle. Because of the lack of suitable thermostable enzymes, some isothermal amplifications will generally require the addition of enzymes to the reaction mixture after denaturation at high temperature, and cool-down to a lower temperature. This requirement is inconvenient, and requires the opening of the amplification reaction tube, which introduces a major opportunity for contamination. Thus, it would be most useful if such reactions could be more easily performed with a reduced risk of contamination by methods which would allow for integrated denaturation and amplification without the need for manual enzyme transfer. Amplification Buffer and Single Reaction Aliquot of Reagents Typical reaction protocols require the use of several different buffers, tailored to optimize the activity of the particular enzyme being used at certain steps in the reaction, or for optimal resuspension of reaction components. For example, while a typical PCR 10×amplification buffer will contain 500 mM KCl and 100 mM Tris HCl, pH 8.4, the concentration of MgCl 2 will depend upon the nucleic acid target sequence and primer set of interest. Reverse transcription buffer (5×) typically contains 400 mM Tris-Cl, pH 8.2; 400 mM KCl and 300 mM MgCl 2 , whereas Murine Maloney Leukemia Virus reverse transcriptase buffer (5×) typically contains 250 mM Tris-Cl, pH 8.3; 375 mM KCl; 50 mM DTT (Dithiothreitol) and 15 mM MgCl 2 . While such reaction buffers can be prepared in bulk from stock chemicals, most commercially available amplification products provide bulk packaged reagents and specific buffers for use with the amplification protocol. For example, commercially available manual amplification assays for detection of clinically significant pathogens (for example Gen-Probe Inc. Chlamydia, and Mycobacterium tuberculosis detection assays) requires several manual manipulations to perform the assay, including dilution of the test sample in a sample dilution buffer (SDB), combination of the diluted sample with amplification reaction reagents such as oligonucleotides and specific oligonucleotide promoter/primers which have been reconstituted in an amplification reconstitution buffer (ARB), and finally, the addition to this reaction mixture of enzymes reconstituted in an enzyme dilution buffer (EDB). The preparation and use of multiple buffers which requires multiple manual additions to the reaction mixture introduces a greater chance for contamination. It would be most useful to have a single unified buffer which could be used in all phases of an amplification protocol. In particular, with the commercially available TMA assays described above, the requirement for three buffers greatly complicates automation of such a protocol. Bulk packaging of the enzyme or other reaction components by manufacturers, may require reconstitution of the components in large quantities, and the use of stock amounts of multiple reagents, can be wasteful when less than the maximal number of reactions are to be carried out, as some of these components may be stable for only a short time. This process of reconstitution also requires multiple manipulations by the user of the stock reagents, and aliquoting of individual reaction amounts of reagents from stocks which creates a major opportunity for contamination. Methods and compositions for the preparation of bulk quantities of preserved proteins are known, see for example, U.S. Pat. Nos. 5,098,893; 4,762,857; 4,457,916; 4,891,319; 5,026,566 and International Patent Publications WO 89/06542; WO 93/00806; WO 95/33488 and WO 89/00012, all of which are hereby incorporated by reference in their entirety. However, the use of pre-aliquoted and preserved reagent components in single reaction quantities/dose is both very useful and economical. Single aliquots of enzyme reagent avoids multiple use of bulk reagents, reducing waste, and greatly reducing the chance of contamination. Further, such single reaction aliquots are most suitable for the automation of the reaction process. The requirement for many changes of buffer and the multiple addition of reagents complicates the automation of such reactions. A single dose unit of reaction buffer mixture, and a unified combination buffer will both simplify automation of the process and reduce the chance of contamination. Automation of nucleic Acid Detection with or without Amplification Nucleic acid probe assays, and combination amplification/probe assays can be rapid, sensitive, highly specific, and usually require precise handling in order to minimize contamination with non-specific nucleic acids, and are thus prime candidates for automation. As with conventional nucleic acid detection protocols, it is generally required to utilize a detection probe oligonucleotide sequence which is linked by some means to a detectable signal generating component. One possible probe detection system is described in U.S. Pat. No. 4,581,333 hereby incorporated by reference in its entirety. In addition, automation of a nucleic acid detection system targeting unamplified or amplified nucleic acid, or a combined automated amplification/detection system will generally be adaptable to the use of nucleic acid capture oligonucleotides that are attached to some form of solid support system. Examples of such attachment and methods for attachment of nucleic acid to solid support are found in U.S. Pat. No. 5,489,653 and 5,510,084 both of which are hereby incorporated by reference. Automation of amplification, detection, and a combination of amplification and detection is desirable to reduce the requirement of multiple user interactions with the assay. Apparatus and methods for optically analyzing test materials are described for example in U.S. Pat. No. 5,122,284 (hereby incorporated by reference in its entirety). Automation is generally believed to be more economical, efficient, reproducible and accurate for the processing of clinical assays. Thus with the superior sensitivity and specificity of nucleic acid detection assays, the use of amplification of nucleic acid sequences, and automation at one or more phases of a assay protocol can enhance the utility of the assay protocol and its utility in a clinical setting. Advantage of Internal Control Sequences Nucleic acid amplification is highly sensitive to reaction conditions, and the failure to amplify and/or detect any specific nucleic acid sequences in a sample may be due to error in the amplification process as much as being due to absence of desired target sequence. Amplification reactions are notoriously sensitive to reaction conditions and have generally required including control reactions with known nucleic acid target and primers in separate reaction vessels treated at the same time. However, internal control sequences added into the test reaction mixture would truly control for the success of the amplification process in the subject test reaction mixture and would be most useful. U.S. Pat. No. 5,457,027 (hereby incorporated by reference in its entirety) teaches certain internal control sequences which are useful as an internal oligonucleotide standard in isothermal amplification reactions for Mycobacterium tuberculosis. However it would be extremely useful to have a general method of generating internal control sequences, that would be useful as internal controls of the various amplification procedures, which are specifically tailored to be unaffected by the nucleic acid sequences present in the target organism, the host organism, or nucleic acids present in the normal flora or in the environment. Generally, such internal control sequences should not be substantially similar to any nucleic acid sequences present in a clinical setting, including human, pathogenic organism, normal flora organisms, or environmental organisms which could interfere with the amplification and detection of the internal control sequences. Detection of More than one Nucleic Acid Sequence in a Single Assay In general, a single assay reaction for the detection of nucleic acid sequences is limited to the detection of a single target nucleic acid sequence. This single target limitation increases costs and time required to perform clinical diagnostic assays and verification control reactions. The detection of more than one nucleic acid sequence in a sample using a single assay would greatly enhance the efficiency of sample analysis and would be of a great economic benefit by reducing costs, for example helping to reduce the need for multiple clinical assays. Multiple analyte detection in a single assay has been applied to antibody detection of analyte as in for example International Patent Publication number WO 89/00290 and WO 93/21346 both of which are hereby incorporated by reference in their entirety. In addition to reducing cost, time required, the detection of more than one nucleic acid target sequence in a single assay would reduce the chance of erroneous results. In particular multiple detection would greatly enhance the utility and benefit using internal control sequences and allow for the rapid validation of negative results. SUMMARY OF THE INVENTION The present invention comprises methods for the automated isothermal amplification and detection of a specific nucleic acid in a test sample to be tested comprising: a) combining a test sample to be tested with a buffer, a mixture of free nucleotides, specific oligonucleotide primers, and optionally thermostable nucleic acid polymerization enzyme, in a first reaction vessel and placing the reaction vessel in an automated apparatus such that; b) the automated apparatus heats the first reaction vessel to a temperature, and for a time sufficient to denature, if necessary, the nucleic acid in the sample to be tested; c) the automated apparatus cools the first reaction vessel to a temperature such that oligonucleotide primers can specifically anneal to the target nucleic acid; d) the automated apparatus transfers the reaction mixture from the first reaction vessel to a second reaction vessel, and brings the reaction mixture in contact with themmolabile nucleic acid amplification enzyme; e) the automated apparatus maintains the temperature of the second reaction vessel at a temperature which allows primer mediated amplification of the nucleic acid; f) the automated apparatus contacts the amplified nucleic acid in the second reaction vessel with a capture nucleic acid specific for the nucleic acid to be tested such that they form a specifically-bound nucleic acid-capture probe complex; g) the automated apparatus optionally washes the specifically captured amplified nucleic acid such that non-specifically bound nucleic acid is washed away from the specifically-bound nucleic acid-capture probe complex; h) the automated apparatus contacts the specifically-bound nucleic acid-capture probe complex with a labeled nucleic acid probe specific for the amplified nucleic acid such that a complex is formed between the specifically amplified nucleic acid and the labeled nucleic acid probe; i) the automated apparatus washes the specifically-bound nucleic acid-capture probe-labeled probe complex such that non-specifically bound labeled probe nucleic acid is washed away from the specifically bound complex; j) the automated apparatus contacts the specifically bound complex with a solution wherein an detection reaction between the labeled nucleic acid probe is effected between the solution and the label attached to the nucleic acid such that a detectable signal is generated from the sample in proportion the amount of specifically-bound amplified nucleic acid in the sample;  wherein the steps h, i, and j may occur sequentially or simultaneously; k) the automated apparatus detects the signal and optionally displays a value for the signal, or optionally records a value for the signal. As used herein, the term test sample includes samples taken from living patients, from non-living patients, from surfaces, gas, vacuum or liquids, from tissues, bodily fluids, swabs from body surfaces or cavities, and any similar source. The term buffer as used here encompasses suitable formulations of buffer which can support the effective activity of a label, for example an enzyme placed into such buffer when treated at the appropriate temperature for activity and given the proper enzymatic substrate and templates as needed. The term specific oligonucleotide nucleic acid primers means an oligonucleotide having a nucleic acid sequence which is substantially complementary to and will specifically hybridize/anneal to a target nucleic acid of interest and may optionally contain a promoter sequence recognized by RNA polymerase. The term reaction vessel means a container in which a chemical reaction can be performed and preferably capable of withstanding temperatures of anywhere from about −80° C. to 100° C. The instant invention further provides for the method described above, wherein the reaction buffer is a unified buffer and as such is suitable for denaturation nucleic acids and annealing of nucleic acids, and is further capable of sustaining the enzymatic activity of nucleic acid polymerization and amplification enzyme. Further encompassed by the invention is the method wherein the nucleic acid amplification enzyme is administered in the second reaction chamber as a single assay dose amount in a lyophilized pellet, and the reaction chamber is sealed prior to the amplification step. The invention teaches an apparatus for the automated detection of more than one nucleic acid target sequences or amplicons comprising a solid phase receptacle (SPR® pipet-like devise) coated with at least two distinct zones of a capture nucleic acid oligonucleotide. The invention teaches a method for the automated detection of more than one nucleic acid target sequence comprising contacting a solid phase receptacle (SPR® pipet-like devise) coated with at least two distinct capture nucleic acid oligonucleotides in a single or multiple zones to a sample to be tested and detecting a signal(s) from specifically bound probe. In one embodiment of the invention, the SPR® is coated with two distinct zones of capture nucleic acid oligonucleotides which are specific for different nucleic acid sequence targets. In another embodiment of the invention, the SPR® is coated with at least one capture probe for a target nucleic acid sequence, and one capture probe for an amplification control nucleic acid sequence which when detected confirms that amplification did take place. The present invention also comprises an internal amplification positive control nucleic acid having the nucleic acid sequence of RIC1 and a second internal amplification positive control nucleic acid having the nucleic acid sequence of RIC2. The present invention further comprises a method for generating an internal amplification positive control nucleic acid consisting of: generating random nucleic acid sequences of at least 10 nucleotides in length, screening said random nucleic acid sequence and selecting for specific functionality, combining in tandem a number of such functionally selected nucleic acid sequences, and screening the combined nucleic acid sequence and optionally selecting against formation of intra-strand nucleic acid dimers, or the formation of hairpin structures. BRIEF DESCRIPTION OF THE DRAWINGS Presently preferred embodiments of the invention will be described in conjunction with the appended drawings, wherein like reference numerals refer to like elements in the various views, and in which: FIG. 1 is a graph illustrating single dose reagent pellet temperature stability; FIG. 2 illustrates the general TMA protocol; FIG. 3A is a schematic representation of a disposable dual chamber reaction vessel and the heating steps associated therewith to perform a TMA reaction in accordance with one possible embodiment of the invention; FIG. 3B is a schematic representation of alternative form of the invention in which two separate reaction chambers are combined to form a dual chamber reaction vessel; FIG. 3C is a schematic representation of two alternative embodiments of a dual chamber reaction vessel that are snapped into place in a test strip for processing with a solid phase receptacle and optical equipment in accordance with a preferred embodiment of the invention; FIG. 4 is a schematic representation of an alternative embodiment of a dual chamber reaction vessel formed from two separate chambers that are combined in a manner to permit a fluid sample in one chamber to be transferred to the other chamber, with the combined dual chamber vessel placed into a test strip such as illustrated in FIG. 3C; FIG. 5 is a perspective view of a stand-alone amplification processing station for the test strips having the dual chamber reaction vessels in accordance with a presently preferred form of the invention; FIG. 6 is a perspective view of one of the amplification modules of FIG. 4 / 31 , as seen from the rear of the module; FIG. 7 is a perspective view of the front of the module of FIG. 5 / 32 ; FIG. 8 is another perspective view of the module of FIG. 7; FIG. 9 is a detailed perspective view of a portion of the test strip holder and 95° C. Peltier heating subsystems of the module of FIGS. 6-8; FIG. 10 is an isolated perspective view of the test strip holder of FIG. 9, showing two test strips installed in the test strip holder; FIG. 11 is a detailed perspective view of the test strip holder or tray of FIG. 7; FIG. 12 is a block diagram of the electronics of the amplification processing station of FIG. 7; FIG. 13 is a diagram of the vacuum subsystem for the amplification processing station of FIG. 6; and FIG. 14 is a graph of the thermal cycle of the station of FIG. 6 . FIG. 15 illustrates a schematic of the operation of the multiplex VIDAS detection. FIG. 16 illustrates the production of SPR® with two distinct capture zones; FIG. 17 illustrates the VIDAS apparatus strip configuration for multiplex detection; FIG. 18 illustrates and graphs the results of verification of the VIDAS multiplex protocol detecting only NG target; FIG. 19 A/ 46 A is a graph showing the results when 1×10 12 CT targets were mixed with 0, 1×10 9 , 1×10 10 , 1×10 11 , or 1×10 12 , NG targets, and detected with the VIDAS instrument using the multiplex protocol and SPRs coated with CT capture probes on the bottom zone of the SPR®, and NG capture probes on the top zone of the SPR®. FIG. 19 B/ 46 B illustrates the results when 1×10 12 NG targets was mixed with 0, 1×10 9 , 1×10 10 , 1×10 11 , or 1×10 12 , NG targets, and detected with the VIDAS instrument using the multiplex protocol and SPR® coated with CT capture probes on the bottom zone of the SPR®, and NG capture probes on the top zone of the SPR®. FIG. 20A is a graph showing detection of Mtb nucleic acid by VIDAS apparatus after amplification. FIG. 20B is a graph showing detection of Mtb nucleic acid by VIDAS apparatus. FIG. 21 is a graph showing detection of Mtb nucleic acid by VIDAS apparatus after amplification. FIG. 22 is a graph showing detection of Mtb nucleic acid by VIDAS apparatus after amplification using the binary/dual chamber protocol. FIG. 23 illustrates the results generated by the method described showing a collection of strings of nucleic acid sequences and screening for specific functional parameters. FIG. 24 shows the nucleic acid sequence of Random Internal Control 1 (RIC1) with the possible oligonucleotide primers/probes for amplification and detection of the control sequence. FIG. 25 shows an analysis of the possible secondary structural components of the RIC1 sequence. FIG. 26 shows the nucleic acid sequence of Random Internal Control 2 (RIC2) with the possible oligonucleotide primers/probes for amplification and detection of the control sequence. FIG. 27 shows an analysis of the possible secondary structural components of the RIC2 sequence. FIG. 28 illustrates results from detection of RIC1 DNA, where the ran21 was the capture probe and ran33 was an enzyme-linked detector-probe, and shows that amplification and detection occurs under standard assay conditions. FIG. 29 shows that RIC1 RNA, amplified by TMA and the chemically activated signal detected on a VIDAS instrument (bioMérieux Vitek, Inc.) using the enzyme-linked detection system, has a limit of sensitivity of about 1000 molecules of RIC1 RNA (without optimization of conditions). DESCRIPTION OF THE INVENTION The following examples are provided to better illustrate certain embodiments of the present invention without intending to limit the scope of the invention. EXAMPLE 1 Single Dose Reagents and Unified Buffer The implementation of a TMA reaction (see U.S. Pat. No. 5,437,990) on-line in a VIDAS or off-line in a separate instrument (with detection occurring on a VIDAS instrument) requires modification of the chemistry used to perform the reaction manually. First, bulk packaged reagents must be modified into single aliquot doses, and second, the buffer components of the reaction has been altered to form a single comprehensive multifunctional unified buffer solution. Under the current manual technology, the reagents are prepared as lyophilized “cakes” of multiple-assay quantities. The amplification and enzyme reagents thus must be reconstituted in bulk and aliquoted for individual assays. Thus the automated form of TMA on the VIDAS system improves on the above manual method by utilizing single dose pellets of lyophilized reaction components that can be resuspended in a single unified buffer which will support sample dilution, denaturation of nucleic acids, annealing of nucleic acids, and desired enzymatic activity. A) Unified Buffer and Single Dose Reagents To test the feasibility of single dose amplification reagents, standard Chlamydia TMA Amplification and Enzyme reagents (Gen-Probe Inc.), the bulk reagents were reconstituted in 0.75 ml of water. 12.5 μl of either the water reconstituted amplification or enzyme reagent (i.e. a single dose aliquots) were aliquoted into microcentrifuge tubes. These tubes were placed in a vacuum centrifuge with low heat to remove water. The end result of this procedure was microcentrifuge tube containing a small, dry cake of either enzyme or amplification reagent at the bottom of the tube. The combined Unified Buffer used in this example, consists of a combination of standard commercially available Gen-Probe Inc. Sample Dilution Buffer (SDB), Amplification Reconstitution Buffer (ARB), and Enzyme Dilution Buffer (EDB) in a 2:1:1 ratio. To each dried amplification reagent microfuge tube was added 100 μl of the combined Unified Buffer, and positive control nucleic acid (+), and overlaid with 100 μl of silicone oil. The tube was then heated to 95° C. for 10 minutes and then cooled to 42° C. for 5 minutes. The 200 μl total volume was then transferred to a tube containing the dried enzyme reagent. This was then gently mixed to resuspend the enzyme reagent, and the solution was heated for one hour at 42° C. Control reactions were prepared using Gen-Probe Control reagents which were reconstituted in the normal 1.5 ml of ARB or EDB according to instructions provided in the Gen-Probe kit. In each control reaction 25 μl of the reconstituted amplification reagent was combined with 50 μl or the SDB with the positive control nucleic acid (+). The mixture was also heated to 95° C. for 10 minutes and then cooled to 42° C. for 5 minutes. To this was added 25 μl of the reconstituted enzyme reagent and incubated at 42° C. for one hour. Negative control had no nucleic acid. Both the test Unified Buffer (Unified) reactions and the standard Control 15 (Control) reactions were then subjected to the Gen-Probe Inc. standard Hybridization Protection Assay (HPA) protocol. Briefly, 100 μl of a Chlamydia trachomatis specific nucleic acid probe was added to each tube and allowed to hybridize for 15 minutes at 60° C. Then 300 μl of Selection Reagent was added to each tube and the differential hydrolysis of hybridized and unhybridized probe was allowed to occur for 10 minutes. The tubes were then read in a Gen-Probe Inc. Leader 50 luminometer and the resultant data recorded as Relative Light Units (RLU) detected from the label, as shown in Table 1 below. Data reported as RLU, standard C. Trachomatis TMA/HPA reaction. TABLE 1 Unified single dose aliquot of amplification and enzyme reagents Control (+) Unified (+) Control (−) Unified (−) 2,264,426 2,245,495 6,734 3,993 2,156,498 2,062,483 3,484 3,765 1,958,742 2,418,531 5,439 5,836 2,451,872 2,286,773 2,346,131 1,834,198 The data in Table 1 demonstrates that comparable results are obtained when using the single dose aliquots of dried amplification and enzyme reagent. In addition, the data shows that the results were comparable using three separate buffers (ARB, EDB and SDB) and one unified combined buffer (SDB, ARB and EDB combined at a ratio of 2:1:1) to resuspend the reagents and run the reactions. B) Pellitization of Single Dose Reagents In order to simplify the single dose aliquoting of reagents, methods which will allow for pelletization of these reagents in single dose aliquots were used. Briefly, reagent pellets (or beads) can be made by aliquoting an aqueous solution of the reagent of choice (that has been combined with an appropriate excipient, such as D(+) Trehalose (α-D-Glucopyranosyl-α-D-glucopyranoside, purchased from Pfanstiehl Laboratories, Inc., Waukegan, Ill.) into a cryogenic fluid, and then using sublimation to remove the water from the pellet. Once the reagent/trehalose mixture is aliquoted into the cryogenic fluid, it forms a spherical frozen pellet. These pellets are then placed in a lyophilizer where the frozen water molecules sublimate during the vacuum cycle. The result of this procedure is small, stable, non-flaking reagent pellets which can be dispensed into the appropriate packaging. Single dose aliquot pellets of reagents which contained RT, T7 and sugar were subjected to a wide range of temperatures to examine pellet stability. After being subject to a test temperature for 10 minutes, the pellets were then used for CT amplification. The results are graphed in FIG. 1 . The results show that the single dose reagent pellet remains stable even after to exposure to high temperatures for 10 minutes. The extraordinary stability of enzymes dried in trehalose has been previously reported (Colaco et al., 1992, Bio/Technology, 10, 1007) which has renewed interest in research on long-term stabilization of proteins has become a topic of interest (Franks, 1994, Bio/Technology, 12, 253). The resulting pellets of the amplification reagent and enzyme reagents were tested by use in C. Trachomatis TMA/PA reactions. The prepared amplification pellets were placed in a tube to which was added 75 μl of a mixture of ARB and SDB (mixed in a 1:2 ratio) with positive control nucleic acid. This sample was then heated to 95° C. for 10 minutes and then cooled to 42° C. for 5 minutes. To this was added 25 μl of enzyme reagent, which had been reconstituted using standard Gen-Probe Inc. procedure. This mixture was allowed to incubate for one hour at 42° C. The reactions were then analyzed by the HPA procedure, as described above. The results of this test are reported as RLU in Table 2, and labeled AMP Pellets(+). As above, negative control reactions were run without nucleic acid (−). The prepared enzyme pellets were tested by heating 100 μl of a combination of SDB with positive control nucleic acid, EDB, and the standard reconstituted amplification reagent (in a 2:1:1 ratio) at 95° C. for 10 minutes and then cooled to 42° C. for 5 minutes. The total volume of the reaction mix was added to the prepared enzyme pellet. After the pellet was dissolved, the reaction was heated to 42° C. for one hour and then subjected to HPA analysis as above. The results of this test are reported as RLU in Table 2 below, labeled Enzyme Pellet (+). Control reactions were prepared using standard Gen-Probe Inc. reagents following standard procedure. Data reported as RLU, standard C. Trachomatis TMA/HPA reaction. TABLE 2 Single dose aliquot of pelleted amplification and enzyme reagents Amp Pellets Amp Pellets Enzyme Enzyme Control (+) (+) (−) Pellets (+) Pellets (−) 2,363,342 2,451,387 2,619 2,240,989 3,418 2,350,028 2,215,235 2,358 3,383,195 1,865 2,168,393 2,136,645 3,421 2,596,041 2,649 2,412,876 2,375,541 2,247 2,342,288 1,653 The data in Table 2 demonstrates that there was no significant difference when using the standard Gen-Probe Inc. reagents, or the dried, prepared, single dose amplification reagent pellet, or the enzyme reagent pellet. Thus the single dose aliquots of reagents are suitable for use with a single unified buffer for application to automation using a VIDAS system. EXAMPLE 2 Automated Isothermal Amplification Using Thermolabile Enzymes In order to automate the isothermal amplification assay reaction for use with clinical assay apparatus, such as a VIDAS instrument (BioMérieux Vitek, Inc.), a novel dual-chamber reaction vessel has been designed to implement the use of the unified buffer and single reaction aliquot reagent pellets described above in isothermal amplification assay of test samples which can be further used in combination with a stand alone processing station. A) Dual Reaction Chambers The use of two chambers will facilitate keeping separate the heat stable sample/amplification reagent (containing the specific primers and nucleotides) from the heat labile enzymatic components (i.e. RNA reverse transcriptase, RNA polymerase RNase H). FIG. 3A is a schematic representation of a disposable dual chamber reaction vessel 10 and the heating steps associated therewith to perform a TMA reaction in accordance with one possible embodiment of the invention. Chamber A contains the amplification mix, namely deoxynucleotides, primers, MgCl 2 and other salts and buffer components. Chamber B contains the amplification enzyme that catalyzes the amplification reaction, e.g., T7 and/or RT. After addition of the targets (or patient sample) into chamber A, heat is applied to chamber A to denature the DNA nucleic acid targets and/or remove RNA secondary structure. The temperature of chamber A is then cooled down to allow primer annealing. Subsequently, the solution of chamber A is brought into contact with chamber B. Chambers A and B, now in fluid communication with each other, are then maintained at the optimum temperature for the amplification reaction, e.g., 42 degrees C. By spatially separating chamber A from chamber B, and applying the heat for denaturation to chamber A only, the thermolabile enzymes in chamber B are protected from inactivation during the denaturation step. FIG. 3B is a schematic representation of an alternative form of the invention in which two separate reaction chambers 12 and 14 are combined to form a dual chamber reaction vessel 10 . Like the embodiment of FIG. 3A, Chamber A is pre-loaded during a manufacturing step with an amplification mix, namely nucleotides, primers, MgCl 2 and other salts and buffer components. Chamber B is pre-loaded during manufacturing with the amplification enzyme that catalyzes the amplification reaction, e.g., T7 and/or RT. Fluid sample is then introduced into chamber A. The targets are heated for denaturation to 95° C. in chamber A. After cooling chamber A to 42° C., the solution in chamber A is brought into contact with the enzymes in chamber B to trigger the isothermal amplification reaction. If the reaction vessel is designed such that, after having brought the contents of chambers A and B into contact, the amplification chamber does not allow any exchange of materials with the environment, a closed system amplification is realized that minimizes the risk of contaminating the amplification reaction with heterologous targets or amplification products from previous reactions. FIG. 3C is a schematic representation of two alternative dual chamber reaction vessels 10 and 10 ′ that are snapped into place in a test strip 19 for processing with a solid phase receptacle and optical equipment in accordance with a preferred embodiment of the invention. In the embodiments of FIG. 3, a unidirectional flow system is provided. The sample is first introduced into chamber A for heating to the denaturation temperature. Chamber A contains the dried amplification reagent mix 16 . After cooling, the fluid is transferred to chamber B containing the dried enzyme 18 in the form of a pellet. Chamber B is maintained at 42° C. after the fluid sample is introduced into Chamber B. The amplification reaction takes place in Chamber B at the optimum reaction temperature (e.g., 42° C.). After the reaction is completed, the test strip 19 is then processed in a machine such as the VIDAS® instrument available from bioMérieux Vitek, Inc., the assignee of the present invention. Persons of skill in the art are familiar with the VIDAS® instrument. The steps of heating and cooling of chamber A could be performed prior to the insertion of the dual chamber disposable reaction vessel 10 or 10 ′ into the test strip 16 , or, alternatively, suitable heating elements could be placed adjacent to the left hand end 24 of the test strip 19 in order to provide the proper temperature control of the reaction chamber A. The stand alone amplification processing station of FIGS. 4-14, described below, incorporates suitable heating elements and control systems to provide the proper temperature control for the reaction vessel 10 . FIG. 4 is a schematic representation of an alternative embodiment of a dual chamber reaction vessel 10 ″ formed from two separate interlocking vessels 10 A and 10 B that are combined in a manner to permit a fluid sample in one chamber to flow to the other, with the combined dual chamber vessel 10 ″ placed into a test strip 19 such as described above in FIG. 3 A. The fluid sample is introduced into chamber A, which contains the dried amplification reagent mix 16 . Vessel A is then heated off-line to 95 degrees C, then cooled to 42 degrees C. The two vessels A and B are brought together by means of a conventional snap fit between complementary locking surfaces on the tube projection 26 on chamber B and the recessed conduit 28 on chamber A. The mixing of the sample solution from chamber A with the enzyme from chamber B occurs since the two chambers are in fluid communication with each other, as indicated by the arrow 30 . The sample can then be amplified in the combined dual chamber disposable reaction vessel 10 ″ off-line, or on-line by snapping the combined disposable vessel 10 ″ into a modified VIDAS® strip. The VIDAS® instrument could perform the detection of the amplification reaction in known fashion. B) Amplification Station FIG. 5 is a perspective view of a stand-alone amplification processing system 200 for the test strips 19 having the dual chamber reaction vessels in accordance with a presently preferred form of the invention. The system 200 consists of two identical amplification stations 202 and 204 , a power supply module 206 , a control circuitry module 208 , a vacuum tank 210 and connectors 212 for the power supply module 206 . The tank 210 has hoses 320 and 324 for providing vacuum to amplification stations 202 and 204 and ultimately to a plurality of vacuum probes (one per strip) in the manner described above for facilitating transfer of fluid from the first chamber to the second chamber. The vacuum subsystem is described below in conjunction with FIG. 14 . The amplification stations 202 and 204 each have a tray for receiving at least one of the strips and associated temperature control, vacuum and valve activation subsystems for heating the reaction wells of the strip to the proper temperatures, transferring fluid from the first chamber in the dual chamber reaction wells to the second chamber, and activating a valve such as a thimble valve to open the fluid channel to allow the fluid to flow between the two chambers. The stations 202 and 204 are designed as stand alone amplification stations for performing the amplification reaction in an automated manner after the patient or clinical sample has been added to the first chamber of the dual chamber reaction vessel described above. The processing of the strips after the reaction is completed with an SPR takes place in a separate machine, such as the VIDAS® instrument. Specifically, after the strips have been placed in the stations 202 and 204 and the reaction run in the stations, the strips are removed from the stations 202 and 204 and placed into a VIDAS® instrument for subsequent processing and analysis in known fashion. The entire system 200 is under microprocessor control by an amplification system interface board (not shown in FIG. 5 ). The control system is shown in block diagram form in FIG. 12 and will be described later. Referring now to FIG. 6, one of the amplification stations 202 is shown in a perspective view. The other amplification station is of identical design and construction. FIG. 7 is a perspective view of the front of the module of FIG. 6 . Referring to these figures, the station includes a vacuum probe slide motor 222 and vacuum probes slide cam wheel 246 that operate to slide a set of vacuum probes 244 (shown in FIG. 7) for the thimble valves up and down relative to a vacuum probes slide 246 to open the thimble valves and apply vacuum so as to draw the fluid from the first chamber of the reaction vessel 10 to the second chamber. The vacuum probes 244 reciprocate within annular recesses provided in the vacuum probes slide 246 . Obviously, proper registry of the pin structure and vacuum probe 244 with corresponding structure in the test strip as installed on the tray needs to be observed. The station includes side walls 228 and 230 that provide a frame for the station 202 . Tray controller board 229 is mounted between the side walls 228 and 230 . The electronics module for the station 202 is installed on the tray controller board 229 . A set of tray thermal insulation covers 220 are part of a thermal subsystem and are provided to envelop a tray 240 (FIG. 7) that receives one or more of the test strips. The insulation covers 220 help maintain the temperature of the tray 240 at the proper temperatures. The thermal subsystem also includes a 42° C. Peltier heat sink 242 , a portion of which is positioned adjacent to the second chamber in the dual chamber reaction vessel in the test strip to maintain that chamber at the proper temperature for the enzymatic amplification reaction. A 95° C. heat sink 250 is provided for the front of the tray 240 for maintaining the first chamber of the reaction well in the test strip at the denaturation temperature. FIG. 8 is another perspective view of the module of FIG. 7, showing the 95° C. heat sink 250 and a set of fins 252 . Note that the 95° C. heat sink 250 is positioned to the front of and slightly below the tray 240 . The 42° C. heat sink 242 is positioned behind the heat sink 250 . FIG. 9 is a detailed perspective view of a portion of the tray 240 that holds the test strips (not shown) as seen from above. The tray 240 includes a front portion having a base 254 , a plurality of discontinuous raised parallel ridge structures 256 with recessed slots 258 for receiving the test strips. The base of the front 254 of the tray 240 is in contact with the 95° C. heat sink 250 . The side walls of the parallel raised ridges 256 at positions 256 A and 256 B are placed as close as possible to the first and second chambers of the reaction vessel 10 of FIG. 3A so as to reduce thermal resistance. The base of the rear of the tray 240 is in contact with a 42° C. Peltier heat sink, as best seen in FIG. 8 . The portion 256 B of the raised ridge for the rear of the tray is physically isolated from portion 256 A for the front of the tray, and portion 256 B is in contact with the 42° C. heat sink so as to keep the second chamber of the reaction vessel in the test strip at the proper temperature. Still referring to FIG. 9, the vacuum probes 244 include a rubber gasket 260 . When the vacuum probes 244 are lowered by the vacuum probe motor 222 (FIG. 6) the gaskets 260 are positioned on the upper surface of the test strip surrounding the vacuum port in the dual chamber reaction vessel so as to make a tight seal and permit vacuum to be drawn on the second chamber. FIG. 10 is an isolated perspective view of the test strip holder or tray 240 of FIG. 9, showing two test strips installed in the tray 240 . The tray 240 has a plurality of lanes or slots 241 receiving up to six test strips 19 for simultaneous processing. FIG. 10 shows the heat sinks 242 and 250 for maintaining the respective portions of the tray 240 and ridges 256 at the proper temperature. FIG. 11 is a detailed perspective view of the test strip holder or tray 240 as seen from below. The 95° C. Peltier heat sink which would be below front portion 254 has been removed in order to better illustrate the rear heat sink 242 beneath the rear portion of the tray 240 . FIG. 12 is a block diagram of the electronics and control system of the amplification processing system of FIG. 5 . The control system is divided into two boards 310 and 311 , section A 310 at the top of the diagram devoted to amplification module or station 202 and the other board 311 (section B) devoted to the other module 204 . The two boards 310 and 311 are identical and only the top section 310 will be discussed. The two boards 310 and 311 are connected to an amplification station interface board 300 . The interface board 300 communicates with a stand alone personal computer 304 via a high speed data bus 302 . The personal computer 304 is a conventional IBM compatible computer with hard disk drive, video monitor, etc. In a preferred embodiment, the stations 202 and 204 are under control by the interface board 300 . The board 310 for station 202 controls the front tray 240 which is maintained at a temperature of 95° C. by two Peltier heat sink modules, a pair of fans and a temperature sensor incorporated into the front portion 254 of the tray 240 . The back of the tray is maintained at a temperature of 42° C. by two Peltier modules and a temperature sensor. The movement of the vacuum probes 244 is controlled by the probes motor 222 . Position sensors are provided to provide input signals to the tray controller board as to the position of the vacuum probes 244 . The tray controller board 310 includes a set of drivers 312 for the active and passive components of the system which receive data from the temperature and position sensors and issue commands to the active components, i.e., motors, fans, Peltier modules, etc. The drivers are responsive to commands from the amplification interface board 300 . The interface board also issues commands to the vacuum pump for the vacuum subsystem, as shown. FIG. 13 is a diagram of the vacuum subsystem 320 for the amplification processing stations 202 and 204 of FIG. 5 . The subsystem includes a 1 liter plastic vacuum tank 210 which is connected via an inlet line 322 to a vacuum pump 323 for generating a vacuum in the tank 210 . A vacuum supply line 324 is provided for providing vacuum to a pair of pinch solenoid valves 224 (see FIG. 6) via supply lines 324 A and 324 B. These vacuum supply lines 324 A and 324 B supply vacuum to a manifold 226 distributing the vacuum to the vacuum probes 244 . Note the pointed tips 245 of the vacuum probes 244 for piercing the film or membrane 64 covering the strip 19 . The vacuum system 320 also includes a differential pressure transducer 321 for monitoring the presence of vacuum in the tank 210 . The transducer 321 supplies pressure signals to the interface board 300 of FIG. 12 . FIG. 14 is a representative graph of the thermal cycle profile of the station of FIG. 5 . As indicated in line 400 , after an initial ramp up 402 in the temperature lasting less than a minute, a first temperature T 1 is reached (e.g., a denaturation temperature) which is maintained for a predetermined time period, such as 5-10 minutes, at which time a reaction occurs in the first chamber of the reaction vessel. Thereafter, a ramp down of temperature as indicated at 404 occurs and the temperature of the reaction solution in the first chamber of the reaction vessel 10 cools to temperature T 2 . After a designated amount of time after cooling to temperature T 2 , a fluid transfer occurs in which the solution in the first chamber is conveyed to the second chamber. Temperature T 2 is maintained for an appropriate amount of time for the reaction of interest, such as one hour. At time 406 , the temperature is raised rapidly to a temperature T 3 of 65° C. to stop the amplification reaction. For a TMA reaction, it is important that the ramp up time from time 406 to time 408 is brief, that is, less than 2 minutes and preferably less than one minute. Preferably, all the ramp up and ramp down of temperatures occur in less than a minute. Other embodiments of reaction vessels and amplification station components are also envisioned, and certain examples of such alternative embodiments are described in copending U.S. patent application of Luigi Catanzariti et al., serial no. hereby incorporated by reference in the entirety. EXAMPLE 3 Automated VIDAS Test for Non-amplified and Amplified Detection of Mycobacterium tuberculosis (Mtb) Using the VIDAS instrument (BioMérieux Vitek, Inc.), modified to 42° C., we have developed an in-line simple rapid nucleic acid amplification and detection assay for the clinical laboratory for the detection of Mtb in test samples which can be completed in a short time. The entire assay is designed to take place on a single test strip, minimizing the potential for target or amplicon contamination. The amplification based assay is capable of detection of Mtb where the sample contains only 5 cells similar to the sensitivity achieved by the Gen-Probe commercial kit. The amplification based assay utilizes isothermal transcription-mediated amplification (TMA) targeting unique sequences of rRNA, followed by hybridization and enzyme-linked fluorescent detection of nucleic acid probe in the VIDAS instrument. The amplification/detection assay can detect approximately 1 fg of Mtb rRNA, or less than one Mtb organism per test, and is specific for all members of the Mtb complex. Specific probes for the detection of Mtb can be found in C. Mabilat, 1994, J. Clin. Microbiol. 32, 2707. Standard smears for acid-fast bacilli are not always reliable as a diagnostic tool, and even when positive may be a mycobateria other than Mtb. Currently, standard methods for diagnosis of tuberculosis requires culturing the slow-growing bacteria, and may take up to 6 weeks or longer. During this time, the patient is usually isolated. Initial results are that this automated test matches or exceeds the clinical sensitivity of the culture method, and offers a highly sensitive method to rapidly (in less than three hours) detect Mtb in infected samples, thereby aiding rapid diagnosis, isolation and treatment. A) Sample Preparation A 450 μl volume of specimen is added to 50 μl of specimen dilution buffer in a lysing tube containing glass beads, sonicated for 15 minutes at room temperature to lyse organisms, heat inactivated for 15 minutes at 95° C. Where required, isothermal S amplification was conducted as per a commercially available manual assay kit (Gen-Probe Inc.) following the kit instructions using standard kit reagents. However, similar assays can be conducted using the modified components as described in the Examples above. B) Detection In order for the automated detection assay to operate, the detection system requires hybridization of the target nucleic acid or amplicon to a specific capture nucleic acid bound to a solid support, (in the VIDAS system called a “solid phase receptacle” SPR® pipet-like devise), and to a labeled detection probe nucleic acid (for example where the label can be alkaline phosphatase, a chemiluminescent signal compound, or other reagent that will allow for specific detection of bound probe). In an automated system such as the VIDAS, after several wash steps to remove unbound probe, the SPR® transfers the probe-target hybrid to an enzyme substrate, whereby the detectable signal is triggered from the bound probe and detected by the assay instrument. In one embodiment, the probe is conjugated to alkaline phosphatase, and once placed in contact with substrate of methyl umbelliferyl phosphate (MUMP), the substrate is converted into 4-methyl umbelliferone (4-MU) by the alkaline phosphatase. The 4-MU produces fluorescence which is measured and recorded by the standard VIDAS instrument as relative fluorescence units (RFU). When target nucleic acid is not present, no probe is bound, and no substrate is converted, thus no fluorescence is detected. C) Analytical Sensitivity: Controls Generally controls are prepared in a matrix of specimen dilution buffer with positive controls containing 5 fg of Mtb rRNA, or the equivalent rRNA of approximately 1 M. tb cell. Sensitivity of the automated probe assay can be determined by testing dilutions of lysed M tb cells. The cell lysates can generally be prepared with a 1 μl loop of cells (the assumption being that there are approximately 1×10 9 colony forming units (CFU) per 1 μl loop-full, based upon previous titration and CFU experiments). Dilutions of the Mtb lysates can then be tested with the automated probe assay. FIG. 20A is a graph showing detection of Mtb amplicons according to the Gen-Probe kit. FIG. 20B is a graph showing detection of Mtb amplicons from the same reactions as in FIG. 20A by the VIDAS instrument. FIG. 21 is a graph showing amplification and detection of Mtb nucleic acids on to the modified VIDAS apparatus. Enzyme was used in liquid form and amplification was performed in-line with VIDAS assay instrument. FIG. 22 is a graph showing amplification and detection of Mtb nucleic acids on the modified VIDAS apparatus using the binary/dual chamber disposable reaction vessel. The denaturation step was performed off-line of the VIDAS instrument, amplification and detection was performed in-line with VIDAS instrument. EXAMPLE 4 Automated VIDAS Test for Amplified Detection of Chlamydia trachomatis (CT) Using the VIDAS instrument (BioMérieux Vitek, Inc.), we have developed a simple, fully automated, highly specific assay for the rapid detection of Chlamydia trachomatis (CT) from test samples. The test utilizes isothermal TMA targeting unique sequences of the rRNA followed by hybridization and enzyme-linked fluorescence detection. The automated test specifically detects all the clinically important serovars of Chlamydia trachomatis (CT) from urogenital specimens in less than two hours. We obtained an analytical sensitivity of 0.5 fg of rRNA, or the equivalent of approximately {fraction (1/10)} th of an elementary body of Chlamydia trachomatis (CT). Agreement between the automated test and Gen-Probe's Amplified CT test for 207 clinical endocervical swabs and urines showed complete agreement. Chlamydia trachomatis (CT) infection is the leading cause of sexually transmitted disease in the United States and Europe. It is currently estimated that about four million new CT infection occur each year in the United States. Chlamydia trachomatis (CT) is a small obligate intracellular parasite that causes infections in both females and males, adults and newborns. The greatest challenge to the control of CT infection is that as many as 75% of infected women and 50% of infected men are asymptomatic. This results in a large reservoir of unrecognized infected individuals who can transmit the CT infection. The rapid and simple detection of CT infection would greatly assist identification infected individuals. A) Patient Specimens and Sample Preparation Coded samples (207) were obtained from patients with symptoms consistent with CT infection. The cervical samples were collected with a Gen-Probe sample collection kit containing Gen-Probe transport medium; the urine samples were collected into standard urine collection devices. All samples were stored at 4° C. Cervical swabs were centrifuged at 425 ×g for 5 minutes to bring all liquid to the bottom of the tube. The swabs were then treated with 40 μl Gen-Probe Specimen Preparation Reagent and incubated at 60° C. for 10 minutes. 20 μl of the treated sample was then pipetted into 400 μl of sample dilution buffer (SDB). Two ml of each urine sample was warmed to 37° C. for 10 minutes and microfuged at 12,000 ×g for 5 minutes. The supernatant was discarded and 300 μl of sample dilution buffer was added to each specimen. All 15 serovars of CT were used for inclusive samples, specimens were quantified and 20 μl of specimens containing 4×10 2 LFU/ml (inclusion forming unit per ml) of each serovar was added to 400 μl of SDB. A panel of exclusive urogenital micororganisms was obtained and quantified and 20 μl of 2×10 9 /ml microorganisms were pipetted into 400 μl of SDB. Positive control containing 0.5 fg rRNA or the equivalent of 0.1 CT elementary body was diluted in SDB. B) Sample Amplification and VIDAS Detection Samples were amplified using the TMA protocol, and rRNA targets were hybridized to oligomer conjugated to AMVE copolymer and an oligomer conjugated to alkaline phosphatase. See for example U.S. Pat. No. 5,489,653 and 5,510,084. As described above, the solid phase receptacle (SPR® pipet-like devise) carries the hybrids through successive wash steps and finally into the substrate 4-MUP. The alkaline phosphatase converts the substrate to fluoresence 4-MU, which is detected by the VIDAS assay machine and recorded as relative fluorescence units. Table 2B below illustrates detection of CT by VIDAS automated assay following amplification as RFV (RFV=RFU—Background RFU) against concentration of CT rRNA. Dilutions of C. trachomatis purified rRNA from 0 to 200 molecules were amplified (n=3) and detected in the VIDAS automated probe assay. Detection limit is 20 molecules of purified rRNA. TABLE 2B CT Detection by VIDAS rRNA Input Molecules VIDAS RFV 0 1 2 121 20 3260 200 8487 C) Analytical Specificity and Results Amplifications and detection were carried out in the presence of each of the following ATCC organisms with detections reported as RFV in Table 3 below. TABLE 3 Exclusivity panel for CT Bacillus subtilis Branhamella Candida albicans Chlamydia Chlamydia 33 catarrhalis 26 pneumoniae psittaci 15 39 11 Escherichia coli Klebsiella Lactobacillus Neisseria Neisseria 11 pneumoniae acidophilus elongata lactamica 13 27 44 18 Neisseria Neisseria Propionibacterium Pseudomonas Staphylococcus meningitidis-D meningitidis-Y acnes aeruginosa aureus 61 52 14 13 13 Streptococcus Streptococcus Streptococcus Yersinia Chlamydia agalactiae bovis pneumoniae enterolitica trachomatis 16 45 34 11 10673 Negative Control 12 Analytical specificity for Chlamydia serovars data reported as RFV is shown in Table 4 below. TABLE 4 Inclusivity Panel for CT Serovar A Serovar B Serovar Ba Serovar C Serovar D 5421 7247 9626 8066 10849 Serovar E Serovar F Serovar G Serovar H Serovar I 4608 9916 10082 7769 9733 Serovar J Serovar K Serovar L1 Serovar L2 Serovar L3 9209 2423 10786 1812 5883 Positive Negative Control 3775 Control 9 Table 5 below illustrates the results of clinical cervical swab specimen testing for CT comparing results from the Gen-Probe manual AMP-CT assay and the VIDAS automated probe assay. TABLE 5 Amplified Clinical Cervical Specimen Detection of CT Gen-Probe manual AMP-CT assay VIDAS off-line + − automated probe + 35  0 assay −  0 85 Table 6 below illustrates the results of clinical urine specimen testing comparing the results of manual AMP-CT assay and the VIDAS automated probe assay. TABLE 6 Amplified Clinical Urine Specimen detection of CT Gen-Probe manual AMP-CT assay VIDAS off-line + − automated probe + 25  0 assay −  0 62 Thus there was perfect agreement in assay results between the automated probe assay using the VIDAS instrument and the manual Gen-Probe AMP-CT assay. EXAMPLE 5 Multiplex (Multiple Sequence) Nucleic Acid Detection The value of diagnostic tests based on nucleic acid probes can be substantially increased through the detection of multiple different nucleic acid targets, and the use of internal positive controls. An automated method has been devised for use with the VIDAS instrument (BioMérieux Vitek, Inc.) which can discretely detect at least two different nucleic acid target sequences in one assay reaction, and is termed the Multiplex protocol. Thus a nucleic acid amplification procedure, or a processed test sample may be screened for more than one amplified nucleic acid target in the same assay. This method relies on the spatial separation of discrete nucleic acid probes which can capture different target nucleic acid sequences, on the Solid Phase Receptacle (SPR® pipet-like devise) of the VIDAS instrument. The SPR® is a disposable pipet-like tip which enables fluid movements as well as acting as the solid support for affinity capture. The multiplex capture by SPR® is demonstrated using capture probes specific for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). FIG. 15 illustrates a schematic of the operation of the multiplex VIDAS detection. Solid phase receptacles (SPR® pipet-like devise) are coated with two distinct zones of oligonucleotides with nucleic acid sequences which are used to specifically capture target nucleic acid sequences with their corresponding specific reporter probe nucleic acids labeled with alkaline phosphatase (AKP). Following washes to remove unbound reporter probes, AKP localized to the SPR® bottom is detected with the fluorescent substrate 4-MUP. The AKP is stripped from the bottom of the SPR® with NaOH. The enzyme reaction well is emptied, washed, and re-filled with fresh 4-MUP. To ensure the removal of AKP from the bottom of the SPR®, the new substrate is exposed to the bottom of the SPR® and residual fluorescence is measured. Finally, target bound to the top of the SPR® is detected by immersing the SPR® in the 4-MUP. FIG. 16 illustrates the production of SPR® with two distinct capture zones. The SPR® is inserted tip-first into a silicon plug, which are held in a rack. Differential pressure is used to uniformly draw a 1 μg/ml solution of a specific capture probe, conjugated to AMVE copolymer, into all SPR®s at one time. Attachment of the conjugate to the SPR® surface is activated by passive adsorption for several hours at room temperature. After washing, and drying, the SPR®s are capped with a small adhesive disc and inserted into new racks in a tip-down orientation. The lower portion of the SPR® is then similarly coated with a second capture probe conjugate. SPR®s are stable when stored dry at 4° C. FIG. 17 illustrates the VIDAS apparatus strip configuration for multiplex detection. The strip can be pre-filled with 200 μl of AKP-probe mix (about 1×10 12 molecules each) in hybridization buffer in well X 1 , 600 μl of wash buffer in wells X 3 , X 4 , X 5 , 600 μl of stripping reagent in wells X 6 and X 7 , and 400 μl of AKP substrate in X 8 and sealed with foil. A foil-sealed optical cuvette (XA) containing 300 μl of 4-MUP is snapped into the strip, and the strips are inserted into the VIDAS instrument at 37° C. The multiplex VIDAS protocol is then executed using SPR®s coated with two capture probes in distinct zones. The VIDAS multiplex protocol can involve many steps. For example the validation test protocol contained 13 steps as follows: 1. Transfer 203 μl target from X 0 to AKP-probes in X 1 , 2. Hybridize and capture to SPR®), 3. Wash SPR® (316 μl) twice with PBS/TWEEN (X 3 , X 4 ), 4. 4-MUP to SPR® bottom (89.6 μl) in XA for 5.3 minutes then read, 5. 4-MUP to SPR® bottom (89.6 μl) in XA for 14.8 minutes then read, 6. Transfer used substrate from XA to X 2 (5×67.1 μl), 7. Strip AKP from SPR® bottom (112.6 μl) with NaOH (X 7 ), 8. Wash XA with fresh NaOH (3×112.6 μl; X 6 to XA to X 6 ), 9. Wash XA with PBS/TWEEN (3×112.6 μl; X 5 to XA to X 5 ), 10. Transfer fresh 4-MUP from X 8 to XA (6×48 μl), 11. 4-MUP to SPR® bottom (89.6 μl) in XA for 10.7 minutes then read, 12. 4-MUP to SPR® top (294 μl) in XA for 5.5 minutes then read, 13. 4-MUP to SPR® top (294 μl) in XA for 15 minutes then read. Hybridization, substrate, wash and stripping steps all involve multiple cycles of pipeting the respective solution into the SPR®, holding the solution for a defined period of time, and pipeting the solution out of the SPR®. Hold times for hybridization, substrate and washing or stripping are 3.0, 0.5 and 0.17 minutes respectively. “Read” means the fluorescence is detected by the apparatus. Total assay time for the research protocol was about 1.75 hours but can be reduced to 75 minutes. FIG. 18 illustrates and graphs the results of verification of the VIDAS multiplex protocol executed as described above, wherein the SPR® was homogeneously coated with only a single capture probe for Neisseria gonorrhoeae (NG). The number of NG oligonucleotide targets in the test sample was varied from 0, 1×10 10 , or 1×10 11 molecules in the test sample. The data shown are averages of replicate samples. The graph as illustrated is divided into two parts; the left and right halves show the results of two fluorescent measurements from the lower and the upper zones of the SPR®, respectively. The measurements taken from the bottom zone after stripping the lower area of bound nucleic acid, and exposure for about 11 minutes in fresh 4-MUP substrate was approximately 46 RFU for all samples tested, and was equivalent to background fluorescence measured. This measurement is shown by the 0 time point in the center of the graph. Thus the graph illustrates two sequential sets of measurements of fluorescence from a single SPR®, the first set of measurements being taken from the bottom half of the SPR® (left half of the graph), and a second set of measurements taken from the top of the SPR® (the right of the graph). FIG. 19 illustrates Multiplex detection of CT and NG oligonucleotide targets at different input amounts. FIG. 19A is a graph showing the results when 1×10 12 CT targets were mixed with 0, 1×10 9 , 1×10 10 , 1×10 11 , or 1×10 12 , NG targets, and detected with the VIDAS instrument using the multiplex protocol and SPR®s coated with CT capture probes on the bottom zone of the SPR®, and NG capture probes on the top zone of the SPR®. FIG. 19B illustrates the results when 1×10 12 NG targets was mixed with 0, 1×10 9 , 1×10 10 , 1×10 11 , or 1×10 12 , CT targets, and detected with the VIDAS instrument using the multiplex protocol and SPR®s coated with CT capture probes on the bottom zone of the SPR®, and NG capture probes on the top zone of the SPR®. The data is graphed as above where the graph illustrates two sequential sets of measurements of fluorescence from a single SPR®, the first set of measurements being taken from the bottom half of the SPR® (left half of the graph), Stripped and verified (the center of the graph) and a second set of measurements taken from the top of the SPR® (the right of the graph). Table 7 below summarizes the data obtained by Multiplex VIDAS detection of CT and NG in a sample at various target levels, reported in RFUs. TABLE 7 Detection of CT and NG targets in sample RFUs A none B 1 × 10 9 1 × 10 10 1 × 10 11 1 × 10 12 1 × 10 13 none C 43 D /40 E 43/116 46/693 62/7116 174/11817 273/12136 1 × 10 9 189/41 246/118 169/773 220/5750 422/12522 399/11401 1 × 10 10 1736/41 2258/125 1937/734 1931/6639 2128/12390 2371/11180 1 × 10 11 10339/48 9815/145 9858/760 9369/4571 9784/11825 10252/10312 1 × 10 12 12149/49 13520/148 12940/796 13593/4397 11239/11786 10158/9900 1 × 10 13 11545/57 11713/121 10804/815 12805/5404 12305/12326 11416/10490 A Data is reported in RFUs, after ˜5 minute exposure of 4-MUP to bound AKP-probe B Columns are data for that number of NG targets in sample C Rows are the data for that number of CT targets in sample D The first value reported is RFU detected from the CT assay portion E The second value reported is RFU detected from the NG assay portion Thus the multiplex VIDAS protocol is clearly operative and enables the rapid and discrete detection of more than one different nucleic acid signal in a sample. This protocol, and the SPR® coating can be manipulated in many formats to present coating zones of different surface area with different sized gaps between detection zones. The SPR® can be coated with nucleic acids which are designed to capture different regions of the same nucleic acid sequence to detect, for example, truncated gene expression, different alleles or alternatively spliced genes. The SPR® can be coated to capture internal control nucleic acid sequences which can be used to detect and confirm successful nucleic acid amplification reactions. Thus the VIDAS protocol is a flexible method for detection of more than one nucleic acid sequence in the same sample, in a single assay. EXAMPLE 6 Internal Control Sequence and Method The construction of internal control sequences composed of functional building blocks of sequences chosen by random generation of nucleic acid sequences for use as amplification reaction internal positive controls ideally requires that the control sequences be specifically designed to be used for the various nucleic acid amplification protocols including but not limited to PCR, LCR, TMA, NASBA, and SDA. The internal control nucleic acid sequence, in combination with the appropriate sequence specific oligonucleotide primers or promoter-primers will generate a positive amplification signal if the amplification reaction was successfully completed. Ideally, the internal control nucleic acid is useful regardless of the nucleic acid sequences present in the target organism, the host organism, or nucleic acids present in the normal flora or in the environment. Generally, the internal control sequences should not be substantially similar to any nucleic acid sequences present in a clinical setting, including human, pathogenic organism, normal flora organisms, or environmental organisms which could interfere with the amplification and detection of the internal control sequences. The internal control sequences of the instant invention are comprised of functional blocks of sequences chosen from a list of randomly generated nucleic acid sequences. The functional blocks are segments which provide for a special property needed to allow for amplification, capture, and detection of the amplification product. For example, in a TMA reaction, the internal control sequences are most useful when the functional blocks meet certain functional requirements of the amplification protocol, such as: a) a primer binding site on the anti-sense strand; b) a capture site; c) a detector probe binding site; d) a T7-promoter containing primer binding site on the sense strand. Each of these functional elements has its own particular constraints, such as length, %G-C content, Tm, lack of homology to known sequences, and absence of secondary structural features (i.e. free from dimer formation or hairpin structures) which can be used to select the appropriate sequence. Thus randomly generated functional blocks of sequences can be screened for the desired functional properties before use in constructing internal control sequences. In order to construct a internal control sequences having the desired properties comprising a specified number of functional blocks and satisfying the desired constraints within each block, a random sequence generator was used to generate strings of numbers; each number being limited to the range from 0.000 to 4.000. The length of the strings is flexible and chosen based upon the desired lengths of the functional blocks. Each number in the string (i.e. n 1 , n 2 , n 3 , n 4 . . . nx where x is the length of the string) was then assigned a corresponding nucleotide as follows: guanosine (G) if 0<n≦1; adenosine (A) if 1<n≦2; thymidine (T) if 2<n≦3; and cytosine (C) if 3<n≦4. A large collection of such strings was produced and screened for those meeting the sequence and structural requirements of each functional block. FIG. 23 illustrates the results generated by the method described showing a collection of strings of nucleic acid sequences and screening for specific functional parameters. Potential internal control (IC) sequences were then constructed by assembling the functional blocks (selected at random) in the proper order. Finally, the assembled internal control sequences were then examined to insure that overall sequence and structural constraints were maintained. For example, in a TMA internal control sequence the two primer binding sites should not have a significant base-pairing potential or form stable 3′ dimer structures. Those internal control sequences which pass thorough these layers of screening were then physically produced using overlapping oligonucleotides and tested for performance in actual amplification/detection assays. Although any one function block may have some homology to sequences present in a clinical setting (a perfect match of 21 nucleotide block is expected at a random frequency of 1 in every 4e12 sequences or about 4×10 21 ; generated sequences were screened against GenBank data base) it is highly unlikely that all functional blocks will be found to have substantial homology. Since the internal control nucleic acid sequences are constructed of a group of functional blocks placed in tandem, the chance possibility that a natural nucleic acid sequence will have an identical string of nucleic acid sequence blocks in the same tandem organization is remote. Two specific internal control sequences have been constructed using the method described above. Random Internal Control 1 (RIC1) is shown in FIG. 24 with the possible oligonucleotide primers/probes for amplification and detection of the control sequence. FIG. 25 shows an analysis of the possible secondary structural components of the RIC1 sequence. RIC1 was constructed using randomly generated strings ran16, ran 19, ran21 and ran33. The functional blocks requiring primer binding were met by ran16 and ran19, while the capture site was satisfied by ran21 and the detector probe binding site was met by ran33. Random Internal Control 2 (RIC2) is shown in FIG. 26 with the possible oligonucleotide primers/probes for amplification and detection of the control sequence. FIG. 27 shows an analysis of the possible secondary structural components of the RIC2 sequence. Similarly to RIC1, RIC2 was constructed using randomly generated strings ran27, ran32, ran39 and ran51. Thus, illustrating that it is also possible that the functional blocks requiring primer binding, capture site, detector probe binding site can be met by alternative random sequences generated by the method described above. FIG. 28 illustrates results from detection of RIC1 DNA, where the ran21 was the capture probe and ran33 was an enzyme-linked detector-probe, and shows that detection occurs under standard assay conditions with expected fluorescence intensities. FIG. 29 shows that RIC1 RNA, amplified by TMA and detected on a VIDAS instrument (BioMérieux Vitek, Inc.) using the enzyme-linked detection system, has a limit of sensitivity of about 1000 molecules of RIC1 RNA (without optimization of conditions). Similar analysis of RIC2 sequences was performed and found to be similar to RIC1. It is significant that the amplification and detection system of the internal control functioned effectively under the conditions optimized for the selected target. As an alternative approach for multiplex detection using internal controls (IC), SPR®s can be homogeneously coated with a mixture of different capture nucleic acid sequences in a single, whole-SPR® zone. For example, two capture nucleic acid sequences can be combined in one zone, one specific for a target test sequence, and one specific for an internal control sequence. Target amplicons, if present, and internal control amplicons are simultaneously hybridized to the SPR® by the capture probes. In the presence of labeled probe nucleic acid sequences specific for the target test nucleic acid sequence. Following washing, a first read is done to so that the presence or absence of label on the SPR® is determined to ascertain the presence of the test target. A second hybridization is then done (sequential hybridization) to the SPR® using a detection label nucleic acid sequence specific for the internal control. The SPR® is washed to remove excess unbound detection probe, and the second label is measured to indicate the presence or absence of the internal control. If the first signal is negative, a positive signal from the IC second read confirms the functionality of the amplification/detection system. In this case, one can conclude that the test target nucleic acid sequence was truly absent (true negative). If the first signal is positive, this alone is enough to confirm functionality of the amplification and detection system, and the second signal is immaterial (positive result). In the special case where the first the first and second label are the same, an additive signal will result from the positive first read and the positive second IC read. If both the first signal is negative and the second IC signal is also negative, then the amplification/detection functionality failed, which could be due to for example, sample interference or mechanical failure. In this case the test result is reported invalid (false negative) and re-testing is recommended. There is great interest in the use of internal controls, the underlying rational being that “. . . if the sample will not support the amplification of the internal control, it is unlikely to support the amplification of the target nucleic acid sequence.” (NCCLS Document MM3-A, Molecular Diagnostic Methods for Infectious Diseases; Approved Guideline, p. 55, March 1995). Using a sequential hybridization approach with multiple detector probes, it has been possible to design protocols which allow for the discrete detection of first read signal (ie. pure CT signal) and an additive “mixed” second read (ie. additive CT and discrete signal for negatives; see Table 7A below). This protocol will not need stripping with NaOH. For example, Table 7A shows the results when different mixtures of synthetic targets were first captured with homogeneously coated SPR®s (CT and IC capture probes) and hybridized with the CT detector probe. After the first read, hybridization was performed with the IC detector probe, followed by a second read (same substrate). This type of protocol can also be used for a combined GC/CT/intemal control assay, if a screening approach is allowed (no discrimination between GC and/or CT positives during the first read). GC and CT specific signals have to be resolved by running the CT and GC specific assays on screen positive samples (5-10% of cases, depending on prevalence) SPR®s would be coated homogeneously with 3 capture probes (CT/GC/internal control). TABLE 7A Homogeneous Coated SPR ® Detection of multiple signals Target CT 1 st Read IC 2 nd Read Bkg. RFU 10 10 CT 7077 8608 58 10 10 IC 58 4110 56 10 10 IC/CT 5594 8273 57 10 10 IC/CT 5712 8317 57 no target 66 89 57 Thus internal control sequences described above are useful for application with VIDAS apparatus with coated SPR® and the use of the Multiplex system to provide for combined assay detection of a nucleic acid and monitoring control for successful reaction.

The present invention relates to the detection of specific nucleic acid sequences after an amplification process, or directly without amplification. In particular, the invention provides for the automation of the amplification and detection process, the amplification and detection of one or more specific nucleic acid sequences, the use of internal controls, reduced potential for contamination caused by the manual manipulation of reagents, and improved reagent compositions to better control assay performance and provide for further protection against contamination.

BACKGROUND—FIELD OF INVENTION This invention relates to cleaning, to materials used in cleaning, and particularly to the employment of electric energy to do the work of cleaning by a method and device which operates to apply electrical energy directly to washing fluid at a site of cleaning, thus affecting the physical properties or characteristics of a cleaning substance, resulting in a reduced dependence on traditional chemical forms of energy to do the work of cleaning, and a reduced discharge of chemical waste, resulting in reduction of environmental pollution due to chemical waste discharge to a greater extent than heretofore possible. BACKGROUND—DESCRIPTION OF PRIOR ART Ideally, there should be no detectable difference in water before and after it is used for cleaning (other than the presence of the soil transferred from the laundry to the water). All forms of energy used to do the work of cleaning should have no lasting effect on the water used and should not be detected in the effluent. In the conventional chemical energy dominated laundry processes of the prior art, chemical energy is the only one of the three form of energy that violates this criteria. The thermal energy of hot water has a temporary effect occurring in the water which is very effective in the cleaning process. There is no detectable difference in water that has been heated to aid in the cleaning process, once the cleaning is done and the water again cooled. Environmentally, this is the ideal situation. The kinetic energy present in agitated water during the laundering process is not detectable once the cleaning is done and the water allowed to come to rest. Water that has induced turbulence during the cleaning process is no different after as compared to before it is used for cleaning. The only source of energy used in the conventional cleaning process that causes a detectable difference is the energy of chemicals added to the water. Chemical energy from the addition of chemical substance to the water remains in the water after the cleaning process, and is the source of pollution caused by the cleaning process. Thus is the long recognized and unfilled need to reduce the amount of polluting detergent chemicals being discharged into the environment. The cleaning process of the prior art as used in the home laundry is a major contributor to pollution of the environment due to the discarding of spent chemicals into the environment. Much of the resources used for producing laundry cleaning chemicals is non renewable. It has not been practical to recycle spent laundry detergent chemicals from home laundry use. Allergic reactions are caused by chemical residue in the fabric of clothes. The health and growth of plants and animals are affected by chemical waste from home laundering. The purity of drinking water is decreased by chemical waste from home laundering. Water treatment requirements of public waste water is increased by chemical waste from home laundering. Traditionally the cleaning process involved three different forms of energy used to dislodge soil from the items that were cleaned. Those forms of energy were kinetic energy, thermal energy, and chemical energy. Kinetic energy was from rubbing, scrubbing, or agitating. Thermal energy was from hot water. Chemical energy was principally from detergents. These forms of energy did the work of cleaning. To some extent, tradeoffs of one form of energy for another were employed. The amount of one form of energy was reduced at the cost of increasing the amount of another form. Chemical energy requirement was reduced by increasing the use of mechanical energy by rubbing, scrubbing, or agitating harder or longer. Thermal energy use was reduced by increasing the dependency on chemical energy. Two significant developments increased the dependency on chemical energy in recent times. First was the development of the automatic washing machine. The old fashioned ringer washer was used to clean several loads of wash before the water with it's laundry chemicals was discarded. The newer modern automatic washing machines, to eliminate the manual labor of removing the clothes from the wash tub to the rinse tub moved the washing and rinsing process to the same tub by changing the water rather than the clothes. Wash water was discarded after washing only one load of laundry. This resulted in a many fold increase in the number of loads of waste water, with it's polluting chemicals, being released into the environment each day. The second development was the advent of the philosophy of saving energy by washing in cold water. In reality, the energy required to do the work of cleaning was not reduced. Only the source of energy was changed. More dependence on chemical energy was the change. More dependence on chemical energy resulted in a greater quantity of chemical pollutants released into the environment. Ever since modern automatic washing machines reduced to one the number of loads of laundry to be cleaned by a single charge of cleaning solution, there has been a long recognized and unfilled need to reduce the amount of polluting detergent chemicals being discharged into the environment. At the same time there has been a demand for improvements in the appearance, odor, and other characteristics of clean laundry. Accordingly, in order to improve the cleaning efficiency, many clothes washing machine makers have utilized various methods including such methods as improving the agitators ability to scrub the laundry, extending the operating time of the motor during agitation, and improving the quality and/or increasing the quantity of detergent used in the washing machine. However, there were limits to improvements in the cleaning efficiency by the aforementioned methods for the following reasons: (a) The methods utilizing increased mechanical force to improve the washing efficiency caused damage to the laundry or reduced efficiency of the washing machine. (b) In methods utilizing increased amounts of detergent, a relatively large amount of the detergent did not react with the laundry and was discharged where it caused environmental pollution. (c) Some detergent residue stuck to the laundry and thus the laundry was not effectively cleaned. Many people were allergic to detergent residue in the clothes they wore. (d) Also, it was well known that if more than the recommended amount of detergent was used in the clothes washing machine, the washing efficiency of the washing machine was reduced. Accordingly, inventors attempted to create several types of ionic water treatment devices to generate water containing non polluting chemical energy in the form of surface tension reducing ions for the purpose of reducing the amount of detergent required. In the absence of chemical detergent, all of these devices had the same shortcoming of the short life of oppositely polarized ions in the absence of energy to hold the mutually attracted ions apart. U.S. Pat. No. 5,309,739 to Lee (1994) disclosed a device which claimed the generation of surface-tension-reducing hydroxyl ions for the purpose of reducing the amount of detergent required using tourmaline and ultrasonic energy. This device was integral to the washing machine and was required to be added on to the standard automatic washing machine at time of manufacture. The process was slow and at a point in the machine that was spatially removed from the point of the cleaning work. Any separation of the water into ions was quickly neutralized before reaching the locality where soil was being removed from the clothes, because the opposite nature of the charge on the ions caused them to attract each other and to be immediately neutralized. It has not become a commercial success because it was not significant in its effect. U.S. Pat. No. 4,066,393 to Morey and Dooley (1978) disclosed a device which utilized a cation exchange resin device to remove calcium and/or magnesium ions from the water for the purpose of reducing the amount of detergent required. However, this device required a manual step in the washing process and it too was an add on to the standard automatic washing machine requiring mechanical assembly. It only softened the water by adding more chemicals to the water so the chemical detergent could work better. It did not replace the use of chemical detergent. It removed some metal ions from the water by adding others in substitution. It did not reduce pollution of the environment, it only moved the pollution from one waste product to another. And it did nothing to improve water that was already soft. U.S. Pat. No. 5,358,617 to Ibbott (1994) disclosed a water treatment devise for use in a standard automatic washing machine which utilized electrically isolated electrodes of different electrochemical potential to ionize the wash water inside the washing machine for the purpose of reducing the amount of detergent required. However, the effectiveness of this device was quite limited by the slow rate of the process, and in this device the separation of the locality of ion generation and ion use was so great that the ions were neutralized by the time they got to the locality of the cleaning work. U.S. Pat. No. 2,997,870 to Serra (1961) disclosed a washing machine claiming ionic generation due to friction of the motion of air, water, and an India rubber vessel for the purpose of reducing the amount of detergent required. However, ions thus produced were not effectively transported to the active site of the cleaning before being neutralized by their very nature of being oppositely polarized. And thus the machine was impractical to solve the unfilled need. Devices utilizing the weak ionization developed by the mineral tourmaline have been proposed, and even marketed, to generate ions which reduce the surface tension of water. However, the process, if it did work, was so weak, and so slow, that it did not prove to be practical. Many attempts have been made to utilize energy in the form of non chemical ionic phenomena to do the work of cleaning, but the products have not been as effective as the claims made. For example, devices such as plastic balls or ceramic discs that had been offered on the market had such a weak effect that courts of law in many states declared them to be fraud. None of them supplied enough energy, in the right place to do sufficient work to take the place of the work done by chemical detergent. Electrostatic precipitators have been used for years to clean air of soil particles rather than let that form of pollution go up the smokestack. Currently there is no equivalent for particles in home laundry waste water. Instead, detergent molecules attach themselves to soil particles and are released with the soil particles into the environment. Less harmful chemicals have been proposed to be substituted for more harmful chemicals. That is, chemicals that have not been declared to be so harmful but with less track record of being safe have been substituted, However, in doing so, the composition of the waste chemical has only been changed, the quantity has not been reduced, and the flow of spent chemicals polluting the environment continues. None of these substitutions or devices have satisfied the unfilled need for reduction of the polluting chemical discharge from household laundry, nor have they contributed significantly to reduce the problem. To the contrary, more polluting chemicals have been developed to overcome the reduced effectiveness of the cleaning process to give the appearance of better cleaning. Among these are chemical brighteners, chemical whiteners, chemical perfumes, and chemical fabric softeners. The current use of the prior art method of cleaning continues to contribute significantly to environmental pollution. The long recognized and unfilled needs for increased cleaning effectiveness, and reduction of pollution produced by household laundry operations has not been met by the prior art. OBJECTS AND ADVANTAGES All three forms of energy of the prior art that are used to do the work of cleaning are related and it is possible by careful adjustment of one component to overcome limitations of either one or both of the other components. As an object of the invention, a fourth form, electric energy, is added, substituting, at least in part, for chemical energy. With the addition of this fourth form of energy, in sufficient quantity, and at the right place, the goal of reducing or even eliminating detergent chemical pollution from household laundering can be accomplished by careful adjustment of the other forms of energy. Electric or electrostatic energy, when properly applied by the inventive method, is used to accomplish, at least in part and to some extent, the work in it's various forms that has been done in the prior art by chemical detergents. Like thermal and kinetic energy, electrostatic energy added during the cleaning process is not detectable once the cleaning process is complete. Surprisingly, the rubbing between the water, laundry articles, and electrically polarized dielectric surfaces of the invention causes a surprising increase in the washing efficiency due to the generation of ionic action in the water at the right time and place to be useful during it's short life. By virtue of a simple looking device, and the unobvious benefits it enables, an entire, normal capacity washing machine is increased in cleaning efficiency. With no need to rinse a chemical residue from the laundry, this invention eliminates an energy wasting need for a separate non cleaning cycle for rinsing, making all cycles of the currently popular automatic washing machine into cleaning cycles. Accordingly, several objects and advantages of the present invention are: (a) to provide a cleaning method which does some of the work of cleaning using electrical energy in sufficient quantity and effectiveness to reduce the requirements for the other forms of energy which are thermal, kinetic, and chemical, in particular chemical, reducing or eliminating the need to discard chemical waste, filling that long recognized and unfilled need for reducing laundry chemical waste polluting the environment; (b) to provide a cleaning method which protects our environment from pollution by making effective use of a minimal amount of detergent by substituting a non polluting source of energy to do the work of cleaning; (c) to provide a form of detergent which is recycled rather than discarded; (d) to provide a cleaning method which fills that long recognized and unfilled need for reducing detergent residue in the clean laundry by substituting a non polluting source of energy to do the work of cleaning; (e) to provide a cleaning method which reduces the effect of chemical effluent on the health and growth of plants and animals by substituting a non polluting source of energy to do the work of cleaning; (f) to provide a cleaning method which reduces the effect of chemical effluent on human drinking water by substituting a non polluting source of energy to do the work of cleaning; (g) to provide a cleaning method which reduces the water treatment requirements of public waste water treatment plants to process laundry chemicals by substituting a non polluting source of energy to do the work of cleaning, thereby reducing the quantity of spent laundry chemicals needing treatment; (h) to provide a cleaning method which reduces the dependency on chemical energy by substituting a non polluting source of energy to do the work of cleaning; (i) to provide a cleaning method which improves the appearance, odor, and other characteristics of clean laundry by substituting a non polluting source of energy to do the work of cleaning; (j) to provide a cleaning device or devices which embodies the methods of this invention; and (k) to provide a cleaning device suitable to be marketed as a commercial product to be used in place of or in addition to laundry detergent. Unlike many other attempts to fill the need reduce chemical pollution of the environment, this invention operates in the manner to which the homemaker is already accustomed, and little, if any, instruction is needed. For the preferred embodiment of the invention the operation is as simple as putting the device in the washing machine with the load of laundry, operating the machine normally, and, when the load is finished, removing the device from the machine, and taking the laundry out. Or the device may be held in a hand and used for scrubbing as with a standard wash cloth or sponge. For other embodiments, such as the one where the washing machine agitator itself is the implementation of the invention, the operation is even simpler. Load the machine with clothes, operate the machine normally, and take the clothes out when the washing is done. In conjunction with the inventive device, other substances may be desired to be used, such as fabric softener. For such cases, just follow the directions that come with the other substances. The water from the home laundry, being free of chemical detergent pollution can optionally be recycled to water the garden or yard. An object of this invention is to exploit a heretofor unexploited form of energy to do the work of cleaning. A further object of the present invention is to provide a means of exploiting the new technology of surface chemistry and utilizing electric energy to reduce the need for other forms of cleaning energy of the prior art. The combination provides a superior process of cleaning without increased damage to the items being cleaned nor to the environment. A further object of the present invention is to provide a means of attracting and holding soil particles, removing them from the wash water, rather than flushing them down the drain. In similar fashion to the electrostatic precipitator removing soil particles from smoke so they do not pollute the air, a device made from the surface chemistry detergent of this invention can attract and hold soil particles removing them from the drained wash water. Again in similar fashion to the electrostatic precipitator, the device made from the inventive surface chemistry detergent can be renewed by reversing the attraction. In an embodiment of the present invention no external power source is needed other than the agitation that is already present in the normal washing machine. With the present invention no renewal parts such as batteries are needed. With the present invention no renewal source of anything is needed such as chemical refills. The present invention is simple and easy to use. The present invention does not require a large bulky attachment; or external machine or process. The present invention is not used up in the washing process. The present invention is not discarded after the cleaning process. Other laundry products which produce pleasant sensations to the human senses are compatible with the present invention. Appearance, feel, or odor enhancement products and process may be used and not interfere with the operation of the current invention. Whiteners, brighteners, softeners, or perfumes are completely compatible and may be used in conjunction if so desired. Accordingly, the above objects and advantages are to provide a non polluting washing method and aid to be used many, many times rather than be discarded with each load of wash, resulting in improving our lives in many ways, including, having cleaner laundry, having less chemical residue to irritate sensitive skin, improving cleaning efficiency without increasing the damage due to abrasion, heat, and chemicals, newly exploiting a form of energy which is non-polluting, eliminating many disruptions in our lives such as running out of laundry detergent at inopportune times, conserving rather than waste and pollute our natural resources to a greater extent than heretofore possible. The aforementioned objects and advantages of the invention, will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawings, which form an integral part thereof. DRAWING FIGURES The present invention will be more fully understood by reference to the following detailed description thereof when read in conjunction with the attached drawings, and wherein: FIGS. 1A and 1B are perspective views of a first embodiment of a laundry cleaning device according to the invention, directly coupled to an agitator; FIGS. 2A and 2B are perspective views of a second embodiment of a laundry cleaning device according to the invention, indirectly coupled to an agitator; FIGS. 3A through 3F are edge views of piezoelectric charge generation according to the invention; FIGS. 3A through 3C are perspective views; FIGS. 3D and 3E are enlarged edge views; FIG. 3F is a cutaway edge view; FIGS. 4A through 4E are perspective views of a third embodiment of a free floating laundry cleaning device according to the invention; FIG. 5 is a schematic view illustrating the mechanism of frictional electric charge generation, distribution, and application powered by washing action; FIG. 6 is a perspective view of a vital part of a preferred embodiment according to the invention; FIG. 7 is a perspective view of a special design agitator of an alternate embodiment according to the invention; FIG. 8 is a perspective view of a flexible agitator made of piezoelectric polymer or composite of another alternate embodiment according to the invention; FIG. 9 is a perspective view of a single anode capacitative agitator according to the invention; FIG. 10 is a perspective view of a spray on coating of a simple, yet practical embodiment according to the invention; and. FIG. 11 is a magnified schematic view illustrating the separation of ions in water due to electric charge. DRAWING REFERENCE NUMERALS 10 tine, nub, point, fin, flange, vane, filament, or elastomer (electric charge generating, distributing, and/or applying means) 12 surface 14 attached end or edge 16 attachment means 18 agitator of wash machine, (washing action imparting means) 20 fin of agitator 22 attachment ring 30 side 32 edge 34 left flex 36 right flex 38 tension 40 compression 42 internal electron movement 44 negative charge (electron concentration) 46 positive charge 48 direction of washing action movement generating friction 50 unattached device 52 bundle of elastomers 54 binder ring or wire 56 knot or tie 58 loose end of elastomer 60 tub of a washing machine 62 water, or washing fluid 64 item to be washed, article of clothing or fabric 66 fiber of cloth 68 surface chemistry detergent coating 70 agitator made out of special material 72 flexible agitator 74 capacitative agitator 76 plastic coated metal 78 spray on coating 80 electric charge generator 82 wire 84 soil, oil, dirt, micro organism, foreign matter 86 Hydrogen ions (H + ) 88 Hydronium ions (H 3 O + ) 90 water molecules (H 2 O) 92 Hydroxide ions (OH − ), 94 Hydroxyl ions (H 3 O 2 − ), 96 detergive attraction SUMMARY OF INVENTION According to this invention, there is provided a method of producing a cleaning effect comprising steps of converting mechanical energy into electrical energy, distributing electric energy in the vicinity of the location of the desired cleaning effect, and applying electric energy so as to provide the effect of cleaning, and there is provided inventive apparatus for implementing the inventive method. In accordance with the invention, mechanical energy, thermal energy, and chemical energy is supplemented by the energy of electric charge applied to effect the work of cleaning. Embodiments optionally comprise one or more of the features described in the following “Features of Invention.” FEATURES OF INVENTION It may be helpful to the understanding of the invention to list many of the features. A feature of the invention is the generation of electric energy to do the work of cleaning. A feature of the invention is the distribution of electric energy to do the work of cleaning. A feature of the invention is the application of electric energy to do the work of cleaning. A feature of the invention is a surface chemistry detergent. A feature of the invention is the modulation of the physical properties of a surface chemistry detergent by electric charge. A feature of the invention is a method of cleaning laundry utilizing surface chemistry effects modified by electric charge. A feature of the invention is a method of cleaning the environment utilizing surface chemistry effects modified by electric charge. A feature of the invention is an anchored device for use inside an automatic laundry washing machine. A feature of the invention is the application of electric energy in such a way as to effect cleaning by such phenomena as temporary chemistry changes or temporary physical changes in water. A feature of the invention is a method of cleaning laundry utilizing the direct effects of electric charge (static and differential) A feature of the invention is an unanchored device for use inside an automatic laundry washing machine. A feature of the invention is a flexible surface, vane, or filament made of a frictioning material. An example of such a material is extruded natural rubber. A feature of the invention is a water treating processing means for the generating of hydroxide ions in wash and rinse water A feature of the invention is a water treating processing means for the generating of hydroxyl ions in wash and rinse water A feature of the invention is a water treating processing means for the generating of Hydronium ions in wash and rinse water A feature of the invention is increased cleaning time by being effective in cleaning during rinse cycles as well as the normal wash cycle of a standard automatic washing machine. A feature of the invention is less injury to garments by elimination of the requirement for increased mechanical agitation time. A feature of the invention is increased cleaning efficiency due to combined action of micro turbulence and non uniform ionic distribution. The aforementioned examples of features of the invention, will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawings, which form an integral part thereof. Although the list above contains many features, these should not be construed as limiting the scope of the invention but merely as providing illustrations of some of the presently preferred embodiments of the invention. This list is not to be taken as a complete list, but as examples of many other features obvious to one versed in the art. Therory of Operation The Inventive Concept It has long been known that water can be prepared for washing which has improved cleaning characteristics. Water can be heated then clothes washed in the heated water. The heat treated water remains effective for a duration of time on the order of minutes because it takes that much time for heat to dissipate. Water can be treated with chemical detergent then used for wash water. The time duration of the effectiveness of detergent treated water is days, or even weeks. Therefore, we have become accustomed to the idea of preparing wash water ahead of time, then washing clothes in the prepared water. That has been the failing of all prior art attempts to prepare ion enhanced wash water without chemical presence. Ionic treatment of water retains it's effectiveness (except for some very weak residual due to secondary effects) for a period of time of only a fraction of a second. It is not practical to enhance the ionic disassociation of wash water and expect it to stay that way in the absence of some force to keep the ions from recombining. Applying ionic treatment to a batch of wash water, then washing clothes in it makes no more sense than applying kinetic energy (in the form of turbulence) to a batch of wash water then putting clothes in the settled water expecting the spent kinetic energy to clean the clothes. Even so, this is exactly the process that has been attempted many times over in the prior art attempts to ionically treat wash water. However, applying kinetic energy to wash water at the right time and right place is very effective in cleaning. In other words, turbulence really does clean clothes. The practical effectiveness of kinetic energy in wash water lasts only a few seconds after application. The practical effectiveness of electric energy in wash water lasts only a fraction of a second after application. The inventive concept is to apply this same philosophy to the application of electric energy that we apply to kinetic energy. The inventive concept is to apply the electric energy at the time and place where the cleaning is expected to occur. Practical useful static electric fields do exist under water, even in highly conductive salty sea water. An example of this is the electric eel. These static fields do, however, have a short life because the conductivity of the water rapidly drains off the charge. One might argue that the water shorts out the field. However, that is exactly the desired result. As the electric charge of the invention is dissipated in the water in the vicinity of the soiled clothes, it does the work of cleaning. This inventive concept is a revolution in the theory of cleaning. The friction of rubbing two dislike solid substances gives rise to the transfer and dislocation of electrons from the surface of one substance to the surface of the other. The movement of the rubbing further dislocates the excess electrons on the surface of one material from the depletion of electrons on the surface of the other. In the presence of low conductivity, electric charge builds up. In the presence of high conductivity, the electrons flow back to regions of the opposite charge. In the case of washing as in the invention, conductivity is low enough that some charge builds up, balanced by some flow of electrons to equalize the charge. While in the presence of the built up charge, the ions of the water are also displaced as they take place in the flow of electrons to neutralize the charges. This displacement of ions in the water give rise to an increase in the natural ionic dissociation of the water and an increase in the concentration of those naturally occurring ions having detergency. The effect of electric energy on water to do the work of cleaning is powerful, but short lived. Where previous attempts of the prior art lacked sufficiency of effect was the failure to apply the energy in sufficient quantity at the location and time the work of cleaning was to be done. In the batch process of preparing the water then washing with prepared water, the effect was so diminished by the time the cleaning was attempted that it was like heating water to do the washing, then waiting for it to cool down before using it. This problem is overcome in the method of the present invention by the application of the electric energy at the same time and location where the kinetic energy of the scrubbing action is taking place The Cleaning Process A practical working prior art description of the cleaning process is found in Publication No. 348 published by The New Zealand Department of Agriculture, Ruakura Agricultural Research Centre, Hamilton, New Zealand. “The aim of the cleaning process is to provide sufficient energy to a system to change soil adhered to a surface into a suspended or dissolved state. Soil is held to surfaces by occlusion in surface interstices, by electrostatic forces between surface and soil and by the attraction of soil fractions for each other, . . . The sum total of all these forces may be expressed as the energy of soil adhesion. The energy in a cleaning solution is made up of the kinetic energy of the solution provided by turbulence, the thermal energy provided by solution temperature and the chemical energy provided by the constituents of a detergent. All three factors are related and it is possible by careful adjustment of one component to overcome limitations of either one or both of the other components.” Cleaning is work. In prior art discussions of cleaning this is work that is done on soil by a combination of kinetic energy, thermal energy, and chemical energy. Kinetic energy is in the form of turbulence. Thermal energy is in the form of elevated temperature. Chemical energy comes in two forms, chemical energy inherent in the chemical composition of water, and chemical energy in the form of detergent composition. Any form of energy that works to overcome the energy of soil adhesion to change soil adhered to a surface into a suspended or dissolved state does the work of cleaning. By careful manipulation of any one or more of these forms of energy, the work required to be done by any or all of the others can be reduced if not eliminated. For example, with more scrubbing, the requirement for hot water and detergent can be reduced. For another example, with the proper detergent, the need for higher temperature of the water can be reduced or eliminated. If another form of energy were found which contributed to the work of cleaning, that form of energy too could be manipulated to reduce or replace any or all of the other forms of energy to some extent. An object of this invention is to effectively exploit another form of energy to do the work of cleaning. The other effects of the work done in cleaning are to dissolve substances that are soluble such as sugar, or to melt substances such as grease, or sterilize by killing germs. Typically, the work done to dissolve substances is not the intention of chemical detergents. Dissolving is left to the natural chemical energy of water enhanced by thermal energy of hot water. Typically the melting of substances is not enhanced by chemical detergents, but again as in dissolving, melting is done by the natural thermal energy of hot water. Historically, the work done to sterilize laundry was accomplished by the thermal energy of hot water. Recently, without hot water, sterilization is left to be done by the heat of the dryer, or done by the addition of a chemical poison which remains in the waste water as a pollutant. Sterilization is not done by the chemical detergents, some of which are actually fertilizers, enhancing the growth of fungus or bacteria. Other Laundry Related Processes Processes other than cleaning are related to the laundering of clothes. Sterilization, fabric softening, static elimination, odor control, appearance related non-cleaning such as whitening and brightening and other processes obvious to one versed in the art of laundering are all processes that apply energy to do the work involved. In the past, various forms of energy were utilized. For example, radiant energy from the sun or ultra violet lamps, or thermal energy from hot water were used for sterilization. In recent times, chemical energy is the dominant form of energy used in such processes. The chemical detergent companies would like us to believe that shifting the work of cleaning and other related processes toward the chemical form of energy is desirable. We have been taught that we do not need hot water to clean clothes. We have been taught that this saves energy and is good. This is because chemical energy can replace the thermal energy of hot water to lower the surface tension and thereby clean the clothes without the need for hot water. However, when we changed the standard method of cleaning clothes to eliminate the hot water, the sterilization work of the heat energy was eliminated. The work of chemical energy again came to the rescue. The work of chemical energy replaced the work of thermal energy by the addition of chemical poisons to sanitize the laundry. In the saving of energy in the thermal form, energy in the chemical form was substituted. The main effect of this substitution of the chemical form of energy for other forms of energy is not the saving of energy, but is the pollution of the environment. Evaluation of Effect The major objection to the electrical treatment of water is not in the observations of the users not seeing cleaning being done, but in the lack of scientific explanation or lack of understanding of any underlying mechanism commonly accepted in the scientific community. Some scientists would assume that because no chemical detergent was added to the water that no detergency action resulted. This is an erroneous assumption. Therefore a dogmatic scientist, in not understanding how or why it worked, would say it did not work and was a fraud. That is like a blind person turning on a light switch and not detecting a light going on would say that electric lighting was a fraud. Since practically no scientist can completely explain why electricity would produce light, a blind scientist would conclude that electricity does not produce light. Those who actually benefit from the light have no problem with the lack of a complete explanation of why. In the same way, those who actually benefit from the clean clothes without the use of chemical detergent do not have a problem with the lack of scientific explanation for how it works. That is, they don't have a problem until some dogmatic scientist who does not understand it tells them it is a fraud. Then, not wanting to appear to be a fool, suddenly have a problem telling someone that their clothes actually got clean. In other words do clothes in a batch of general household laundry get clean without chemical detergent? Be careful here how you define clean. By clean we mean the removal of soil or contaminants. In judging the results of any tests be careful not be fooled by the addition of chemical contaminants that fool the eye into thinking laundry is cleaner. Chemical agent whitener is added by some detergent manufactures, and the chemical detergent may even be weakened to prevent the detergent from removing the whitener. Clothes washed in this product appear to be whiter but do not remove very much (if any) more contaminants than washing in plain water. The whiteness of the laundry washed in this product can be removed by immediate repeated multiple washings in plain water after washing in this product. It is suggested that the user of a detergent run an experiment by washing some white towels with stains in their favorite detergent. Save one of the clean towels out and wash the others over again a couple of times in water alone. When you compare the results of the multiple washes, see for yourself that the whitener of the detergent is washed out. The towels washed extra times in plain water will have the whitener chemical removed leaving a cleaner, yet less white towel. If this whitener is desired, it can be added without the use of a chemical detergent, but should not be confused with cleanness. The same is the case with the addition of chemical brighteners. The results of chemical brighteners should not be confused with cleanness. Chemical brighteners too can be added to the cleaning process if desired, without sacrificing the environment by the addition of chemical detergent. In addition to whiteners and brighteners, there are fabric softeners and perfumes to give the clothes the feel and odor we associate with cleanness. There are also germicides and fungicides, which are actually chemical poisons to sterilize the laundry. Whiteners, brighteners, fabric softeners, perfumes, germicides and fungicides are actually the addition of foreign substances to the laundry, rather than the removal of foreign substances from the laundry. If these additives are desired to give the laundry the appearance, feel and odor of cleanness, they can be added without adding the chemical detergent. With the scientific explanation for the present invention being so straight forward and documented, that problem with the blind dogmatic scientist has gone away. Now there is a scientific explanation of how electric fields are generated in substances like plastic or rubber and how electric fields from such substances produce reactions in the water, and how the reactions in the water are related to cleaning of laundry, and why there is no detectable difference in the water before and after the treatment of the water which is effective only during the cleaning process, leaving no residual effect. This lack of residual difference in the water which is a stumbling block to the doubting scientist, is not a weakness, but is the most desired effect sought after in the quest to keep the environment pollution free. Many tests and demonstrations have been performed demonstrating the effectiveness of the invention. Theoretical Basis It may be helpful to understand the theory behind some features of this invention. While we believe this theory to be valid, we do not wish to be limited thereto as other considerations may be pertinent. The validity of the invention has been empirically established. Several effects will be explained. Electrically Induced Detergency The Matsuoka Experiment Takahisa Matsuoka and Mutsuo Iwamoto describe the effect on surface tension and permeability due to the electrical treatment of water in an experiment described in the Japanese Journal of Food Science and Technology, Nippon Shokuhin Kaogyao Gakkaishi, Volume 38, No. 5, 1991, pages 422-424. The article is entitled “Surface Tension and Permeability of Water Treated by Polar Crystal Tourmaline.” In the experiment, water was electrically treated using the electrically polar crystalline substance tourmaline. The treated water, which started out with a normal surface tension of approximately 65 dynes per centimeter, had a surface tension of approximately 50 dynes per centimeter immediately after treatment. The surface tension reduction was a temporary effect and returned to normal after a few minutes. After returning to normal, the water had no detectable difference in any properties from before the treatment. The electrical treatment did not result in any permanent change in the water any more than water which has been heated and then cooled back down is any different than water that has never been heated. The results of the experiment can be summarized by saying that just like water that has been heated has lower surface tension, water that has been electrically treated has lower surface tension, neither has any permanent detectable effect. However, in the Matsuoka experiment, there is a discrepancy between the effect on distilled water and city tap water. The water containing impurities had a greater measured effect and retained the effect longer in time. This discrepancy gives a clue to the reason the ionic separation lasted even long enough to be measured. It appears that the effect was much greater immediately upon treatment in the immediate vicinity of the electric charge, and was preserved by the detergency attachment to impurities in the water. More impurities in the water resulted in greater accumulation of effect, and longer duration of effect. This effect of impurities causing electrically treated water to retain detergency longer is explained by the chemical formulas in the next section. Even so, the effect measured immediately after accumulating a batch of treated water was only on the order of half the effect of chemical laundry detergent. The water treatment process used in the Matsuoka experiment is very slow. The treatment of water by the electrically polar crystalline substance tourmaline requires much longer time to fill up one washing machine tub than the effect lasts. This yields this process of batch treatment before use as impractical as a laundry solution. In the current inventive method the treatment is done simultaneously with the work of cleaning and in the same location as the work of cleaning is being done. This temporary reduction in surface tension in this experiment is significant, because water that has had it's surface tension lowered by the addition of chemical detergent does have a permanent change that can be measured in the waste water. It has chemical pollutant which in many cases would not be allowed to be discharged if it were from an industrial plant. Hypothetical Explanations Several hypotheses have been proposed to explain the increase in the effectiveness of the physical property of detergency when water is treated electrically. One hypothesis uses dissolved oxygen, another the liberation of hydrogen, another the disassociation of water only with no gain or loss of hydrogen or oxygen. Which hypothetical mechanism is in operation may depend on the voltage and current conditions of the electric charge or some other factor, but the net results are the same: Temporary detergency is induced into the water, and impurities prevent the induced detergency from immediate dissipation. Two of the hypothesis have been herein expanded in detail sufficient for one versed in the art to develop others. Hypothesis 1: Dissolved Oxygen In Water In the washing machine are water (H 2 O), oil, cloth, and an embodiment of the current invention. In the washing machine the agitator causes kinetic energy to do the work of whipping air, containing Oxygen (O 2 ), and oil into the water (H 2 O). H 2 O+O 2 +Oil The water is naturally, weakly disassociated into Hydrogen ions (H + ) and Hydroxide ions (OH − ), and Oxygen (O 2 ) is naturally dissolved. 6(H 2 O)+O 2 +Oil⇄8(H + )+4(OH − )+4(O = )+Oil With the introduction of an electric charge into the water by an embodiment of the current invention, the Hydroxide ions (OH − ) are repelled by the negative charge and the Hydrogen ions (H + ) are attracted to the negative charge, and vise versa for the positive charge. Thus the energy of the electric charge does the work of spatially separating the Hydrogen ions (H + ) from the Hydroxide ions (OH − ) where the Hydrogen ions (H + ) combine with dissolved oxygen (O = ) and the Hydroxide ions (OH − ) having the physical property of detergency attach themselves to the oil, resulting in an oil water emulsion. 8(H + )+4(OH − )+4(O = )+Oil.→4(H 2 O)+(4(OH − )+Oil) The total reaction in the presence of electrical charge driving the arrows to the right being: 6(H 2 O)+O 2 +Oil→8(H + )+4(OH − )+4(O = )+Oil.→4(H 2 O)+(4(OH − )+Oil). The first arrow is by natural dissociation. The second arrow is by the work of electrical charge energy. With the removal of the electrical charge, the source of energy driving the second arrow to the right, the wash water slowly returns to the natural state, being slowed by the attachment of the Hydroxide ions (OH − ) to the oil. 6(H 2 O)+O 2 +Oil←8(H + )+4(OH − )+4(O = )+Oil.←4(H 2 O)+(4(OH − )+Oil After the removal of the source of electrical energy the duration of time for the return reaction being on the order of approximately an hour to approximately three hours is sufficient for the water and soil emulsion to be rinsed out of the wash machine. This is of the same order of magnitude time as the cooling time for hot water to return to ambient temperature once the source of thermal energy is removed. As the emulsion separates the water returns to it's normal composition and the water looses it's detergency, the soil held in suspension separates from the water and settles out, aiding the natural process of purifying the water as it is returned to the environment. Hypothesis 2: Disassociation Of Water Only In the washing machine are water (H 2 O), oil, cloth, and an embodiment of the current invention. H 2 O+Oil Naturally, water is weakly disassociated into Hydrogen ions (H + ) and Hydroxide ions (OH − ).  (H 2 O)+Oil⇄(H + )+(OH − )+Oil With the introduction of an electric charge into the water by an embodiment of the current invention, the Hydroxide ions (OH − ) are repelled by the negative charge and the Hydrogen ions (H + ) are attracted to the negative charge, and vise versa for the positive charge. Thus the energy of the electric charge does the work of spatially separating the Hydrogen ions (H + ) from the Hydroxide ions (OH − ). The Hydrogen ions (H + ), being spatially separated from the Hydroxide ions (OH − ) due to the work done by the electric charge of an embodiment of the current invention, combine with other water molecules (H 2 O) forming Hydronium ions (H 3 O + ). (H 2 O)+(H + )→(H 3 O + ) Meanwhile, the Hydroxide ions (OH − ), being spatially separated from the Hydrogen ions (H + ) due to the work done by the electric charge of an embodiment of the current invention, combine with other water molecules (H 2 O) forming Hydroxyl ions (H 3 O 2 − ). (H 2 O)+(OH − )→(H 3 O 2 − ) Hydronium ions (H 3 O + ), and Hydroxyl ions (H 3 O 2 − ), being spatially separated from each other due to the work done by the electric charge of an embodiment of the current invention, and each having the physical property of detergency attach themselves to the oil, resulting in an oil water emulsion. (H 3 O + )+Oil→(H 3 O + +Oil) (H 3 O 2− )+Oil→(H 3 O 2 − +Oil) The total reaction in the presence of electrical charge driving the arrows to the right being: 3(H 2 O)+Oil→2(H 2 O)+(H + )+(OH − )+Oil→(H 3 O + )+Oil+(H 3 O 2 − )→(H 3 O + +Oil)+(H 3 O 2 − +Oil) The first arrow is by natural dissociation in the abundance of water (H 2 O ) driven right by the removal of Hydrogen ions (H + ) and Hydroxide ions (OH − ) from the right side of that equation by the second arrow. The second arrow is by the work of electrical charge energy. The third arrow is driven right by the detergency physical property of Hydronium ions (H 3 O + ), and Hydroxyl ions (H 3 O 2 − ) and the abundance of Hydronium ions (H 3 O + ), and Hydroxyl ions (H 3 O 2 − ) due to the work of electrical charge driving the second arrow to the right. With the removal of electrical charge, the source of energy driving the second arrow to the right, the wash water slowly returns to the natural state, being slowed by the attachment of Hydronium ions (H 3 O + ), and Hydroxyl ions (H 3 O 2 − ) to the oil. 3(H 2 O)+Oil←2(H 2 O)+(H + )+(OH − )+Oil←(H 3 O + )+Oil+(H 3 O 2 − )←(H 3 O + +Oil)+(H 3 O 2 − +Oil) After the removal of the source of electrical energy the duration of time for the return reaction being on the order of approximately an hour to approximately three hours is sufficient for the water and oil emulsion to be rinsed out of the wash machine. This is of the same order of magnitude time as the cooling time for hot water to return to ambient temperature once the source of thermal energy is removed. As the emulsion separates the water returns to it's normal composition and the water looses it's detergency, the soil held in suspension separates from the water and settles out, aiding the natural process of purifying the water as it is returned to the environment. Micro-Turbulence Surface tension prevents water from penetrating the micro interstices of cloth to remove the soil particles entrapped therein. Turbulence reduces this effect of surface tension by forcing water into and out of smaller spaces. Micro-turbulence is induced in water by static electric charges. Water is attracted to a charge opposite that contained in the water, and repelled by a like charge. An experiment was done with a comb run through hair to gain a static electric charge. The charged comb was then brought near a cup of water filled to the point of overflowing prevented only by surface tension. A camcorder was positioned like a microscope to record the effect. As the charged comb was brought near the water, a small droplet of water, in less than one fifteenth of a second, overcoming the surface tension, jumped toward the comb, but never touched the comb. As the droplet approached the comb, charge was transferred to the water so that the charge on the water droplet became the same polarity as the comb and the droplet was immediately repelled by the charge remaining on the comb. It is believed that this process is present in the froth of air and water in the immediate vicinity of the electric charge distributing means of the current invention. This rapid moving back and forth of the water on a scale smaller than that of the droplets formed by surface tension, is called micro-turbulence. This effect is especially probable where the oscillating action of the agitator causes one polarity charge to be produced by movement in one direction and then the opposite polarity charge to be produced in the other direction, resulting in the article of clothing in the immediate vicinity of the electric charge distributing means of the current invention to have the opposite polarity charge as the electric charge generating means of the current invention. Of the two types of turbulence, micro turbulence is more on the size scale of the interstices of the cloth in which the soil is entrapped. Another example of micro turbulence is the turbulence induced by ultrasonic sound energy in ultrasonic cleaning. Both are the result of an outside source of energy doing the work of overcoming the energy of surface tension. Direct Electrostatic Effect The forces that hold soil to surfaces includes electrostatic forces. Soil is held to surfaces by occlusion in surface interstices, by electrostatic forces between surface and soil and by the attraction of soil fractions for each other. The sum total of all these forces may be expressed as the energy of soil adhesion. Since electrostatic forces are included in the forces of attraction, and since opposite forces attract and like forces repel, electrostatic forces have a direct effect in overcoming those electrostatic forces of soil adhesion. It is hypothesized that in the immediate vicinity of the electric charge distributing means of the current invention this energy of soil adhesion is overcome by work expended by the electric charge energy of the current invention. Surface Tension Surface tension is the force which causes water to have self attraction. Surface tension is the force which prevents water from entering small interstices of cloth that has not been prewetted. Surface tension causes water when slowly exiting a capillary tube to form up into a ball until the forces of attraction of water for itself are overcome by the force of gravity causing the ball of water to drop. A commonly accepted method of measuring the force of surface tension is called the drop weight method, or drop volume method. I have constructed a relative surface tension meter based on a variation of that method. I call it the drop count or drop frequency method. The device forces one ml of fluid through a steel capillary tube in four minutes. (It is driven by a clock mechanism which turns once in sixty seconds.) The reciprocal of the time between drops gives the number of drops in one ml. The number of drops per ml. is inversely proportional to the surface tension. With the relative surface tension meter, normal tap water at room temperature drops approximately every four seconds, yielding 58 drops per ml. When water is mixed with a popular brand of laundry detergent in a wash machine according to the proportions directed on the container, the relative surface tension meter yields 132 drops per ml., indicating less than half the surface tension of normal tap water. However, in measuring normal tap water at room temperature, while dropping approximately every four seconds, connecting a high voltage static electric charge to the steel capillary tube causes the drop size to so drastically decrease as to raise the drop rate to between 1200 and 1400 drops per ml. That is a approximately one twentieth the size of drop formed by the same water the instant before the electric charge is connected and the instant after the electric charge is disconnected. Stated another way, the electric charge affects the surface tension ten times as much as the laundry detergent. The experiment was repeated using the electric charge of a plastic comb run through my hair and brought near the forming drop. The effect was of a similar order of magnitude. Permeability Permeability is a measure of the ability of water to pass through material which is prewetted to remove surface tension effects. The Matsuoka experiment demonstrated that related to the reduction of surface tension due to electrical treatment is also an increase of permeability, a reduction of the resistance of water to flow through the interstices of prewetted cloth. Surface Chemistry Detergency Modulated by Electric Charge An inventive feature of this invention is the use of a surface chemistry detergent. Surface chemistry detergent is a solid having detergent molecules attached to the surface of the solid, possibly by chemical bonding. Alternately the detergent molecules are an integral fraction of the solid with the detergent molecules at the surface extending out and attached at only one end. Examples of surface chemistry molecules having detergency are long polymer string molecules terminated at the free end with a terminal benzoic acid group conjugated to a piezoelectric polymer. This gives the surface the physical characteristic of attracting and holding soil particles by molecular bonding. Another inventive feature of this invention is the use of electric charge to modulate the attraction of a surface chemistry detergent. This modulation is performed by reversing the electric charge at the terminal end of the detergent molecule by exploiting the electrical properties of the main bulk of the solid. As shown in FIG. 3D, FIG. 3E, and FIG. 3F, in the case of a main bulk containing a piezoelectric polymer, flexing the main bulk of the solid in one direction makes the whole bulk negatively charged, and flexing the main bulk of the solid in the other direction makes the whole bulk positively charged. Alternatively, stretching the main bulk makes one side positive and the other side negative. In either case, the surface with the detergent molecule has a reversing polarity electric charge which modulates the detergency properties. When stretched or flexed in one direction, the molecule attracts and holds soil by virtue of the molecular characteristic of hydrophobic attraction. When relaxed or flexed in the other direction the molecule releases the soil into the charged water where it is held in suspension or emulsion by the temporary detergency properties of water having been charged by the charge draining off the same surface. Think of it as a rubber band which when stretched by being dragged past a particle of soil on an article of clothing, attracts and holds that particle until the agitator reverses and the rubber band snaps back ejecting the soil particle into the water along with electric charge which gives the water the physical property of detergency to hold that particle until the water is drained from the washing machine. As explained elsewhere herein, the detergency physical property induced into the water by the electric charge is temporary and after a short period of time the soil will automatically separate from the discarded wash water leaving clear non polluting water to return to the environment, thus filling that long recognized and unfilled need for reducing laundry chemical waste which is polluting the environment. A material having piezoelectric properties produces an electric charge when flexed, then produces an electric charge of the opposite polarity when flexed the other direction. Piezoelectric polyvinylidene fluoride (PVDF) is an example of such a substance. Other examples are composite materials too numerous to list. Piezoelectric polyvinylidene fluoride (PVDF) is an example of a plastic substance having piezoelectric properties: Such a substance or a copolymer is synthesized with the added physical property of surface molecular attraction detergency due to hydrophobic attraction. The object of the synthesis is to attach a detergent type molecule to a piezoelectric polymer such as PVDF or to make a copolymer that acts to break up surface tension of water and attract grease or soil particles in a way similar to existing chemical additive detergents. General Scheme: (Protected Amine is One Example of Possible Chemical Synthesis) The resulting copolymer with a terminal benzoic acid group conjugated to the piezoelectric polymer results in alternating negative (deprotonated) and neutral (protonated) charges upon mechanical agitation. This alternating charge breaks the surface tension while the long conjugated greasy part of the molecule attracts soil by hydrophobic attraction, then alternatingly, by the opposite charge overcoming the molecular hydrophobic attraction, releases the soil as fine particles into the wash water to be held in suspension or emulsion until rinsed away. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As will become obvious, there are multiple preferred embodiments of the present invention. In general, each embodiment has a body such as a central core, or an agitator, and external parts more resembling fins which sometimes flex, or sometimes a flange which rubs without flexing. The body is usually a mass with inertia, and the fins are points or areas of application of the electric energy to the process of cleaning. First Embodiment—FIGS. 1A and 1B Direct Attachment to Agitator FIGS. 1A and 1B illustrate a first embodiment of the present invention. In this embodiment there is direct attachment to a source of kinetic energy, and electric energy is generated using the principle of piezoelectricity. Generally at 10 is an external part 10 , which is a tine, nub, point, fin, vane, filament, or elastomer. Throughout the descriptions of the figures, this part, fin 10 , takes on various forms and is made of various materials having various characteristics. This part, fin 10 , functions as a means for generating, distributing, and/or applying of electric charge. As long as the function and general appearance remain the same, this item 10 will be referred to with the number 10 . Fin 10 of this first embodiment is made of material having a physical property of piezoelectric electric charge generation. An example of such a material is piezoelectric polyvinylidene fluoride (PVDF). The molecular structure of PVDF is described above in the section on theoretical basis. Fin 10 of a first embodiment of the invention has a width dimension which is much greater than a thickness dimension such that fin 10 will flex more readily in the width plane than in the thickness plane. An attached end or edge 14 has an attachment means 16 such as a conventional adhesive, weld, or clamp. Attachment means 16 secures fin 10 to an agitator 18 of a conventional clothes washing machine (not shown.) FIG. 1B shows a plurality of fins 10 of various shapes attached to agitator 18 in various locations on agitator 18 . A plurality of fins 10 are attached to agitator 18 . When a conventional washing machine (not shown) applies a washing action by agitation action of agitator 18 , such washing action moves the fins against water (not shown) and against clothes (not shown.) This causes fins 10 to flex, generating electric charge and distributing electric charge in the vicinity of the clothes (shown.elsewhere herein) Second Embodiment—FIGS. 2A and 2B Indirect Attachment to Agitator FIGS. 2A and 2B illustrate a second embodiment of the present invention. In this embodiment there is indirect attachment to a source of kinetic energy, and electric energy is generated using the principle of piezoelectricity. In this embodiment fins 10 are attached to an intermediate device 22 which in turn secures fins 10 to agitator 18 . Intermediate device 22 is removable from agitator 18 . Filaments or fins 10 made of material having a physical property of piezoelectric electric charge generation, as in the first embodiment described above, are attached by conventional attachment means 16 to a donut shaped ring 22 which fits around agitator 18 of a conventional washing machine (not shown.). An attaching device 22 can be made of various designs as would be obvious to one versed in the art. In the case illustrated in FIGS. 2A and 2B, ring 22 is made from a flexible material of shape and form similar to a donut with a large hole through which agitator 18 snugly fits. An example of such a material is conventional clear polyvinyl chloride (PVC) tubing formed into a ring of a size appropriate to fit on agitator 18 . The back and forth washing action of agitator 18 flexes fins 10 back and forth as fins 10 move against the water and clothes in the washing machine. Piezoelectric Charge Generation—FIGS. 3A Through 3F FIGS. 3A through 3F illustrate piezoelectric electric charge generation. Each figure is an edge view of fin 10 made of material having a physical property of piezoelectric electric charge generation. FIG. 3A shows fin 10 having a broad side 30 and a narrow edge 32 and having one end attached 14 . FIG. 3B shows fin 10 having a left flex 34 . FIG. 3C shows fin 10 having a right flex 36 . In use the flex alternates between right and left. FIGS. 3D and 3E are edge views of a fin 10 type part illustrating a conventional prior art use of a similar piezoelectric material used to convert kinetic energy to electric energy as in, for example, the generation of electric power from the action of ocean waves. In FIG. 3D, depending on the alignment of the piezoelectric properties, an applied tension 38 results in an internal electron movement 42 to the left resulting in a negative electric charge 44 on the left side and a positive electric charge 46 on the right side. In conventional electric generation use, a conventional conductor (not shown) on each side of fin 10 leads the charge away as a current to do useful work elsewhere. In FIG. 3E, the same fin 10 is shown under compression 40 . This compression 40 reverses the direction of internal electron movement 42 to the right, resulting in a negative electric charge 44 on the right side and a negative electric charge 46 on the left side, the opposite sides as in FIG. 3 D. FIG. 3F illustrates this inventive use of material having a physical property of piezoelectric electric charge generation. An edge view of fin 10 is shown in the same orientation as in FIGS. 3D and 3E. However, the fin 10 of FIG. 3F is flexed such that compression 40 occurs on the left side, and tension 30 simultaneously occurring on the right side. This causes the internal electron movement 42 direction to be left near the left surface, and right near the right surface, resulting in a concentration of electrons near both outer sides of fin 10 when flexed left. The opposite positive charge is concentrated in the middle of the thickness of fin 10 , the dielectric properties of the material of fin 10 preventing the flow of electrons to neutralize the charge. This negative charge on the outer surface of fin 10 , being closer to the water (not shown) and clothes (not shown) surrounding fin 10 appears to this surrounding water and clothes to be the only charge, and thus has the desired effect as described in the preceding section entitled theoretical basis. When that same fin 10 is flexed in the opposite direction (not shown) the mechanism is similar, with reversal of the polarity to positive near the outer surface of fin 10 . In either case, electric charge does the work of cleaning in the water as described in the preceding section entitled theoretical basis. Third Embodiment—FIGS. 4A through 4E Inertial Coupling to Agitator FIGS. 4A through 4E illustrate a third embodiment of the present invention. In this embodiment, an electric charge generating means, an electric charge distributing means, and an electric charge applying means are all integrated into one device. In this embodiment this device is an external part more resembling a filament 10 . In this embodiment electric energy is generated using the principle of frictional electric charge generation. In this embodiment a great plurality of fins, vanes, filaments, or elastomers 10 are attached to a free floating unattached device 50 . Filaments or fins 10 are made of material having a physical property of frictional electric charge generation. An example of such a material is extruded natural rubber. Free floating unattached device 50 is put into a tub 60 of a conventional washing machine (not shown) along with water or a washing fluid 62 and items of laundry 64 . Kinetic energy is transmitted to unattached device 50 by the interaction of agitator 18 , water 62 , items of laundry 64 , and device 50 , in the presence of conventional agitation washing action, device 50 generates electric charge and transmits it directly to the immediate vicinity of the cleaning work being done by the kinetic energy, where the electric energy does work of modifying the physical properties of water to increase the naturally occurring detergency properties of water, as described in the above theoretical basis section. Alternatively, device 50 may be hand held as shown in FIG. 4E to be used as a scrubbing device for such diverse cleaning tasks as spot removal, bathing and shampooless hair cleaning. FIG. 4A illustrates the general appearance of a third embodiment of a device constructed to be used in accordance with the invention. Device 50 is formed with a large plurality of elongate, floppy, elastomeric filaments 10 , each of which, as is clearly evident in FIG. 4B, has cross-sectional dimensions of the loose ends 58 of filaments 10 which are extremely small in relation to the length of the filament. As will be more fully explained shortly, these filaments are joined in a central core region in such a manner that they radiate outwardly in a fairly uniform dense and bushy fashion, in multiple angularly offset planes to form a substantially spherical or ragged pompom like configuration. In this embodiment the central core region is the body as defined above. While the outside diameter of device 50 may be of any desired size, a very satisfactory diameter lies in the range of about 3 to about 10 inches. While, to be sure, various techniques and devices may be used for joining these filaments to produce the desired resultant object, device 50 has been formed, as is illustrated in FIG. 4 C. A large plurality of extruded rubber filaments are bundled and stretched to about three times their relaxed length. Next a conventional cinching device 54 is wound as illustrated around the mid point of the bundle and secured by a knot or twist tie 56 . The stretched rubber filaments are then released, with the result that the stretched filaments spring back toward their gathered centers, with a natural tendency to fan out radially in all planes to have the substantially spherical form which is illustrated. Clearly, device 50 is extremely simple and inexpensive in construction. The specific nature of device 50 can be altered, of course by changing cross-sectional dimensions, cross sectional aspect ratios and specific materials employed for the filaments 10 and cinching device 54 . The material selected can have a piezoelectric characteristic in place of or in addition to a frictioning characteristic. The device 50 can optionally have a conventional floatation device (not shown) attached or be made from material having a floatation characteristic for the purpose of achieving floatation just above neutral buoyancy such that device 50 floats with approximately 3 to 15 percent of its volume above the surface of water 62 . This device 50 can be used in a washing machine for washing clothes, or as a hand held scrubbing device as in, for example, shampooless hair cleaning. When used in a washing machine, the floatation at nearly neutral buoyancy will allow the device to occasionally be drawn under the surface of water 62 as agitator 18 turns the clothes over with it's scrubbing action. The action of agitator 18 causes differential movement between the device 50 and clothes 64 , giving rise to friction causing the conversion of kinetic energy to electric energy. As the device is moved the resulting positive and negative electric charges are displaced causing the charge to effect water 62 in the immediate vicinity. This embodiment of this invention is made with surfaces, vanes, or filaments of a material having frictioning properties, and is caused to pass through the water among the clothes in a standard washing machine of the prior art by the flexing action induced by the agitator of that washing machine, thus rubbing against fabric, giving rise to electric charge. Simultaneously those same surfaces, vanes, or filaments distribute that charge in the vicinity of the fabric being cleaned. Frictional Electric Charge Generation—FIG. 5 FIG. 5 illustrates the mechanism of frictional electric charge generation, distribution, and application means. Differential movement 48 between a fiber of cloth 66 and filament 10 as filament 10 is dragged along by attached end 14 causes rubbing to occur between fiber 66 and filament 10 . This washing action rubbing along with the frictional and electrical properties of the material with which filament 10 is made, cause electrons 44 to be rubbed off fiber 66 and stick to filament 10 . As filament 10 is dragged along, the distance between the source of electrons 44 and their current location gives rise to a negative static electric charge 44 on the surface of filament 44 and an unbalanced positive electric charge on the fiber. In the presence of a substance having low conductivity, such as water, surface electric charges 44 and 46 do persist, but for only a short time. There is empirical evidence that electric charge also builds up inside the material of which fin 10 is made, and, being much more effectively insulated from the water by the dielectric characteristic of that material remains active, functioning as an electret. The function of electric charge in doing the work of cleaning is adequately described in the section on theoretical basis. Independent of the source of the differential electric charge 44 and 46 , be it from friction, a conventional electronic device, piezoelectric properties of materials of construction, or any other source, the mechanism of hydrolization within water 62 remains the same. There are theories that different parts of the mechanism are more dominant dependent on voltage and current, but the results are always changes in the physical properties of water 62 if only momentarily, but long enough to do the work of cleaning. Preferred Embodiment FIG. 6 shows a fin, vane, filament, or elastomer 10 of a preferred embodiment having the same function and general appearance as in other embodiments. Each of the plurality of fins 10 of this preferred embodiment are made of or coated with a substance 68 which has detergent acting surface molecules as described elsewhere herein in the section on theoretical basis. An example of such a material is a copolymer with a terminal benzoic acid group. These surface detergent molecules alternately attract and repel, (cling to and release) dirt as the polarity of the electric charge alternates due to the back and forth flexing of fin 10 caused by the agitator or by other means. The net result can be visualized as similar to the result obtained by rubbing something with a wash rag to transfer the dirt to the rag, then rinsing the rag in wash water. However, in this case, the electric energy rather than kinetic energy does the work more efficiently. Alternate Embodiments The inventive method of utilizing electric energy to do the work of cleaning by producing a charge, distributing that charge to the location of cleaning, and applying the charge to the water in the immediate vicinity of the work to be done, may be embodied by many various designs. One design shown in FIG. 7 is a special agitator 70 of a conventional washing machine (not shown) made out of special electric charge producing material. Such special material is at least one of those described elsewhere herein, or an alternate material functioning to produce charge. Another design shown in FIG. 8 is a piezoelectric agitator 72 in a conventional washing machine (not shown.) Piezoelectric agitator 72 is made out of durable, flexible, piezoelectric polymer or composite such that the edges of agitator 72 flex, providing generation, distribution, application of electric charge in similar fashion as the agitator fin extenders described in embodiment one above. Another design shown in FIG. 9 is a special capacitative agitator 74 and/or other parts (not shown) of a conventional washing machine (not shown). Agitator 74 is designed as be a one electrode capacitor to be means to distribute and apply the electric charge generated elsewhere. One design for agitator 74 is plastic coated metal 76 (one electrode capacitor with environment as second electrode) then optionally coated with surface detergent 68 . The energy of electric charge is supplied by a conventional electric charge generator 80 connected to agitator 74 by electric wiring 82 The charge supply is either constant or alternating. FIG. 10 shows still another simple, yet practical embodiment. An agitator 18 of an existing conventional washing machine (not shown) is sprayed with the proper composition material in the form of a spray on coating 78 . Each of the alternate embodiments produces the electric charge by some means, distributes the energy of the charge by virtue of being at the right place at the time, and applies that charge by virtue of continuing to produce charge by the input of kinetic or some other form of energy as the distribution takes place. FIG. 11 shows the hypothetical separation of ions in water due to electric charge, and the resulting concentration of ions having detergency in a highly magnified schematic view. This description of FIG. 11 should be read with the above theoretical basis description of Hypothesis 2 in mind. Hydrogen ions (H + ) 86 and Hydronium ions (H 3 O + ) 88 being positively charged are attracted to the negative charge 44 which is a build up of electron concentration 44 in the vicinity of fin 10 , where Hydrogen ions (H + ) 86 and Hydronium ions (H 3 O + ) 88 are concentrated due to attraction of opposite charges. Hydroxide ions (OH − ) 92 and Hydroxyl ions (H 3 O 2 − ) 94 being negatively charged are repelled from the negative charge 44 , away from fin 10 , to the vicinity of a fiber of cloth 66 with particles of soil, oil, dirt, micro organism, or foreign matter 84 being held to fiber of cloth 66 by forces of soil adhesion which must be overcome in the cleaning process, where Hydroxide ions (OH − ) 92 and Hydroxyl ions (H 3 O 2 − ) 94 are concentrated due to repulsion of like charges. Having detergency characteristics, Hydroxyl ions (H 3 O 2 − ) 94 are attracted to soil particle 84 by detergive attraction 96 where Hydroxyl ions (H 3 O 2 − ) 94 surround soil particle 84 and separate soil particle 84 from fiber of cloth 66 , thus cleaning fiber of cloth 66 . Water molecules (H 2 O) 90 , being neutral in charge, are more concentrated in the area between the concentrations of charged ions where the charged ions are separated from water molecules (H 2 O). Being separated from the charged ions, the natural disassociation of water into ions results in more charged ions, which are further separated from each other, thus driving even greater concentration of detergive ions into the area immediate to the fiber of cloth where cleaning takes place. Operation of Invention How the Invention Works An object of this invention is to exploit another form of energy, the energy of electric charge, in an application which fills those long recognized and unfilled needs for increased effectiveness of cleaning, and reduction of pollution produced by household laundry operations. The general embodiment of this invention is made with surfaces, vanes, or filaments of a material having frictioning properties, and sufficient surface area, and is caused to pass through the water among the clothes in a standard washing machine of the prior art by the flexing action induced by the agitator of that washing machine, thus rubbing against fabric, giving rise to electric charge. Simultaneously those same surfaces, vanes, or filaments distribute and apply that charge in the vicinity of the fabric being cleaned. As an embodiment 50 (FIG. 4D) according to the invention passes through the water 62 among the clothes 64 it drags electrons 44 (FIG. 5) along by friction with the fiber 66 of clothes or by flexing of vanes or filaments 10 (FIG. 3F) causing the rise of electric charge 44 . The electric charge 44 causes several immediate effects in the water. As the electric charge immediately drains off, (described in section on theoretical basis) the electric charge causes micro turbulence and hydrolyzes the water in the immediate vicinity of the micro turbulence. This hydrolization of the water reduces the surface tension momentarily in the vicinity of the micro turbulence. This sets up the conditions which causes removal of soil particles from the interstices of the cloth. These conditions include turbulence, reduced surface tension, and the physical property of detergency. No lasting effect is caused in the properties of the water. The only lasting effect is the soil particles have been removed from the clothes and are held in suspension in the water until the water is removed from the clothes by draining away. That lasting effect too, is short lived. After a few minutes the residual detergive qualities of the discarded waste water which hold the soil in suspension fade away, and the water naturally separates itself from the soil particles held in suspension. Of the four forms of energy added to water to effect the work of cleaning, the electrostatic energy is the safest. Hot water can scald your hand. Hot water sets stains. An agitator used to induce turbulence can injure your hand. Turbulence wears out fabric. Chemical detergents can irritate your skin. Chemical detergents pollute the environment. Electrostatic energy does not set stains, does not wear and tear the fabric and does not pollute the environment. Electrostatic energy simply overcomes the forces holding the soil to the fabric thus separating the soil from the fabric. Electrostatic energy simply promotes temporary physical property changes in the water which work to separate the soil and hold it separate in the water until the water is separated from the laundry. The electrostatic energy is the same as is built up on the comb when combing your hair when it is very dry. When combing your hair, long before you can experience a slight shock, electrostatic energy can be detected by picking up bits of paper with an electrified comb. Electrostatic build-up only occurs in air when the air is very dry. In wet laundry there is no dangerous static build-up, the conditions are very wet and the electrostatic energy is quickly dissipated into the water as it does it's work of cleaning. Surface Detergent Modulated by Electric Charge Another object of this invention is to exploit surface chemistry properties of detergency, and using the energy of electric charge to modulate these properties in an application which fills that long recognized and unfilled need for reducing laundry chemical waste which is polluting the environment. Surface chemistry refers to chemical reactions that occur on the surface of a solid reacting in and with a fluid rather than reactions between and among chemicals dissolved in a fluid. In the past, detergents were chemicals in solution rather than on and part of a surface. Being in solution, the chemical detergent was discarded with the wash water. This new inventive method uses a chemical detergent which is detergent attached to the surface of a solid substance rather than dispersed throughout the wash water. The chemical detergent is therefore completely recycled and never thrown away with the wash water. The function of a surface detergent is to separate the soil from the laundry. In conjunction, the function of alternating electric charge is to modulate the function of the surface detergent to periodically cause the surface detergent molecules to separate themselves from the soil and to stimulate temporary detergency properties of plain water. Only the removed waste soil is left in the water. Since most of the soil in laundry is from the environment, returning the soil to the environment is non-polluting. In addition, since there is no chemical detergent in the waste water to hold the soil in suspension, the soil rapidly settles out after being discarded, leaving a much cleaner water to be recycled to the environment. A material having piezoelectric properties will produce an electric charge when flexed, then produce an electric charge of the opposite polarity when flexed the opposite direction. Piezoelectric polyvinylidene fluoride (PVDF) is an example of a plastic substance having piezoelectric properties. Other examples are composite materials too numerous to list. An embodiment of this invention made with vanes or filaments of a flexible material having piezoelectric properties, and having a surface chemistry physical property of detergency is modulated as described above by the flexing action induced by the agitator of a washing machine. Conclusions, Ramifications, and Scope Accordingly the reader will see that according to the invention, electric energy is added to the traditional three forms of energy to do the work of cleaning. Providing any means to supply electric energy, any means to distribute electric energy, and any means to apply electric energy, according to this invention, reduces or eliminates the need for chemical detergent pollution from home laundry operation to a greater extent than possible with heretofore available technology. While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the invention. No particular apparatus description is to limit the scope of the means to provide electric energy. No particular apparatus description is to limit the scope of the means to provide distribution and application of that energy. For example, a piezoelectric, or frictional electric device, when flexed or rubbed under water induces electric charge into the water, distributing that energy in the water and applying that energy at the site of the work of cleaning. The device is flexed back and forth by the action of agitation. The device can be attached to the agitator in the washing machine as an add on device, it can be integrated into the agitator itself, it could be a spray on substance having particular frictional electric properties, or it could be a device not connected to anything, yet receive kinetic energy through the agitation action of the water itself. It could be positioned away from the agitator and receive kinetic energy to do the flexing from some other source. It could be assisted by or wholly dependent upon electric charge from a charge producing electronic device wired to distribute the electric energy to the vicinity of the cleaning work being done. Very simply implemented, the electric energy could be generated at the same point in space and time that the turbulence is working, thus the means for distributing and application are incorporated in the generation means. A further example is a laundry cleaning ball shaped device coated with a polymer having surface detergent properties and having these properties modulated by an electric charge from energy transmitted to the ball from a conventional transmitter via ultra sonic or microwave energy. Such a ball could be a passive energy receiver having conventional electronic receiving circuitry and conventional electronic power conversion circuitry to convert received energy into an electric charge which changes with time or with a change in characteristics of signal transmitted to such a ball. Such a ball could have segments of it's surface of opposite polarity by use of metal segments underlying the surface detergent polymer coating. Such a ball could be of any size from micro circuit to a large proportion of a washing machine such balls could be used in multiple quantities and automatically separated from the items being washed after washing by another property of the ball such as magnetism. The balls could even be automatically removed from items of laundry after being put inside a dryer by such a mechanism as a special trap to capture and hold the balls. Such a device need not be round in the shape of a ball. Almost any shape could be used as long as it did not interfere with the circulation of the object within a cleaning container. Surface detergent of this invention could be used without electrical modulation during the laundry process. It could be made into tiny laundry granules just large enough to be caught and trapped by a screen such as a lint screen. These granules could be added to the laundry just as conventional detergent powder, then toward the end of the washing cycles the water could be circulated through such a trap where the granules could be caught to be externally renewed and recycled. The invention has uses beyond normal home laundry. Dry cleaning, car parts washing, farm produce washing, separation of clay from gold in a mining operation are but a few of the obvious uses. Many obvious modifications come to mind that have not been included above. Examples of such things that anyone versed in the art would assume to be obvious are: The size is not limited to that of the standard household washing machine. A much larger or smaller version is obviously within the scope of the invention. Substitution of various assemblies for individual components, or the addition or deletion of various assemblies in place of individual components are but a few among many of the various options. Where various mechanisms of charge generation have been described others such as direct thermal energy conversion could be substituted. Cleaning fluid or other washing solution could be used instead of water. Other water treatment device or devices may be used in conjunction with the invention. Water treatment device may be an option depending on water condition in users area. The washing container does not have to be a conventional laundry washing machine. It may be oval or some other shape. It may be a dish washing machine with electric charge distribution among the dishes and electric charge from a conventional electronic high voltage circuit. It may even be a scrub board and bucket of water. The shape does not have to be round. It could be curved. It could be in the shape of a conveyor belt. Many parts that have been shown one shape could be another. The invention may be implemented as a single-unit or as multiple units. The invention may be free to move randomly or it may be anchored. Some embodiments could even be operated in case of a lack of power. The embodiment could be used to massage the item of clothing in the presence of water, by hand or by foot, then the clothing removed and hand wrung. In an alternate design for an anchored embodiment, the items to be cleaned could be moved rather than the device itself. Alternate uses could by made such as washing one's hair with the inventive device rather than with or in addition to using shampoo. While plastic or rubber has been described, a more rugged embodiment could have many parts made of metal. Many items detailed above are optional, and can be omitted. Many can be changed in size, made of different material, made of a different shape, connected or associated in a different manner, made integrally or in sections, or varied in other ways without departing from the invention in its broader aspects. These items are offered by way of illustration only and not as a limitation. Several alternate scrubbing actions and means of generating those actions have been described. Others too numerous to include are obvious to one versed in the art. A set of multiple agitating methods could be used simultaneously, or alternatingly. While specific theory and hypothesis have been described, actual detail may vary. For example it is not clear whether electron build up in under water charge is exterior to surface or interior to surface of diaelectric material. We do not wish to be limited thereto as the validity of the invention has been empirically established. While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. For example, where water is mentioned throughout the descriptions, it is obvious that other cleaning solution may be substituted. (Other fluids, for example, petroleum based fluids, have demonstrated a similar physical properties change when under the influence of an electric charge.) Where plastic or rubber are mentioned throughout the descriptions, it is obvious that other non conductive or piezoelectric materials may be substituted, where piezoelectric electric charge is mentioned in the descriptions, it is obvious that electric charge from another source may be substituted, where textiles or clothes are mentioned throughout the descriptions, other objects could be washed including such diverse items as farm produce or the removal of clay from placer gold. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

A washing method and apparatus characterized by employment of the electric form of energy in addition to the traditional three forms of energy (kinetic energy, thermal energy, and chemical energy) to do the work of cleaning, thereby reducing the requirement for and dependency on the traditional three forms of energy. Electric charge is employed to do work of cleaning by various physical phenomena. The phenomena include, but are not limited to effecting the physical characteristics of surface chemistry, the physical characteristics of water, and the chemical characteristics of water, Such characteristics include but are not limited to surface tension, agitation, hydrolization, and adhesion. Such effects of the physical or chemical characteristics are temporary, and are not detectable after the washing water is discarded so as to have minimal polluting effect on the environment. After the cleaning work is done, this temporary energy effect of the physical or chemical characteristics is just as transient, undetectable and non-polluting as is the thermal energy of hot water that has been cooled or the kinetic energy of moving water that has been stopped. Previous to this invention, the work of cleaning was done by three forms of energy: Thermal energy, kinetic energy, and chemical energy. This invention adds electric energy to the forms of energy that do the work of cleaning. Of the four forms of energy, the only one that remains in the waste water is chemical energy. Adding this additional form of energy allows the reduction of requirement for work to be done by any or all of the other forms of energy. The net result is the transfer of the work load from chemical energy, thus resulting in less dependence on the one form of energy that pollutes the environment.

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/379,156, filed Sep. 1, 2010, the entirety of which is hereby incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to systems for simulating parameters of electronic circuits and, more specifically, to a system that simulates temperature and resistance in a circuit. [0004] 2. Description of the Related Art [0005] With integrated circuit (IC) fabrication technology scaling below 90 nm nodes, power supply voltages of IC chips have been reduced to 1.2 V and below in order to reduce power consumption and increase functionality. Due to the low noise margin and threshold level voltage of such circuits, DC voltage drop analysis in package level and board level is becoming increasingly important. However, due to the continuing growth of IC integration density, the power density of a single chip can increase beyond 100 W/cm. In addition, with three dimensional (3D) system integration enabled by through-silicon via (TSV) technology, the power density in 3D integrated systems is expected to become much larger. As a result, thermal analysis of IC's is becoming critical in the design process. [0006] Due to the temperature-dependent electrical resistivity, temperature is becoming an important factor in the direct current (DC) IR (i.e., voltage) drop simulations. In the past, DC IR drop analysis has been based on equivalent circuit approaches. However, temperature-dependent resistivity has not been considered in such approaches. In order to capture the temperature effects on DC IR drop in 3D integrated systems, an electrical-thermal co-simulation method has been attempted and the effects of system components on electrical and thermal characteristics of power delivery networks (PDN) in 3D system integration have been studied. However, such approaches have not taken into account temperature distribution across the geometry of the integrated circuit, nor have they considered the effects of convection and fluidic cooling. As a result, circuit designers have not been able to examine temperature effects on an integrated circuit in relation to specific adjustments to a circuit design. [0007] Therefore, there is a need for a circuit simulation system that relates temperature variation to IR drop across a circuit. SUMMARY OF THE INVENTION [0008] The disadvantages of the prior art are overcome by the present invention which, in one aspect, is a method, operable on a digital computer coupled to a user interface, for simulating electrical characteristics and temperature characteristics in an electronic circuit. A routine for generating a three-dimensional mesh is executed on the digital computer so that the mesh includes a plurality of cells and a plurality of nodes. Each cell represents a heat conducting volume within the circuit and each node represents an electrically conducting point within the circuit. Each of several variables are initialized. These variables include: a previous iteration temperature variable associated with each cell; a current iteration temperature variable associated with each cell; a previous iteration resistance variable associated with each node; and a current iteration resistance variable associated with each node. Until the previous iteration temperature variable associated with each cell is within a first predetermined tolerance of the current iteration temperature variable associated with each cell and the previous iteration resistance variable associated with each node is with a second predetermined tolerance of the current iteration resistance variable associated with each node, the following steps are performed: (i) calculating for each cell an average temperature of the cell based on: heat generated in the cell as a result of a pre-calculated current, from the DC voltage drop, flowing through a previous resistance having a value corresponding to the previous iteration resistance variable associated with a node within the cell and heat transferred out of the cell and storing the average temperature in the current iteration resistance variable associated with the cell; (ii) calculating for each node a current resistance associated with the node based on the previous iteration temperature variable for a cell in which the node resides and storing the current resistance in the current iteration resistance variable associated with the node; (iii) comparing the previous iteration temperature variable associated with each cell to the current iteration temperature variable associated with each cell and calculating the previous iteration resistance variable associated with each node to the current iteration resistance variable associated with each node; and (iv) after the comparing step, storing the average temperature in the previous iteration temperature variable and storing the current iteration resistance in the previous iteration resistance variable. Once the previous iteration temperature variable associated with each cell is within the first predetermined tolerance of the current iteration temperature variable associated with each cell and when the previous iteration resistance variable associated with each node is with the second predetermined tolerance of the current iteration resistance variable associated with each node, then an output that indicates an average temperature associated each cell is generated. [0009] In another aspect, the invention is a method, operable on a digital computer coupled to a user interface, for simulating temperature and electrical characteristics within an circuit. A temperature of at least one volume within the circuit as a function of a resistance within the at least one volume is repeatedly calculated and the resistance as a function of the temperature is repeatedly calculated until the temperature is within a predetermined tolerance of a previous temperature result and until the resistance is within a predetermined tolerance of a previous resistance result. Once the temperature is within a predetermined tolerance of the previous temperature result and the resistance is within a predetermined tolerance of the previous resistance, then an output indicative of the temperature is generated. [0010] In yet another aspect, the invention is a circuit simulation device. A mesh generator is configured to generate a three-dimensional mesh that includes a plurality of cells and a plurality of nodes. Each cell represents a heat conducting volume within a circuit and each node represents an electrically conducting point within the circuit. An initializer is configured to initialize each of: a previous iteration temperature variable associated with each cell; a current iteration temperature variable associated with each cell; a previous iteration resistance variable associated with each node; and a current iteration resistance variable associated with each node. A simulator is configured to repeatedly until a current iteration average temperature for each cell is within a first predetermined tolerance of a previous iteration average temperature and until a current iteration resistance for each node is within a second predetermined tolerance of a previous iteration average temperature for each cell: (i) determine the current iteration average temperature for each cell and the current iteration resistance associated with each node; (ii) compare the current iteration average temperature for each cell to the previous iteration average temperature for each cell and compare the current iteration resistance associated with each node to the previous iteration resistance associated with each node; and (iii) save the current iteration average temperature for each cell as the previous iteration average temperature for each cell and save the current iteration resistance associated with each node as the previous iteration resistance associated with each node. An interface is configured to output an indication of the current iteration average temperature of each cell. [0011] These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations and modifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure. BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS [0012] FIG. 1 is a schematic representation of one embodiment of a circuit simulating system. [0013] FIG. 2 is a schematic representation of a 2D rectangular grid. [0014] FIG. 3A is a diagram showing the relationship between electrical and thermal fields. [0015] FIG. 3B is a flow chart showing one method employed in a circuit simulating system. [0016] FIG. 4 is a perspective view of a plurality of micro-fluidic cooling channels. [0017] FIG. 5A is a top perspective view of a mounted circuit. [0018] FIG. 5B is a cross-sectional view of the circuit shown in FIG. 5A , taken along line 5 B- 5 B. [0019] FIG. 6 is a schematic representation of a portion of a circuit model grid that includes a fluid flowing about a portion thereof [0020] FIG. 7 is a cross-sectional view of a circuit with microfluidic channels and a detail showing the meshing thereof. [0021] FIG. 8A is a graphic representation of a voltage drop result of a circuit simulation. [0022] FIG. 8B is a graphic representation of a temperature result of a circuit simulation. [0023] FIG. 9 is a schematic representation of a portion of a circuit model grid that includes a fluid flowing adjacent to a portion thereof. DETAILED DESCRIPTION OF THE INVENTION [0024] A preferred embodiment of the invention is now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. Unless otherwise specifically indicated in the disclosure that follows, the drawings are not necessarily drawn to scale. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” In the context of microfluidic fluid flow, a fluid flowing “near a cell” or “near a volume” also includes a fluid flowing through the cell or through the volume (such as through a microfluidic channel passing through the cell or volume). [0025] As shown in FIG. 1 , one embodiment of a circuit simulating device 100 includes a digital computer 110 with a computer-readable memory that is coupled to a video monitor display interface 112 , upon which a graphic circuit simulation result 114 may be displayed. The computer 110 is programmed to run a meshing routine and a circuit simulation routine. As shown in FIG. 2 , the meshing routine generates a circuit model that includes a mesh 200 representing the circuit. In the model, the mesh includes a plurality of volumes 202 (also referred to herein as “cells”) and a plurality of nodes 204 , each associated with a different volume 202 . (It should be noted that FIG. 2 shows a two-dimensional mesh for simplicity, whereas a three-dimensional mesh would be used in a practical embodiment.) Each volume 202 has an associated temperature due to heat generated by electrical components within the volume 202 and heat transferred into and out of the volume 202 . Each node 204 has an associated temperature-dependent resistance that represents the resistance of electrical components within the circuit that are associated with the node 204 . One of many types of mesh can be used, including a rectangular prismatic mesh, a tetrahedral mesh, or any other type of mesh supported by common meshing algorithms. Also, either a regular mesh or an irregular mesh may be employed. [0026] Due to the temperature-dependent electrical resistivity ρ(x,y,z,T) and Joule heating generated in the conductors, the electrical and thermal characteristics couple to each other and form a non-linear system of equations, as shown in FIG. 3A . These equations describe a thermal field 280 and an electrical field 282 , each of which is dependant upon the other. [0027] The simulator routine calculates the temperature of each cell based on a pre-calculated current flowing through the cell (based on the DC voltage drop) and the resistance of the node within the cell then it calculates a new value of resistance for each cell based on the temperature of the cell. These calculations are repeated until the current values of temperature and resistance converge to within a predetermined range of the previous values of temperature and resistance. As shown in FIG. 3A , in one embodiment, to obtain accurate voltage distribution with convection and Joule heating effects, the simulator solves the nonlinear electrical-thermal equations (1-4), simultaneously as part of an iterative electrical-thermal co-simulation method. The iterative simulation technique includes the following steps: 1. Input: Setting input information on system layout parameters, initial material properties, excitations, and boundary conditions for steady state electrical and thermal analysis 300 . 2. Voltage drop simulation: Steady state electrical voltage distribution simulation for voltage, current, and power distribution profiles in the PDN 302 . 3. Heat calculation based on electrical resistances and currents: Heat sources (Joule heat) calculation from the power distribution profile 304 . 4. Thermal simulation calculating temperature distribution: Using the updated Joule heat excitation for steady state thermal simulation with thermal conduction, air convection and fluidic cooling 306 . 5. Update resistances: Based on the temperature distribution profile obtained, the electrical resistivity of conductors in the PDN is updated and thereby thermal effect on voltage drop is included 308 . 6. Determining if the temperature and voltage distributions have converged. 310 The final thermal and voltage distributions are displayed 312 if convergence is reached. Otherwise, the iterations are continued. [0034] One embodiment is directed to determining thermal effects in a power delivery network (PDN) circuit. Such a PDN could include the power and ground planes of a circuit board, the power and ground layers of an integrated circuit mounted on the circuit board, connecting pins and any through-silicon vias in the integrated circuit. (It should be understood that in other embodiments, the system could simulate isolated elements in a PDN, or combinations thereof.) [0035] In steady state, the governing equation for voltage distribution in PDN can be expressed as: [0000] ∇ · ( 1 ρ  ( x , y , z , T )  ∇ φ  ( x , y , z ) ) = 0 ( 1 ) [0000] where φ(x,y,z) represents the voltage distribution and ρ(x,y,z,T) is the temperature-dependent electrical resistivity of conductors. [0036] For steady-state thermal analysis, the governing heat equations for solid medium and fluid flow can be expressed as: [0000] ∇·[ k ( x,y,z )∇ T ( x,y,z )]=− P ( x,y,z )   (2a) [0000] σ c p {right arrow over (v)} ( x,y,z )·∇ T ( x,y,z )=∇·( k f ∇T( x,y,z ))   (2b) [0000] where, k(x,y,z) and T(x,y,z) represent the thermal conductivity of solid medium and temperature distribution, respectively; σ, c p and {right arrow over (v)}(x,y,z) represent the density, heat capacity and velocity distribution of the fluid, respectively; k f is the thermal conductivity of the fluid. [0037] In equation (2a), P(x,y,z) is the total heat source excitation including the heat source from chip and Joule heating converted from the Ohmic loss due to current flowing through conductors in the PDN. The Joule heating can be expressed as: [0000] P Joule ( x,y,z )= {right arrow over (J)}·{right arrow over (E)} ( x,y,z )   (3) [0000] where, {right arrow over (J)} is the current density and {right arrow over (E)}(x,y,z) is the electrical field distribution in the PDN. [0038] Since the electrical resistivity is temperature-dependent, it is described by: [0000] ρ=ρ 0 [1+α( T−T 0 )]  (4) [0000] where, ρ 0 is the electrical resistivity at T 0 which is 20° C., and α is the temperature coefficient of the electrical resistance. [0039] By solving equation (1) in the presence of the boundary conditions given below in (5), the voltage distribution of the PDN can be computed. [0000] φ   Γ 1 = V input ( 5 ) ∂ φ ∂ n   Γ 3 = I output ∂ φ ∂ n   Γ 3 = 0 [0000] where Γ 1 , Γ 2 represent the voltage supply boundary and current source boundary; Γ 3 represents all the other homogenous Neumann boundaries in the PDN. V input and I output represent voltage excitation and output current density, respectively. [0040] Since three dimensional power delivery networks usually have large size planes and small size structures such as through-silicon vias (TSVs), C4s, apertures etc, a 3D non-uniform mesh is used to reduce the number of unknowns, reduce the simulation time and also to capture all geometries accurately. In this embodiment, a 3D non-uniform rectangular grid is used. Though 3D non-uniform rectangular grid is used, the finite volume formulation is explained on the 2D non-uniform grid shown in FIG. 2 for simplicity. [0041] The formulation for solving the voltage distribution equation (1) is performed during each iteration using location-dependent resistivity. In FIG. 2 , φ i,j represents the voltage at grid point (i,j), which is surrounded by four nodes. Δx 1 , Δx 2 , Δy 1 , and Δy 2 , are the nodal distances between node (i,j) and its adjacent nodes in x and y directions, respectively. It is assumed that the four surrounding cells of node (i,j) have different resistivities ρ 1 , ρ 2 , ρ 3 and ρ 4 , and have different temperatures T 1 T 2 T 3 and T 4 which can be obtained from the thermal simulation. [0042] In order to apply the finite volume method, node (i,j) is surrounded by a finite volume cell 206 . The intersection points between the dashed cell 206 and other four cells are the center points of each cell. By integrating equation (1) over the dashed cell and applying the divergence theorem, we obtain: [0000] ∫ dashed line  1 ρ  ( x , y , z , T )  ∇ φ  ( x , y , z ) · n ^    l = 0 ( 6 ) [0000] where {circumflex over (n)} is the outward pointing unit normal vector at the boundary of the dashed cell 206 . Initially, the electrical resistivity is assumed uniform and thus the electrical resistivity ρ(x,y,z,T) is a constant. By applying the finite difference approximation to the first order derivative of φ in equation (6), the finite volume scheme at node (i,j) can be obtained as: [0000] φ i , j - φ i - 1 , j ρΔ   x 1 d + φ i , j - φ i + 1 , j ρΔ   x 2 d + φ i , j - φ i , j - 1 ρΔ   y 1 w + φ i , j - φ i , j + 1 ρΔ   y 2 w = 0 ( 7 ) [0000] where w=(Δc 1 +Δx 2 )/2 and d=(Δy 1 +Δy 2 )/2. Note that the finite volume (7) is analogous to the Kirchhoff's Current Law (KCL). [0043] In order to include the temperature effect on voltage distribution, the temperature distribution T 1 T 2 T 3 and T 4 in the surrounding cells are considered. Finally, the finite volume scheme with temperature-dependent resistivity can be generalized as: [0000] ( Δ   y 1 ρ  ( T 1 )  Δ   x 1 + Δ   y 2 ρ  ( T 4 )  Δ   x 1 )  ( φ i , j - φ i - 1 , j ) + ( Δ   y 1 ρ  ( T 2 )  Δ   x 2 + Δ   y 2 ρ  ( T 3 )  Δ   x 2 )  ( φ i , j - φ i + 1 , j ) + ( Δ   x 1 ρ  ( T 1 )  Δ   y 1 + Δ   x 2 ρ  ( T 2 )  Δ   y 1 )  ( φ i , j - φ i , j - 1 ) + ( Δ   x 1 ρ  ( T 4 )  Δ   y 2 + Δ   x 2 ρ  ( T 3 )  Δ   y 2 )  ( φ i , j - φ i , j + 1 ) = 0 ( 8 ) [0044] Based on the above finite volume formulation, the DC IR drop problem can be converted to a system of equations [0000] Yx=b   (9) [0000] where Y, is the impedance matrix, which is sparse and symmetric positive definite (SPD). [0045] For 3D DC IR drop problem discretized with N cells in x, y and z direction, respectively, the impedance matrix Y has bandwidth of 2N 2 . As a result, for a 10 million problem with N=215, the bandwidth of Y is approximately 92.4 K. Because of the very large bandwidth and limited memory, it becomes very difficult to solve problems with millions of unknowns using a direct method such as LU or Cholesky factorization. [0046] Due to the SPD property of impedance matrix Y, the Krylov subspace based conjugate gradient (CG) method can be used to solve equation (9). In addition, to reduce the condition number and hence improve the convergence rate of the CG iteration, a pre-conditioning matrix M needs to be used. Instead of solving equation (9), the following equation is solved. [0000] MYx=Mb   (10) [0047] A commonly used pre-conditioner is incomplete LU factorization of the Y matrix. However, for large scale DC IR problems with more than one million unknowns, to form an incomplete LU preconditioner, a large amount of memory is required. With limited memory, it can even cause breakdown of simulation. To overcome this issue, the diagonal matrix is used as the pre-conditioner. One example of a pre-conditioned conjugate gradient algorithm can include the following: [0000] 1. r=b−Yx 0 , ρ 0 =∥r∥ 2 2 , k= 1, x=x 0 [0000] 2. Do While √{square root over (ρ k−1 )}>ε∥b∥ 2 and k<k max [0000] (a) z=Mr [0000] ( b ) τ k−1 =z T r [0000] ( c ) if k=1 then β=0 and p=z [0000] else [0000] β=τ k−1 /τ k−2 , p=z+βp [0000] (d) w=Yp [0000] ( e ) α=τ k−1 /p T w [0000] ( f ) x=x+αp [0000] ( g ) r=r−αw [0000] ( h ) ρ k =r T r [0000] ( i ) k=k+ 1 [0048] In this algorithm x 0 is the initial iterate and r is the initial residual in Step 1; ε is the stop criteria in the CG method. Comparing to the CG method, the PCG method has additional computational cost of one matrix-vector multiplication in Step 2a and one vector-vector multiplication in Step 2b. Since M is a diagonal preconditioner, the additional computing cost in PCG method is nearly minimum. In addition, due to the symmetric property of Y matrix, it only needs to store the upper triangular portion of Y matrix as well as the per-conditioner M and corresponding vectors in CG iteration. As a result, the CG method with a diagonal pre-conditioner M can solving large scale DC IR drop problem by using limited memory efficiently. [0049] Moreover, a good starting iteration of x 0 can make CG method converge faster than using default setting of x 0 =0. For DC IR problems with mesh refinement, the initial start iteration of x 0 can be obtained by interpolating from the solution of previous mesh. In order to save simulation time for problems with mesh refinement, the original problem with previous mesh is first simulated, and solution x old is generated. Secondly, the solution x old from previous mesh is interpolated to obtain the initial iteration x o for problem with mesh refinement. Finally, the DC IR problem with mesh refinement is simulated with interpolated initial iteration x 0 . [0050] While use of the PCG solver for DC voltage drop described above, it is important to realize that the system is not limited to PCG solver, but can use any available solver to solve the system equation Yx=b. [0051] As shown in FIG. 4 , one embodiment also models the effect of a cooling fluid (such as deionized water or air) passing through microfluidic channels 402 passing through a portion of the circuit 400 . As shown in FIGS. 5A and 5B , a modeled circuit 500 can include an integrated circuit package 520 mounted on a circuit board 510 . The circuit board 510 can, for example, include a signal plane 512 , a power plane 516 and a resin plane 514 . The integrated circuit package 520 can include a filler layer 526 , an integrated circuit chip 522 , through which a plurality of micro-fluidic channels 528 pass and a cover portion 524 . All of these components in the circuit 500 can be part of the meshed model. A conceptional model 600 of such a fluid cooled circuit, including a mesh, is shown in FIG. 6 . [0052] For the heat equation (2a) with only conduction, since it has the same form as equation (1), the same finite volume formulation can be applied resulting in: [0000] T i , j - T i - 1 , j Δ   x 1 k   d + T i , j - T i + 1 , j Δ   x 2 k   d + T i , j - T i , j - 1 Δ   y 1 k   w + T i , j - T i , j + 1 Δ   y 2 k   w = P total ( 11 ) [0000] where [0000] P total  ∫ ∫ dashed cell - P  ( x , y , z )   S [0000] is the total heat source in the dashed cell. [0053] In order to obtain accurate temperature distribution in the thermal simulation of realistic systems, the convection boundary condition [0000] k   ∂ T ∂ n   convection = - h c  ( T - T a ) ( 12 ) [0000] is considered. In equation (12), T a and h c represent the ambient temperature and convection coefficient, respectively. The same finite volume formulation procedure can also be applied at the convection boundary with non-uniform mesh 900 , as shown in FIG. 9 . [0054] In FIG. 9 , node (i,j) at the convection boundary is surrounded by a finite volume cell (dashed line). By integrating equation (2a) over the dashed cell and applying the divergence theorem, we obtain: [0000] ∫ dashed line  k  ( x , y , z )  ∇ T  ( x , y , z ) · n ^   l = ∫ ∫ dashed cell - P  ( x , y , z )   S ( 13 ) [0055] By applying the finite difference approximation to the first order derivative of T(x,y,z) in equation (13) and incorporating equation (12), the finite volume scheme for heat equation with convection boundary condition at node (i,j) can be expressed as: [0000] T i , j - T a 1 h c  d + T i , j - T i - 1 , j Δ   x k   d + T i , j - T i , j - 1 Δ   y 1 k   Δ   x / 2 + T i , j - T i , j + 1 Δ   y 2 k   Δ   x / 2 = P total ( 14 ) [0000] where d=(Δy 1 +Δy 2 )/2. [0056] In fluidic cooling, since the micro-channel cross-sectional dimension is much smaller than its length, the flow velocity along the longitudinal direction is much larger than in the lateral direction. It can therefore be assumed that the fluid only flows in the longitudinal direction and flow velocity therefore is constant. The average flow velocity ‘v’ along y direction has been used for simulating the fluid flow. As a result, equation (2b) can be written as: [0000] σ   c p  v  ∂ T  ( x , y , z ) ∂ y = ∇ · ( k f  ∇ T  ( x , y , z ) ) ( 15 ) [0000] By integrating equation (15) over the dashed cell in FIG. 6 and applying the divergence theorem, equation (15) becomes [0000] ∫ S   1 + S   2  σ   c p  vT  y ^ · n ^    l = ∫ dashed   line  k f  ∇ T · n ^    l ( 16 ) [0000] where, S1 and S2 are the upper and bottom boundaries of the dashed cell, as shown in FIG. 6 . [0057] For the right hand side of equation (16), the same formulation can be used. For the left hand side, since the central finite difference scheme can generate instability in certain cases, the backward difference approximation is used. The finite volume scheme for solving the heat equation for fluid flow can be expressed as: [0000] T i , j - T i - 1 , j Δ   x 1 k   d + T i , j - T i + 1 , j Δ   x 2 k   d + T i , j - T i , j - 1 Δ   y 1 k   w + T i , j - T i , j + 1 Δ   y 2 k   w = σ   c p  v  ( T i , j - T i , j - 1 ) ( 17 ) [0000] where w=(Δx 1 +Δx 2 )/2, d=(Δy 1 +Δy 2 )/2. [0058] Since the average flow velocity along the longitudinal direction is used in the model, the heat transfer coefficient h needs to be applied at the boundary of the micro-channel to model the heat transfer between the solid medium and the fluid flow. The effect of this boundary condition is important, since eliminating it can cause incorrect chip temperatures. For fluid flow in micro-channels of IC chip, the Reynolds number is usually less than 2300 and the flow is laminar. For fully developed laminar flow inside rectangular micro-channels with constant heat flux, the Nusselt number can be expressed as: [0000] Nu = 8.235  ( 1 - 2.0421 α + 3.0853 α 2 - 2.4765 α 3 + 1.0578 α 4 - 0.1861 α 5 ) ( 18 ) [0000] where, α is the aspect ratio of the rectangular micro-channel. [0059] The average heat transfer coefficient can be obtained analytically from the Nusselt number and expressed as: [0000] h=Nu·k/D h   (19) [0000] where, D h is the hydraulic diameter of the micro-channel. The same formulation for air convection boundary can be used to model the water convection boundary between the solid medium and water flow. [0060] Based on the above finite volume formulations for voltage distribution equation, heat equations for solid medium and fluid flow with non-uniform rectangular grid, a new steady-state electrical-thermal co-simulation solver (referred to herein as “PowerET”) has been developed. This solver has been used to simulate voltage distribution and thermal distribution with Joule heating, air convection, and fluid cooling effects. [0061] In one experimental embodiment, the length of the micro-channel is 20 mm and its cross-sectional dimension is 0.12 mm×0.24 mm. The bulk silicon thermal conductivity is 150 W/(m·K). The cover thickness is 0.05 mm and its thermal conductivity is set to at 0.2 W/(m·K). The heat flux density of 400,000 W/m 2 is applied at the bottom of the silicon substrate. The input water temperature is set to be 20° C. To test the convergence of the micro-fluidic simulation, the cross-section of the micro-channel is meshed with 2×2, 4×4, 8×8, 16×16 and 32×32 cells (mesh level-1 to mesh level-5), respectively. [0062] With a flow rate of 14.4 mg/s (0.864 ml/min) and using 4×4 meshed cells (mesh level-2) at the cross-section of the micro-channel, the average micro-channel outlet temperature and base temperature are 46.070° C. and 41.93° C., respectively. Compared to the final converged outlet temperature and base temperature of 46.074° C. and 42.17° C., the errors for the average micro-channel outlet temperature and base temperature are both less than 1%. Therefore, using 4×4 meshed cells for the micro-channel cross-section is adequate to obtain accurate results for this example. [0063] In order to verify the model for micro-fluidic cooling against measurement results, the test vehicle with micro-fluidic cooling has been simulated. The structure used is shown in FIGS. 5A and 5B . The chip size was 1 cm×1 cm and the power consumption is 45 W. A total number of 51 micro-channels were distributed uniformly on the chip. The cross-sectional dimension of each micro-channel was 0.1 mm×0.2 mm. A Pyrex glass cover plate is placed on top of the micro-channels. Natural air convection with convection coefficient of 5 W/(m 2 K) was applied to both the top and bottom surfaces of the package. The thermal conductivity of silicon chip was set to be 110 W/(m·K). The input water temperature at the inlets of micro-channels is set to be 22° C. and water heat capacity c p is set to be 4180 J /(K g ·K). The detailed material thickness and thermal conductivity are listed as follows: [0000] Thermal Thickness Conductivity (mm) (W/mK) Substrate 0.35 0.8 Copper 0.036 400 Chip 0.3 110 Underfill 0.2 4.3 C4 0.2 60 Micro-channel 0.2 0.6 Pyrex glass 0.1 1.1 Channel pitch 0.094 [0064] A 3D non-uniform mesh was used to approximate the chip, TSVs, underfill, substrate as well as micro-channels. For each micro-channel, the cross-section was also meshed using 4×4 cells, as shown in FIG. 7 , in which each micro channel 528 included four rows and four columns, resulting in a mesh of 16 cells 700 . This test vehicle was simulated with different water flow rates using the PowerET solver. The comparisons of simulated and measured average outlet temperature of the micro-channels and average chip temperature are plotted and with water flow rates of 65 and 104 ml/min, the differences between the simulated average outlet temperature and actual measurements were 0.1° C. and 0.28° C., respectively. The relative error was less than 4.5% for the outlet temperature. For average chip temperature, with water flow rates of 65 and 104 ml/min, the temperature differences between the simulation and measurements were 2.6 and 1.7° C., respectively. Their corresponding errors were 13.7% and 13.9%, respectively. The relative larger error for the average chip temperature may due to the average heat transfer coefficient h employed in the fluidic cooling model. [0065] In practical package or board designs, the power delivery network usually has irregular shape with many voids or apertures. In order to simulate practical designs, a new interface, which can import board and package design files from the Cadence SPB software into the PowerET solver. A Cadence board design example dimension was 60 mm×31 mm and the chip was 9 mm×9 mm. The chip total power consumption was 50 W. The thermal conductivity of thermal interface material (TIM) was 2 W/(mK). The heat sink was modelled as an ideal heat sink with constant room temperature of 25° C. This example was simulated with convection coefficient of 5 W/(m 2 K) on both sides of the board. The simulated voltage and temperature of the chip with electrical-thermal iterations shows that the final chip temperature was increased to 92.1° C. because of the power density from the chip and Joule heating effect from PDN. Compared to an initial voltage drop of 15 mV, the final voltage drop is increased to 18.2 mV. Therefore, the thermal effect on voltage drop is 21.3%. The final voltage distribution 810 is shown in FIG. 8A and the final and temperature distribution 820 is shown in FIG. 8B . In the example shown the temperature distribution shows a hot spot 822 in an area where an integrated circuit is mounted. [0066] In the finite volume modelling of voltage distribution equation and heat equations with fluidic cooling and air convection are presented, electrical-thermal co-simulations of PDN with Joule heating, air convection and micro-fluidic cooling are carried out. Good agreement between the simulated results, measurement and analytical results validate the correctness and accuracy of the electrical-thermal co-simulation method. Moreover, the simulation shows that micro-fluidic cooling method can remove heat more efficiently than traditional heat sink for high power density 3D sub-systems. Therefore, the thermal effect on the voltage drop in PDN is reduced using micro-fluidic cooling technology. [0067] This system allows users to perform both local modeling and global modeling of electronic circuits. For example, the following may be modeled: chips, under fill, solder, through silicon vias (even a single TSV) and any component that has operational parameters affected by temperature. [0068] The output from the simulator could take one of many forms. For example, it could be a temperature plot, a voltage plot, a plot of an equivalent resistance, etc. It could also take the form of tables or lists that show operating parameters (e.g., temperature, IR drop, voltage drop, etc.) of individual components or volumes within a circuit. In addition post processing can also include calculations of current density along with electrical current plots, temperature gradients and voltage gradients. [0069] The above described embodiments, while including the preferred embodiment and the best mode of the invention known to the inventor at the time of filing, are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the specific embodiments disclosed in this specification without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is to be determined by the claims below rather than being limited to the specifically described embodiments above.

In a method for simulating temperature and electrical characteristics within an circuit, a temperature of at least one volume within the circuit as a function of a resistance within the at least one volume is repeatedly calculated and the resistance as a function of the temperature is repeatedly calculated until the temperature is within a predetermined tolerance of a previous temperature result and until the resistance is within a predetermined tolerance of a previous resistance result. Once the temperature is within a predetermined tolerance of the previous temperature result and the resistance is within a predetermined tolerance of the previous resistance, then an output indicative of the temperature is generated.

FIELD OF THE INVENTION [0001] The invention relates to a computer-implemented method for digitally designing a dental restoration and to a computer-readable medium. BACKGROUND [0002] The design of tooth restorations requires a deep dental knowledge. The challenge of computer aided tooth design lies in the computation of a functional correct morphology of the missing chewing surface. A solution must be robust and automated such that the user actually benefits from time saving and better results. [0003] The article “Dental inlay and onlay construction by iterative Laplacian surface editing” by T. Steinbrecher et al. (Eurographics Symposium on Geometry Processing 2008; Jul. 2-4, 2008 in Copenhagen, Denmark; Volume 27(2008), No. 5; p. 1441-1447) discloses that a model tooth may be adapted by using Laplacian surface editing to a patient's tooth. After adaptation, the part of the model tooth lying above the cavity will be joined with the cavity mesh to create the actual inlay reconstruction. The part of the model tooth lying above the healthy part of the tooth should be adapted to the remaining tooth surface. The model tooth is segmented into parts that lie “above cavity” or “on surface”. [0004] From each vertex of the model tooth that is not yet clarified as “above cavity”, two rays are cast, one towards the centre of the tooth to be reconstructed, and one away from it. Thereby all rays by definition pass through the centre of the tooth to be reconstructed. Only the closest hit point is considered. The hit points are then classified according to their location as “above cavity”, “on surface”, or “undefined”. [0005] The adaptation is an iterative process, alternating segmentation and deformation. For vertices classified as “on surface”, ray collisions with the tooth to be reconstructed are used again. [0006] As the rays are cast starting from a vertex of the model tooth for each iteration also the segmentation has to be performed again. This is because by starting from a vertex of the model tooth, it is unknown where the location of a hit point on the tooth to be reconstructed will be. Even before the first deformation of the model tooth it needs to be segmented. [0007] After the adaptation is completed, all vertices classified as “on surface” and not having a neighbour that is classified as “above cavity” will be removed and thus a mesh that covers the cavity remains wherein its boundary is aligned to the preparation margin. SUMMARY OF THE INVENTION [0008] It is the object of the present invention to enable an automatic design of dental restorations by means of Laplacian surface deformation resulting in stable and reliable data for a dental restoration. [0009] All the method steps described in the following may be performed automatically and do not necessarily need the interaction of a user. [0010] The present invention relates to a computer-implemented method for digitally designing a dental restoration, such as a inlay, onlay, veneer, or partial crown or the like, for a rest tooth, wherein the rest tooth is described by data of the rest tooth and wherein a tooth template is described by data of the tooth template, wherein the method comprises the step of automatically deforming the tooth template by means of Laplacian surface deformation such that a prepared part of the rest tooth is covered (matched) by a portion of the tooth template, wherein the Laplacian surface deformation comprises automatically generating a line which is going through a point, such as a vertex or a point inside a polygonal of a mesh, on the surface of the rest tooth or the tooth template and which is directed along the normal direction at said point and when the line intersects with the tooth template and with the surface of the rest tooth, automatically choosing the intersection point of the line with the tooth template as handle and the intersection point with the surface of the rest tooth as target and automatically deforming the tooth template. [0011] A normal direction to a surface at a point is typically the same as the normal direction to the tangent plane to said surface at said point. [0012] A rest tooth may be considered as a tooth of a patient and/or (digital) data describing it, wherein said tooth is not complete, i.e. has missing parts, due to caries, dental preparation like milling and so on. For the processes in the computer-implemented method digital data of the rest tooth may be used, wherein these data may be achieved by scanning of a dental model of the rest tooth or by directly scanning the patient's rest tooth. The surface of the rest tooth may be described by a mesh of triangles, wherein the triangles may all be the same or wherein the triangles may have different shapes. It is also possible to use other polygons and/or use different polygons (e.g. like triangles and pentagons) in one mesh. [0013] The rest tooth may have a prepared surface/prepared part which in general means that this surface/part has been prepared, e.g. by a dentist by milling. Preferably, the prepared surface/part may be provided with a dental restoration. Further, the rest tooth may have an unprepared surface/unprepared part at which the intact surface of the rest tooth is present. In some cases a non-intact surface of the rest tooth may be considered as “unprepared”, e.g. in case no dental restoration should or will be provided to this surface of the rest tooth. [0014] A tooth template may represent a digital representation of a generic tooth, wherein tooth templates according to the different tooth types (molar, premolar, incisor etc.) may be provided. The surface of the tooth template may be described by a mesh of triangles, wherein the triangles may all be the same or wherein the triangles may have different shapes. It is also possible to use other polygons and/or use different polygons (e.g. like triangles and pentagons) in one mesh. [0015] The data of the tooth template may comprise a polygonal mesh describing the surface of the tooth template and the Laplacian surface deformation may further comprise using a handle that lies inside a polygon of the mesh of the tooth template. [0016] The normal direction of a point within a triangle may be defined as the normal of that triangle or an average of the normal of this triangle and neighbouring triangles. A normal direction at a vertex (corner of a triangle) can be defined by the average of the normal directions of the triangles that have this vertex as a corner point or of triangles that lie within a sphere or volume of a predefined size (and/or shape) around the vertex. The average may be a weighted average wherein the weight may depend on the size of a triangle or it may be an unweighted average where all triangles considered for averaging are taken into account with equal weights. [0017] Moreover, automatically deforming the tooth template in the Laplacian surface deformation may further comprise moving the handle towards the target. [0018] It has been found that by using a handle that lies in a direction normal to the surface at the point of the target or a target that lies in a direction normal to the surface at the point of the handle yields very robust and reliable results using the Laplace surface deformation. By having handles and targets aligned in a direction normal either to the surface of the rest tooth or normal to the surface of the tooth template a surprisingly good choice of a handle and a corresponding target is found which allows for deformation of a template into a proper tooth surface. [0019] It turns out to be of advantage to firstly define a target on the surface of the rest tooth and then to identify the corresponding handle in a direction normal to the surface of the rest tooth for various reasons. It can be assured that a target is provided at specific points of the surface of the rest tooth which are of particular interest. Such a point may e.g. be on the preparation margin. By firstly choosing the target on the surface of the rest tooth and then a corresponding handle it can be assured that a point of particular importance is taken into account for the surface deformation. If first the handles are defined and afterwards the corresponding targets are chosen, then it can not be assured that specific points of the surface of the rest tooth which are of particular interest are is taken into account. The preparation margin defines the border line of the prepared surface and the unprepared surface of the rest tooth that should be provided with a dental restoration. Taking points of the preparation margin into account for the surface deformation results in a smooth transition at the preparation margin, i.e. a smooth transition between the dental restoration and the rest tooth at the preparation margin. [0020] For the targets and for the handles any point of a surface can be used. This means that a point on a surface of the rest tooth or a point on the template can be either a point inside a triangle (or polygon in general) or may be a corner of a triangle (or polygon in general) in case the surface of the rest tooth and the template are described by a mesh comprising triangles (or polygons in general). This on the one hand gives more flexibility in the choice of targets and handles as compared to the prior art but additionally allows for triangles (or polygons in general) of largely different sizes to be used. There is no need to have a large number of relatively small triangles in order to describe the surface of the rest tooth or the tooth template which assures that there is a sufficiently high density of vertices in order to perform a reasonable surface deformation. Since in the present method also points inside a triangle may be used there is no need for a large number of vertices and triangles of largely different size may be used. E.g. triangles having a two dimensional size of their surface 10 times or 50 times the two dimensional size of the surface of the smallest triangle of the data set can be used. This allows for reduced data sets for the digital description of the surface of the rest tooth and of the template in comparison to the prior art. [0021] All vertices of a portion of a mesh describing the rest tooth portion that is considered for the Laplacian deformation can be used as targets or only a portion (subset thereof). Also at least one point of each triangle (polygon) of a mesh describing the rest tooth portion that is considered for the Laplacian deformation can be used as targets or only a portion (subset) of the triangles. [0022] The Laplacian surface deformation may further comprise iteratively performing the deformation of the tooth template. [0023] By having the targets defined on the surface of the rest tooth the handles can be identified without significant computational effort between two iterations. In particular there is no need for a new separate segmentation of the template as in the prior art since the targets, which are used for defining the position of handles do not necessarily change from one iteration to another. In the cited prior art after each iteration a new segmentation has to be carried out which is computationally very expensive. [0024] Iteratively performing the deformation of the tooth template may use a handle weight that is increased as the iteration process proceeds, preferably starting with a pre-defined minimum handle weight. [0025] By iteratively increasing the weight, the general position of the tooth template may be first adjusted to the outer surface of the rest tooth, thus the shape preservation may be predominant and self-intersection may be avoided. As the iteration proceeds and weights increase, the method may find correct handles and the template may be more and more deformed towards the surface of the rest tooth. [0026] The method may further comprise the step of defining the handle weight for the deformation step as a product comprising a global weight increasing with each iteration step, and at least one or two of a distance weight decreasing with increasing distances between the target and the handle, wherein the dependence of the distance weight on the distance may vary with each iteration step, or an angle weight that depends on the angle between the normal direction of the target and the normal direction of the handle. [0027] The global weight may increase with the iteration process and may deform the tooth template more and more. To further penalize false handle selections both distance and normal derivation between the target and the handle may be taken into account. [0028] In order to allow for a general position of the template, weights may be independent from the distance at the beginning of the iteration process. As the iteration proceeds large distances may be penalized more and more by reducing the respective handle weights. This may reduce the impact of false projections. The less the distance, the more certain it may be that a correct projection is found. [0029] A result of the inventive method may be that the transition between the rest tooth and the tooth template is as smooth as possible, which means that sharp edges and transitions which may achieve high loads are prevented. [0030] The method may further comprise the step of automatically extracting a portion of the tooth template by digitally cutting the deformed tooth template along a preparation margin. [0031] For designing the dental restoration, it may be sufficient to use the deformed tooth template that is located within the preparation margin as this is the area that should be provided with the dental restoration in order to achieve a complete tooth structure. [0032] Moreover, the method may comprise the step of combining data representing the cut out deformed tooth template portion with data representing the surface of the rest tooth inside the preparation margin to provide a three-dimensional design of the dental restoration. [0033] The surface of the rest tooth may have been scanned in order to get a corresponding data set. The rest tooth may comprise prepared regions, i.e. regions where original tooth material is missing either by medical defects and/or milling. The preparation margin defines the border line between prepared regions of the rest tooth and regions in which the rest tooth has its original shape. Thus, for the definition and thus also for the design of a complete dental restoration both the cut out deformed tooth template and the surface of the rest tooth inside the preparation margin have to be known in order to define and thus may be able to design the shape of the dental restoration. [0034] Further, a cement gap and/or a spacer gap may be added to the data representing the surface of the dental restoration that would be in contact with or facing towards the rest tooth, the so-called lower surface. [0035] The cement gap may be filled with dental cement or the like in order to fix a physical dental restoration to a rest tooth of a patient. This gap may be provided between the dental restoration and the surface of the rest tooth by providing a dental restoration with dimensions smaller than the space available at the rest tooth. The thickness of the cement gap may be between 10 and 60 μm, or may be smaller or thicker, e.g. depending on the grain size of the dental cement and/or the thickness of the dental restoration. [0036] The spacer gap may be provided in addition to the cement gap (or alone), e.g. to provide a broadening of the cement gap at positions away from the preparation margin, e.g. to increase the amount of cement that may be used for fixing the dental restoration. [0037] The adding may be performed by applying an offset along the normal directions of points on the lower surface, such as vertices, wherein preferably the normal directions may be averaged about a defined region around each point. [0038] A cement gap may be required to provide space for the cement that is needed to securely attach a physical dental restoration to a rest tooth of a patient. An additional spacer gap may be provided. Next to the preparation margin only the cement gap may be provided and at a first predefined distance to the preparation margin a smooth transition from the cement gap to the spacer gap may be provided, reaching some predefined spacer gap thickness at a second predefined distance from the preparation margin. [0039] The surface of the dental restoration may be further adapted according to a cutter radius (e.g. of a milling tool) that will be used for preparing the physical dental restoration. [0040] An adaptation to the cutter radius may be needed to ensure that the manufactured dental restoration fits to the rest tooth and to ensure that the dental restoration may be manufactured with all its required details. For example, when the cutter radius has a dimension that is larger than a structure that the dental restoration to be manufactured should have this structure would have to be adapted, i.e. the structure must be designed to have a size corresponding to the cutter radius. [0041] The method may further comprise the step of determining whether the dental restoration has a pre-defined minimum thickness, wherein the minimum pre-defined thickness may have different or equal values in different regions of the dental restoration, preferably by determining whether the vertices of the cut out deformed tooth template have a predetermined distance to the lower surface, wherein the pre-defined distance may have different or equal values in different regions of the dental restoration. [0042] One possibility to determine whether the dental restoration would have a pre-defined minimum thickness is defining a volume on the prepared part of the rest tooth, the surface of the volume not being in contact with the prepared part of the rest tooth and describing a so-called minimal surface which may define the minimum wall thickness the dental restoration may have. [0043] The method may further comprise the step of moving vertices of the cut out deformed tooth template that lie inside the volume to the surface of the volume not being in contact with the prepared part of the rest tooth by means of the Laplacian surface deformation. [0044] For a computer-aided manufacturing of the dental restoration or any other manufacturing process the dental restoration may have to have a predefined minimal wall thickness to ensure that the dental restoration will not break or will not be damaged in some way during the manufacturing process and/or when being attached to a rest tooth and/or to during daily use in the attached state. [0045] For this Laplacian surface deformation (to ensure a minimal thickness), a handle weight may be defined wherein no iteration depending weight is needed as no general positioning is required in case of adapting the dental restoration to provide a minimum wall thickness. [0046] During this Laplacian surface deformation, first the deformation may be applied to the boundary of the deformed tooth template while fixing handles in the interior of the deformed tooth template, and then in a second step the deformation may be applied to the interior while fixing handles on the boundary. The boundary of the deformed tooth template may be defined by the circumferential border of the surface. [0047] These two subsequent processes ensure that the Laplacian surface deformation does not only move the deformed tooth template out of the minimal surface but deforms it such that is is located out of the minimal surface. [0048] The method may further comprise the step of positioning the tooth template, which preferably may be selected from a data base comprising one or more tooth templates for one or more tooth types, with respect to rest tooth by aligning the rest tooth and the tooth template to coincide in x direction and in z direction. [0049] Both the coordinate systems of the rest tooth and the tooth template may have the x direction in buccal (vestibular) direction, the y direction along the mesial-distal axis and the z direction in occlusal direction. [0050] The position of the tooth template may be adjusted to a maximum z value that may be defined by a highest extend of one or more neighbouring teeth. A plane may be drafted perpendicular to the occlusal axis of said rest tooth and its maximum value of height of the rest tooth of any of the neighbouring tooth. Then the tooth template may be adjusted such that it has at least one common point with this plane but does not intersect the plane. In case no neighbouring tooth or teeth is or are present the plane may be provided at a z value which may be offset by predefined value from the top value of the rest tooth. [0051] Moreover, the tooth template may be scaled to x and y direction according to the horizontal extent of the prepared surface of the rest tooth, wherein preferably no scaling in z direction is performed. [0052] Due to the local coordinate systems of rest tooth and tooth template, the translation of the tooth template to adjust it to a defined height and the scaling in buccal direction, an automated positioning of the tooth template (prior to the Laplace surface deformation) may be achieved. [0053] A further aspect is given by a computer-implemented method for digitally designing a dental restoration for a rest tooth, wherein the rest tooth is described by data of the rest tooth and wherein a tooth template is described by data of the tooth template, the method comprising the step of automatically deforming the tooth template by means of Laplacian surface deformation such that a prepared part of the rest tooth is covered (matched) by a portion of the tooth template wherein the data describing the tooth template define a mesh comprising polygons, such as triangles and one or more handles for the Laplacian surface deformation are provided inside of the polygon. [0055] By having one or more handle provided inside of a polygon, such as a triangle, there is no need for a dense set of small triangles as explained above. [0056] According to another aspect there is provided a computer-implemented method for digitally designing a dental restoration for a rest tooth, wherein the rest tooth is described by data of the rest tooth and wherein a tooth template is described by data of the tooth template, the method comprising the step of automatically deforming the tooth template by means of Laplacian surface deformation such that a prepared part of the rest tooth is covered by a portion of the tooth template wherein firstly a point on the surface of the rest tooth is chosen as a target of the Laplacian surface deformation and then based on the chosen target a point on the tooth template is chosen as a handle. [0058] Thereby firstly it can be assured that specific points such as points on the preparation margin are used for defining a target (as explained above) and secondly no renewed segmentation of the template is necessary as the target points do not change from iteration to iteration. [0059] In a further aspect there is provided a computer-implemented method for digitally modifying a dental restoration for a rest tooth, wherein the dental restoration is described by data of the dental restoration, the method comprising the step of: automatically deforming the dental restoration by means of Laplacian surface deformation such that the thickness thereof is increased up to a predefined minimum thickness of the dental restoration. [0061] Thereby it is made sure that the dental restoration has a minimum thickness, which makes sure that the dental restoration can be manufactured without significant problems and also makes sure that the dental restoration does not break in use due to a to small thickness. At the same time the digital deformation of the dental restoration by the Laplacian surface deformation leads to smooth surfaces without kinks or sharp bends. Details of this Laplacian surface deformation are disclosed above in and in relation to FIG. 6 . [0062] Further, the present invention is related to a computer-readable medium having stored thereon instructions, which when executed by a processor, are adapted to perform any of the above identified method steps. BRIEF DESCRIPTION OF THE DRAWINGS [0063] Preferred embodiments of the invention will be illustrated with reference to the enclosed figures. In the figures: [0064] FIG. 1 shows a prepared tooth with surrounding teeth and a tooth template; [0065] FIG. 2 shows a prepared tooth, a tooth template, first and second bounding boxes; [0066] FIG. 3 shows rays to select handles and targets; [0067] FIG. 4 a shows the result of a surface deformation in a single step; [0068] FIG. 4 b shows the result of a surface deformation using an iterative process with successively increasing handle weights; [0069] FIG. 5 shows cement gap and spacer gap; and [0070] FIG. 6 shows prepared tooth, deformed tooth template and minimal surface. DETAILED DESCRIPTION [0071] The schematic representations shown in FIGS. 1 to 6 may be displayed for example on a computer display or the like, wherein data sets may be provided corresponding to the depicted objects. [0072] FIG. 1 shows schematically a rest tooth 1 comprising a prepared region, the so-called lower surface 2 , which is separated from the unprepared rest tooth, the so-called outer surface 3 , by the preparation margin 4 . The depicted rest tooth 1 has a neighbouring tooth 5 with an approximal surface 5 ′ and two opposite teeth 6 with occlusal surfaces 6 ′. In order to provide the rest tooth 1 with a dental restoration a tooth template 7 may be used. The tooth template 7 may be positioned with respect to the rest tooth 1 such that the local coordinate systems of the rest tooth 1 and the tooth template 7 coincide in x direction and in z direction. For example, the x direction may be given by the buccal direction, the y direction by the mesial-distal axis and the z direction by the occlusal direction. [0073] The rest tooth 1 shown in FIG. 1 comprises a cavity as prepared region, which means that the dental restoration to be designed may be an inlay. However, a rest tooth may also have prepared regions extending on surface regions, such as one or more cusp tips, which means that the dental restoration to be designed may be an onlay or partial crown. A veneer may have to be designed when a thin layer of the tooth surface has to be provided with a dental restoration. [0074] As shown in FIG. 2 , for performing the deformation of the tooth template 7 a first bounding box 8 may be defined by the preparation margin 4 . A second bounding box 9 may be defined in a predefined distance from the first bounding box 8 such that part of the tooth template 7 and part of the outer surface 3 of the rest tooth 1 are cut out. By using the second bounding box 9 the deformation process may be simplified and accelerated as not the whole tooth template 7 will be deformed but only the part of it which is located within the second bounding box 9 . A predefined distance to the first bounding box 8 may be kept in order to avoid cut out fissures in the tooth template 7 . However, for performing the deformation of the tooth template 7 , the use of bounding boxes is not necessarily required. [0075] For deforming the tooth template 7 such that the cavity in the rest tooth 1 may be covered by a suitable part of the tooth template 7 , an algorithm may be used, wherein as shown in FIG. 3 , lines 10 1 - 10 8 are cast each going through a point on the surface of the rest tooth, each of the lines being directed along the normal direction of the point of the surface of the rest tooth. The lines may be cast starting at points on the outer surface 3 of the rest tooth 1 or starting at points on the preparation margin 4 . [0076] If an intersection of a line 10 1 - 10 8 with the tooth template 7 is observed the respective intersection point on the template 7 may be chosen as handle 11 1 - 11 8 (squares) and the respective point on the rest tooth 1 as respective target 12 1 - 12 8 (circles). If an intersection of a line 10 1 - 10 8 with the tooth template 7 is observed in both positive and negative normal directions, the intersection point with the smaller distance to the point the line going through of the surface of the rest tooth 1 may be chosen. [0077] The open circles 12 2 - 12 8 correspond to targets on the outer surface 3 of the rest tooth 1 having respective handles on the tooth template 7 indicated by the open squares 11 2 - 11 8 . The filled circle 12 1 corresponds to a point on the preparation margin 4 and the respective handle on the tooth template 7 is indicated by the filled square 11 1 . [0078] After having determined the handles 11 1 - 11 8 on the tooth template 7 and respective targets 12 1 - 12 8 on the rest tooth 1 , the deformation of the tooth template 7 may be performed as an iterative process. [0079] The deformation of the tooth template 7 , according to the targets 12 1 - 12 8 may be performed in the unprepared region of the rest tooth 1 and at the preparation margin 4 . As the algorithm starts at points on the surface of the rest tooth 1 and the algorithm uses these points as targets 12 1 - 12 8 , it is not required to make a determination after each iteration step whether a point of the tooth template 7 which may be a handle for the next iteration step lies above the prepared or the unprepared region of the rest tooth 1 or above the preparation margin 4 . The algorithm may be considered to deform the tooth template 7 by pulling the tooth template 7 towards the rest tooth 1 and as the location of the targets 12 1 - 12 8 on the rest tooth 1 is known, it is also known that a handle on the tooth template 7 will be deformed towards this location. [0080] In the article of T. Steinbrecher et al., the deformation vectors are determined starting from vertices on the model tooth and thus after each iteration step a new classification of the hits on the surface of the rest tooth has to be performed. [0081] Handle weights may increase form low values to bigger values successively during the iterative process. FIGS. 4 a and 4 b illustratively show the result when performing the deformation in a single step and when performing the deformation using an iterative process, respectively. When using a single step for performing the deformation, self-intersections may be produced resulting in a deformed surface that is not usable for a dental restoration. However, when the iteration starts with low handle weights, the shape preservation characteristic of the Laplacian surface deformation is predominant and self-intersection is avoided. As shown in FIG. 4 b the deformed tooth template 7 is adjusted to fit the outer surface 3 . [0082] Once new handles are selected, the new deformed shape of the tooth template has to be calculated. This may be achieved by solving an optimization problem, wherein a global deformation energy E may be constructed that measures how much a deformed triangle mesh with vertex coordinates p 1 ′, . . . , p n ′ differs from its initial rest pose with vertex coordinates p 1 , . . . , p n . The deformation energy E integrates locally defined changes of the shape. The local shape of vertex i is described by the discrete Laplacian Δp=2H i n i which is a three dimensional vector that points in the direction of the unit length vertex normal n i and has a magnitude twice the mean curvature H i . [0083] The global deformation energy may be formulated as [0000] E  ( p 1 ′ , …   p n ′ ) = ∑ i  A i   δ i ′ - δ i  2 + ∑ j  w j   h j ′ - h j  2 , ( 1 ) [0000] wherein the left term measures the weighted squared distance between local shapes in the deformed mesh and local shapes in the rest pose. The right term of equation 1 measures the weighted squared distance between the positions of the deformed handles h′ j =h j (p′ 1 , . . . , p′ n ) and their targets h j =h j ( 1 , . . . , p n ). A i is the two dimensional Voroni area around the vertex land w j =1. [0084] The discrete Laplacian may be computed as [0000] δ i = 1 2 · A i · ∑  ( cot   α ij + cot   β ij ) · ( p i - p j ) , ( 2 ) [0000] wherein vertices j are the one-ring neighbours of vertex i and α ij and β ij are the two angles opposite to the edge (i,j). In the presence of obtuse triangles, the respective Voroni region extends beyond the one-ring neighbours of the vertex. To guarantee a perfect tiling of the surface without overlapping the Voroni area is truncated, resulting in the Laplacian of a deformed vertex being: [0000] δ i ′ = 1 2 · A i ′ · ∑  ( cot   α ij ′ + cot   β ij ′ ) · ( p i ′ - p j ′ ) . ( 3 ) [0085] The handles j are allowed to be at any point of the triangle surface (and not only being vertices) by using barycentric coordinates (λ j1 , λ j2 , λ j3 ) of the respective triangle (p j1 , p j2 , p j3 ): [0000] h j  ( p 1 , …  , p n ) = λ j   1  p j   1 + λ j   2  p j   2 + λ j   3  p j   3 ,  where ( 4 ) λ jk =  ( p ja - h j ) × ( p jb - h j )   ( p j   2 - p j   1 ) × ( p j   3 - p j   1 )  ( 5 ) [0086] for a≠b, a≠k and b≠k. [0087] It is assumed that areas and angles are preserved such that α′ ij =α ij , β′ ij =β ij and A′ i =A i and hence, the Laplacian operator Δp′ i can be described linearly in the deformed vertex coordinates. Thus, the global deformation energy E has a quadratic form [0000] E ( p′ )=∥√ {square root over (M)} ( Lp′− δ)∥ 2 +∥√{square root over (W)} ( Cp′−h )∥ 2 ,   (6) [0000] is where L is the matrix form of the Laplacian operator, C encapsulates the barycentric coordinates, δ is a vector with the x, y or z coordinates of Laplacian δ i , h is a vector containing the respective handle coordinates, M and W are diagonal matrices containing the weights A i and w i , respectively, and p′ is the vector with the deformed vertex coordinates. The deformed tooth template can be reconstructed by a minimization in the linear least square sense. [0088] The global deformation energy can be reformulated to: [0000] E ( p′ )= p′ T ( L T ML+C T WC ) p′− 2 p′ T ( L T Mδ+C T Wh )+δ T Mδ+h T Wh.   (7) [0089] The minimization [0000] ∂ ∂ p ′  E  ( p ′ ) = 0 ( 8 ) [0000] leads to the normal equations [0000] ( L T ML+C T WC ) p′=L T Mδ+C T Wh   (9) [0000] which are basically a linear system of size n×n. [0090] For the Laplacian surface deformation of the tooth template 7 the handleweights handlew g,I,p,D (i, d, α) may be defined by the following formula: [0000] handlew g , I , p , D  ( i , d , α ) = globalw g , I , p  ( i ) · distw  ( i , d ) D , I · anglew  ( α ) . ( 10 )  globalw g , I , p  ( i ) = g · ( i I ) p , ( 11 ) [0000] wherein g≧1 is a global weighting factor, I≧1 is the number of iteration steps, i≧1 is the current iteration step and the power p≧1 determines the shape of the function. [0091] The distance weighting function may be defined by [0000] distw  ( i , d ) D , I = 1 - wendland 4 , I  ( I - i ) + { 0 for   d ≥ D wendland 4 , I  ( I - i ) · wendland 4 , D  ( d ) else , ( 12  a ) [0000] or preferably by [0000] distw  ( i , d ) D , i = wendland 8 , I  ( i ) + { 0 for   d ≥ D ( 1 - wendland 8 , I  ( i ) ) · wendland 4 , D  ( d ) else , ( 12  b ) [0000] wherein d≧0 is the distance, D≧0 is the support. [0092] The Wendland weighting function is defined by [0000] wendland p , r  ( x ) = ( 1 - x r ) p · ( p · x r + 1 ) ( 13 ) [0000] wherein r≧0 is the radius of support and p≧2 determines the shape of the function. [0093] The angleweight is defined by the following formula: [0000] anglew  ( α ) = { 0 for   α ≥ π / 2 wendland 4 , π / 2  ( a ) else , ( 14 ) [0000] wherein αε[0,π] is the angle between the normal direction of the target and the normal direction of the handle. [0094] After applying a fixed number of iterations i a tooth template 7 may exist that has been deformed such that it describes the unprepared regions of the rest tooth 1 . This part of the tooth template 7 that lies inside the preparation margin 4 may describe the surface of the dental restoration to be designed, wherein this surface represents the surface of the dental restoration that will not be hidden by the rest tooth after attaching the dental restoration to the rest tooth 1 . This surface may be e.g. a part of the chewing surface of a molar. [0095] For the final design of the dental restoration the part of the tooth template 7 inside the preparation margin is relevant. To extract this part, the so-called deformed tooth template 18 , from the tooth template 7 , a virtual cut along the preparation margin 4 may be performed, such that only data being related to the tooth template 7 inside of the preparation margin is taken into account for further processes. [0096] After finalizing the deformation of the tooth template 7 , the surface of the dental restoration describing the lower surface 2 may be adapted by adding a cement gap 13 and a spacer gap 14 , wherein a at some distance 15 from the preparation margin 4 a spacer transition 16 may exist. For example, an offset function may be chosen to achieve a smooth transition from the cement gap 13 to the spacer gap 14 : [0000] offset b , t , c , s  ( d ) = c + { 0 for   d ≤ b s for   d ≥ b + t s 2 · ( 1 + sin  ( π · d - b t - π 2 ) ) else , ( 15 ) [0000] wherein d is the geodesic distance to the preparation margin 4 , b is the distance of the spacer gap 14 to the preparation margin 4 , t is the spacer gap transition 16 , c is the thickness of the cement gap 13 and s is the thickness of the spacer gap 14 . [0097] For the manufacturing of the dental restoration it is required that a certain minimum wall thickness is ensured. Therefore, a minimal surface 17 , as shown in FIG. 6 , may be constructed and every vertex of the deformed tooth template 18 may be required to lie above this minimal surface 17 . The minimal surface 17 may be constructed by an offset on the rest tooth 1 and the mesh of the cavity to be provided with the dental restoration. [0098] To correct the deformed tooth template 18 with respect to the minimal surface 17 , rays (i.e. lines) may be cast from vertices of the deformed tooth template 18 along the positive normal direction of the respective vertex. A vertex is below the minimum wall thickness if the ray belonging to said vertex intersects a mesh triangle of the minimal surface and the difference between the normal direction of the vertex and the normal direction of the triangle is less than π/2. In such a case, a respective handle is selected and the intersection point on the minimum surface 17 is selected as target. Handle weights may be set in the same manner as for the deformation process of the tooth template 7 , but the distance weighting is described independent from the current iteration as no general positioning is required. [0099] In order to achieve a good correction result, first the deformation may be applied to the boundary of the deformed tooth template 18 while fixing handles in the interior using large handle weights. In a second deformation step, the boundary may be fixed and the interior may be adjusted to the minimal surface 17 . [0100] One exemplary for an offset to define the minimal surface is given by [0000] o b , w , W  ( d ) = { 0 for   d ≤ 0 b  1 - ( 1 - d b ) 2 for   d > 0 , d ≤ b w for   d ≥ W b + w - b 2 · ( 1 + sin  ( π · d - b W - b - π 2 ) ) else , ( 16 ) [0000] wherein b>0 is a predefined wall thickness at the boundary and w>b a predefined wall thickness at a geodesic distance W>b from the boundary. This function guarantees a minimum wall thickness b at the boundary and ensures that deformed tooth template 18 forms at least almost a rectangular angle at the preparation margin 4 with respect to the lower surface 2 of rest tooth 1 . [0101] Depending on the shape of the transition between the lower surface 2 and the unprepared part of the rest tooth 1 , the thickening near the preparation margin 4 may have different forms. In case, the transition forms almost a rectangular angle, then almost no or none thickening can be observed and a flat and smooth transition between the corrected, deformed tooth template (Le. the deformed tooth template 18 that has been corrected taking into account a minimal thickness) and the unprepared part of the rest tooth 1 is provided. In case, the transition has an angle smaller than 90°, then a thickening may be provided ensuring that the dental restoration will have a sufficient thickness also near the preparation margin. [0102] Another possibility for defining a minimal surface 17 is to apply an offset along the normal direction of each vertex of the lower surface 2 (wherein preferably the cement gap 13 and/or spacer gap 14 has already be added to the lower surface 2 ). Such an offset may have a predefined value over the whole range of the lower surface 2 or the to offset may have smaller values near the preparation margin 4 and larger values at some predefined distance from the preparation margin 4 or vice versa. Instead of taking into account the normal direction of each vertex, an average of several normal directions of several vertices may be determined and then an offset may be applied to this averaged normal direction.

Computer-implemented method for digitally designing a dental restoration for a rest tooth, wherein the rest tooth is described by data of the rest tooth and wherein a tooth template is described by data of the tooth template, the method comprising automatically deforming the tooth template by means of Laplacian surface deformation such that a prepared part of the rest tooth is covered by a portion of the tooth template, wherein the Laplacian surface deformation comprises automatically generating a line which is going through a point, such as a vertex or a point inside a polygonal of a mesh, on the surface of the rest tooth or the tooth template and which is directed along the normal direction at said point; when the line intersects with the tooth template and with the surface of the rest tooth, automatically choosing the intersection point of the line with the tooth template as handle and the intersection point with the surface of the rest tooth as target; and automatically deforming the tooth template. Further, the invention is related to a computer-readable medium having stored thereon instructions, which when executed by a processor, are adapted to perform the method steps of the inventive computer-implemented method.

TECHNICAL FIELD [0001] The present invention concerns improvements relating to fault-tolerant computers. It relates particularly, although not exclusively, to a method of matching the status of a first computer such as a server with a second (backup) computer communicating minimal information to the backup computer to keep it updated so that the backup computer can be used in the event of failure of the first computer. BACKGROUND ART [0002] Client-server computing is a distributed computing model in which client applications request services from server processes. Clients and servers typically run on different computers interconnected by a computer network. Any use of the Internet is an example of client-server computing. A client application is a process or a program that sends messages to the server via the computer network. Those messages request the server to perform a specific task, such as looking up a customer record in a database or returning a portion of a file on the server's hard disk. The server process or program listens for the client requests that are transmitted via the network. Servers receive the requests and perform actions such as database queries and reading files. [0003] An example of a client-server system is a banking application that allows an operator to access account information on a central database server. Access to the database server is gained via a personal computer (PC) client that provides a graphical user interface (GUI). An account number can be entered into the GUI along with how much money is to the withdrawn from, or deposited into, the account. The PC client validates the data provided by the operator, transmits the data to the database server, and displays the results that are returned by the server. A client-server environment may use a variety of operating systems and hardware from multiple vendors. Vendor independence and freedom of choice are further advantages of the client-server model. Inexpensive PC equipment can be interconnected with mainframe servers, for example. [0004] The drawbacks of the client-server model are that security is more difficult to ensure in a distributed system than it is in a centralized one, that data distributed across servers needs to be kept consistent, and that the failure of one server can render a large client-server system unavailable. If a server fails, none of its clients can use the services of the failed server unless the system is designed to be fault-tolerant. [0005] Applications such as flight-reservations systems and real-time market data feeds must be fault-tolerant. This means that important services remain available in spite of the failure of part of the computer systems on which the servers are running. This is known as “high availability”. Also, it is required that no information is lost or corrupted when a failure occurs. This is known as “consistency”. For high availability, critical servers can be replicated, which means that they are provided redundantly on multiple computers. To ensure consistent modifications of database records stored on multiple servers, transaction monitoring programs can be installed. These monitoring programs manage client requests across multiple servers and ensure that all servers receiving such requests are left in a consistent state, in spite of failures. [0006] Many types of businesses require ways to protect against the interruption of their activities which may occur due to events such as fires, natural disasters, or simply the failure of servers which hold business-critical data. As data and information can be a company's most important asset, it is vital that systems are in place which enable a business to carry on its activities such that the loss of income during system downtime is minimized, and to prevent dissatisfied customers from taking their business elsewhere. [0007] As businesses extend their activities across time zones, and increase their hours of business through the use of Internet-based applications, they are seeing their downtime windows shrink. End-users and customers, weaned on 24-hour automatic teller machines (ATMs) and payment card authorization systems, expect the new generation of networked applications to have high availability, or “100% uptime”. Just as importantly, 100% uptime requires that recovery from failures in a client-server system is almost instantaneous. [0008] Many computer vendors have addressed the problem of providing high availability by building computer systems with redundant hardware. For example, Stratus Technologies has produced a system with three central processing units (the computational and control units of a computer). In this instance the central processing units (CPUs) are tightly coupled such that every instruction executed on the system is executed on all three CPUs in parallel. The results of each instruction are compared, and if one of the CPUs produces a result that is different from the other two, that CPU having the different result is declared as being “down” or not functioning. Whilst this type of system protects a computer system against hardware failures, it does not protect the system against failures in the software. If the software crashes on one CPU, it will also crash on the other CPUs. [0009] CPU crashes are often caused by transient errors, i.e. errors that only occur in a unique combination of events. Such a combination could comprise an interrupt from a disk device driver arriving at the same time as a page fault occurs in memory and the buffer in the computer operating system being full. One can protect against these types of CPU crashes by implementing loosely coupled architectures where the same operating system is installed on a number of computers, but there is no coupling between the two and thus the memory content of the computers is different. [0010] Marathon Technologies and Tandem Computers (now part of Compaq) have both produced fault-tolerant computer systems that implement loosely coupled architectures. [0011] The Tandem architecture is based on a combination of redundant hardware and a proprietary operating system. The disadvantage of this is that program applications have to be specially designed to run on the Tandem system. Whereas any Microsoft Windows™ based applications are able to run on the Marathon computer architecture, the architecture requires proprietary hardware and thus off-the-shelf computers cannot be employed. [0012] The present invention aims to overcome at least some of the problems described above. SUMMARY OF INVENTION [0013] According to a first aspect of the invention there is provided a method of matching the status configuration of a first computer with the status configuration of a second (backup) computer for providing a substitute in the event of a failure of the first computer, the method comprising: receiving a plurality of requests at both the first computer and the second computer; assigning a unique sequence number to each request received at the first computer in the order in which the requests are received and are to be executed on the first computer; transferring the unique sequence numbers from the first computer to the second computer; and assigning each unique sequence number to a corresponding one of the plurality of requests received at the second computer such that the requests can be executed on the second computer in the same order as that on the first computer. [0014] One advantage of this aspect of the invention is that the status configuration of the first computer can be matched to the status configuration of the second computer using transfer of minimal information between the computers. Thus, the status configurations of the two computers can be matched in real-time. Moreover, the information that is exchanged between the two computers does not include any data which is stored on the first and second computers. Therefore any sensitive data stored on the first and second computers will not be passed therebetween. Additionally, any data operated on by the matching method cannot be reconstructed by intercepting the information passed between the two computers, thereby making the method highly secure. [0015] The method is preferably implemented in software. The advantage of this is that dedicated hardware is not required, and thus applications do not need to be specially designed to operate on a system which implements the method. [0016] A request may be an I/O instruction such as a “read” or “write” operation which may access a data file. The request may also be a request to access a process, or a non-deterministic function. [0017] The transferring step preferably comprises encapsulating at least one unique sequence number in a message, and transferring the message to the second computer. Thus, a plurality of requests can be combined into a single message. This further reduces the amount of information which is transferred between the first and second computers and therefore increases the speed of the matching method. As small messages can be exchanged quickly between the first and the second computers, failure of the first computer can be detected quickly. [0018] The plurality of requests are preferably initiated by at least one process on both the first and second computers, and the method preferably comprises returning the execution results to the process(es) which initiated the requests. A pair of synchronised processes is called a Never Fail process pair, or an NFpp. [0019] Preferably the assigning step further comprises assigning unique process sequence numbers to each request initiated by at the least one process on both the first and second computers. The process sequence numbers may be used to access the unique sequence numbers which correspond to particular requests. [0020] If the request is a call to a non-deterministic function the transferring step further comprises transferring the execution results to the second computer, and returning the execution results to the process(es) which initiated the requests. [0021] Preferably the assigning step carried out on the second computer further comprises waiting for a previous request to execute before the current request is executed. [0022] The matching method may be carried out synchronously or asynchronously. [0023] In the synchronous mode, the first computer preferably waits for a request to be executed on the second computer before returning the execution results to the process which initiated the request. Preferably a unique sequence number is requested from the first computer prior to the sequence number being transferred to the second computer. Preferably the first computer only executes a request after the second computer has requested the unique sequence number which corresponds to that request. If the request is a request to access a file, the first computer preferably only executes a single request per file before transferring the corresponding sequence number to the second computer. However, the first computer may execute more than one request before transferring the corresponding sequence numbers to the second computer only if the requests do not require access to the same part of the file. The synchronous mode ensures that the status configuration of the first computer is tightly coupled to the status configuration of the backup computer. [0024] In either mode, the matching method preferably further comprises calculating a first checksum when a request has executed on the first computer, and calculating a second checksum when the same request has executed on the second computer. If an I/O instruction or a non-deterministic function is executed, the method may further comprise receiving a first completion code when the request has executed on the first computer, and receiving a second completion code when the same request has executed on the second computer. [0025] In the asynchronous mode, preferably the first computer does not wait for a request to be executed on the second computer before it returns the result of the process which initiated the request. Using the asynchronous matching method steps, the backup computer is able to run with an arbitrary delay (i.e. the first computer and the backup computer are less tightly coupled than in the synchronous mode). Thus, if there are short periods of time when the first computer cannot communicate with the backup computer, at most a backlog of requests will need to be executed. [0026] The matching method preferably further comprises writing at least one of the following types of data to a data log, and storing the data log on the first computer: an execution result, a unique sequence number, a unique process number, a first checksum and a first completion code. The asynchronous mode preferably also includes reading the data log and, if there is any new data in the data log which has not been transferred to the second computer, transferring those new data to the second computer. This data log may be read periodically and new data can be transferred to the second computer automatically. Furthermore, the unique sequence numbers corresponding to requests which have been successfully executed on the second computer may be transferred to the first computer so that these unique sequence numbers and the data corresponding thereto can be deleted from the data log. This is known as “flushing”, and ensures that all requests that are executed successfully on the first computer are also completed successfully on the backup computer. [0027] The data log may be a data file, a memory-mapped file, or simply a chunk of computer memory. [0028] In either mode, where the request is an I/O instruction or an inter-process request, the matching method may further comprise comparing the first checksum with the second checksum. Also, the first completion code may be compared with the second completion code. If either (or both) do not match, a notification of a fault condition may be sent. These steps enable the first computer to tell whether its status configuration matches that of the second (backup) computer and, if it does not match, the backup computer can take the place of the first computer if necessary. [0029] Furthermore, the first checksum and/or first completion code may be encapsulated in a message, and this message may be transferred to the first computer prior to carrying out the comparing step. Again, this encapsulating step provides the advantage of being able to combine multiple checksums and/or completion codes in a single message, so that transfer of information between the two computers is minimised. [0030] The matching method may further comprise synchronising data on the first and second computers prior to receiving the plurality of requests at both the first and second computers, the synchronisation step comprising: reading a data portion from the first computer; assigning a coordinating one of the unique sequence numbers to the data portion; transmitting the data portion with the co-ordinating sequence number from the first computer to the second computer; storing the received data portion to the second computer, using the coordinating sequence number to determine when to implement the storing step; repeating the above steps until all of the data portions of the first computer have been written to the second computer, the use of the coordinating sequence numbers ensuring that the data portions stored on the second computer are in the same order as the data portions read from the first computer. [0031] The matching method may further comprise receiving a request to update the data on both the first and second computers, and only updating those portions of data which have been synchronised on the first and second computers. Thus, the status configuration of the first and second computers do not become mismatched when the updating and matching steps are carried out simultaneously. [0032] According to another aspect of the invention there is provided a method of synchronising data on both a primary computer and a backup computer which may be carried out independently of the matching method. The synchronising method comprises: reading a data portion from the first computer; assigning a unique sequence number to the data portion; transmitting the data portion and its corresponding unique sequence number from the first computer to the second computer; storing the received data portion to the second computer, using the unique sequence number to determine when to implement the storing step; repeating the above steps until all of the data portions of the first computer have been stored at the second computer, the use of the unique sequence numbers ensuring that the data portions stored on the second computer are in the same order as the data portions read from the first computer. [0033] The matching method may further comprise verifying data on both the first and second computers, the verification step comprising: reading a first data portion from the first computer; assigning a coordinating one of the unique sequence numbers to the first data portion; determining a first characteristic of the first data portion; assigning the transmitted co-ordinating sequence number to a corresponding second data portion to be read from the second computer; reading a second data portion from the second computer, using the co-ordinating sequence number to determine when to implement the reading step; determining a second characteristic of the second data portion; comparing the first and second characteristics to verify that the first and second data portions are the same; and repeating the above steps until all of the data portions of the first and second computers have been compared. [0034] According to a further aspect of the invention there is provided a method of verifying data on both a primary computer and a backup computer which may be carried out independently of the matching method. The verification method comprises: reading a first data portion from the first computer; assigning a unique sequence number to the first data portion; determining a first characteristic of the first data portion; transmitting the unique sequence number to the second computer; assigning the received sequence number to a corresponding second data portion to be read from the second computer; reading a second data portion from the second computer, using the sequence number to determine when to implement the reading step; determining a second characteristic of the second data portion; comparing the first and second characteristics to verify that the first and second data portions are the same; and repeating the above steps until all of the data portions of the first and second computers have been compared. [0035] According to a yet further aspect of the invention there is provided a system for matching the status configuration of a first computer with the status configuration of a second (backup) computer, the system comprising: request management means arranged to execute a plurality of requests on both the first and the second computers; sequencing means for assigning a unique sequence number to each request received at the first computer in the order in which the requests are received and to be executed on the first computer; transfer means for transferring the unique sequence numbers from the first computer to the second computer; and ordering means for assigning each sequence number to a corresponding one of the plurality of requests received at the second computer such that the requests can be executed on the second computer in the same order as that on the first computer. [0036] The transfer means is preferably arranged to encapsulate the unique sequence numbers in a message, and to transfer the message to the second computer. [0037] According to a further aspect of the invention there is given a method of providing a backup computer comprising: matching the status configuration of a first computer with the status configuration backup computer using the method described above; detecting a failure or fault condition in the first computer; and activating and using the backup server in place of the first computer. The using step may further comprise storing changes in the status configuration of the backup computer, so that these changes can be applied to the first computer when it is re-connected to the backup server. [0038] Preferably, the transferring steps in the synchronisation and verification methods comprise encapsulating the unique sequence numbers in a message, and transferring the message to the second computer. [0039] The present invention also extends to a method of matching the operations of a primary computer and a backup computer for providing a substitute in the event of a failure of the primary computer, the method comprising: assigning a unique sequence number to each of a plurality of requests in the order in which the requests are received and are to be executed on the primary computer; transferring the unique sequence numbers to the backup computer; and using the unique sequence numbers to order corresponding ones of the same plurality of requests also received at the backup computer such that the requests can be executed on the second computer in the same order as that on the first computer. [0040] The matching method may be implemented on three computers: a first computer running a first process, and first and second backup computers running respective second and third processes. Three synchronised processes are referred to as a “Never Fail process triplet”. An advantage of utilising three processes on three computers is that failure of the first computer (or of the second or third computer) can be detected more quickly than using just two process running on two computers. [0041] The present invention also extends to a data carrier comprising a computer program arranged to configure a computer to implement the methods described above. BRIEF DESCRIPTION OF DRAWINGS [0042] Presently preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [0043] FIG. 1 a is a schematic diagram showing a networked system suitable for implementing a method of matching the status of first and second servers according to at least first, second and third embodiments of the present invention; [0044] FIG. 1 b is a schematic diagram of the NFpp software used to implement the presently preferred embodiments of the present invention; [0045] FIG. 2 is a flow diagram showing the steps involved in a method of coordinating a pair of processes on first and second computers to provide a matching method computers according to the first embodiment of the present invention; [0046] FIG. 3 a is a schematic diagram showing the system of FIG. 1 a running multiple local processes; [0047] FIG. 3 b is a flow diagram showing the steps involved in a method of coordinating multiple local processes to provide a matching method according to the second embodiment of the present invention; [0048] FIG. 4 is a flow diagram illustrating the steps involved in a method of coordinating non-deterministic requests to provide a matching method according to a third embodiment of the present invention; [0049] FIG. 5 is a flow diagram showing the steps involved in a method of synchronising data on first and second computers for use in initialising any of the embodiments of the present invention; [0050] FIG. 6 is a flow diagram showing the steps involved in a method of coordinating a pair of processes asynchronously to provide a matching method according to a fourth embodiment of the present invention; [0051] FIG. 7 is a flow diagram illustrating the steps involved in a method of verifying data on first and second computers for use with any of the embodiments of the present invention; and [0052] FIG. 8 is a schematic diagram showing a system suitable for coordinating a triplet of processes to provide a matching method according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0053] Referring to FIG. 1 a , there is now described a networked system 10 a suitable for implementing a backup and recovery method according to at least the first, second and third embodiments of the present invention. [0054] The system 10 a shown includes a client computer 12 , a first database server computer 14 a and a second database server computer 14 b . Each of the computers is connected to a network 16 such as the Internet through appropriate standard hardware and software interfaces. The first 14 a database server functions as the primary server, and the second computer 14 b functions as a backup server which may assume the role of the primary server if necessary. [0055] The first 14 a and second 14 b database servers are arranged to host identical database services. The database service hosted on the second database server 14 b functions as the backup service. Accordingly, the first database server 14 a includes a first data store 20 a , and the second database server 14 b includes a second data store 20 b . The data stores 20 a and 20 b in this particular example comprise hard disks, and so the data stores are referred to hereinafter as “disks”. The disks 20 a and 20 b contain respective identical data 32 a and 32 b comprising respective multiple data files 34 a and 34 b. [0056] Database calls are made to the databases (not shown) residing on disks 20 a and 20 b from the client computer 12 . First 22 a and second 22 b processes are arranged to run on respective first 14 a and second 14 b server computers which initiate I/O instructions resulting from the database calls. The first and second processes comprise a first “process pair” 22 (also referred to as an “NFpp”). As the first process 22 a runs on the primary (or first) server 14 a , it is also known as the primary process. The second process is referred to as the backup process as it runs on the backup (or second) server 14 b . Further provided on the first 14 a and second 14 b servers are NFpp software layers 24 a and 24 b which are arranged to receive and process the I/O instructions from the respective processes 22 a and 22 b of the process pair. The NFpp software layers 24 a,b can also implement a sequence number generator 44 , a checksum generator 46 and a matching engine 48 , as shown in FIG. 1 b . A detailed explanation of the function of the NFpp software layers 24 a and 24 b is given later. [0057] Identical versions of a network operating system 26 (such as Windows NT™ or Windows 2000™) are installed on the first 14 a and second 14 b database servers. Memory 28 a and 28 b is also provided on respective first 14 a and second 14 b database servers. [0058] The first 14 a and second 14 b database servers are connected via a connection 30 , which is known as the “NFpp channel”. A suitable connection 30 is a fast, industry-standard communication link such as 100 Mbit or 1 Gbit Ethernet. The database servers 14 a and 14 b are arranged, not only to receive requests from the client 12 , but to communicate with one another via the Ethernet connection 30 . The database servers 14 a and 14 b may also request services from other servers in the network. Both servers 14 a and 14 b are set up to have exactly the same identity on the network, i.e. the Media Access Control (MAC) address and the Internet Protocol (IP) address are the same. Thus, the first and second database servers 14 a and 14 b are “seen” by the client computer 12 as the same server, and any database call made by the client computer to the IP address will be sent to both servers 14 a and 14 b . However, the first database server 14 a is arranged to function as an “active” server, i.e. to both receive database calls and to return the results of the database calls to the client 12 . The second database server 14 b , on the other hand, is arranged to function as the “passive' server, i.e. to only receive and process database calls. [0059] In this particular embodiment a dual connection is required between the database servers 14 a and 14 b to support the NFpp channel 30 . Six Ethernet (or other suitable hardware) cards are thus needed for the networked system 10 a : two to connect to the Internet (one for each database server) and four for the dual NFpp channel connection (two cards for each database server). This is the basic system configuration and it is suitable for relatively short distances (e.g. distances where routers and switches are not required) between the database servers 14 a and 14 b . For longer distances, one of the NFpp channel connections 30 , or even both connections, may be run over the Internet 16 or an Intranet. [0060] Assume the following scenario. The client computer 12 is situated in a call centre of an International bank. The call centre is located in Newcastle, and the database servers 14 a and 14 b are located in London. A call centre operator receives a telephone call from a customer in the UK requesting the current balance of their bank account. The details of the customer's bank account are stored on both the first 20 a and second 20 b disks. The call centre operator enters the details of the customer into a suitable application program provided on the client computer 12 and, as a result, a database call requesting the current balance is made over the Internet 16 . As the database servers 14 a and 14 b have the same identity, the database call is received by both of the database servers 14 a and 14 b . Identical application programs for processing the identical database calls are thus run on both the first 14 a and second 14 b servers, more or less at the same time, thereby starting first 22 a and second 22 b processes which initiate I/O instructions to read data from the disks 20 a and 20 b. [0061] The disks 20 a and 20 b are considered to be input-output (i.e. I/O) devices, and the database call thus results in an I/O instruction, such as “read” or “write”. The identical program applications execute exactly the same program code to perform the I/O instruction. In other words, the behaviour of both the first 22 a and second 22 b processes is deterministic. [0062] Both the first 22 a and second 22 b processes initiate a local disk I/O instruction 38 (that is, an I/O instruction to their respective local disks 20 a and 20 b ). As the data 32 a and 32 b stored in respective first 20 a and second 20 b disks is identical, both processes “see” an identical copy of the data 32 a , 32 b and therefore the I/O instruction should be executed in exactly the same way on each server 14 a and 14 b . Thus, the execution of the I/O instruction on each of the database servers 14 a and 14 b should result in exactly the same outcome. [0063] Now assume that the customer wishes to transfer funds from his account to another account. The database call in this instance involves changing the customer's data 32 a and 32 b on both the first 20 a and second 20 b disks. Again, both processes 22 a and 22 b receive the same database call from the client computer 12 which they process in exactly the same way. That is, the processes 22 a and 22 b initiate respective identical I/O instructions. When the transfer of funds has been instructed, the customer's balance details on the first 20 a and second 20 b disks are amended accordingly. As a result, both before and after the database call has been made to the disks 20 a and 20 b , the “state” of the disks 20 a and 20 b and the processes 22 a and 22 b should be the same on both the first 14 a and second 14 b database servers. [0064] Now consider that a second pair 36 of processes are running on the respective first 14 a and second 14 b database servers, and that the second pair of processes initiates an I/O instruction 40 . As both the first 14 a and second 14 b servers run independently, I/O instructions that are initiated by the processes 22 a and 36 a running on the first server 14 a may potentially be executed in a different order to I/O instructions that are initiated by the identical processes 22 b and 36 b running on the second server 14 b . It is easy to see that this may cause problems if the first 22 and second 36 processes update the same data 32 a , 32 b during the same time period. To ensure that the data 32 a , 32 b on both first 14 a and second 14 b servers remain identical, the I/O instructions 38 and 40 must be executed in exactly the same order. The NFpp software layers 24 a and 24 b that are installed on the first 14 a and second 14 b servers implement a synchronisation/matching method which guarantees that I/O instructions 38 , 40 on both servers 14 a , 14 b are executed in exactly the same order. [0065] The synchronisation method implemented by the NFpp software layers 24 a and 24 b intercepts all I/O instructions to the disks 20 a and 20 b . More particularly, the NFpp software layers 24 a , 24 b intercept all requests or instructions that are made to the file-system driver (not shown) (the file system driver is a software program that handles I/O independent of the underlying physical device). Such instructions include operations that do not require access to the disks 20 a , 20 b such as “file-open”, “file-close” and “lock-requests”. Even though these instructions do not actually require direct access to the disks 20 a and 20 b , they are referred to hereinafter as “disk I/Os instructions” or simply “I/O instructions”. [0066] In order to implement the matching mechanism of the present invention, one of the two database servers 14 a , 14 b takes the role of synchronisation coordinator, and the other server acts as the synchronisation participant. In this embodiment, the first database server 14 a acts as the coordinator server, and the second database server 14 b is the participant server as the active server always assumes the role of the coordinator. Both servers 14 a and 14 b maintain two types of sequence numbers: 1) a sequence number that is increased for every I/O instruction that is executed on the first server 14 a (referred to as an “SSN”) and 2) a sequence number (referred to as a “PSN”) for every process that is part of a NeverFail process pair which is increased every time the process initiates an I/O instruction. [0067] Referring now to FIG. 2 , an overview of a method 200 wherein an I/O instruction 38 is initiated by a NeverFail process pair 22 a and 22 b and executed on the first 14 a and 14 b second database servers is now described. [0068] The method 200 commences with the first process 22 a of the process pair initiating at Step 210 a disk I/O instruction 38 a on the coordinator (i.e. the first) server 14 a in response to a database call received from the client 12 . The NFpp software 24 a running on the coordinator server 14 a intercepts at Step 212 the disk I/O 38 a and increases at Step 214 the system sequence number (SSN) and the process sequence number (PSN) for the process 22 a which initiated the disk I/O instruction 38 a . The SSN and the PSN are generated and incremented by the use of the sequence number generator 44 which is implemented by the NFpp software 24 . The SSN and the PSN are then coupled and written to the coordinator server buffer 28 a at Step 215 . The NFpp software 24 a then executes at Step 216 the disk I/O instruction 38 a e.g., opening the customer's data file 34 a . The NFpp software 24 a then waits at Step 218 for the SSN to be requested by the participant server 14 b (the steps carried out by the participant server 14 b are explained later). [0069] When this request has been made by the participant server 14 b , the NFpp software 24 a reads the SSN from the buffer 28 a and returns at Step 220 the SSN to the participant server 14 b . The NFpp software 24 a then waits at Step 222 for the disk I/O instruction 38 a to be completed. On completion of the disk I/O instruction 38 a , an I/O completion code is returned to the NFpp software 24 a . This code indicates whether the I/O instruction has been successfully completed or, if it has not been successful, how or where an error has occurred. [0070] Once the disk I/O instruction 38 a has been completed, the NFpp software 24 a calculates at Step 224 a checksum using the checksum generator 46 . The checksum can be calculated by, for example, executing an “exclusive or” (XOR) operation on the data that is involved in the I/O instruction. Next, the NFpp software 24 a sends at Step 226 the checksum and the I/O completion code to the participant server 14 b . The checksum and the I/O completion code are encapsulated in a message 42 that is sent via the Ethernet connection 30 . The NFpp software 24 a then waits at Step 228 for confirmation that the disk I/O instruction 38 b has been completed from the participant server 14 b . When the NFpp software 24 a has received this confirmation, the result of the I/O instruction 38 a is returned at Step 230 to the process 22 a and the I/O instruction is complete. [0071] While the disk I/O instruction 38 a is being initiated by the first process 22 a , the same disk I/O instruction 38 b is being initiated at Step 234 by the second process 22 b of the process pair on the participant (i.e. second) server 14 b . At Step 236 , the disk I/O instruction 38 b is intercepted by the NFpp software 24 b , and at Step 238 the value of the PSN is increased by one. The participant server 14 b does not increase the SSN. Instead, it asks the coordinator server 14 a at Step 240 for the SSN that corresponds to its PSN. For example, let the PSN from the participant process 22 b have a value of three (i.e. PSN_b=3) indicating that the process 22 b has initiated three disk I/O instructions which have been intercepted by the NFpp software 24 b . Assuming that the coordinator process 22 a has initiated at least the same number of disk I/O instructions (which have also been intercepted by the NFpp software 24 a ), it too will have a PSN value of three (i.e. PSN_a=3) and, for example, an associated SSN of 1003. Thus, during Step 240 , the participant server 14 b asks the coordinator server 14 a for the SSN value which is coupled to its current PSN value of 3 (i.e. SSN=1003). At Step 241 , the current SSN value is written to the participant server buffer 28 b. [0072] The participant NFpp software 24 b then checks at Step 242 whether the SSN it has just received is one higher than the SSN for the previous I/O which is stored in the participant server buffer 28 b . If the current SSN is one higher than the previous SSN, the NFpp software 24 b “knows” that these I/O instructions are in the correct sequence and the participant server 14 b executes the current I/O instruction 38 b. [0073] If the current SSN is more than one higher than the previous SSN stored in the participant server buffer 28 b, the current disk I/O instruction 38 b is delayed at Step 243 until the I/O operation with a lower SSN than the current SSN has been executed by the participant server 14 b . Thus, if the previous stored SSN has a value of 1001, the participant NFpp software 24 b “knows” that there is a previous I/O instructions which has been carried out on the coordinator server 14 a and which therefore must be carried out on the participant server 14 b before the current I/O instruction 38 b is executed. In this example, the participant server 14 b executes the I/O instructions associated with SSN=1002 before executing the current I/O operation having an SSN of 1003. [0074] The above situation may occur when there is more than one process pair running on the coordinator and participant servers 14 a and 14 b . The table below illustrates such a situation: Coordinator Participant SSN PSN PSN 1001 A1 A1 1002 A2 A2 1003 A3 B1 1004 B1 A3 1005 A4 B2 1006 B2 A4 [0075] The first column of the table illustrates the system sequence numbers assigned to six consecutive I/O instructions intercepted by the coordinator NFpp software 24 a : A1, A2, A3, A4, B1 and B2. I/O instructions A1, A2, A3 and A4 originate from process A, and I/O instructions B1 and B2 originate from process B. However, these I/O instructions have been received by the NFpp software 24 a,b in a different order on each of the servers 14 a,b . [0076] The request for the current SSN may arrive at the coordinator server 14 a from the participant server 14 b before the coordinator server 14 a has assigned an SSN for a particular I/O instruction. In the table above, it can be seen that the participant server 14 b might request the SSN for the I/O instruction B1 before B1 has been executed on the coordinator server 14 a . This can happen for a variety of reasons, such as processor speed, not enough memory, applications which are not run as part of a process pair on the coordinator and/or participant servers, or disk fragmentation. In such cases, the coordinator server 14 a replies to the SSN request from the participant server 14 b as soon as the SSN has been assigned to the I/O instruction. [0077] It can be seen from the table that the I/O instruction A3 will be completed on the coordinator server 14 a (at Step 228 ) before it has been completed on the participant server 14 b . The same applies to I/O instruction B1. This means that I/O instruction A4 can only be initiated on the coordinator server 14 a after A3 has been completed on the participant server 14 b. Thus, according to one scenario, there will never be a queue of requests generated by one process on one server while the same queue of requests is waiting to be completed by the other server. The execution of participant processes can never be behind the coordinator server by more than one I/O instruction in this scenario, as the coordinator waits at Step 228 for the completion of the I/O instruction from the participant server 14 b. [0078] Once the previous I/O instruction has been executed, the NFpp software 24 b executes at Step 244 the current I/O instruction 38 b and receives the participant I/O completion code. The NFpp software 24 b then waits at Step 246 for the I/O instruction 38 b to be completed. When the I/O instruction 38 b has been completed, the NFpp software 24 b calculates at Step 248 its own checksum from the data used in the I/O instruction 38 b . The next Step 250 involves the participant NFpp software 24 b waiting for the coordinator checksum and the coordinator completion code to be sent from the coordinator server 14 a (see Step 226 ). At Step 252 , the checksum and the I/O completion code received from the coordinator server 14 a are compared with those from the participant server 14 b (using the matching engine 48 ), and the results of this comparison are communicated to the coordinator server 14 a (see Step 228 ). [0079] If the outcome of executing the I/O instructions 38 a and 38 b on the respective coordinator 14 a and the participant 14 b servers is the same, both servers 14 a and 14 b continue processing. That is, the participant NFpp software 24 b returns at Step 254 the result of the I/O instruction 38 b to the participant process 22 b , and the coordinator NFpp software 24 a returns the result of the same I/O instruction 38 a to the coordinator process 22 a . The result of the I/O instruction 38 a from the coordinator process 22 a is then communicated to the client 12 . However, as the participant server is operating in a passive (and not active) mode, the result of the I/O instruction 38 b from its participant process 22 b is not communicated to the client 12 . [0080] In exceptional cases, the results of carrying out the I/O instruction on the coordinator server 14 a and participant server 14 b may differ. This can only happen if one of the servers 14 a , 14 b experiences a problem such as a full or faulty hard disk. The errant server (whether it be the participant 14 b or the coordinator 14 a server) should then be replaced or the problem rectified. [0081] The data that is exchanged between the coordinator server 14 a and the participant server 14 b during Steps 240 , 220 , 226 and 252 is very limited in size. Exchanged data includes only sequence numbers (SSNs), I/O completion codes and checksums. Network traffic between the servers 14 a and 14 b can be reduced further by combining multiple requests for data in a single message 42 . Thus, for any request from the participant server 14 b , the coordinator server 14 a may return not only the information that is requested, but all PSN-SSN pairs and I/O completion information that has not yet been sent to the participant server 14 b . For example, referring again to the above table, if in an alternative scenario the coordinator server 14 a is running ahead of the participant server 14 b and has executed all of the six I/O instructions before the first I/O instruction A1 has been executed on the participant server, the coordinator server 14 a may return all of the SSNs 1001 to 1006 and all the corresponding I/O completion codes and checksums in a single message 42 . The participant server 14 b stores this information in its buffer 28 b at Step 241 . The NFpp software 24 b on the participant server 14 b always checks this buffer 28 b (at Step 239 ) before sending requests to the coordinator server 12 at Step 240 . [0082] In addition to intercepting disk I/O instructions, the NFpp software 24 can also be used to synchronise inter-process communications in a second embodiment of the present invention. That is, communications between two or more processes on the same server 14 . If a process requests a service from another local process (i.e. a process on the same server) this request must be synchronised by the NFpp software 24 or inconsistencies between the coordinator 14 a and participant 14 b servers may occur. Referring now to FIG. 3 a , consider that a process S on the coordinator server 14 a receives requests from processes A and B, and the same process S on the participant server 14 b receives requests from a single process B. S needs access to respective disk files 34 a and 34 b to fulfil the request. As the requesting processes A and B (or B alone) run independently on each server 14 a,b , the requests may arrive in a different order on the coordinator 14 a and the participant 14 b servers. The following sequence of events may now occur. [0083] On the coordinator server 14 a process A requests a service from process S. Process S starts processing the request and issues an I/O instruction with PSN=p and SSN=s. Also on the coordinator server 14 a , process B requests a service from process S which is queued until the request for process A is finished. Meanwhile, on the participant server 14 b , process B requests a service from process S. It is given PSN=p and requests the corresponding SSN from the coordinator server 14 a . Unfortunately the coordinator server 14 a returns SSN=s which corresponds to the request for the results of process A. The NFpp software 24 synchronises inter-process communications to prevent such anomalies. In this scenario, the NFpp software 24 a on the coordinator server 14 a detects that the checksums of the I/O instructions differ and hence shuts down the participant server 14 b , or at least the process B on the participant server. [0084] As in the first embodiment of the invention, for inter-process communication both the coordinator 14 a and participant 14 b servers issue PSNs for every request, and the coordinator server 14 a issues SSNs. [0085] Referring now to FIG. 3 b , the steps involved in coordinating inter-process requests (or IPRs) according to the second embodiment are the same as those for the previous method 200 (the first embodiment) and therefore will not be explained in detail. In this method 300 , the application process 22 a on the coordinator server 14 a initiates at Step 310 an IPR and this request is intercepted by the NFpp software 24 a on the coordinator server 14 a . At Step 334 , the application process 22 b on the participant server 14 b also initiates an IPR which is intercepted by the participant NFpp software 24 b . The remaining Steps 314 to 330 of method 300 which are carried out on the coordinator server 14 a are equivalent to Steps 212 to 230 of the first method 200 , except that the I/O instructions are replaced with IPRs. Steps 338 to 354 which are carried out on the participant server 14 b are the same as Steps 238 to 254 , except that the I/O instructions are replaced with IPRs. [0086] In some cases the operating system 26 carries out identical operations on the coordinator server 14 a and the participant server 14 b , but different results are returned. This may occur with calls to functions such as ‘time’ and ‘random’. Identical applications running on the coordinator 14 a and participant 14 b servers may, however, require the results of these function calls to be exactly the same. As a simple example, a call to the ‘time’ function a microsecond before midnight on the coordinator server 14 a , and a microsecond after midnight on the participant server 14 b may result in a transaction being recorded with a different date on the two servers 14 a and 14 b . This may have significant consequences if the transaction involves large amounts of money. The NFpp software 24 a , 24 b can be programmed to intercept non-deterministic functions such as ‘time’ and ‘random’, and propagate the results of these functions from the coordinator server 14 a to the participant server 14 b . A method 400 of synchronising such non-deterministic requests on the first 14 a and second 14 b servers is now described with reference to FIG. 4 . [0087] Firstly, the non-deterministic request (or NDR) is initiated at Step 410 by the application process 22 a running on the coordinator server 14 a . The NDR is then intercepted at Step 412 by the coordinator NFpp software 24 a . Next, the PSN and SSN are incremented by one at Step 413 by the coordinator NFpp software 24 a , and the SSN and PSN are coupled and written at Step 414 to the coordinator buffer 28 a . Then the NDR is executed at Step 415 . The coordinator server 14 a then waits at Step 416 for the SSN and the result of the NDR to be requested by the participant server 14 b . The coordinator server 14 a then waits at Step 418 for the NDR to be completed. Upon completion of the NDR at Step 420 , the coordinator server 14 a sends at Step 422 the SSN and the results of the NDR to the participant server 14 b via the NFpp channel 30 . The NFpp 24 a then returns at Step 424 the NDR result to the calling process 22 a. [0088] The same NDR is initiated at Step 428 by the application process 22 b on the participant server 14 b . The NDR is intercepted at Step 430 by the participant NFpp software 24 b . Next, the participant NFpp software 24 b increments at Step 432 the PSN for the process 22 b . It then requests at Step 434 the SSN and the NDR from the coordinator server 14 a by sending a message 42 via the NFpp channel 30 (see Step 416 ). When the participant server 14 b receives the SSN and the results of the NDR from the coordinator server 14 a (see Step 422 ), the NFpp software 24 b writes the SSN to the participant buffer 28 b at Step 435 . The NFpp software then checks at Step 436 if the SSN has been incremented by one by reading the previous SSN from the buffer 28 b and comparing it with the current SSN. As for the first 200 , second 200 and third 300 embodiments, if necessary, the NFpp software 24 b waits at Step 436 for the previous NDRs (or other requests and/or I/O instructions) to be completed before the current NDR result is returned to the application process 22 b . Next, the NDR result received from the coordinator server 14 a is returned at Step 438 to the application process 22 b to complete the NDR. [0089] Using this method 400 , the NFpp software 24 a,b on both servers 14 a,b assigns PSNs to non-deterministic requests, but only the coordinator server 14 a generates SSNs. The participant server 14 b uses the SSNs to order and return the results of the NDRs in the correct order, i.e. the order in which they were carried out by the coordinator server 14 a. [0090] Network accesses (i.e. requests from other computers in the network) are also treated as NDRs and are thus coordinated using the NFpp software 24 . On the participant server 14 b network requests are intercepted but, instead of being executed, the result that was obtained on the coordinator server 14 a is used (as for the NDRs described above). If active coordinator server 14 a fails, the participant server 14 b immediately takes activates the Ethernet network connection and therefore assumes the role of the active server so that it can both receive and send data. Given that the coordinator and participant servers exchange messages 42 through the NFpp channel 30 at a very high rate, failure detection can be done quickly. [0091] As explained previously, with multiple process pairs 22 and 36 running concurrently, the processes on the participant server 14 b may generate a queue of requests for SSNs. Multiple SSN requests can be sent to the coordinator server 14 a in a single message 42 (i.e. a combined request) so that overheads are minimized. The coordinator server 14 a can reply to the multiple requests in a single message as well, so that the participant server 14 b receives multiple SSNs which it can use to initiate execution of I/O instructions (or other requests) in the correct order. [0092] Consider now that the coordinator system 14 a fails while such a combined request is being sent to the coordinator server via the connection 30 . However, suppose that upon failure of the coordinator server 14 a the participant server 14 b logs the changes made to the files 34 a (for example at Step 244 in the first method 200 ). Suppose also that the failure of the coordinator server 14 a is only temporary so that the files 34 a on the coordinator server 14 a can be re-synchronised by sending the changes made to the files 34 b to the coordinator server 14 a when it is back up and running, and applying these changes to the coordinator files 34 a . Unfortunately, the coordinator server 14 a may have executed several I/O instructions just before the failure occurred, and will therefore not have had the chance to communicate the sequence of these I/O instructions to the participant server 14 b . As the coordinator server 14 a has failed, the participant server will now assume the role of the coordinator server and will determine its own sequence (thereby issuing SSNs) thereby potentially executing the I/O instructions in a different order than that which occurred on the coordinator server 14 a. [0093] A different sequence of execution of the same I/O instructions may lead to differences in the program logic that is followed on both servers 14 a and 14 b and/or differences between the data 32 a and 32 b on the disks 20 a and 20 b . Such problems arising due to the differences in program logic will not become evident until the coordinator server 14 a becomes operational again and starts processing the log of changes that was generated by the participant server 14 b. [0094] To avoid such problems (i.e. of the participant and co-ordinator servers executing I/O instructions in a different order) the NFpp software 24 must ensure that interfering I/O instructions (i.e. I/O instructions that access the same locations on disks 20 a and 20 b ) are very tightly coordinated. This can be done in the following ways: 1. The NFpp software 24 will not allow the coordinator server 14 a to run ahead of the participant server 14 b , i.e. the coordinator server 14 a will only execute an I/O instruction at Step 216 after the participant server 14 b has requested at Step 240 the SSN for that particular I/O instructions. 2. The NFpp software 24 allows the coordinator server 14 a to run ahead of the participant server 14 b , but only allows the coordinator server 14 a to execute a single I/O instruction per file 34 before the SSN for that I/O instruction is passed to the participant server 14 b . This causes fewer delays than the previous option. 3. The NFpp software 24 allows the coordinator server 14 a to execute at Step 216 multiple I/O instructions per file 34 before passing the corresponding SSNs to the participant server 14 b (at Step 220 ), but only if these I/O instructions do not access the same part of the file 34 . This further reduces delays in the operation of the synchronisation method (this is described later) but requires an even more advanced I/O coordination system which is more complex to program than a simpler system. [0098] These three options can be implemented as part of the synchronous methods 200 , 300 and 400 . [0099] It is possible to coordinate the process pairs either synchronously or asynchronously. In the synchronous mode the coordinator server 14 a waits for an I/O instruction to be completed on the participant server 14 b before it returns the result of the I/O instruction to the appropriate process. In the asynchronous mode, the coordinator server 14 a does not wait for I/O completion on the participant server 14 b before it returns the result of the I/O instruction. A method 600 of executing requests asynchronously on the coordinator 14 a and participant 14 b servers is now described with reference to FIG. 6 . [0100] The method 600 commences with the coordinator process 22 a of the process pair initiating at Step 610 a request. This request may be an I/O instruction, an NDR or an IPM. The coordinator NFpp software 24 a intercepts at Step 612 this request, and then increments at Step 614 both the SSN and the PSN for the process 22 a which initiated the request. The SSN and the PSN are then coupled and written to the coordinator buffer 28 a at Step 615 . The NFpp software 24 a then executes at Step 616 the request. It then waits at Step 618 for the request to be completed, and when the request has completed it calculates at Step 620 the coordinator checksum in the manner described previously. The NFpp software 24 a then writes at Step 622 the SSN, PSN, the result of the request, the checksum and the request completion code to a log file 50 a . At Step 624 the NFpp software 24 a returns the result of the request to the application process 22 a which initiated the request. [0101] Next, at Step 626 , the coordinator NFpp software 24 a periodically checks if there is new data in the log file 50 a . If there is new data in the log file 50 a (i.e. the NFpp software 24 a has executed a new request), the new data is encapsulated in a message 42 and sent at Step 628 to the participant server via the NFpp channel 30 , whereupon it is copied to the participant log file 50 b. [0102] At the participant server 14 b , the same request is initiated at Step 630 by the application process 22 b . At Step 632 the request is intercepted by the participant NFpp software 22 b , and the PSN for the initiating process is incremented by one at Step 634 . Next, the data is read at Step 636 from the participant log file 50 b . If the coordinator server 14 a has not yet sent the data (i.e. the SSN, PSN, request results, completion code and checksum) for that particular request, then Step 636 will involve waiting until the data is received. As in the previously described embodiments of the invention, the participant server 14 b uses the SSNs to order the requests so that they are carried out in the same order on both the coordinator 14 a and participant servers 14 b. [0103] If the request is an NDR (a non-deterministic request), then at Step 638 the result of the NDR is sent to the participant application process 22 b . If, however, the request is an I/O instruction or an IPM, the NFpp software 24 b waits at Step 640 for the previous request to be completed (if necessary), and executes at Step 642 the current request. Next, the NFpp software 24 b waits at Step 644 for the request to be completed and, once this has occurred, it calculates at Step 646 the participant checksum. At Step 647 the checksums and the I/O completion codes are compared. If they match, then the NFpp software 24 b returns at Step 648 the results of the request to the initiating application process 22 b on the participant server 14 b . Otherwise, if there is a difference between the checksums and/or the I/O completions codes, an exception is raised and the errant server may be replaced and/or the problem rectified. [0104] As a result of operating the process pairs 22 a and 22 b asynchronously, the coordinator server 14 a is able to run at full speed without the need to wait for requests from the participant server 14 b . Also, the participant server 14 b can run with an arbitrary delay. Thus, if there are communication problems between the coordinator 14 a and participant 14 b servers which last only a short period of time, the steps of the method 600 do not change. In the worse case, if such communications problems occur, only a backlog of requests will need to be processed by the participant server 14 b. [0105] With the method 600 all log-records to the participant server 14 b may be flushed when requests have been completed. Flushing of the log-records may be achieved by the participant server 14 b keeping track of the SSN of the previous request that was successfully processed (at Step 642 ). The participant NFpp software 24 b may then send this SSN to the coordinator server 14 a periodically so that the old entries can be deleted from the coordinator log file 50 a . This guarantees that all requests which are completed successfully on the coordinator server 14 a also completed successfully on the participant server 14 b. [0106] As for the synchronous methods 200 , 300 and 400 , if the process 22 b on the participant server fails, the following procedure can be applied. The NFpp software 24 can begin to log the updates made to the data 32 a on the coordinator disk 20 a and apply these same updates to the participant disk 20 b . At some convenient time, the application process 22 a on the coordinator server 14 a can be stopped and then restarted in NeverFail mode, i.e. with a corresponding backup process on the participant server 14 b. [0107] In another embodiment of the invention an NF process triplet is utilised. With reference to FIG. 8 of the drawings there is shown a system 10 b suitable for coordinating a process triplet. The system 10 b comprises a coordinator server 14 a , a first participant server 14 b and a second participant server 14 c which are connected via a connection 30 as previously described. Each of the computers is connected to a client computer 12 via the Internet 16 . The third server 14 c has an identical operating system 26 to the first 14 a and second 14 b servers, and also has a memory store (or buffer) 28 c . Three respective processes 22 a , 22 b and 22 c are arranged to run on the servers 14 a , 14 b and 14 c in the same manner as the process pairs 22 a and 22 b. [0108] As previously described, the third server 14 c is arranged to host an identical database service to the first 14 a and second 14 b servers. All database calls made from the client computer are additionally intercepted by the NFpp software 24 c which is installed on the third server 14 c. [0109] Consider that a single database call is received from the client 12 which results in three identical I/O instructions 38 a , 38 b and 38 c being initiated by the three respective processes 22 a , 22 b and 22 c . The coordinator server 14 a compares the results for all three intercepted I/O instructions 38 a , 38 b and 38 c . If one of the results of the I/O instructions differs from the other two, or if one of the servers does not reply within a configurable time window, the outlying process or server which has generated an incorrect (or no) result will be shut down. [0110] As in the process pairs embodiments 200 , 300 and 400 , the information that is exchanged between the NeverFail process triplets 22 a , 2 b and 22 c does not include the actual data that the processes operate on. It only contains checksums, I/O codes, and sequence numbers. Thus, this information can be safely transferred between the servers 14 a , 14 b and 14 c as it cannot be used to reconstruct the data. [0111] Process triplets allow for a quicker and more accurate detection of a failing server. If two of the three servers can “see” each other (but not the third server) then these servers assume that the third server is down. Similarly, if a server cannot reach the two other servers, it may declare itself down: this avoids the split-brain syndrome. For example, if the coordinator server 14 a cannot see either the first 14 b or the second 14 c participant servers, it does not assume that there are problems with these other servers, but that it itself is the cause of the problem and it will therefore shut itself down. One of the participant servers 14 b or 14 c will then negotiate as to which server takes the role of the coordinator. A server 14 a , 14 b or 14 c is also capable of declaring itself down if it detects that some of its critical resources (such as disks) are no longer functioning as they should. [0112] The NeverFail process pairs technology relies on the existence of two identical sets of data 32 a and 32 b on the two servers 14 a and 14 b (or three identical sets of data 32 a , 32 b and 32 c for the process triplets technology). There is therefore a requirement to provide a technique to copy data from the coordinator server 14 a to the participant server(s). This is known as “synchronisation”. The circumstances in which synchronisation may be required are: 1) when installing the NFpp software 24 for the first time; 2) restarting one of the servers after a fault or server failure (which may involve reinstalling the NFpp software); or 3) making periodic (e.g. weekly) updates to the disks 20 a and 20 b. [0113] After data on two (or more) database servers has been synchronised, the data thereon should be identical. However, a technique known as “verification” can be used to check if, for example, the two data sets 32 a and 32 b on the coordinator server 14 a and the participant server 14 b really are identical. Note that although the following synchronisation and verification techniques are described in relation to a process pair, they are equally application to a process triplet running on three servers. [0114] In principle, any method to synchronise the data 32 a,b on the two servers 14 a and 14 b before the process pairs 22 a and 22 b are started in NeverFail mode can be used. In practice however, the initial synchronisation of data 32 is complicated by the fact that it is required to limit application downtime when installing the NFpp software 24 . If the NFpp software 24 is being used for the first time on the first 14 a and second 14 b servers, data synchronisation must be completed before the application process 22 b is started on the participant server 14 b . However, the application process 22 a may already be running on the coordinator server 14 b. [0115] A method 500 for synchronising a single data file 34 is shown in FIG. 5 and is now explained in detail. [0116] Firstly, at the start of the synchronisation method a counter n is set at Step 510 to one. Next, the synchronisation process 22 a on the coordinator server 14 a reads at Step 512 the nth (i.e. the first) block of data from the file 34 which is stored on the coordinator disk 20 a . Step 512 may also include encryption and/or compressing the data block. At Step 514 , the coordinator NFpp software 24 a checks whether the end of the file 34 has been reached (i.e. whether all the file has been read). If all of the file 34 has been read, then the synchronisation method 500 is complete for that file. If there is more data to be read from the file 34 , an SSN is assigned at Step 516 to the n th block of data. Then the coordinator NFpp software 24 a queues at Step 518 the n th block of data and its corresponding SSN for transmission to the participant server 14 b via the connection 30 , the SSN being encapsulated in a message 42 . [0117] At Step 520 the NFpp software 24 b on the participant server 14 b receives the n th block of data, and the corresponding SSN. If necessary, the participant NFpp software 24 b waits at Step 522 until the previous (i.e. the (n-1) th ) data block has been written to the participant server's disk 20 b . Then, the nth block of data is written at Step 524 to the participant disk 20 b by the participant synchronisation process 22 b . If the data is encrypted and/or compressed, then Step 524 may also include decrypting and/or decompressing the data before writing it to the participant disk 20 b . The synchronisation process 22 b then confirms to the participant NFpp software 24 b at Step 526 that the nth block of data has been written to the disk 20 b. [0118] When the participant NFpp software 24 b has received this confirmation, it then communicates this fact at Step 528 to the NFpp software 24 a on the coordinator server 14 a . Next, the NFpp software 24 a sends confirmation at Step 530 to the coordinator synchronisation process 22 a so that the synchronisation process 22 a can increment at Step 532 the counter (i.e., n=2). Once the counter n has been incremented, control is returned to Step 512 where the second block of data is read from the file 34 . Steps 512 to 532 are repeated until all the data blocks have been copied from the coordinator disk 20 a to the participant disk 20 b. [0119] The synchronisation method 500 may be carried out while updates to the disks 20 a and 20 b are in progress. Inconsistencies between the data 32 a on the coordinator disk 20 a and the data 32 b on the participant disk 20 b are avoided by integrating software to carry out the synchronisation process with the NFpp software 24 which is updating the data. Such integration is achieved by using the NFpp software 24 to coordinate the updates made to the data 32 . The NFpp software 24 does not send updates to the participant server 14 b for the part of the file 34 which has not yet been synchronised (i.e. the data blocks of the file 34 which have not been copied to the participant server 34 b ). For example, if a customer's file 34 a contains 1000 blocks of data, only the first 100 of which have been copied to the participant disk 20 b , then updates to the last 900 data blocks which have not yet been synchronised will not be made. However, since the application process 22 a may be running on the coordinator server 14 a , updates may occur to parts of files that have already been synchronised. Thus, updates will be made to the first 100 blocks of data on the participant disk 20 b which have already been synchronised. The updates made to the data on the coordinator disk 20 a will then have to be transmitted to the participant server 14 b in order to maintain synchronisation between the data thereon. [0120] The SSNs utilised in this method 500 ensure that the synchronisation updates are done at the right moment. Thus, if a block of data is read by the synchronisation method 500 on the coordinator server 14 a between the n th and the n+1 th update of that file 34 , the write operation carried out by the synchronisation process on the participant server 14 b must also be done between the n th and the n+1 th update of that file 34 . [0121] Once the data has been synchronised, the processes 22 a and 22 b can be run in the NeverFail mode. To do this, the process 22 a on the coordinator server 14 a is stopped and immediately restarted as one of a pair of processes (or a triplet of processes). Alternatively, the current states of the process 22 a running on the coordinator server 14 a can be copied to the participant server 14 b so that the process 22 a does not have to be stopped. [0122] As explained above, during the synchronisation process, data files 34 are copied from the coordinator server 14 a to the participant server 14 b via the Ethernet connection 30 . Even with effective data compression, implementing the synchronisation method 500 on the system 10 a will result in a much higher demand for bandwidth than during normal operation when only sequence numbers (SSNs), checksums and I/O completion codes are exchanged. The synchronisation method 500 is also quite time consuming. For example, if a 100 Mb Ethernet connection were to be used at 100% efficiency, the transfer of 40 GB of data (i.e. a single hard disk) would take about one hour. In reality however, it takes much longer because there is an overhead in running data communication protocols. The disks 20 a and 20 b have to be re-synchronised every time the system 10 a fails, even if it is only a temporary failure lasting a short period of time. The NFpp software 24 offers an optimization process such that if one server fails, the other server captures all the changes made to the disk and sends them to the server that failed when it becomes available again. Alternative approaches are to maintain a list of all offsets and lengths of areas on disk that were changed since a server became unavailable, or to maintain a bitmap where each bit tells whether a page in memory has changed or not. This optimisation process can also be applied in case of communication outages between the servers and for single-process failures. [0123] As mentioned previously, the NFpp software 24 can be used to verify that a file 34 a and its counterpart 34 b on the participant server 14 b are identical, even while the files are being updated by application processes via the NFpp software 24 . This is done in the following manner. [0124] Referring now to FIG. 7 , the verification method 700 commences with the verification process 22 a on the coordinator server 14 a setting a counter n to one at Step 710 . Next, the n th -block (i.e. the first block in this case) of data is read at Step 712 from the file 34 a which is stored on the coordinator disk 20 a . At Step 714 , the verification process 22 a checks whether the end of the file 34 has been reached. If it has, the files 34 a and 34 b on the coordinator 14 a and participant 14 b server are identical and the verification method 700 is terminated at Step 715 . If the end of the file 34 a has not been reached, the coordinator verification process 22 a calculates at Step 716 the coordinator checksum. The value of the counter n is then passed to the coordinator NFpp software 24 a which assigns at Step 718 an SSN to the n th block of data from the file 34 . Then, the coordinator NFpp software 24 a queues at Step 720 the counter and the SSN for transmission to the participant server 14 b via the connection 30 . The SSN and the counter are transmitted to the participant server 14 b as part of a verification message 42 . [0125] At Step 722 the NFpp software 24 b on the participant server 14 b receives the counter and the SSN. It then waits at Step 724 until the previous SSN (if one exists) has been processed. The verification process 22 b on the participant server 14 b then reads at Step 726 the n th block of data from the participant disk 20 b . The verification process 22 b then calculates at Step 728 the participant checksum. When the participant checksum has been calculated it is then passed at Step 730 to the participant NFpp software 24 b via the Ethernet connection 30 . The participant NFpp software 24 b returns at Step 732 the participant checksum to the coordinator NFpp software 24 a via the Ethernet connection 30 . Then, the coordinator NFpp software 24 a returns the participant checksum to the coordinator verification process 22 a at Step 734 . The coordinator verification process 22 a then compares as Step 736 the participant checksum with the coordinator checksum. If they are not equal, the respective files 34 a and 34 b on the participant 14 b and coordinator 14 a server are different. The process 22 b on the participant server 14 b can then be stopped and the files 34 a and 34 b re-synchronised using the synchronisation method 500 —either automatically or more typically with operator-intervention. Alternatively, verification process 22 b may pass a list of the different data blocks to the synchronisation method 500 , so that only this data will be sent to the coordinator server via the connection 30 . [0126] If the participant checksum and the coordinator checksum are equal, the counter n is incremented at Step 738 (i.e. n=2), and control returns to Step 712 wherein the 2 nd block of data is read from the file 34 a . Steps 712 to 738 are carried out until all of the data has been read from the file 34 a and written to the participant disk 20 b, or until the verification process is terminated for some other reason. [0127] The verification method 700 can be done whilst updates to the disks 20 a and 20 b are in progress. This could potentially cause problems unless the verification of data blocks is carried out at the correct time in relation to the updating of specific blocks. However, as the reading of data 34 b to the participant disk 20 b is controlled by the order of the SSNs, the reading Step 726 will be carried out on the participant server 14 b when the data is in exactly the same state as it was when it was read from the coordinator server 14 a . Thus, once a particular block has been read, it takes no further part in the verification process and so can be updated before the end of the verification process on all the blocks is complete. [0128] The verification process can also be undertaken periodically to ensure that the data 32 a and 32 b on the respective disks 20 a and 20 b is identical. [0129] In summary, the present invention provides a mechanism that allows two (or three) processes to run exactly the same code against identical data 32 , 34 on two (or three) servers. At the heart of the invention is a software-based synchronisation mechanism that keeps the processes and the processes' access to disks fully synchronised, and which involves the transfer of minimal data between the servers. [0130] Having described particular preferred embodiments of the present invention, it is to be appreciated that the embodiments in question are exemplary only and that variations and modifications such as will occur to those possessed of the appropriate knowledge and skills may be made without departure from the spirit and scope of the invention as set forth in the appended claims. For example, although the database servers are described as being connected via an Ethernet connection, any other suitable connection could be used. The database servers also do not have to be in close proximity, and may be connected via a Wide Area Network. Additionally, the process pairs (or triplets) do not have to be coordinated on database servers. Any other type of computers which require the use of process pairs to implement a recovery system and/or method could be used. For example, the invention could be implemented on file servers which maintain their data on a disk. Access to this database could then be gained using a conventional file system, or a database management system such as Microsoft SQL Server™.

A method of matching the operations of a primary computer and a backup computer for providing a substitute in the event of a failure of the primary computer is described. The method comprises assigning a unique sequence number to each of a plurality of requests in the order in which the requests are received and are to be executed on the primary computer, transferring the unique sequence numbers to the backup computer, and using the unique sequence numbers to order corresponding ones of the same plurality of requests also received at the backup computer such that the requests can be executed on the second computer in the same order as that on the first computer. In this manner, the status of the primary and backup computers can be matched in real-time so that, if the primary computer fails, the backup computer can immediately take the place of the primary computer.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This U.S. non-provisional patent application claims the benefit of priority as a divisional of U.S. patent application Ser. No. 11/020,311 filed Dec. 22, 2004, which claims the benefit of and priority under 35 U.S.C. § 119 to Korean Patent Application 2004-64400 filed on Aug. 16, 2004. The disclosures of the above referenced U.S. and Korean applications are hereby incorporated herein in their entirety by reference. FIELD OF THE INVENTION [0002] The present invention relates to semiconductor devices, and more particularly to high voltage semiconductor devices and related methods. BACKGROUND [0003] Semiconductor devices require a suitable operation voltage according to the characteristics thereof. With continuous advancement in developing device technologies to reduce power consumption, internal voltages have been reduced. However, there may be a need for devices or logic circuits operable at relatively high voltages. Flash memory devices, for example, may need high writing and/or erasing voltages. High voltage transistors may thus be integrated into flash memory devices to supply such a high voltage to a cell array and/or to pump a low voltage up to a high voltage. [0004] A junction of a high voltage transistor may be formed using an LDD (lightly doped drain) structure or a DDD (double doped drain) structure. There may be limits to manufacturing more highly integrated devices capable of resisting high voltages using such junction structures. If the depth of a low-concentration diffusion layer is reduced for the purpose of overcoming a short-channel effect, for example, a junction breakdown between a high-concentration diffusion layer and a substrate may result. If a concentration distribution of a high-concentration diffusion layer is alleviated to overcome junction breakdown, an effective area of the high-concentrated diffusion layer may increase. [0005] An elevated source/drain technology has thus been developed with an epitaxial layer being formed on a substrate and impurities being implanted into the epitaxial layer. Korean Patent Publication No. 2001-109783 and U.S. Pat. No. 6,087,235 disclose methods of fabricating a transistor with an elevated source/drain structure being formed using selective epitaxial growth. FIGS. 1 through 3 are cross-sectional views illustrating a conventional method of fabricating a transistor. [0006] Referring to FIG. 1 , in the conventional transistor, a field isolation film 121 is formed in a semiconductor substrate 102 to define an active region. A gate insulation layer 302 is formed on the active region, and a conductive gate layer 304 is formed on the gate insulation layer 302 . A capping layer 309 is formed on the gate layer 304 . A drain diffusion region 306 and a source diffusion region 308 are formed by implanting impurities into the semiconductor substrate 102 at opposite sides of the gate layer 304 . First spacers 310 are formed at sidewalls of the gate layer 304 . Elevated drain and source contact structures 314 and 316 , having a drain facet 318 and a source facet 320 respectively, are formed on the semiconductor substrate 102 beside the first spacers 310 . [0007] Referring to FIG. 2 , second spacers 330 are formed at both sides of the gate layer 304 , covering the source facet 320 and the drain facet 318 . The capping layer 309 is etched away from the gate layer 304 . Impurities are implanted into the elevated drain contact structure 314 and the elevated source contact structure 316 . Portions of the substrate 102 adjacent to the gate layer 304 may be shielded from the implanted impurities by the second spacers 330 . [0008] Referring to FIG. 3 , a drain silicide layer 340 is formed on the elevated drain contact structure 314 , a source silicide layer 342 is formed on the elevated source contact structure 316 , and a gate silicide layer 344 is formed on the elevated gate contact structure 304 . An inter-level insulation layer 354 is deposited on the resultant structure for electrical isolation of components of the transistor 300 . Next, drain and source contacts 350 and 352 are formed to provide connections to the drain and source silicide layers 340 and 342 passing through the inter-level insulation layer 354 . [0009] In the conventional transistor architecture described above, the impurity implantation is performed to dope the elevated drain contact structure 314 and the elevated source contact structure 316 to form a drain region and a source region. Accordingly, the source and drain low-concentration diffusion regions may be shallowly formed on the substrate to reduce short-channel effects. Further, since the second spacers 330 cover the source and drain facets 320 and 318 and the high-concentration impurities are implanted into the elevated drain and source contact structures, an impurity layer may not be formed deeply in lower portions of the source and drain facets 320 and 318 . A silicon layer, however, may be grown with crystallization between the gate layer and the impurity layer. Thus, when a high voltage is applied to the source contact or the drain contact, an electric field may be exerted on the silicon layer between the gate layer and the impurity layer. More particularly, when a voltage of 10 to 20 volts or higher is applied to the source contact or the drain contact, the voltage may be provided through the silicon layer to cause an increase of a gate potential. An increase of the gate potential due to a source or drain voltage may thus be reduced by enlarging a thickness of the gate spacer. There may be limits, however, to extending thicknesses of gate spacers in highly integrated circuit devices. SUMMARY OF THE INVENTION [0010] According to some embodiments of the present invention, methods of forming an electronic device may include forming a gate electrode on a semiconductor substrate, and forming first and second impurity doped regions of the semiconductor substrate on opposite sides of the gate electrode. An insulating layer may be formed on the semiconductor substrate including the first and second impurity doped regions, and first and second holes may be formed in the insulating layer. More particularly, the first and second holes may respectively expose portions of the first and second impurity doped regions. In addition, first and second semiconductor layers may be formed in the respective first and second holes on the exposed portions of the first and second impurity doped regions of the semiconductor substrate. [0011] Forming the first and second semiconductor layers may include forming first and second epitaxial semiconductor layers, and a crystal structure of the first and second semiconductor layers may be aligned with respect to a crystal structure of the semiconductor substrate. Moreover, forming the insulating layer may include forming the insulating layer on the gate electrode such that the gate electrode is between the insulating layer and the semiconductor substrate. In addition, the first and second impurity doped regions of the semiconductor substrate may have impurity concentrations that are less than impurity concentrations of at least portions of the respective first and second semiconductor layers. [0012] After forming the first and second semiconductor layers, first and second conductive plugs may be formed in the respective first and second holes on the respective first and second semiconductor layers. More particularly, each of the first and second conductive plugs may include doped polysilicon. In addition or in an alternative, each of the first and second conductive plugs may include a metal, and the first and second conductive plugs may be in ohmic contact with the respective first and second semiconductor layers. [0013] Before forming the insulating layer, sidewall spacers may be formed on sidewalls of the gate electrode such that a sidewall spacer and portions of the insulating layer are between the gate electrode and each of the first and second semiconductor layers. Moreover, an impurity dopant concentration of each of the first and second semiconductor layers may increase with increasing distance from the semiconductor substrate. In addition, a gate insulating layer may be formed such that the gate insulating layer is between the gate electrode and the semiconductor substrate. [0014] According to additional embodiments of the present invention, an electronic device may include a semiconductor substrate and a gate electrode on the semiconductor substrate. The first and second impurity doped regions of the semiconductor substrate may be on opposite sides of the gate electrode, and an insulating layer may be on the semiconductor substrate including the first and second impurity doped regions. More particularly, the insulating layer may have first and second holes therein respectively exposing portions of the first and second impurity doped regions. In addition, first and second semiconductor layers may be in the respective first and second holes on the exposed portions of the first and second impurity doped regions of the semiconductor substrate. [0015] The first and second semiconductor layers may be first and second epitaxial semiconductor layers, and the insulating layer may be on the gate electrode such that the gate electrode is between the insulating layer and the semiconductor substrate. The first and second impurity doped regions of the semiconductor substrate may have impurity concentrations that are less than impurity concentrations of at least portions of the respective first and second semiconductor layers. [0016] First and second conductive plugs may be provided in the respective first and second holes such that the first and second semiconductor layers are between the respective first and second conductive plugs and the first and second impurity doped regions of the semiconductor substrate. More particularly, each of the first and second conductive plugs may include doped polysilicon. In addition or in an alternative, each of the first and second conductive plugs may include a metal, and the first and second conductive plugs may be in ohmic contact with the respective first and second semiconductor layers. [0017] Sidewall spacers may be provided on sidewalls of the gate electrode such that a sidewall spacer and portions of the insulating layer are between the gate electrode and each of the first and second semiconductor layers. Moreover, an impurity dopant concentration of each of the first and second semiconductor layers may increase with increasing distance from the semiconductor substrate. In addition, a gate insulating layer may be provided between the gate electrode and the semiconductor substrate. [0018] According to some embodiments of the present invention, transistor structures and methods may be provided which reduce short-channel effects and elevate junction breakdown voltages without increasing an area of a high-concentration diffusion region. Transistor structures and methods may also be provided which regulate a potential change of a gate electrode due to a high voltage applied to a high-concentration diffusion region. [0019] According to some embodiments of the present invention, a transistor may be provided having a partially elevated source/drain structure. The transistor may include a gate electrode formed on a semiconductor substrate and a low-concentration diffusion region formed in the semiconductor substrate around both sides of the gate electrode. An inter-level insulation film may be formed on an entire surface of the semiconductor substrate on which the gate electrode and the low-concentrated diffusion region are formed. The inter-level insulation film may have contact holes penetrating the low-concentration diffusion region to reach the semiconductor substrate. An epitaxial layer may be formed on a part of the semiconductor in the contact holes. A high-concentration diffusion region may be formed in the epitaxial layer. A contact pattern may fill the contact holes on the epitaxial layer. [0020] The transistor may further include sidewall spacers formed at sidewalls of the gate electrode. Accordingly, the inter-level insulation film may be sandwiched between the sidewall spacers and the epitaxial layer. The high-concentration diffusion region may extend to the semiconductor substrate with a predetermined depth, and its concentration may become gradually higher away from the low-concentrated diffusion region. The contact pattern may be formed of a doped polysilicon or metal pattern. When the contact pattern is formed by metal, the contact pattern and the epitaxial layer may be in ohmic contact with each other. [0021] According to more embodiments of the present invention, methods of fabricating a transistor having a partially elevated source/drain structure may be provided. The method may include forming a gate layer on a semiconductor substrate and implanting low-concentration impurities into the semiconductor substrate around both sides of the gate layer to form a low-concentration diffusion region. An inter-level insulation film may be formed on an entire surface of the semiconductor substrate on which the low-concentration diffusion region is formed. The inter-level insulation film may be patterned to form contact holes exposing the semiconductor substrate on which the low-concentration diffusion region is formed. An epitaxial layer may be grown on portions of the semiconductor substrate exposed by the contact holes. High-concentration impurities may be implanted into the epitaxial layer to form a high-concentration diffusion region. A contact pattern filling the contact holes may be formed. During growth of the epitaxial layer, impurities may be implanted with a gradually increasing concentration. The high-concentration diffusion region may extend a predetermined depth into the semiconductor substrate. BRIEF DESCRIPTION OF THE DRAWINGS [0022] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate examples of embodiments of the present invention and, together with the description, serve to explain principles of the present invention. [0023] FIGS. 1 through 3 are cross-sectional views illustrating a conventional method of fabricating a transistor. [0024] FIG. 4 is a cross-sectional view illustrating transistors according to some embodiments of the present invention. [0025] FIGS. 5 through 9 are cross-sectional views illustrating steps of fabricating transistors according to some embodiments of the present invention. DETAILED DESCRIPTION [0026] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. [0027] In the drawings, the thickness of layers and regions are exaggerated for clarity. It will also be understood that when an element such as a layer, region or substrate is referred to as being on another element, it can be directly on the other element or intervening elements may also be present. In contrast, if an element such as a layer, region or substrate is referred to as being directly on another element, then no other intervening elements are present. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items. [0028] Furthermore, relative terms, such as beneath, upper, and/or lower may be used herein to describe one element's relationship to another element as illustrated in the figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as below other elements would then be oriented above the other elements. The exemplary term below, can therefore, encompass both an orientation of above and below. [0029] It will be understood that although the terms first and second are used herein to describe various regions, layers and/or sections, these regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one region, layer or section from another region, layer or section. Thus, a first region, layer or section discussed below could be termed a second region, layer or section, and similarly, a second region, layer or section could be termed a first region, layer or section without departing from the teachings of the present invention. Like numbers refer to like elements throughout. [0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. [0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. [0032] FIG. 4 is a cross-sectional view illustrating a transistor according to some embodiments of the present invention. Referring to FIG. 4 , a field isolation film 52 may be formed on a semiconductor substrate 50 to define an active region 54 . A transistor may be formed at the active region 54 , and a gate electrode 56 may be formed on the active region 54 . [0033] Shallow low-concentration impurity doped regions 58 of a depth t1 may be formed in the active region 54 around both sides of the gate electrode 56 . Sidewall spacers 60 may be formed at sidewalls of the gate electrode 56 . An epitaxial layer 66 may be selectively grown on a part of each shallow impurity doped region 58 . High-concentration impurity doped regions 68 may be formed at the epitaxial layer 66 . The high-concentration impurity doped regions 68 may extend to a predetermined depth t2 of the semiconductor substrate 50 . The epitaxial layer 66 may be formed in contact holes 64 penetrating inter-level insulation film 62 covering the semiconductor substrate 50 . Accordingly, portions of the inter-level insulation film 62 separate the epitaxial layer 66 and the gate electrode 56 . When a sidewall spacer 60 is formed at sidewalls of the gate electrode 56 , the inter-level insulation film 62 may separate the sidewall spacer 60 and the epitaxial layer 66 . [0034] Upper portions of the epitaxial layers 66 in the contact holes 64 may be filled with contact patterns 70 . Each of the contact patterns 70 may be formed using doped polysilicon and/or a metal. Since the epitaxial layer 66 is doped to a higher concentration, the epitaxial layer 66 and a material used as the contact pattern 70 may be in ohmic contact with one another. [0035] As shown in FIG. 4 , parasitic capacitors C 1 and C 2 are formed between the epitaxial layer 66 and the gate electrode 56 . The parasitic capacitors C 1 and C 2 may be modeled as serially connected capacitors using an inter-level insulation film and a sidewall spacer as dielectric films. According to embodiments of the present invention, since an inter-level insulation film is provided between a doped epitaxial layer and a sidewall spacer, elevation of the gate voltage may be reduced because of a voltage drop in the inter-level insulation film. A thickness of the sidewall spacer may thus be reduced and/or a separate sidewall spacer may be eliminated to lessen an effective area of the transistor. [0036] The high-concentration impurity doped region 68 may have a concentration distribution that is higher away from a boundary with the low-concentrated impurity doped region 58 . This distribution pattern may be achieved by forming an epitaxial layer having an impurity concentration that gradually increases from a lower portion to an upper portion. In other words, since the epitaxial layer 66 may have a concentration distribution that increases gradually from a lower portion to an upper portion, a concentration of the high-concentration impurity doped region 68 formed at the epitaxial layer 66 may gradually increase from a lower portion to an upper portion. As the high-concentration impurity doped region 68 extending to the semiconductor substrate 50 comes nearer to the boundary with the low-concentrated impurity doped region 58 , the concentration thereof may gradually reduce. [0037] FIGS. 5 through 9 are cross-sectional views illustrating steps of fabricating a transistor according to embodiments of the present invention. [0038] Referring to FIG. 5 , field isolation film(s) 52 are formed in a semiconductor substrate 50 to define an active region 54 . A gate insulation layer 51 is formed on the active region 54 , and a gate electrode 56 is formed on the gate insulation layer 51 . Low-concentration impurities are implanted into the semiconductor substrate 50 at both sides of the gate electrode 56 to form low-concentration impurity doped regions 58 . In addition or in an alternative, impurity doped regions 58 may be formed using diffusion. To reduce extension of the low-concentration impurity doped regions 58 to a lower portion of the gate electrode 56 , the low-concentration impurities may be shallowly implanted. Additionally, sidewall spacers 60 can be formed at sidewalls of the gate electrode 56 . [0039] Referring to FIG. 6 , an inter-level insulation film 62 may be formed on an entire surface of the semiconductor substrate 50 . The inter-level insulation film 62 may be patterned to form contact holes 64 exposing portions of the impurity doped regions 58 of a lower concentration. Epitaxial layers 66 may be formed on portions of the semiconductor substrate 50 exposed through contact holes 64 . The epitaxial layers 66 can be grown using selective epitaxial growth. During growth of the epitaxial layers 66 , the epitaxial layers 66 may be doped in situ using an impurity source during deposition. In addition or in an alternative, the epitaxial layer may be doped using ion implantation and/or diffusion. During growth of the epitaxial layer 66 , the epitaxial layer 66 may have an impurity concentration distribution that gradually increases from the lower portion to the higher portion. By doing this, a high-concentration impurity doped region to be formed later may provide a coupling with the low-concentration impurity doped region 58 without an abrupt variation of an electric field. Since the epitaxial layers 66 may be partially formed in the contact hole 64 , a partially elevated source/drain structure can be formed on the active region 54 . [0040] Referring to FIG. 7 , by implanting a high-concentration of impurities into a resulting structure in which the epitaxial layers 66 have been formed, an impurity doped layer 68 having a relatively high concentration may be provided at the epitaxial layers 66 . Since the epitaxial layers 66 may provide a predetermined depth, boundaries may be defined in the low-concentration impurity doped regions 58 into which the high-concentration impurities may extend. Prior to forming the high-concentration impurity doped regions 68 , the epitaxial layers 66 may be formed with a concentration profile that decreases from upper portions to the lower portions. Thus, the high-concentration impurity doped regions 68 may also have concentration profiles that decrease gradually from the upper portion of the epitaxial layer 66 to the lower portion thereof. Even when there has not been any prior doping step for the epitaxial layer(s), the high-concentration impurity doped region(s) 68 formed by an impurity implant and/or diffusion may have a concentration profile that is lower near the low-concentration diffusion region(s) 58 . [0041] The high-concentration impurity doped region 68 may extend into the semiconductor substrate 50 a predetermined depth. In this case, the nearer the high-concentration impurity doped regions 68 to the low-concentration impurity depend region 58 , the lower the concentration thereof. Accordingly, the high-concentration impurity doped regions 68 may have a concentration distribution profiles that are higher away from the boundary of the low-concentration impurity doped region 58 . [0042] Referring to FIG. 8 , the contact holes 64 are filled with a conductive film to form contact patterns 70 connected to the epitaxial layers 66 . The contact patterns 70 may be polysilicon plugs. At this time, the polysilicon plugs may be in-situ doped or doped by ion implantation. In an alternative, the contact patterns 70 can be formed of metal. [0043] Referring to FIG. 9 , contact holes 64 may be filled with metal to form the contact patterns 70 . The contact patterns 70 may include metal barrier layers 70 a and metal core layers 70 b. The metal barrier layers 70 a may conformally cover inner walls of the contact holes 64 and upper surfaces of the epitaxial layers 66 . The metal barrier layer(s) 70 a may be a titanium/titanium nitride film(s). The contact holes 64 in which the metal barrier layers 70 a are formed may be filled with the metal layer(s) 70 b. The metal layers 70 b may include tungsten, tungsten nitride aluminum, and/or copper. [0044] In this case, the contact patterns 70 and the epitaxial layers 66 may be in ohmic contact with each other. The epitaxial layers 66 may be doped at a higher concentration and a metal silicide may be formed at the boundary between the epitaxial layers 66 and the metal barrier layers 70 a allowing the contact patterns 70 and the epitaxial layers 66 to be in ohmic contact with each other. [0045] As discussed above, an epitaxial layer is not formed on portions of the semiconductor substrate exposed at opposite sides of a gate electrode before forming an inter-level insulation film. Contact holes exposing a part of the semiconductor substrate may be formed on opposite sides of the gate electrode, and the epitaxial layers may be formed on exposed portions of the substrate. Accordingly, the epitaxial layers may be formed at portions of impurity doped regions having a lower concentration but the epitaxial layers may be spaced apart from portions of the substrate in the vicinity of a gate electrode and/or a sidewall spacer. [0046] Such a structure according to embodiments of the present invention may provide a potential barrier by an inter-level insulation film separating the epitaxial layer(s) and the gate electrode. Accordingly, although a high voltage may be applied to the epitaxial layer(s), a voltage drop due to an inter-level insulation film separating the epitaxial layer(s) and the gate electrode may reduce voltage increases at the gate electrode. [0047] In addition, since there may be a parasitic capacitor of relatively low capacitance between the gate electrode and the epitaxial layer, fluctuations of a gate potential due to electrical signals from the source and/or drain regions may be reduced. [0048] While the present invention has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Methods of forming an electronic device may include forming a gate electrode on a semiconductor substrate, and forming first and second impurity doped regions of the semiconductor substrate on opposite sides of the gate electrode. An insulating layer may be formed on the semiconductor substrate including the first and second impurity doped regions, and first and second holes may be formed in the insulating layer, with the first and second holes respectively exposing portions of the first and second impurity doped regions. In addition, first and second epitaxial semiconductor layers may be formed in the respective first and second holes on the exposed portions of the first and second impurity doped regions of the semiconductor substrate. Related devices are also discussed.

FIELD OF INVENTION [0001] The present invention relates to operating systems and related methods for multi-processor computer systems and more particularly to an operating system and method for dispatching/wait signaling of a multi-processor computer system, more specifically an operating system and method in which a system wide global dispatching lock is not a requisite to performing the dispatching operation. BACKGROUND OF THE INVENTION [0002] Many current computer systems employ a multi-processor configuration that includes two or more processing units interconnected by a bus system and each being capable of independent or cooperative operation. Such a multi-processor configuration increases the total system processing capability and allows the concurrent execution of multiple related or separate tasks by assigning each task to one or more processors. Such systems also typically include a plurality of mass storage units, such as disk drive devices to provide adequate storage capacity for the number of task executing on the systems. [0003] One type of multi-processor computer system embodies a symmetric multiprocessing (SMP) computer architecture, which is well known in the art as overcoming the limitations of single or uni-processors in terms of processing speed and transaction throughput, among other things. Typical, commercially available SMP systems are generally “shared memory” systems, characterized in that multiple processors on a bus, or a plurality of busses, share a single global memory or shared memory. In shared memory multiprocessors, all memory is uniformly accessible to each processor, which simplifies the task of dynamic load distribution. Processing of complex tasks can be distributed among various processors in the multiprocessor system while data used in the processing is substantially equally available to each of the processors undertaking any portion of the complex task. Similarly, programmers writing code for typical shared memory SMP systems do not need to be concerned with issues of data partitioning, as each of the processors has access to and shares the same, consistent global memory. [0004] There is shown in FIG. 1 a block diagram of an exemplary multiprocessor system that implements an SMP architecture. For further details regarding this system, reference shall be made to U.S. Ser. No. 09/309,012, filed Sep. 3, 1999, the teachings of which are incorporated herein by reference. [0005] Another computer architecture known in the art for use in a multi-processor environment is the Non-Uniform Memory Access (NUMA) architecture or the Cache Coherent Non-Uniform Memory Access (CCNUMA) architecture, which are known in the art as being an extension of SMP but which supplants SMPs “shared memory architecture.” NUMA and CCNUMA architectures are typically characterized as having distributed global memory. Generally, NUMA/CCNUMA machines consist of a number of processing nodes connected through a high bandwidth, low latency interconnection network. The processing nodes are each comprised of one or more high-performance processors, associated cache, and a portion of a global shared memory. Each node or group of processors has near and far memory, near memory being resident on the same physical circuit board, directly accessible to the node's processors through a local bus, and far memory being resident on other nodes and being accessible over a main system interconnect or backbone. Cache coherence, i.e. the consistency and integrity of shared data stored in multiple caches, is typically maintained by a directory-based, write-invalidate cache coherency protocol, as known in the art. To determine the status of caches, each processing node typically has a directory memory corresponding to its respective portion of the shared physical memory. For each line or discrete addressable block of memory, the directory memory stores an indication of remote nodes that are caching that same line. [0006] There is shown in FIG. 2 a high-level block diagram of another exemplary multiprocessor system but which implements a CCNUMA architecture. For further details regarding this system, reference shall be made to U.S. Pat. No. 5,887,146, the teachings of which are incorporated herein by reference. [0007] As is known to those skilled in the art, each of these multiprocessor computer systems includes an operating system that is executed on these systems so that software programs (e.g., spreadsheet, word processing programs, etc.) are executed on these multiprocessor systems, to control the access of these programs when being executed to various resources such as computer readable medium (e.g. hard drives), output media (e.g., printers), communications media (e.g., modem), and to control the execution of the one or more programs being executed/accessed on the multiprocessor computer system at or about the same time. [0008] Before proceeding with describing prior art operating systems for use on multiprocessor computer systems, in particular dispatching, an understanding as to what certain terms are intended to mean is first undertaken. Although programs and processes appear similar on the surface, they are fundamentality different. A program is a static sequence of instructions, whereas a process is a set of resources reserved for the thread(s) that execute the program. For example, at the highest level of abstraction a process in a Windows NT environment comprises the following: an executable program, which defines initial code and data; a private virtual address space, which is a set of virtual memory addresses that the process can use; system resources, such as semaphores, communications ports, and files, that the operating system allocates to the process when threads open them during the program's execution; a unique identifier called a process ID (internally called a client ID); and at least one thread of execution. [0009] A thread is the entity within a process that the operating system schedules for execution, without it the process's program cannot run. A thread typically includes the following components: the contents of a set of volatile registers representing the state of the processor; two stacks, one for the thread to use while executing in the kernel mode and one for executing in the user mode; a private storage area for use by subsystems, run-time libraries, and dynamic link libraries (DLLs); and a unique identified called a thread identifier (also internally called a client ID), process IDs and thread IDs are generated out of the same namespace, so they do not overlap. The volatile registers, the stacks and the private storage areas are called the thread's context. Because this information is different for each machine architecture that the operating system runs on, this structure is architecture specific. [0010] Although threads have their own execution context, every thread within a process shares the process's virtual address space in addition to the rest of the resources belonging to the process. This means that all of the threads in a process can write to and read from each other's memory. Threads cannot reference the address space of another process, unless the other process makes available part of its private address as a shared memory section. In addition, to a private address space and one or more threads, each process has a list of open handles to objects such as files, shared memory sections, one or more synchronization objects such a mutexes, events or semaphores. [0011] The kernel component of the operating system, sometimes referred to simply as the kernel, performs the most fundamental operations in the operating system, determining how the operating system uses the processor or processors and ensuring that the processor(s) are used prudently. The primary functions of the kernel included, thread scheduling and dispatching, trap handling and exception dispatching, multiprocessor synchronization and providing the base kernel objects that are used by the operating system executive. The kernel also handles context swapping, kernel event notification, IO and memory management. The kernel of a multi-processor computer system, more specifically determines which threads or processes run on which processors and also determines when the thread/process will run on a given processor. [0012] The dispatcher is that part of the kernel that focuses on the scheduling function of when and where to run processes, more particularly the threads of such processes. The dispatcher also controls how long each thread can be allowed to run before being preempted to run another thread. Reference is made herein to Chapter 4 of “Inside Windows NT”, Second Edition, A. Solomon, 1988, the teachings of which are incorporated herein by reference, for further details as to the general process in a Windows NT environment for inter alia thread scheduling. [0013] A crucial concept in operating systems is typically referred to as mutual exclusion and generally refers to making sure that one, and only one, thread can access a particular resource at a time. Mutual exclusion is necessary when a resource does not lend itself to shared access or when sharing would result in an unpredictable outcome. For example, the output of two threads from two files being copied to a printer port at the same time could become intermingled. Similarly, if one thread is reading from a memory address at the same time another thread is writing to the same address, the data being read by the first thread becomes unpredictable or unusable. [0014] This concept of mutual exclusion is of particular concern for multi-processor computing systems because code is being run simultaneously on more than one processors, which code shares certain data structures stored in the particular form of system memory of the SMP or NUMA type of multi-processor system. Thus for multiprocessor computing systems the kernel typically is configured to provide mutual exclusion primitives that it and the rest of the operating system executive use to synchronize their access to global data structures. The mechanism by which the kernel achieves multi-processor mutual exclusivity is a locking mechanism associated with the global data structure, commonly implemented as a spinlock. Thus, before entering and updating a global data structure, the kernel first acquires the spinlock and locks the global data structure. The kernel then updates the data structure and after updating the data structure, the spinlock is released. [0015] One widely held and highly contended spinlock is the kernel dispatcher lock that provides a mechanism for protecting all data structures associated with thread execution, context swapping and kernel event notification. Because event notification can result in a change of executing thread and/or context swap, some operating systems including for example Windows NT utilize a single global lock to protect all dispatching data structures. The current dispatcher design, with reference to FIG. 3, implements a structure whereby the execution of threads of all processes coordinate wait notification through defined wait blocks. These software constructs allow any thread in the system to wait for any other dispatcher object in the system to be signaled. [0016] There is shown in FIG. 3 illustrative wait data structures that show the relationship of dispatcher object to wait blocks to threads. In this illustrative example, none of the threads are being executed because they are waiting on dispatcher objects. As is also illustrated, thread 1 is waiting on both visible dispatcher objects and threads 2 and 3 are each waiting on only one of the two dispatcher objects. Thus, if only one of the two visible objects is signaled, the kernel will see that because thread 1 is also waiting on another object it cannot be readied for execution. On the other hand, the kernel will see that the thread waiting on the dispatcher object that is signaling can be readied for execution because it isn't waiting on other objects. There also is shown in FIG. 4 some selected kernel dispatcher objects as well as illustrating system events that can induce a change in the state of a thread(s), and the effect of the signaled state on waiting threads. In the case of an IO the completion of a DMA operation may signal a dispatcher object and a waiting thread would be readied for execution when the kernel dispatcher determines that the dispatcher object indicating the completion of DMA operation/IO process and referenced by (linked to) the waiting thread has been signaled. [0017] Now referring to FIG. 5 there is shown a high level flow diagram illustrating the process followed to reschedule execution of a thread and updating of the data structure associated with dispatching. When the execution of a running thread is pre-empted, terminated or otherwise stopped, the kernel locks the entire dispatch database and examines the dispatch database structure to identify the next thread to be executed, STEPS 102 , 104 . This determination is achieved using any of a number of techniques and criteria known to those skilled in that art and is typically particular to the specific operating system. As noted above, some illustrative criterion are provided in Chapter 4 of “Inside Windows NT” for the scheduling of threads. In a multiprocessor computing system, such identification also includes identifying the processor on which the released or readied thread is to be executed. [0018] The kernel then updates the dispatch database, STEP 106 . For example, the kernel updates the database to note the change in state of the thread to be executed on a processor. The kernel also would evaluate the wait list or wait list structure and update it based on the actions taken to pre-empt or stop the thread that had been running. If it is determined that the thread which had been pre-empted or otherwise stopped (e.g., timer expiring) is to continue running then the kernel would update the database based on the added quantum or time the thread is to be run. Once, all of the updating, evaluating is completed, the kernel releases the global dispatcher lock, STEP 108 . Thereafter, the identified readied or released thread is executed on the identified processor. [0019] As noted above, the dispatcher lock is a global lock that prevents any other thread rescheduling to occur until the lock is released. Because each of the processes running on a multi-processor computing system involve or require thread scheduling/rescheduling, the scheduling of execution of the threads for different processes are in competition with each other no matter how simple or brief the process the kernel follows for dispatching. Likewise, because the notification (signaling) and querying of dispatcher objects (events) is also involved in the execution of many threads, these operations also are in competition with each other. Additionally, the dispatching process performed by the kernel becomes increasingly more time consuming as more concurrent thread rescheduling or event notification operations are performed and therefore contend for the dispatcher spinlock. Further, while the dispatching operation is being performed for one thread, the dispatching of other threads presently stopped and needing to be re-scheduled cannot be accomplished, and thus the applications processes/processors for these other threads are unable to proceed (i.e., pended or delayed). Consequently, the time to perform a task by the applications program/process is in effect increased by such delays. [0020] It thus would be desirable to provide a methodology and operating system particularly for multi-processor computing systems that would allow parallel dispatching, at least for frequently occurring events, without having to employ a system wide global lock of the dispatching database or structure. It would be particularly desirable to provide such a methodology and operating system having a plurality of local locks for dispatching, each of the plurality of local locks locking a grouping of dispatchable objects. It also would be desirable to provide a multiprocessor computing system and/or software for execution on such systems embodying such methodologies. Further, it would be desirable to provide such, methods, operating systems, and multiprocessor computing systems that reduce the amount of time to perform a task in comparison to that provided using prior art dispatching methods. SUMMARY OF THE INVENTION [0021] The present invention features a method for reducing the contention of the highly contended global lock(s) of an operating system, hereinafter dispatcher lock(s) that protects all dispatching structures. More particularly, such a method reduces the need for acquiring the global lock for many event notification tasks by introducing local locks for event notifications that occur frequently among well defined, or consistent dispatcher objects. For these frequently occurring event notifications a subset of the dispatching structure is locked thereby providing mutual exclusivity for the subset and allowing concurrent dispatching for one or more of other data structure subsets. Such a method also includes acquiring one or more local locks where the level of protection of the data structure requires locking of a plurality or more of data structure to provide mutual exclusivity. Such a method further includes acquiring all local locks and/or acquiring a global lock of the system wide dispatcher data structures wherever a system wide local is required to provide mutual exclusivity. In this way, only those portions of the dispatching data structure needing to be locked are locked, thereby providing a mechanism that allows parallel dispatching across the multiprocessor computing system. [0022] In a well-tuned multiprocessing environment, many kernel notification or signaling events frequently occur between a given set of one or more resources and a given set of one or more executing threads. The collection of threads, resources and events that frequently interact with only each other are referred to as a group or a dispatch group. According to the methodology of the present invention, the single global lock protecting all dispatch data structures and dispatching wait signaling in the operating system is replaced with one or more local locks that are configured to protect separate dispatch groups. Each dispatchable object of each given dispatch group, including threads, is assigned a group identifier, unique for that given dispatch group. Using this identifier, the dispatch code paths in the operating system are optimized to acquire only the locks corresponding to the thread(s) and dispatch object(s) being waited on. Such optimization can be achieved using the methodology as set forth in U.S. Ser. No. 09/675,396 filed Sep. 29, 2000 the teachings of which are incorporated herein by reference. In an exemplary embodiment, the dispatch group identifier is implemented as either a portion of an existing field in the dispatch header for each dispatchable object or as a new field in the dispatch header. [0023] In the case of a CCNUMA type of multiprocessor computing system, dispatching activity can occur within groups comprised of individual NUMA nodes or blocks of such nodes. In such a case, the dispatcher groups would be defined by such nodes or blocks and the group identifier. [0024] In another aspect of the present invention, threads are assigned to a default group upon creation based on the processor affinity mask, or are left unassigned. Other dispatcher objects also are assigned to default group or are left unassigned. In such cases, for all unassigned dispatchable objects including unassigned threads, all local dispatch locks are initially acquired and the usage pattern(s) of the unassigned objects is evaluated. Based on the usage pattern(s), the unassigned dispatcher objects are assigned to a specific dispatch group. During normal operation the group identifiers of all dispatcher objects involved in processing are evaluated and, if required, the group identifier is revised based on a changed usage pattern. In this way, a dispatcher object located temporally in a given dispatch group can be assigned to another dispatch group, when this temporal relationship lapses. [0025] In a more specific embodiment of the present invention, the so-modified operating system is evaluated to determine if the modified code paths of the operating system relating to the dispatching function increases the overall performance of the multi-processor computing system to a desired or acceptable level. If the computing system's overall performance is determined not to be acceptable, then other code paths of the operating system are modified in accordance with the methodology of the present invention. Such modification continues until an acceptable level of performance has been obtained or all code paths making up the dispatching function are modified. [0026] Also featured is an operating system embodying such a methodology and a multi-processor computing system configured with such an operating system. [0027] Other aspects and embodiments of the invention are discussed below. DEFINITIONS [0028] The instant invention is most clearly understood with reference to the following definitions: [0029] A computer readable medium shall be understood to mean any article of manufacture that contains data that can be read by a computer or a carrier wave signal carrying data that can be read by a computer. Such computer readable media includes but is not limited to magnetic media, such as a floppy disk, a flexible disk, a hard disk, reel-to-reel tape, cartridge tape, cassette tape or cards; optical media such as CD-ROM and writeable compact disc; magneto-optical media in disc, tape or card form; paper media, such as punched cards and paper tape; or on carrier wave signal received through a network, wireless network or modem, including radio-frequency signals and infrared signals. BRIEF DESCRIPTION OF THE DRAWING [0030] For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference character denote corresponding parts throughout the several views and wherein: [0031] [0031]FIG. 1 is a block diagram of an exemplary multiprocessor system that implements an SMP architecture; [0032] [0032]FIG. 2 is a high-level block diagram of another exemplary multiprocessor system that implements a CCNUMA architecture; [0033] [0033]FIG. 3 is a schematic view of a illustrative wait data structures that illustrate the relationship of dispatcher objects to wait blocks to threads; [0034] [0034]FIG. 4 is a view of some kernel dispatcher objects and the system events that induce a state change in the tread(s) waiting on the dispatcher object; [0035] [0035]FIG. 5 is a flow diagram of a conventional technique for dispatching threads in a queue waiting for execution; [0036] [0036]FIG. 6 is a view of an exemplary optimized SMP computing system illustrating the formation of dispatch groups; [0037] [0037]FIG. 7 is a high-level flow diagram illustrating the process or method of the present invention for optimizing an operating system; and [0038] [0038]FIGS. 8A,B is a high level flow diagram illustrating the process followed to signal kernel events or reschedule execution of a thread and to update the data structures associated with dispatching. DESCRIPTION OF THE PREFERRED EMBODIMENT [0039] Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown in FIG. 6 an exemplary optimized SMP computing system illustrating the formation of distinct groups 200 a - d . In a well tuned SMP, NUMA, CCNUMA or other multiprocessor environment, many kernel notifications or signaling events frequently occur between a given set of one or more resources and a given set of one or more executing threads. The collection of threads, resources, and events that frequently interact with only each other is referred hereinafter as a dispatch group. This grouping can be seen from the following illustrative example. In a multiprocessor environment, disk IO is often optimized such that only one or two processors in the system communicate with one particular disk adapter, resulting in a natural grouping of the IO threads and IO wait events. While this optimization is often configured to reduce cache thrashing or pollution, this natural grouping provides an excellent environment for dispatch grouping as well. [0040] In general, and in accordance with the method of the present invention, a programmer(s) or software designer(s) evaluates any one or more of the computer system and/or the particular operational characteristics, functions and tasks of the software as well as the data of the data set, including the kind and type of data, that is stored in the system memory (RAM, SDRAM, etc.) of the computer system, and the various dispatchable objects. From this evaluation, the programmer determines how to group the dispatchable objects, i.e., define dispatcher groups, and in effect divide or partition the dispatcher data structure or database into subsets or partitions. In general terms, the number of dispatcher groups and the definition of the contents of each dispatcher group are established so as to provide a mechanism to redefine the locking requirements of one or more code paths of the software. The redefinition of the locking requirements of one or more code paths, further provides a mechanism for reducing contention of the highly contended global dispatcher lock that would have been provided if one used conventional software dispatching techniques for the one or more code paths. The following provides some exemplary system configurations and some exemplary grouping schemes that one skilled in the art might contemplate for use in connection with the methodology of the present invention. Such discussion also further describes the methodology of the present invention. [0041] As a result of the attendant spatial and temporal localities in processing, the distinct groups 200 a - d are frequently stable and seldom interact. Occasionally, however, kernel notification or signaling events occur across localized groups 200 a - d , such as for example, an executing thread in one group 200 a is waiting on a resource in another group 200 c . These groups 200 a - d , because of the spatial and/or temporal localities established, also respectively each form dispatch groups. [0042] In such a case, and in accordance with the present invention, the traditional single global dispatch lock protecting all dispatch data structures and dispatch wait signaling is replaced with multiple local locks protecting separate dispatch groups, groups 0-3, hereinafter groups 200 a - d , will be referred to as dispatch groups 200 a - d . In addition, each dispatchable object including threads within each group is identified by or assigned a unique group identifier. For example, in the zeroth dispatch group 200 a , each of the dispatachable objects would be uniquely identified as being in the zeroth group. [0043] In an exemplary embodiment, such unique identification is implemented or accomplished as either a portion of an existing field in the dispatch header or as a new field in the dispatch header. For an exemplary dispatch header in a Windows NT environment see “Inside Windows NT:, Second Edition, pp. 132-133. A dispatch header is a well known software construct for purposes of identification a dispatchable object including threads. It is within the scope of the present invention to create such an identifier by adapting and/or using any of a number of software techniques known to those skilled in the art by which each dispatachable object falling within a given group can be so identified as being part of that group. [0044] In the case of a NUMA or CCNUMA type of computing system, and for well tuned systems, it is not uncommon to see that most dispatching activity occurs within groups comprised of individual NUMA nodes or blocks of such nodes. Thus, the dispatch groups can be easily and naturally defined along the individual NUMA nodes or blocks of nodes in which most of the dispatching activity is being grouped. In this case, the dispatch group identifier would reflect the grouping established by the individual NUMA node or block of nodes. [0045] The foregoing is illustrative of some operational examples of SMP or NUMA type of computing systems that lend themselves to a natural grouping of dispatchable objects into unique dispatch groups. This shall not be construed as being a limitation because the operational characteristics of any given process, the execution of threads and accessing of resources by threads and wait signaling of threads also can lend themselves to such grouping. It is equally possible, therefore that a particular implementation of an SMP computing system would derive benefit from defining dispatch groups that contain one and only one processor, such that an N processor SMP computing system would have N dispatch groups. [0046] In one case, a temporal locality can be established for a dispatchable group because if a thread is running on a processor this thread typically will remain running on that processor even though it could be rescheduled for execution on another processor. This is one of the criterion the kernel dispatcher utilizes for rescheduling a thread. As noted above, a thread being executed can be preempted prior to completion of the designated task when the timer expires or when a higher priority threads is to be executed. In other words the dispatching criterion establishes in effect a de facto grouping. In another case, a spatial grouping is established because things, data and the like in cache and the computer readable storage medium relate to the where the data is being used in the system. Consequently, a processor running a given thread will generate a natural grouping between the processor and the data sources the thread will tend to use. In general, the thread's execution, accessing of resources, or criterion implemented by the kernel can establish a grouping of dispatchable objects. [0047] The affinity mask for the process that defined a specific subset of the total number of available processors on which the process is to be run also can be used to create a default grouping for threads and other dispatchable objects. Alternatively, the dispatchable objects can remain unassigned. When the dispatchable objects are not assigned a unique group identifier, the operating system is configured to acquire all local dispatch locks and the global locks. The operating system also is configurable so as to evaluate the usage of the threads and dispatchable during normal operation to determine if a usage pattern(s) has developed showing the formation of a temporal locality, spatial locality or other locality upon which some or all of the unassigned dispatchable objects can be grouped. In such cases, the operating system would assign these dispatchable objects to a specific dispatch group and so identify these dispatchable objects. [0048] In sum, each process created on a multiprocessor computing system is evaluated to determine if the dispatchable objects can be formed in one or more separate groupings. During the creation of threads for the process, the dispatchable objects including the threads are uniquely identified with a group identifier, which identifier is used to locally lock all dispatchable objects that fall within that group. When dispatchable objects of the process cannot be so-grouped, the operating system is configured to lock all local dispatch locks and/or the global dispatch lock. Such an arrangement and local locking of a dispatch groups results in an effective decrease in the overall run time for a process or applications program because the frequency of intra-group event signaling and dispatching typically occurs with much greater frequency than in the case of inter-group event signaling and dispatching. [0049] The foregoing is illustrative of various techniques by which the dispatcher data structure can be divided or partitioned so as to form dispatch groups and by which the different dispatch groups are uniquely identified. After so defining the dispatch groups and the identification mechanism for the groups, the one or more code paths of the operating system need to be evaluated and modified to effect local locking of selective portions or partitions of the dispatcher data structure. One illustrative technique for modifying these code paths is as follows. It should be noted that reference also should be made to U.S. Ser. No. 09/675,396 filed Sep. 29, 2000, the teachings of which are herein incorporated by reference for further details concerning the following. [0050] There is shown in FIG. 7 a high-level flow diagram that illustrates the process or method of the present invention for optimizing the software of an operating system so as to reduce the contention of the highly contended dispatcher lock, a global lock, protecting multiple data items of the dispatcher database/data structure. The present method begins by determining the methodology by which the dispatchable objects are to be grouped, STEP 402 , which is the process described above. [0051] After determining the grouping method, N local dispatch locks are established or created in the software for one or more dispatchable groups in the one or more code paths of the software, step 404 , where N is ≧1, more particularly N is ≧2. Such local locks are created with the same locking mechanism employed by the original global lock or using any other technique known to those skilled in the art that is otherwise compatible with the software code being modified or written. [0052] Following the creation of the N local locks, the software is modified or is written such that wherever the global lock was acquired, all N local locks and the global lock are now acquired, Step 406 . With this provision in the software, the data comprising the original, or initial, data set is effectively defined so as to be protected by both the global lock and all of the local locks. [0053] Because a plurality of local locks may be held at the same time in any one or more code paths, when creating the local locks the software also shall include a locking hierarchy as is known to those skilled in the art to prevent deadlock scenarios. In an illustrative embodiment, when acquiring multiple local locks, the lowest numbered local lock is acquired first and other local locks are acquired in order through the highest numbered local lock and the global lock is acquired last. A higher numbered local lock, or the global lock, can be acquired when a lower numbered local lock is held. If a lower numbered local lock than one that is already held must be acquired, then the higher numbered local lock(s) is/are released and reacquired in the manner described above. The locks can be released in any order. As indicated above, the concept of a locking hierarchy is well understood in the field of computer science, see for example, J. W. Havender, Avoiding Deadlock in Multitasking Systems, IBM Systems Journal 7,2 (1968), 74-84. [0054] According to one aspect of the present invention, the software comprising the operating system is written/revised so that at least selected ones of the plurality or more code paths thereof are optimized with regards to the locking requirements of these selected code paths so as to reduce the contention for acquiring the dispatcher lock(s). Thus, each of the various code paths are evaluated to determine the code path which experiences the heaviest use for dispatching, hereinafter the hottest code path, STEP 408 . Such a determination is effected using any of a number of methods or techniques known to those skilled in the art, including, but not limited to instrumentation of the software, such as by the addition of counters; or analysis with commercially available tools such as VTUNE© Intel. [0055] As indicated above, at creation the dispatchable objects of each group are identified with a group identifier. Thus, the locking requirements for the identified code path are optimized so only the locks associated with the group(s) of dispatchable object(s) required for this code path is locked, STEP 412 . In other words, the locking requirements of the identified code path are modified from acquiring all locks to acquiring only the locks needed to lock the dispatchabe objects within a given group. For purposes of the present invention, a software code path according to the present invention, begins at a location in the software code that acquires the global lock (i.e., before the locking is modified), and ends when the global lock is released (i.e., before the locking is modified). The code path can branch and loop, and have multiple release points. The code paths also can share code (i.e., common routines) with other code paths. [0056] After optimizing the locking requirements of a code path, the operating system remains functional or operational. Thus, after optimizing the locking requirements of the identified code path, the programmer(s) or software designer(s) also can perform any or a number of tests on the so-modified software to determine the overall operational performance of the modified software. Such tests can be any of a number of tests known to those skilled in the art, any of a number of tests known in the art that can be adapted for use by any one skilled in the art, or can be developed by one of ordinary skill in the art. The programmer(s) or software designer(s) also evaluate the operational performance of the software to determine if the overall performance of the software is adequate for the intended use, STEPS 414 , 416 . In the case where an existing, working piece of code is being modified or upgraded, the so-modified code is evaluated to determine if the overall operational performance has been improved from the earlier version of the code as intended and/or meets any improvement goals that may have been established, expected or intended. Such testing and evaluation of the operational performance is achievable, because the code path(s) where locking requirements for dispatching were not optimized, remain in operational condition as a result of the “all locks” code modification of STEP 406 . In other words, dispatching and locking requirements of selected code paths can be optimized because of such grouping of dispatchable objects without effecting the operational capabilities of the other non-optimized code paths. Furthermore, this provides a mechanism by which the incremental improvement in overall performance of the software resulting from the optimization of by code path locking requirements can be determined and evaluated. Such evaluation of incremental performance also provides a mechanism to perform a cost-benefit analysis to determine if the incremental increase in performance warrants the time taken to optimize locking requirements for a working piece of software. [0057] As indicated above, the programmer(s) or software designer(s) evaluate the overall performance of the modified software (i.e., operating system) so as to determine if the increase in performance is acceptable, STEP 416 . If the overall increase is determined to be acceptable (YES, STEP 416 ) then the programmer(s) or software designers(s) end the process of optimizing the software to reduce the contention of a highly contended lock(s), STEP 420 . [0058] If the overall increase is determined not to be acceptable (NO, STEP 416 ) then the next heaviest code path (i.e., the next hottest code path) is identified, STEP 418 . Thereafter, STEPS 410 - 416 are repeated for the next heaviest code path. This process is repeated until the overall performance of the software is determined to be acceptable (YES, STEP 416 ) or until the optimization process has exhausted all code paths accessing data of the date set. Thereafter, the programmer(s) or software designers(s) end the process of optimizing the software to reduce the contention of a highly contended lock(s), STEP 420 . [0059] It is not generally necessary to group all dispatchable objects of a given process to achieve reduced contention and improved performance. In order to determine the most advantageous items to partition, the most often used paths need to be identified. If these paths have multiple branches, the most commonly taken branches must be identified. The items used by the most commonly called paths and most often taken branches are the items that will typically result in the greatest reduction in contention if dispatch locking is optimized. Thus, it is not necessary to adjust the locking of all paths. The paths that are rarely called may continue to globally lock the dispatch database or structure system because they will have little or no effect on overall contention or overall system performance. [0060] When the locking requirements for a heavily used code path is reduced by grouping of dispatchable objects, the new locking requirements must be determined and the path modified to only acquire the necessary locks. The correct locking may be any combination of local dispatch locks with or without the global lock, or it may be all locks. The code path determines the correct locking by reading the locales of the items it will touch. The path may or may not be able to determine ahead of time what branch will be taken. It may be possible to lock a group(s) of dispatchable objects and wait until later in the path to adjust the locking as needed consistent with the established locking hierarchy. If the items in the path are used in such a way that this is not appropriate then the lock must be acquired at the beginning of the path even if it is not required by the branch that is taken. [0061] Through this process of grouping of dispatchable objects and adjusting the dispatching locking for the important paths, the so-modified/updated software becomes more distributed and contention for the global dispatching lock is reduced. It is useful to note that after each step of grouping and optimizing the dispatch locking, the software remains in working condition and the performance and lock contention can be measured. [0062] Referring now to FIGS. 8A,B there is shown there is shown a high level flow diagram illustrating the process followed to signal kernel events and reschedule execution of a thread and to update the data structure associated with dispatching to illustrate an exemplary locking routine for a code path of the operating system, one path for local locking and another path for global locking. After starting dispatching, STEP 800 , the process determines if the dispatchable object, such as a thread or kernel event, is within a dispatch group, namely is there a group identifier present, STEP 802 . If there is a dispatch group (YES, STEP 802 ) then the operating system acquires a local lock over all of the dispatchable objects within the identified group, STEP 804 . As to other dispatchable objects not within the dispatch group and thus not subject to the local lock, these other objects remain accessible to the operating system. Although the foregoing is descriptive of a process where a single dispatch group is identified, it is within the scope of the present invention for the foregoing process to apply in cases where the kernel determines that dispatchable objects from multiple groups are involved in the operation. In such cases, and following the rules of hierarchal locking, the operating system acquires all necessary local locks over all of the dispatchable objects within the identified multiple groups. [0063] The kerenel/dispatcher examines the locked portion of the dispatch database/database structure for the identified dispatch group or groups and identifies the next thread to be executed, STEP 806 . This determination is achieved using any of a number of techniques and criteria known to those skilled in that art and is typically particular to the specific operating system. As noted above, some illustrative criterion are provided in Chapter 4 of “Inside Windows NT” for the scheduling of threads. In a multiprocessor computing system, such identification also includes identifying the processor on which the released or readied thread is to be executed. [0064] The kernel/dispatcher then updates the dispatch database for the items falling within the confines of the identified dispatch group or groups, STEP 808 . For example, the kernel updates the database to note the change in state of the thread to be executed on a processor or the change in state of a kernel event from unsignaled to signaled. The kernel also would evaluate the wait list or wait list structure and update it based on the actions taken to pre-empt or stop the thread that had been running. If it is determined that the thread, which had been pre-empted or otherwise stopped (e.g., timer expiring), is to continue running then the kernel would update the database based on the added quantum or time the thread is to be run. Once, all of the updating and evaluating is completed, the kernel releases the local lock(s), STEP 810 acquired over the dispatchable items of the identified dispatch group(s). Thereafter, the identified readied or released thread of the identified dispatch group is executed on the identified processor. [0065] If a dispatch group is not identified (NO, STEP 802 ) then the operating system acquires all local locks over all of the dispatchable objects within all dispatch groups of all processes presently being run on the multiprocessor computing system, STEP 852 (FIG. 8B) starting with first local lock and continuing until reaching the Nth local lock and then acquires a global lock, STEP 854 . [0066] After acquiring all of the local locks and the global lock, all of the dispatchable objects are locked for all running processes. In other words all items of the dispatch database or dispatch data structure are inaccessible to all other competing dispatching operations except to the dispatching operation presently being performed. [0067] The kerenel/dispatcher examines the dispatch database/database structure and identifies the next thread to be executed, STEP 856 . See also the discussion above for STEP 806 for further details. The kernel/dispatcher then updates the dispatch database for the items falling within the confines of the identified dispatch group, STEP 858 . Once, all of the updating and evaluating is completed, the kernel releases all of the local locks, STEP 860 and then releases the global lock. Thereafter, the identified readied or released thread of the identified dispatch group is executed on the identified processor. The release of the local and global locks then frees up the dispatcher so that it can handle any dispatching operations that were pended or stayed while the all-locks process proceeded to completion. [0068] As noted above, the modification of the software for the operating system to acquire all-locks (all local and global locks), maintains the operating system in an operational state, functionally equivalent to the original state of the unaltered operating system. Such an operational state of the operating system is maintained even in cases where other activities or actions are taken in accordance with the teachings of the present invention to optimize locking requirement in selected ones of the plurality or more of code paths. [0069] Although the foregoing describes a process whereby all of the code paths relating to dispatching need not be modified, it is within the scope of the present invention to modify all such dispatching code paths. [0070] Although a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

Featured is a method for reducing the contention of the highly contended global lock(s) of an operating system, hereinafter dispatcher lock(s) that protects all dispatching structures. Such a method reduces the need for acquiring the global lock for many event notification tasks by introducing local locks for event notifications that occur frequently among well defined, or consistent dispatcher objects. For these frequently occurring event notifications a subset of the dispatching structure is locked thereby providing mutual exclusivity for the subset and allowing concurrent dispatching for one or more of other data structure subsets. The method also includes acquiring one or more local locks where the level of protection of the data structure requires locking of a plurality or more of data structures to provide mutual exclusivity. The method further includes acquiring all local locks and/or acquiring a global lock of the system wide dispatcher data structures wherever a system wide lock is required to provide mutual exclusivity.

FIELD The present application is directed to the field of patient ventilators. More specifically, the present application is directed to ventilator circuit carbon dioxide (CO 2 ) removal. BACKGROUND A circle system is used to ventilate patients undergoing general anesthesia. To minimize wastage of excess expired anesthetic breathed out by the patient, the circle breathing system is designed to enable patient expired gases to be rebreathed after carbon dioxide is removed using CO 2 absorbent. In addition, oxygen and anesthetic agent is replenished to maintain desired concentration of gases breathed by the patient. CO 2 absorbent housed in a canister has a finite capacity to remove CO 2 from the expired patient gases. They can be replaced at the start of day or end of day on a routine basis. This is wasteful as unused absorbent capacity is discarded. Alternatively, the absorbent is replaced during an anesthesia case when it is spent. This is detected by measurement of significant inspired CO 2 concentration. A typical threshold value is 0.5% of sustained inspired CO 2 concentration. This cost saving practice exposes the patient while unconscious and requires mechanical ventilation assistance during anesthesia, where the risk is disruption of ventilation that include temporarily pausing ventilation, disconnecting the breathing system, installing a CO 2 canister with fresh absorbent, checking the integrity of the reconnected breathing system, and resuming ventilation. Dye with color changes in the presence of CO 2 is also used to indicate sent absorbent, as is computation of remaining CO 2 absorption capacity based on the absorbent refilled quantity and rate of CO 2 recirculated. Since quantity of refill and efficiency of the packed absorbent is a poor estimate of usable absorbent, the estimator/gauge is inaccurate. SUMMARY The above-mentioned shortcomings, disadvantages and problems are addressed herein which will be understood by reading and understanding the following specification. The system and method of the present application predicts if there is sufficient CO 2 absorbent capacity for the next anesthesia case. If insufficient, the canister can be preemptively replaced when no patient is connected to the breathing system. Such prediction also allows clinicians to determine if the CO 2 canister has to be changed during the present case or to wait until the end of the case. In the latter, the clinician may buy time by increasing the fresh gas flow rate to reduce the amount of patient CO 2 gases recirculated. A predictive estimation of CO 2 breakthrough allows more time to prepare for an orderly CO 2 canister replacement during a quiet period in the anesthesia care. In one aspect of the present application, a computerized method of predicting carbon dioxide (CO 2 ) breakthrough in an anesthesia ventilator comprises inputting into a computing system a pre-determined minimum threshold for a minimum averaged inspired CO 2 concentration (FiCO 2 ) and a CO 2 absorbent replacement, inputting into the computing system a set of data received from the anesthesia ventilator, wherein the set of data includes a measured FiCO 2 , determining whether the measured FiCO 2 exceeds the pre-determined minimum threshold, extrapolating, a number of breaths for the measured FiCO 2 to reach the CO 2 absorbent replacement threshold, and calculating a CO 2 absorbent replacement time with the number of breaths and a breaths interval time. In another aspect of the present application, a non-transitory computer readable medium including instructions that, when executed on a computing system, cause the computing system to receive from a user interlace a pre-determined minimum threshold for a minimum averaged inspired CO 2 concentration (FiCO 2 ) and a CO 2 absorbent replacement, receive a set of data from the anesthesia ventilator, wherein the set of data includes a measured FiCO 2 , determine whether the measured FiCO 2 exceeds the pre-determined minimum threshold, extrapolate a number of breaths for the measured FiCO 2 to reach the CO 2 absorbent replacement threshold, and calculate a CO 2 absorbent replacement time with the number of breaths and a breaths interval time. In another aspect of the present application, an anesthesia ventilator comprises a CO 2 canister containing CO 2 absorbent, a computing system including the storage device and a processor, the storage device including instructions that, when executed on the processor, cause the computing system to receive from a user interface a pre-determined minimum threshold for a minimum averaged inspired CO 2 concentration (FiCO 2 ) and a CO 2 absorbent replacement for the CO 2 absorbent, receive a set of data from the anesthesia ventilator, wherein the set of data includes a measured FiCO 2 , determine whether the measured FiCO 2 exceeds the pre-determined minimum threshold, extrapolate a number of breaths for the measured FiCO 2 to reach the CO 2 absorbent replacement threshold, wherein the extrapolation utilizes a set of predetermined parameters, and calculate a CO 2 absorbent replacement time with the number of breaths and a breaths interval time, and output the CO 2 absorbent replacement time to a user interface. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a breathing circuit illustrating an embodiment of the present application; FIG. 2 is a schematic illustration of a breathing circuit illustrating an embodiment of the present application; FIG. 3 is a flow chart illustrating an exemplary method in accordance with an embodiment of the present application; and FIG. 4 is a block diagram illustrating an embodiment of the system of the present application. DETAILED DESCRIPTION In the present description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be applied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different systems and methods described herein may be used alone or in combination with other systems and methods. Various equivalents, alternatives and modifications are possible within the scope of the appended claims. Each limitation in the appended claims is intended to invoke interpretation under 35 U.S.C. §112, sixth paragraph, only if the terms “means for” or “step for” are explicitly recited in the respective limitation. In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the embodiments. The following detailed description is, therefore, not to be taken as limiting the scope of the invention. Referring to FIG. 1 , the system and method of the present application relates to an anesthesia ventilator 10 with a circle breathing system 12 having a CO 2 canister 14 with absorbent (abs). The patient 22 is ventilated via mechanically through a volume reservoir (e.g. bellows, inflatable bag, long gas conduit) or manual bag (not shown). Concentrations of inspired and expired gases breathed by the patient 22 are monitored by a gas monitor (not shown). Gas concentrations measured include O 2 , CO 2 , N 2 O, air, and anesthetic gas. Inspired and expired gas flows are measured and gas volumes are computed by integrating the flow over a breath. As in any circle anesthesia breathing system 12 , fresh gases (FG) 16 are added to replenish gases consumed by the patient 22 . Excess FG 16 that is not consumed by the patient 22 is exhausted via an exhaust (exh) 24 having a pop off valve. Recirculated expired CO 2 passes through the CO 2 canister 14 and are absorbed by the CO 2 abs. As absorbent is spent, some CO 2 passes through the CO 2 canister 14 and is diluted by the FG 16 to form part of the inspired patient 22 gases. The measured concentration of inspired CO 2 is reported to a computing system 200 that predicts the rate of concentration increase of CO 2 breakthrough. Referring to FIG. 1 , the anesthesia ventilator 10 includes a circle breathing system 12 as stated above. The circle breathing system 12 includes an expiratory hose 20 , the inspiratory hose 18 , and the CO 2 canister 14 , that make up the main portion of the circle breathing system 12 . The circle breathing system 12 further includes the breathing hose that leads to the patient 20 , as well as the fresh gases 16 source and the exhaust 24 . As pictures in FIG. 1 , the gases flow in a clockwise direction in the circle breathing system 12 shown in FIG. 1 , and the hose that connects the patient 22 to the circle breathing system 12 allows gas flow to and from the circle breathing system 12 as shown in FIG. 2 . Gas flows in the circle breathing system is directed by two one-way valves typically located in line with the inspiratory ( 18 ) and expiratory ( 20 ) breathing hoses. The fresh gases 16 source flowing from a high pressure supply flow one-way direction into the circle breathing system 12 . Likewise, the exhaust 24 allows one-way flow to ambient or scavenging and away from the circle breathing system 12 which is positively pressured during ventilation. In high flow recirculating anesthesia system a blower fan (flowing in excess of 50 lpm) determines the unidirectional flow of the recirculating gas flows. Referring to FIG. 2 , it should be noted that all of the references to the various formulas and abbreviations will be described and defined in the following description. Furthermore, it should be noted that the arrows included in the circle breathing system 12 of FIG. 2 are illustrative of gas flow direction of the circle breathing system 12 . As stated above, current dye solutions to indicate spent absorbent are imprecise and the dye color changes tend to regenerate. Predicting CO 2 expenditure of absorbent based on recirculated CO 2 without considering CO 2 concentration breakthrough is associated with error from uncertain absorption capacity based on quantity of absorbent refilled. Inefficiencies in the CO 2 absorption such as channeling, operating temperatures that contribute to this uncertainty. However, the system and method of the present application utilizes the actual breakthrough CO 2 concentration to extrapolate the instance when a threshold CO 2 will be reached given current or what if operating setting of the breathing system. Knowing when and if the absorbent in the CO 2 canister 14 can last through the next case allows the canister 14 to be replaced when the patient 22 is not connected between anesthesia cases, and when the canister 14 will not last through the next anesthesia case Referring now the FIGS. 1 and 2 , the derivation of Gas Exchange in the System will be determined as follows: First considering the gas exchange in the lungs; inspired gases breathed into the lungs equal expired gases breathed out of the lungs plus gas entering or leaving the lungs from pulmonary blood. Applying conservation of mass to CO 2 exchange over a breath; Inspired CO 2 volume=expired CO 2 volume+CO 2 from blood or V T ×FiCO 2 =V T ×FeCO 2 +VCO 2 , where V T is the tidal volume per breath (in mL/min), FiCO 2 is the averaged inspired CO 2 concentration, and VCO 2 is the CO 2 production (in mL/min), in other words, CO 2 from the pulmonary blood. The product of tidal volume (V T ) and respiratory rate per minutes yield minute ventilation Rearranging ⁢ ⁢ Fe ⁢ CO 2 = Fi ⁢ CO 2 - V ⁢ CO 2 V T ( 1 ) Still referring to FIGS. 1 and 2 , the movement of CO 2 in the circle breathing system 12 over a breath inspired and expired gas movement to the patient 22 are transported by the ventilator 10 at the rate of minute ventilation which is the product of tidal volume (VT) and respiratory rate per minute. In some high flow recirculating ventilators, the recirculating flows can be much higher than minute ventilation. However, the effective flow of gas exchange with the lungs remains at the rate of minute ventilation. As such, the high flow recirculation helps to even out gas concentration in the circle breathing system 12 but has the same effective gas exchange rate with the patient 22 and consumption of CO 2 absorbent, and is thus considered as equivalent in its gas exchange over a breath as the conventional circle system 12 . Still referring to FIGS. 1 and 2 , the movement of CO 2 through the CO 2 canister 14 per breath includes applying from the law of conservation applied over a breath, where inflow of CO 2 into the canister 14 equals outflow of CO 2 from the canister 14 plus CO 2 absorbed by the CO 2 absorbent in the canister 14 . Inflow of CO 2 into the absorber 14 equals CO 2 expired by the patient 22 less CO 2 exhausted via the exhaust 24 , so volume = ⁢ V T × FeCO 2 - V exh × FeCO 2 = ⁢ ( V T - V exh ) × FeCO 2 ( 2 ) where FeCO 2 is the average patient 22 expired gases. FeCO 2 can be derived from the end tidal CO 2 measured using a gas monitor, which is used routinely as a standard of anesthesia care, and using the formula FeCO 2 = E T ⁢ CO 2 ⁡ ( 1 - V D V T ) , where E T CO 2 is the measured end tidal CO 2 and V D is the deadspace per breath and the ratio of V D V T is typically about 10 to 20%. The outflow of CO 2 from the canister 14 =V R ×F R CO 2 , where V R = ⁢ tidal ⁢ ⁢ volume ⁢ ⁢ to ⁢ ⁢ the ⁢ ⁢ patient ⁢ ⁢ 22 ⁢ ⁢ less ⁢ ⁢ the ⁢ ⁢ fresh ⁢ ⁢ ⁢ gas ⁢ ⁢ flow ⁢ in ⁢ ⁢ a ⁢ ⁢ breath ⁢ ⁢ interval ⁢ ⁢ ( Vfg ) = ⁢ V T - V fg , and ⁢ ⁢ is ⁢ ⁢ the ⁢ ⁢ total ⁢ ⁢ gas ⁢ ⁢ flow ⁢ ⁢ from ⁢ ⁢ the ⁢ ⁢ CO 2 ⁢ ⁢ absorber . Now, substituting gas flow into the CO 2 flow through the CO 2 canister 14 yields: ( V T −V exh )×FeCO 2 =( V T −V fg )× F R CO 2 +D CO 2 , where DCO 2 is the CO 2 absorbed by the CO 2 canister 14 over the breath time. Rearranging and solving for F R CO 2 yields: F R ⁢ CO 2 = ( 1 - V exh V T ) × FeCO 2 - D ⁢ CO 2 V T ( 1 - V fg V T ) ( 3 ) Considering the confluence of fresh gas 16 and CO 2 outflow of the CO 2 canister 14 where the fresh as 14 free of CO 2 dilutes the recirculating CO 2 concentration from the CO 2 canister 14 to yield the inspired CO 2 concentration (FiCO 2 ): V R ×F R CO 2 +V fg ×F fg CO 2 =V T ×Fi CO 2   (4) Since fresh gas is free of CO 2 , F fg CO 2 =0 yielding: V R ×F R CO 2 =V T ×Fi CO 2 Substituting V R =V T −V fg and rearranging yields: F R ⁢ CO 2 = F i ⁢ CO 2 ( 1 - V fg V T ) ( 5 ) Further substitute (5) into (3) and solving for F i CO 2 yields: Fi ⁢ CO 2 = ( 1 - V exh V T ) ⁢ FeCO 2 - D ⁢ CO 2 V T ( 6 ) Still referring to FIG. 2 , since V exh is the net excess gas volume popped off from the circle breathing system 12 and the net excess gas volume is made up of fresh gas 16 , patient CO 2 production, O 2 uptake (metabolism), agent exchange and CO 2 absorbed by the CO 2 canister 14 . V exh can be derived from the equation: V exh =V CO 2 −D CO 2 +V fg −V O 2 −V AX   (7) During anesthesia maintenance phase, V CO 2 , V O 2 fairly constant and at agent equilibrium the agent uptake V AX is fairly constant and small compared to V CO 2 and V O 2 . For simplicity, let V C represent the net gas exchange from the fresh gas and the patient, i.e.: V C =V fg +V CO 2 −V O 2 −V AX , and substituting V C into (T) and (6) yield: Fi ⁢ CO 2 = ⁢ ( 1 - V C - D ⁢ CO 2 V T ) ⁢ FeCO 2 - D ⁢ CO 2 V T = ⁢ ( 1 - V C V T ) ⁢ FeCO 2 - D ⁢ CO 2 V T ⁢ ( 1 - FeCO 2 ) ⁢ ⁢ or ⁢ ⁢ Fi ⁢ CO 2 = ( 1 - V C V T ) ⁢ FeCO 2 - D ⁢ CO 2 V T ⁢ ⁢ since ⁢ ⁢ FeCO 2 ≅ 0.05 ⪡ 1. ( 8 ) Considering a sequence of regular breathing during anesthesia, leading, up to the n th breath where the V T and V CO 2 remain constant is: V T n =V T n−1 = . . . =V T and V CO2 n−1 = . . . V CO2 At CO 2 break through, DCO 2 decreases as additional CO 2 is absorbed in each break. From C1 we have: Fe n ⁢ CO 2 = Fi n ⁢ CO 2 - V n ⁢ CO 2 V T n ⁢ ⁢ or ⁢ ⁢ Fe n ⁢ CO 2 = Fi n ⁢ CO 2 - V ⁢ CO 2 V T ( 9 ) From C8 we have: Fi n ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe CO 2 n - 1 - D n ⁢ CO 2 V T n ⁢ ⁢ or ⁢ ⁢ Fi n ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe n - 1 ⁢ CO 2 - D n ⁢ CO 2 VT ( 10 ) That is new inspired FiCO 2 concentration is the result of circulating the partially exhausted and absorbed patient CO 2 breath and further diluted by the fresh gas 16 . Since Fi n CO 2 , Fe n−1 CO 2 , V C , VT are measured, set or approximately known, D n CO 2 can be computed as: D n ⁢ CO 2 = { ( 1 - VC VT ) ⁢ Fe n - 1 ⁢ CO 2 - Fi n - 1 ⁢ CO 2 } * VT ( 11 ) At the previous (n−1) breath, Fi CO 2 n - 1 = ( 1 - VC VT ) ⁢ Fe CO 2 n - 2 - D n - 1 ⁢ CO 2 VT ( 12 ) Depending on the design of the absorber canister 14 , and the absorbent, at CO 2 breakthrough the rate of change of CO 2 depletion as the absorbent is spent can be constant, linearly or nonlinearly proportion to the remaining capacity of the CO 2 absorbent. In this description, assuming that the change in depletion rate per breath is a constant D or, D n−1 CO 2 =D n CO 2 −D   (13) In order to extrapolate and predict the responses of FiCO 2 and FeCO 2 , D n CO 2 and D must be solved. Substituting (13) into (12) yield: Fi n - 1 ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe n - 2 ⁢ CO 2 - D n ⁢ CO 2 - D VT ( 14 ) Since D n CO 2 can be found from equation (11), D can be computed using measured and approximated values of Fe n−1 Co 2 , Fe n−2 CO 2 , V C , VT. With D known on a breath-to-breath basis the future response of F i n+k CO2 can be predicted using the following set of equations: Applying equation (10) to predict k number of breaths into the future yield, Fi n ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe n - 1 ⁢ CO 2 - D n ⁢ CO 2 VT ( 15 ⁢ a ) Fi n + 1 ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe n ⁢ CO 2 - D n ⁢ CO 2 + D VT ( 15 ⁢ b ) ⋮ ⁢ ⁢ ⋮ ⁢ ⁢ or ( 15 ) Fi n + k ⁢ CO 2 = ( 1 - VC VT ) ⁢ Fe n + k ⁢ CO 2 - D n ⁢ CO 2 + kD VT ( 15 ⁢ k ) Likewise applying equation (9) to predict k number of breaths into the future yields, Fe n ⁢ CO 2 = Fi n ⁢ CO 2 + V ⁢ CO 2 VT ( 16 ⁢ a ) Fe n + 1 ⁢ CO 2 = Fi n + 1 ⁢ CO 2 + V ⁢ CO 2 VT ( 16 ⁢ b ) ⋮ ⁢ ⁢ ⋮ ⁢ ⁢ or ( 16 ) Fe n + k ⁢ CO 2 = Fi n + k ⁢ CO 2 + V ⁢ CO 2 VT . ( 16 ⁢ k ) The system of equations 15 and 16 can be iterated and solved sequentially to predict the CO 2 concentrations at the n+k breath, or the number of breaths k) needed to reach a concentration of FiCO 2 breakthrough. In a particular example, assume that at breath n, the breakthrough inspired CO 2 FiCO 2 is at 0.1% and at breath n+k the breakthrough CO 2 is Fi n+k CO 2 is 0.5%. The time for the FiCO 2 to rise from 0.1% to 0.5% is therefore k times the breath interval. Note that the user can change the values of say Vfg, VT, VCO 2 or other related ventilations parameter to predict “what if” situations if these parameters are varied. Such variation is helpful to assist the clinician to adjust future values of ventilation or the fresh gas 16 setting to prolong or better estimate the duration of CO 2 breakthrough, and for the given CO 2 canister 14 be replaced. For linear and non-linear proportional changes in the depletion rate of absorbent, a similar approach can be used to iteratively solve these two sets of equations to predict future responses of FiCO 2 breakthrough. In this case, several breaths leading to the nth breath may be required to solve for D n CO 2 and the depletion profile of the absorbent. Referring now to FIG. 3 , a method of the present application is illustrated in the flow chart. In the method 100 , at the start of an anesthesia case, users set or default FiCO 2 thresholds for minimum measureable FiCO 2 and CO 2 absorbent replacement R input. In step 104 , V fg , Vmv, FiCO 2 , FeCO 2 from the anesthesia machine, ventilator and gas monitor are set and/or measured and inputted into the computing system. In step 106 , if the minimum detectable FiCO 2 is met, then the method moves on to step 108 . If the minimum detectable FiCO 2 is not met in step 106 , then the method remains at step 106 until the minimum detectable FiCO 2 is obtained. In step 108 , the CO 2 depletion model is updated and constants that describe the FiCO 2 response are computed, and in step 110 , if the user does not request an “what if” prediction, then the method continues to step 112 . It the user does request as “what if” predictions in step 110 , then the method continues to step 120 . Still referring to the method 100 , in step 120 , the user alternate “what if” parameters are inputted. Examples of such inputs are fresh gas and ventilation parameters and the CO 2 . In step 122 , alternate “what if” parameters are used to extrapolate and compute the number of breaths to reach FiCO 2 threshold to replace the CO 2 absorbent. In step 124 , the replacement time is determined based on the number of breaths to threshold times the breath intervals, and in step 126 , the method reports and displays the “what if” ventilator and fresh gas delivery parameters, and time to replace the CO 2 absorbent. If this is the end of the anesthesia case in step 118 , then the method ends. If this is not the end of the anesthesia case, then the method goes back to step 104 . Still referring to FIG. 3 and the method 100 , in step 112 the set/measured parameters are used to extrapolate the number of breaths for FiCO 2 to reach a threshold to replace the CO 2 absorbent. In step 114 , the time for replacement is calculated by the number of breaths to the threshold times the breath intervals, and in step 116 , the current ventilator and fresh gas delivery parameters and time to replace the CO 2 absorbent are reported and displayed for the user. Once again, in step 118 , if the end of the anesthesia case has been reached, then the method ends. However, if the end of the anesthesia case has not been reached, then the method continues in step 104 . FIG. 4 is a system diagram of an exemplary embodiment of as computing system 200 as may be used to implement embodiments of the method 100 , or in carrying out embodiments of portions of the anesthesia ventilator 10 . The computing system 200 includes a processing system 206 , storage system 204 , software 202 , communication interface 208 , and as user interface 210 . The processing system 206 loads and executes software 202 from the storage system 204 , including a software module 230 . When executed by the computing system 200 , software module 230 directs the processing system to operate as described herein in further detail in accordance with the method 200 , or a portion thereof. It should be noted that the computing system 200 may be configured in a number of locations proximate or remote from the anesthesia ventilator 10 . For example, the computing system 200 may be included in the ventilator 10 in the RFID reader 30 , and/or in any user workstation proximate to the ventilator 150 or remote in a practitioner's station, care station, or other computer station. Although the computing system 200 as depicted in FIG. 4 includes one application module 230 in the present example, it is to be understood that one or more modules could provide the same operations or that exemplary embodiments of the method 100 may be carried out by a plurality of modules 230 . Similarly, while the description as provided herein refers to a computing system 200 and a processing system 206 , it is to be recognized that implementations of such system can be performed by using one or more processors 206 , which may be communicatively connected, and such implementations are considered with be within the scope of the description. Exemplarily, such implementations may be used in carrying out embodiments of the system 10 depicted in FIGS. 1 and 2 . Referring back to FIG. 4 , the processing system 206 can comprise a microprocessor or other circuitry that retrieves and executes software 202 from storage system 204 . Processing system 206 can be implemented within a single processing device but can also be distributed across multiple processing devices or sub-systems that cooperate in executing programming instructions. Examples of processing system 206 includes general purpose central processing units, application specific processor, and logic devices, as well as any other type of processing device, combinations of processing device, or variations thereof. The storage system 204 can include any storage media readable by the processing system 206 and capable of storing the software 202 . The storage system 304 can include volatile and non-volatile, removable and non-removable media implemented in any method of technology for storage of information such as computer readable instructions, data structures, program modules or other data. Storage system 204 can be implemented as a single storage device but may also be implemented across multiple storage devices or sub-systems. Storage system 204 can further include additional elements, such as a controller capable of communicating with the processing system 206 . Examples of storage media include random access memory, read only memory, magnetic disc, optical discs, flash memory, virtual and non-virtual memory, magnetic sets, magnetic tape, magnetic disc storage or other magnetic storage devices or any other medium which can be used to store the desired information and that may be accessed by an instruction execution system, as well as any combination or variation thereof, or any other type of storage medium. In some implementations, the storage media can be a non-transitory storage media. It should be understood that in no case the storage media propagated signal. User interface 210 can include a mouse, a keyboard, a voice input device, a touch input device for receiving a gesture from a user, a motion input device for detecting non-touch gestures, and other motions by a user, and other comparable input devices and associated processing elements capable of receiving user input from a user. User interface 210 can also include output devices such as a video display or a graphical display that can display an interface associated with embodiments of the systems and methods as disclosed herein. Speakers, printers, haptic devices, and other types of output devices may also be included in the user interface 210 . The user interface 210 is configured to receive user inputs 240 which in non-limiting embodiments may be irregularity user preferences as disclosed in further detail herein. It is also understood that embodiments of the user interface 210 can include a graphical display that presents the reports or alerts as described in further detail herein. As has been described in further detail herein, the communication interface 208 is configured to receive gas measurement concentrations 220 . The anesthesia ventilator data 225 includes all data set of measured and utilized in the formulas discussed above with respect to FIG. 2 . Accordingly, the gas measurement concentrations 220 and the rest of the anesthesia ventilator data 225 is inputted into the communication interface 208 . User input 240 as described in the description of FIG. 2 and the method of FIG. 3 , is input into the user interface 210 . The computing system 200 processes the measured patient gas concentrations 220 including concentrations of inspired and expired CO 2 , anesthesia ventilator data 225 and user input 240 according to the software 302 and method 100 , and as described in detail herein to produce output data 250 which may be pushed to one or more users through the user interface 310 . The output data 250 may include any analysis conducted by the computing system including current ventilator and fresh gas delivery parameters, time to replace CO 2 absorbent, “what if” ventilator and fresh gas delivery parameters, and “what if” time to replace CO 2 absorbent information. Further as described herein, the computing system 200 can output alerts, and/or reports 250 to the user, and may further accept user input 240 , such as but not limited to, setting off of alerts, modifications of the reports, and other administration of the alerts and data. While the invention has been described with reference to preferred embodiments, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made to the embodiments without departing from the spirit of the invention. Accordingly, the foregoing description is meant to be exemplary only, and should not limit the scope of the invention as set forth in the following claims. In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different configurations, systems, and method steps described herein may be used alone or in combination with other configurations, systems and method steps. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims.

The system and method of the present application predicts if there is sufficient CO 2 absorbent capacity for the next anesthesia case. If insufficient, the canister can be preemptively replaced when no patient is connected to the breathing system. Such prediction also allows clinicians to determine if the CO 2 canister has to be changed during the present case or to wait until the end of the case. In the latter, the clinician may buy time by increasing the fresh gas flow rate to reduce the amount of patient CO 2 gases recirculated. A predictive estimation of CO 2 breakthrough allows more time to prepare for an orderly CO 2 canister replacement during a quiet period in the anesthesia care.

This application is a 371 of PCT/GB97/03413 filed on Dec. 11, 1997. FIELD OF THE INVENTION This invention relates to a process and plant for the production of methanol. BACKGROUND OF THE INVENTION Methanol is synthesised in large volumes annually by conversion of a carbonaceous feedstock, usually a hydrocarbonaceous feedstock such as natural gas, into a mixture of carbon oxides and hydrogen. Such a mixture of gases is often referred to as synthesis gas. The conversion of a hydrocarbon-containing feedstock, such as natural gas, into synthesis gas can be effected by steam reforming. In steam reforming a mixture of desulphurised hydrocarbon feedstock, such as natural gas, and steam is passed at high temperature, typically at a temperature of from about 600° C. to about 1000° C., and elevated pressure, typically from about 10 bar up to about 50 bar, over a suitable reforming catalyst, such as a supported nickel catalyst. One commercially recommended catalyst which can be used for this purpose uses a mixture of calcium and aluminium oxides as support for the nickel. When natural gas is the feedstock, the principal reaction is: CH 4 +H 2 O⇄CO+3H 2 The reaction products themselves are further subject to the reversible “water gas shift” reaction in which carbon dioxide and hydrogen are produced from carbon monoxide and steam: CO+H 2 O⇄CO 2 H 2 Conversion of the carbon oxides and hydrogen to methanol occurs according to the following reactions: CO+2H 2 ⇄CH 3 OH CO 2 +3H 2 ⇄CH 3 OH+H 2 O These reactions are conventionally carried out by contacting the synthesis gas with a suitable methanol synthesis catalyst under an elevated synthesis gas pressure, typically in the range of from about 50 bar up to about 100 bar, usually about 80 bar, and at an elevated methanol synthesis temperature, typically from about 210° C. to about 270° C. or higher, e.g. up to about 300° C. A conventional methanol synthesis plant can be considered to comprise four distinct parts, namely: 1. a reforming plant, which produces a mixture of carbon oxides and hydrogen from a hydrocarbon feedstock; 2. a compression stage lifting the carbon oxides and hydrogen mixture to a higher pressure suitable for downstream methanol synthesis; 3. a methanol synthesis section, in which crude methanol is produced from the carbon oxides and hydrogen; and 4. a distillation section, in which the final refined methanol product is produced from the crude methanol. Such a plant is described, for example, in WO-A-96/21634. In order to achieve high yields of methanol, prior art processes have commonly included a recycle loop around the methanol synthesis zone so that unreacted materials leaving the methanol synthesis zone are recycled to the methanol synthesis zone. Thus, U.S. Pat. No. 4,968,722 relates to a process for the production of methanol by reacting carbon monoxide and hydrogen in which the reactants are introduced into a methanol synthesis zone comprising one or more fixed catalyst beds. The effluent from the methanol synthesis zone is fed to an absorption zone where methanol is absorbed. Unreacted reactants are fed to a further methanol synthesis and recovery zone. U.S. Pat. No. 5,472,986 discloses a methanol production process in which hydrogen is recovered by use of a membrane from a purge gas taken from the methanol synthesis zone. The purged and separated hydrogen is recycled to the methanol synthesis zone as a reactant for methanol synthesis. U.S. Pat. No. 4,181,675 relates to a methanol synthesis process in which synthesis gas is passed over a methanol synthesis catalyst in a methanol synthesis zone and is then cooled to condense methanol. The remaining gas is recycled to the methanol synthesis zone. A purge stream from this recycle stream may be passed through a membrane to control any build up of inert gases in the recycle stream. Inert materials are separated from carbon oxide and hydrogen, the latter being supplied to the methanol synthesis zone as reactants for methanol synthesis. DE-A-3244302 discloses a process for the production of methanol in which unreacted methanol synthesis gas is supplied to a three-way separation stage. In the separation stage, CO is separated and recycled to the methanol synthesis zone; CO 2 is separated and supplied to the reforming zone in order to replace part of the water vapour required for reforming; and a residual gas comprising hydrogen, nitogen and methane is supplied to the reforming zone as fuel to heat the reformer tubes. Various other methanol Production processes are known in the art, and reference may be made, for example, to U.S. Pat. No. 5,063,250, U.S. Pat. No. 4,529,738, U.S. Pat. No. 4,595,701, U.S. Pat. No. 5,063,250, U.S. Pat. No. 5,523,326, U.S. Pat. No. 3,186,145, U.S. Pat. No. 344,002, U.S. Pat. No. 3,598,527, U.S. Pat. No. 3,940,428, U.S. Pat. No. 3,950,369 and U.S. Pat. No. 4,051,300. A number of different types of reformer are known in the art. One such type is known as a “compact reformer” and is described in WO-A-94/29013, which discloses a compact endothermic reaction apparatus in which a plurality of metallic reaction tubes are close-packed inside a reformer vessel. Fuel is burned inside the vessel, which comprises air and fuel distribution means to avoid excessive localised heating of the reaction tubes. In a compact reformer of this type heat is transferred from the flue gas vent and from the reformed gas vent of the reformer to incoming feedstock, fuel and combustion air. Other types of reformer are not as efficient as the compact reformer in transferring heat internally in this way. However, many other reformer designs are known and some are described in EP-A-0033128, U.S. Pat. No. 3,531,263, U.S. Pat. No. 3,215,502, U.S. Pat. No. 3,909,299, U.S. Pat. No. 4,098,588, U.S. Pat. No. 4,692,306, U.S. Pat. No. 4,861,348, U.S. Pat. No. 4,849,187, U.S. Pat. No. 4,909,808, U.S. Pat. No. 4,423,022, U.S. Pat. No. 5,106,590 and U.S. Pat. No. 5,264,008. In a conventional plant, synthesis gas is compressed in passage from the reforming plant to the methanol synthesis zone. The synthesis gas compression stage is essentially present in order to provide the required pressure of from 50 bar to 100 bar in the methanol synthesis zone. The synthesis gas compressor is an expensive item which has a significant impact on the overall cost of the plant. Furthermore, the presence in the plant of synthesis gas at such high pressures necessitates the use in the plant of thick walled stainless steel or alloyed steel high pressure pipework. This pipework is expensive to buy, to weld and to use as a construction material. It therefore represents a substantial financial cost in the building of the plant. BRIEF SUMMARY OF THE INVENTION It is an object of the invention to provide a plant for methanol production which is cost-efficient to build and which avoids the use of at least some of the expensive components hitherto favoured in conventional methanol plants. A further object of the invention is to provide a process for the production of methanol which is carbon-efficient, providing good yields of methanol and which does not rely essentially on the use of very high pressure in the methanol synthesis zone. It is yet another object of the invention to provide a methanol production plant which is suitable for construction and operation in remote or offshore locations. According to the present invention, there is provided a plant for the production of methanol from a hydrocarbon feedstock material comprising: a) a steam reforming zone, adapted to be maintained under steam reforming conditions and charged with a catalyst effective for catalysis of at least one steam reforming reaction, for steam reforming of a vaporous mixture of the hydrocarbon feedstock and steam to form a synthesis gas mixture comprising carbon oxides, hydrogen and methane; b) a methanol synthesis zone, adapted to be maintained under methanol synthesis conditions and charged with a methanol synthesis catalyst, for conversion of material of the synthesis gas mixture to a product gas mixture comprising product methanol and unreacted material of the synthesis gas mixture; c) a methanol recovery zone, adapted to be maintained under methanol recovery conditions, for recovery of a crude methanol product stream from the product gas mixture, and for recovery of a vaporous stream comprising unreacted material of the synthesis gas mixture; d) a separation zone for separation of material of the synthesis gas mixture into a first hydrogen-rich stream and a second hydrogen-depleted stream comprising carbon oxides and methane; e) means for supplying at least part of the first hydrogen-rich stream to the steam reforming zone as fuel; and f) means for recycling at least part of the second hydrogen-depleted stream to the reforming zone for admixture with the vaporous mixture of hydrocarbon feedstock and steam. The separation of the first hydrogen-rich stream from the second hydrogen-depleted stream may occur upstream or downstream of the methanol synthesis zone. Thus, in one preferred embodiment of the invention the separation zone is located downstream of the methanol synthesis zone, means being provided for supplying the at least part of the second hydrogen-depleted stream from the separation zone to the reforming zone without passing through the methanol synthesis zone. In an alternative embodiment of the invention, the separation zone is located upstream of the methanol synthesis zone, means being provided for supplying the at least part of the second hydrogen-depleted stream to the methanol synthesis zone and thereafter recovering an unreacted part of the second hydrogen-depleted stream and supplying the unreacted part to the reforming zone. Usually, the carbon oxides referred to will comprise a mixture of CO and CO 2 . The invention further provides a process for the production of methanol from a hydrocarbon feedstock comprising: a) contacting a vaporous mixture comprising the feedstock and steam in a steam reforming zone with a catalyst effective for catalysis of at least one reforming reaction; b) recovering from the reforming zone a synthesis gas mixture comprising carbon oxides, hydrogen and methane; c) supplying material of the synthesis gas mixture to a methanol synthesis zone charged with a methanol synthesis catalyst and maintained under methanol synthesis conditions; d) recovering from the methanol synthesis zone a product gas mixture comprising methanol and unreacted material of the synthesis gas mixture; e) supplying material of the product gas mixture to a methanol recovery zone maintained under methanol recovery conditions; f) recovering from the methanol recovery zone a crude methanol product stream and a vaporous stream comprising unreacted material of the synthesis gas mixture; g) separating material of the synthesis gas mixture into a first hydrogen-rich stream and a second hydrogen-depleted stream comprising carbon oxides and methane; h) supplying at least part of the first hydrogen-rich stream to the steam reforming zone as fuel; and i) recycling at least part of the second hydrogen-depleted stream to the steam reforming zone to form part of the mixture of step a) The separation step may take place upstream or downstream of the methanol synthesis zone. Thus, it may be preferred that the separation step g) takes place downstream of the methanol synthesis zone, the at least part of the second hydrogen-depleted stream being supplied from the separation step g) to the reforming zone without passing through the methanol synthesis zone. Alternatively, it may be preferred that the separation step g) takes place upstream of the methanol synthesis zone, the at least part of the second hydrogen-depleted stream being supplied to the methanol synthesis zone, an unreacted part of the second hydrogen-depleted stream being recovered thereafter and supplied to the reforming zone. The process and plant of the invention have significant advantages over conventional plants and processes for the production of methanol, as will now be described. The process and plant of the invention operate such that unreacted carbon oxides and methane recovered from the methanol synthesis zone are, after separation from hydrogen, recycled as feedstock to the reforming zone. Hydrogen recovered from the separation zone is supplied to the reforming zone as fuel. This arrangement differs from prior art arrangements in which unconverted synthesis gas, usually after enrichment in either hydrogen or carbon oxides,is recycled to the methanol synthesis zone and has a number of significant advantages over such prior art processes. In the process and plant of the invention, there is provided a recycle circuit for unconverted carbon-containing compounds, the reforming zone and the methanol synthesis zone being inside the same recycle circuit. By “carbon-containing compounds” is meant principally carbon oxides, methane, or mixtures thereof. By “carbon oxides” is meant principally carbon monoxide and carbon dioxide. The recycle of unconverted carbon oxides and methane to the reforming zone means that, overall, the process of the invention is highly carbon efficient, with little or no carbon being lost from the process, regardless of the conversion yields obtained in either or both of the reforming zone and the methanol synthesis zone. Thus, the operator of a plant designed in accordance with the invention has the option to operate the process of the invention at relatively low conversion yields per pass in one or both of the reforming zone and the methanol synthesis zone. This has potential cost-saving advantages. For example, the methanol synthesis zone may be operated at lower pressure and/or with a smaller catalyst volume than in conventional processes. In the steam reforming zone of a plant according to the invention and operated in accordance with the process of the invention, the degree of conversion of the feedstock to synthesis gas may be maintained at a low level, relative to conventional plants, because the hydrogen-depleted stream comprising unreacted carbon oxides and methane is recycled as feedstock to the reforming zone in any event. The synthesis gas mixture recovered from the steam reforming zone in the plant and process of the invention comprises hydrogen, carbon oxides and methane. If the steam reforming zone is maintained under conditions such that the overall conversion of hydrocarbon feedstock to carbon oxides and hydrogen is relatively low, methane will be present in the synthesis gas mixture in larger quantities than if the conversion is high, in which case methane will be present in relatively smaller quantities in the synthesis gas mixture. This is the case regardless of whether the hydrocarbon feedstock is predominantly methane (as in natural gas) or whether the hydrocarbon feedstock is predominantly composed of some higher hydrocarbon. Higher hydrocarbons which are not steam reformed to carbon oxides and hydrogen are hydrocracked under the steam reforming conditions to methane. Thus, an ethane feedstock, a propane feedstock or a mixed butane/methane feedstock, for example, will reform to give a mixture of carbon oxides, hydrogen and methane. In conventional plants, it is desirable to ensure that reforming of hydrocarbon to carbon oxides and hydrogen is as complete as possible. Thus, because low pressure favours the steam reforming reactions, it is desirable in conventional plants to maintain the reforming zone under a relatively low pressure, for example about 20 bar. Whilst it is certainly possible to operate the process and plant of the invention such that a pressure of about 20 bar is used in the reforming zone, in practice it is a desirable feature of the invention that higher reforming pressures, for example from about 25 bar to about 50 bar, for example about 30 bar can be used. This has important advantages downstream of the reforming zone. In conventional processes, a make up gas compressor is used to compress the synthesis gas mixture entering the methanol synthesis loop. In addition, a recycle compressor is provided within the loop to circulate unreacted synthesis gas therein. In the process of the invention, because the reforming zone is included within a recycle circuit it is possible to provide a single compressor to drive the supply of the make-up gas to the methanol synthesis zone and the recirculation of unreacted synthesis gas around the circuit. Moreover, the provision of a single circuit including the reformer means that the position of the compressor may be selected by the designer of the plant as desired. When only one compressor is used in this way, the plant of the invention may be significantly more compact than prior art plants. Thus, driving equipment and pipework associated with multiple compression in the prior art is much reduced. This is significant because the plant of the invention may be built conveniently in remote, even offshore, locations. It has not hitherto been possible economically to construct a commercial methanol plant in an offshore location. It is therefore an important feature of the present invention that the unreacted material of the synthesis gas mixture recovered from the methanol recovery zone, or the material of the synthesis gas mixture recovered from the reforming zone as the case may be, comprises hydrogen, carbon oxides and methane and is separated into a hydrogen-rich stream, which is supplied as fuel to the steam reforming zone, and a hydrogen-depleted stream, comprising carbon oxides and methane, which is recycled to the steam reforming zone for admixture with the feedstock. The plant and process of the invention therefore includes the reforming zone, the methanol synthesis zone, the methanol recovery zone and the separation zone inside one carbon oxide and methane recycle circuit. This arrangement enables the plant and process of the invention to be operated with a single compression stage driving the flow of materials around the recycle circuit. The compression stage may be provided at any convenient location inside the recycle circuit, the position of the compressor depending upon the balance between capital and operating costs of the plant. This contrasts with conventional processes, in which unconverted carbon oxides are recycled to the front end of the methanol synthesis zone and a recycle compressor must be provided to maintain the pressure or the recycle stream at the high pressures used in conventional methanol synthesis plants. In conventional processes, it is not desirable to have a large quantity of methane present in this recycle stream and so a purge stream may be taken to control any build up of methane present in the synthesis gas mixture as a result of incomplete reaction in a reforming zone. When the degree of conversion in the reforming zone is maintained at a relatively low level, this has little or no impact on the overall methanol yield of a process in accordance with the invention because unconverted methane is recycled to the reforming zone in any event. This enables the use, in the process and plant of the invention, of a relatively low steam to carbon ratio and/or a relatively low outlet temperature in the reforming zone. Thus, in the process of the invention the steam to carbon ratio in the steam reforming zone is preferably less than about 3:1, even more preferably less than about 2.8:1, for example about 2.5:1 or less. The outlet temperature of the reforming zone, by which is meant the temperature at the exit end of the reforming catalyst inside the zone, may range from about 700° C. to about 1000° C., for example about 850° C. The use of a lower reforming temperature, compared to conventional plants, allows the operator of a plant and process according to the invention to use a relatively high reforming pressure, for example a reforming pressure of more than about: 20 bar, for example about 30 bar or about 40 bar or more. In particular, the use of a “compact reformer”, as described in WO-A-94/29013, operated at relatively low temperatures and relatively high pressures allows a plant according to the invention to be significantly more compact than conventional plants. This is significant because a plant according to the invention may conveniently be built in remote, even offshore, locations. It has not hitherto been possible economically to construct a commercial methanol plant in an offshore location. The process and plant of the invention have great flexibility and may be designed such that in the methanol synthesis zone the conversion yield per pass of carbon oxides to methanol is from about 40% to about 95% or higher, preferably from 70% to 90% for example about 80%. The process and plant of the present invention preferably utilise pressures of from about 20 bar to about 50 bar, e.g. from about 35 bar to about 45 bar, e.g. about 40 bar in the methanol synthesis zone. The use of relatively low pressures in the methanol synthesis zone has the further advantage that the cost of building a plant in accordance with the invention is significantly reduced, relative to conventional plants, by avoiding the need to use thick-walled, high pressure pipework. In conventional plants, a synthesis gas compressor is required to drive the synthesis gas into the methanol synthesis zone at a pressure of about 80 bar. Typically, the motive force for gas compression is provided by high pressure steam generated within the plant by a steam turbine. The plant and process of the invention may be operated at much lower pressures, as has been explained above. The process of the invention can use a smaller compressor than has been used in prior art processes. The pressure in the methanol synthesis zone of the plant of the invention may be provided by a single compression stage which may be located at any suitable position inside the recycle circuit. The possibility to operate the plant of the invention with only one relatively small compressor has ramifications beyond cost. The absence of any associated steam turbine, steam generation and transfer system, significantly reduces the size of a plant according to the invention, in relation to conventional plants. This reduction in size allows the plant of the invention to be constructed economically in remote or offshore locations. In conventional plants, the fuel used in the steam reforming zone is generally a hydrocarbon feedstock material which may contain sulphurous impurities such as hydrogen sulphide. In the plant and process of the present invention, the separated hydrogen-rich stream is supplied as fuel to the reforming zone. The flue gas from the reforming zone of a plant according to the invention is therefore substantially sulphur free and can, if desired, be cooled below its dew point for immediate disposal, without the need for further treatment to remove sulphurous acids, as may be required in conventional plants. If desired, a purge stream may be taken from the carbon oxide and methane containing recycle stream. The purge stream may be supplied as fuel to the reforming zone. Usually, a purge stream will be taken, the rate of purge being selected to control any accumulation in the recycle circuit of chemically inert materials, such as nitrogen, argon and helium, that may be present in the feedstock material. In a preferred plant and process of the invention, the separation zone comprises a membrane separator which may be of any suitable design. A number of membrane separators suitable for use in the process and plant of the present invention are described in U.S. Pat. No. 4,181,675, referred to hereinabove. It is further preferred that the methanol synthesis zone comprise a number of methanol synthesis reactors connected in series. A methanol recovery zone may be provided between each successive methanol synthesis reactor and after the last methanol synthesis reactor in the series. A vaporous carbon oxide and hydrogen-containing stream from each methanol recovery zone, other than the last in the series, is supplied to a next successive methanol synthesis reactor in the series. The methanol synthesis reactions are equilibrium limited and this arrangement has the advantage that methanol is removed from the reaction mixture between each methanol synthesis reactor, thereby favouring the methanol forming reactions in the next successive methanol synthesis reactor. Methanol recovery may be achieved by any suitable method, such as chilling or solvent washing. If solvent washing is chosen, suitable solvents include ethylene glycol, tetraethyleneglycol dimethyl ether, water and the like. Conveniently, the or each crude methanol product stream is supplied to a refining zone for recovery of a refined methanol product stream. The refining zone may be remotely located from the plant. Thus, if the plant is constructed in an offshore location, a crude methanol product containing about 6% water may be recovered from the methanol recovery zone and shipped ashore for subsequent refining. Desirably, a single gas compressor is provided to drive the feedstock, synthesis gas and vaporous carbon oxide and hydrogen-containing streams. The plant and process of the invention may be operated using a single stage compressor when the methanol synthesis pressure is maintained at or beneath about 50 bar. If methanol synthesis pressures of over about 50 bar are required, it may become desirable to employ a second compressor. The use of a single compressor has beneficial effects on the cost of building a plant in accordance with the invention and also on the space occupied by such a plant. The use of a single compressor in combination with a compact reformer, of the type mentioned above, enables a plant according to the invention to be economically constructed and operated at an offshore location. The provision of offshore methanol synthesis facilities is an important aspect of the invention and represents a significant improvement on conventional reformer based methanol synthesis technology, which cannot currently be provided offshore on a cost-effective basis. The methanol synthesis zone is preferably maintained at a temperature of from about 210° C. to about 300° C., e.g. about 230° C. to about 270° C., e.g. about 240° C. In a preferred process according to the invention, in which the reforming zone is a compact reforming zone of the type hereinbefore described, combustion air supplied to the reforming zone is saturated or partially saturated with water vapour before being supplied to the reforming zone. This has the advantage of modifying the combustion characteristics within the reforming zone, giving a more even heating of reforming elements within the zone and a reduction in emissions of nitrogen oxides, and carbon dioxide in the flue gas, relative to conventional plants. In a preferred plant according to the invention the reforming zone is a compact reforming zone of the type hereinbefore described. However, the steam reforming zone used in the process and plant of the invention may be of any suitable design. A preferred feedstock for use in the process of the invention is natural gas. An advantageous feature of the plant and process of the invention is that the flue gas from the steam-reforming zone contains significantly lower quantities of carbon oxides and sulphur-containing compounds than a conventional plant of equivalent methanol production capacity. In order that the invention may be clearly understood and readily carried into effect, a number of methanol synthesis plants constructed and arranged in accordance with the invention and designed to operate a preferred process in accordance with the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified flow diagram of diagram of a first methanol synthesis plant according to the invention; FIGS. 2 a , 2 b and 2 c combine to show a more detailed flow diagram of a second methanol synthesis plant according to the invention. DETAILED DESCRIPTION OF THE INVENTION It will be understood by those skilled in the art that the drawings are diagrammatic and that further items of equipment such as reflux drums, pumps, vacuum pumps, temperature sensors, pressure sensors, pressure relief valves, control valves, Flow controllers, level controllers, holding tanks, storage tanks, and the like may be required in a commercial plant. The provision of such ancillary items of equipment forms no part of the present invention and is in accordance with conventional chemical engineering practice. Referring to FIG. 1, a stream of natural gas is supplied in line 101 and, after passing through natural gas compressor 102 , passes on in line 103 at a pressure of around 40 bar. Feedstock compressor 102 is further supplied with a recycle stream of carbon oxides and methane from line 104 , as will be explained later. The compressed feedstock and recycle stream in line 103 is supplied to a feed pretreatment zone 105 . In feed pretreatment zone 105 , the details of which are not shown in FIG. 1, the compressed stream is heated to around 380° C. before passing on to a desulphurisation reactor. The natural gas feedstock contains a minor amount or sulphur as hydrogen sulphide which is a poison to downstream catalysts. Sulphur is removed in passage through the desulphurisation reactor which contains a charge of desulphurisation materials, such as nickel molybdate and zinc oxide. The desulphurised gas is cooled by passage through an interchanger and flows into the bottom of a saturator column in which the gas flows countercurrent to hot water supplied to the top of the saturator column. In passage through the saturator column the gas mixture is saturated with water vapour. The water vapour-saturated gas mixture exits the saturator at about 200° C. and contains approximately 90% of the steam required for subsequent reforming. The gas/steam mixture is mixed with further steam supplied from a gas turbine and passes on through a mixed feed heater which is mounted in the flue gas duct of reformer 106 . In passage through the mixed feed heater the temperature of the gas/steam mixture is raised to about 400° C. The resulting hot gas is fed in line 107 to reformer 106 . The detail of reformer 106 is not shown in FIG. 1 . The reformer is preferably of the compact type hereinbefore described. Hot gas from line 107 is fed into the reaction tubes of compact reformer 106 which are packed with a suitable steam reforming catalyst, for example a supported nickel catalyst. The heat required to drive the endothermic reforming reactions is supplied by burning a hydrogen-rich fuel inside compact reformer 106 , thus transferring heat to the reaction tubes by radiation and convection. Reformer 106 is fed with hot combustion air from line 108 , which is pre-heated in a combustion air pre-heater (not shown) heated by reformed gas inside compact reformer 106 and pre-compressed in combustion air compressor 109 after being supplied to the plant in line 110 . Hydrogen to fuel reformer 106 is supplied in line 111 from a downstream separation step, as will be explained later. Hydrogen is combusted inside reformer 106 , thus supplying radiant and convective heat to the reformer reaction tubes. Flue gas is vented from reformer 106 in line 112 . In compact reformer 106 the feed mixture of natural gas, steam and recycled carbon oxides is reformed to a mixture of carbon monoxide, carbon dioxide, hydrogen and methane, a mixture commonly known as synthesis gas. In the presence of the nickel catalyst at elevated temperatures, steam reacts with vaporous hydrocarbons at elevated temperatures and pressures to give a synthesis gas consisting of carbon dioxide, carbon monoxide, and hydrogen, together with methane. The concentration of each constituent in the synthesis gas depends on the ratio of steam to hydrocarbon passing over the catalyst, and on the temperature and pressure at which the gases leave the catalyst. The reactions taking place are complex but the end product is determined by two reactions, i.e. (i) the water gas shift equilibrium reaction: CO+H 2 O⇄CO 2 +H 2 +Heat (ii) the steam-methane equilibrium reaction Heat+CH 4 +H 2 O⇄CO+H 2 Overall the reactions are endothermic. A large excess of steam and a high temperature are required to move the equilibrium to the right and to reduce the residual methane content of the synthesis gas. The synthesis gas leaves compact reformer 106 in line 113 at about 450° C. and about 30 bar. In operation sufficient carbon oxides and/or methane are preferably introduced through line 104 to provide a stoichiometric synthesis gas in line 113 ; hence the rate of carbon oxide and/or methane recycle may be controlled so that, on a molar basis, the hydrogen content is equal to twice the carbon monoxide content plus three times the carbon dioxide content. The hot synthesis gas is cooled and passes by way of line 113 to methanol converter 114 . Typical methanol synthesis conditions in accordance with the invention include use of a pressure in the region of 30 bar and an outlet temperature of from about 210° C. to about 240° C. using a copper/zinc catalyst, for example the catalysts sold as ICI 51-7, Haldor Topsoe MK-101 or Súd-Chemie C79-5GL. The methanol synthesis equilibria are as follows: CO+2H 2 ⇄CH 3 OH CO 2 +3H 2 ⇄CH 3 OH+H 2 O Typically, the gas in line 113 contains about 10 to about 20 vol % carbon oxides, the balance being hydrogen, methane and nitrogen. Nitrogen can be present as an impurity in the natural gas feedstock. A product mixture is recovered in line 115 and passed to a methanol wash column 116 , from which a crude methanol product is recovered in line 117 . Unreacted synthesis gas from wash column 116 is supplied in line 119 to a separation zone 120 . Separation zone 120 can operate using any convenient known technique, for example pressure swing absorption, membrane technology, liquefaction, or a combination of two or more thereof. The use of membrane technology is preferred, often being the most economical. A hydrogen-rich recycle stream is recovered in line 121 and supplied in line 111 as fuel to compact reformer 106 . A carbon oxide and/or methane-rich stream is recovered in line 122 and supplied to line 104 as a recycle stream for admixture with the feedstock. A purge may be taken in line 123 to control any build up of inert materials. Crude methanol product in line 117 is supplied to a refining zone 124 , from which is recovered a refined methanol product in line 125 . Referring now to FIG. 2 a , natural gas from battery limits is supplied to the plant in line 201 and enters natural gas knockout drum 202 before passing on in line 203 . A portion of the gas in line 203 is taken in line 204 to power gas turbine 205 . Hot gas from gas turbine 205 passes along line 206 into heat recovery duct 207 . Flue gas is vented to the atmosphere in line 208 . Steam is withdrawn in line 209 and separated into two streams in line 210 and line 211 . Steam in line 210 is further separated into two streams in line 212 and line 213 . Steam in line 213 is supplied to the steam reforming process, as will be described later. Steam in line 212 is supplied to a methanol refining process, as will be described later. Steam in line 211 passes into deaerator 214 , which is vented in line 215 . Deaerated water is withdrawn in line 216 and passed via boiler water pump 217 into line 218 . Water in line 218 passes on in line 219 and is fed to heat recovery duct 207 . A make-up water stream is taken in line 220 and fed to a converter steam drum (not shown). The remaining gas in line 203 passes on in line 221 and is compressed to around 25 bar in natural gas compressor 222 . Compressed gas passes on in line 223 and combines in line 224 with a recycle stream from line 225 . The combined stream in line 224 is cooled through interchanger 226 which is supplied with cooling water in line 227 . The cooled stream passes on in line 228 and into knock out pot 229 , where any condensate from the cooled stream is removed. The mixed gas stream then passes on in line 230 and is compressed to around 38 bar in recycle compressor 231 . The compressed gas stream passes on in line 232 , is heated through interchanger 233 , passes on in line 234 and is further heated through interchanger 235 which is mounted in the flue gas stream from reformer 236 . Hot gas, now at a temperature of about 380° C., passes on in line 237 and into desulphurisation vessel 238 which contains a charge 239 of a suitable sulphurisation catalyst, such as nickel molybdate or cobalt molybdate. In the plant of FIG. 2 a , zinc oxide is used as catalyst. Gas from desulphurisation vessel 238 flows on in line 241 to desulphurisation vessel 240 , which contains a charge 242 of a zinc oxide desulphurisation catalyst. The desulphurised gas stream, now containing less than about 0.1 parts per million of sulphur, flows on in line 243 through interchanger 233 , where it is cooled, and passes via line 244 into the bottom of feed saturator 245 . Feed saturator 245 is supplied with hot water in line 246 . Fresh water is supplied to the plant in line 247 and is pumped by pump 248 into lines 249 , 250 , 251 and 252 , through pump 253 and into line 254 . Water in line 254 is heated through interchanger 255 and is supplied in line 256 to interchanger 257 . The heated water or steam passes on in line 258 to a further interchanger 259 and then into line 246 . In feed saturator 245 the mixed gas stream flows upwards and the hot water stream flows downwards. The gas leaves saturator 245 in line 260 containing around 90% of the steam required for downstream reforming reactions. The remaining 10% of steam is supplied in line 213 so that a gas stream containing 100% of the steam required for steam reforming passes on in line 261 . Water from the bottom of saturator 245 is recycled through lines 262 and 263 to combine in line 215 with Fresh water from line 250 . A small blowdown taken from stream 262 passes on in line 264 for disposal. A warm water stream proceeds in lines 251 and 252 and is pumped by pump 253 into line 254 , through interchanger 255 , line 256 , interchanger 257 , line 258 , interchanger 259 and into line 246 for supply to the top of saturator 245 . The remainder of the blowdown stream from line 260 passes on in line 264 for disposal. The gas stream in line 261 is heated in passage through interchanger 265 and passes on in line 266 to reformer 236 . Interchangers 235 , 265 and 257 are mounted in the flue gas duct of reformer 236 . Interchangers 259 and 255 are mounted in the reformed gas duct of reformer 236 . Reformer 236 comprises, in the plant shown in FIG. 2 a , a number of compact reformer tubes arranged in parallel with each other. A reforming catalyst (not shown), such as a supported nickel catalyst, is provided within the reformer tubes. The feedstock and steam mixture from line 266 , now at a temperature of about 400° C., passes into reformer 236 and flows therethrough from top to bottom. The heat to drive the endothermic reforming reactions is supplied by burning a hydrogen-rich fuel inside reformer 236 . Hydrogen fuel is supplied to reformer 236 in line 267 . The fuel is recycled from a downstream separation process, as will be described later. Combustion air for compact reformer 236 is supplied to the plant in line 268 and passes by means of air compressor 269 into line 270 and then into an air saturator column 271 . The purpose of saturating the combustion air is to control the heat recovery inside compact reformer 236 , to allow greater recovery of energy within the plant. Hot water is supplied to air saturator column 271 in line 272 after being recycled from a downstream refining step, as will be explained later. Water from the bottom of air saturator column 271 in line 273 is cooled in passage through heat exchanger 274 supplied with cooling water in line 275 . The cooled water stream passes on in line 276 and is combined in line 277 with fresh water from line 278 before being pumped by pump 279 into line 280 for ultimate use in a downstream methanol recovery process, as will be described later. A saturated combustion air stream emerging from the top of air saturator column 271 is supplied to reformer 236 in line 281 . Although not shown in the plant of FIG. 2 a , 2 b and 2 c , it is also possible to saturate the reformer fuel in line 267 . It may be especially preferred to saturate the reformer fuel when the plant of the invention uses a compact reformer, of the type hereinbefore described. The use of compact reformer 236 means that much of the heat generated within the reformer is recovered internally to reduce the overall fuel requirements of the plant. Also, reformed gas and flue gas from reformer 236 is used (in interchangers 255 , 257 and 259 ) to heat the circulation water for the feed saturator 245 . The water is heated first by reformed gas in saturator water heater 255 , then by flue gas in saturator water heater 257 and finally by hot reformed gas in saturator water heater 259 . The arrangement of heat exchangers can be modified to suit alternate reformer designs. The arrangement depicted in FIG. 2 takes advantage of the compact reformer to provide a heat recovery system with no “heat recycle” from the synthesis section to the reforming section. This makes plant start-up both easier and quicker than in conventional methanol plants. A synthesis gas mixture, comprising carbon oxides, hydrogen and methane, is recovered from reformer 236 in line 282 and is cooled through interchanger 259 , line 283 and interchanger 255 before passing on in line 284 . The reformed gas stream exiting saturator water heater 255 is used to provide from about 35% to about 40% of the reboil heat for a downstream distillation column, as will be described later. A flue gas stream exits reformer 236 in line 283 a and exchanges heat with various streams in passage through interchanger 235 , line 284 a , interchanger 265 , line 285 and interchanger 257 before passing into line 286 . The flue gas stream leaves the plant via stack 287 . Referring now to FIG. 2 b , synthesis gas in line 284 is further cooled in interchanger 370 , by means of which reboil heat is supplied to distillation column 289 . Cooled synthesis gas is passed by line 290 to knock out pot 291 . Condensate from knock out pot 291 is supplied via line 292 , pump 293 and line 294 to, and referring back now to FIG. 2 a , line 295 , line 296 and is then combined in line 252 with water from line 251 . The combined stream in line 252 is eventually supplied to feed saturator column 245 , as hereinbefore described. Referring back to FIG. 2 b , a synthesis gas mixture is recovered from the top of knock out pot 291 in line 297 and passes through interchanger 298 where it is cooled, supplying heat to a crude methanol stream supplied to distillation column 289 , as will be described later. The cooled synthesis gas stream from interchanger 298 passes on in line 299 . The stream in line 299 passes through interchanger 300 , where it is used to pre-heat demineralised water for supply to the process as steam, as will be now be described. Interchanger 300 is supplied in line 301 with demineralised water supplied to the plant via, and referring briefly back to FIG. 2 a , line 302 and pump 303 . Referring back to FIG. 2 b , heated demineralised water passes on in line 304 and into, referring briefly back to FIG. 2 a , deaerator 214 . Referring back to FIG. 2 b , further cooled synthesis gas from interchanger 300 passes on in line 305 to gas cooler 306 , line 307 , interchanger 308 supplied with cooling water in line 309 , into line 310 and is supplied to a second knockout pot 311 . Condensate from knock out pot 311 is recovered in line 312 and is supplied, via pump 313 and line 314 , to, and referring back to FIG. 2 a , line 296 and is combined in line 252 with make-up water from line 250 and 251 . Referring back to FIG. 2 b , synthesis gas emerging from the top of knock out pot 311 is supplied in line 315 to, and referring now to FIG. 2 c , interchanger 316 ., through which it is pre-heated to a methanol synthesis temperature of about 210° C. before passing on in line 317 to methanol synthesis reactor 318 containing a charge 319 of a methanol synthesis catalyst, such as a copper/zinc catalyst, e.g. the catalyst sold under the designation Haldor Toopsoe MK-101. In the illustrated methanol converter 318 , the exothermic heat of reaction is removed by raising steam in tubes mounted in the hot catalyst bed. A circulation loop around methanol converter 318 is formed by line 320 , converter steam drum 321 and line 322 . Make-up water to the converter steam drum 321 is supplied from line 220 (FIG. 2 a ) via a connecting line (not shown). Product steam from converter steam drum 321 in line 323 is supplied to line 324 , where it combines with steam from line 212 , and is ultimately supplied as a reboiler heat to distillation column 289 , as will be explained later. A product gas mixture comprising methanol, carbon oxides, methane and hydrogen is recovered from methanol converter 318 in line 325 . The stream in line 325 is cooled through interchanger 316 and passes on in line 326 to methanol wash column 327 which is supplied with wash water in line 328 . If desired, an additional cooler (not shown) can be incorporated in line 326 . Referring briefly to FIG. 2 a , line 328 is supplied with wash water from line 280 . Crude methanol product is recovered from methanol wash column 327 in line 329 and is passed through a filter 330 into line 331 and on into line 332 for ultimate supply to a downstream refining step, as will be described later. Synthesis gas mixture emerging from the top of methanol wash column 327 is passed in line 333 to a second methanol synthesis loop identical to the loop just described. A third and a fourth loop are also provided. On exiting the fourth methanol wash column 334 , unreacted synthesis gas mixture is supplied in line 335 to interchanger 336 and on into membrane separator 337 . Hydrogen passes through membrane 338 and exits separator 337 in line 339 , from where it passes on in line 267 to, and referring briefly to FIG. 2 a , reformer 236 . Carbon oxides and unreacted feedstock do not pass through membrane 338 and exit separator 337 in line 340 . A purge stream may be taken from line 340 in line 341 to control any build up of inert materials in the recycle stream. Purge line 341 is controlled by valve 342 . After the purge, if any, the recycle stream in line 340 passes on in line 225 and, referring back to FIG. 2 a , is combined in line 224 with make-up natural gas from line 223 . Referring back to FIG. 2 c , crude methanol product in line 332 is supplied, and referring now to FIG. 2 b , via interchanger 298 to line 343 . Crude methanol product in line 343 is supplied to the middle of a methanol refining column 289 . Refined methanol product is recovered from near the top of column 289 in line 344 . The refined stream in line 344 is cooled through interchanger 345 , supplied in line 346 by cooling water, and passes into line 347 and into methanol shift tank 348 . Product methanol is recovered from shift tank 348 via line 349 , pump 350 and line 351 . Vaporous material exits the top of column 289 in line 352 and is passed through condenser 353 . Product from condenser 353 is recovered in line 354 , which is vented in line 355 . Unvented material flows on in line 35 G to column reflux drum 357 , before being recycled in line 358 , via pump 359 and line 360 , to the top of column 289 . The vented stream in line 355 is cooled through heat exchanger 361 , cooled by cooling water in line 362 , and passes on in line 363 and line 354 to column reflux drum 357 . Gas in line 363 could be recovered by suitable compression but here is vented in line 365 to the atmosphere. A bottoms product is recovered from column 289 in lines 366 , 367 and 368 . The stream in line 366 is supplied via pump 369 to line 272 and, referring briefly back to FIG. 2 a , to combustion air saturation column 271 . Referring back to FIG. 2 b , bottoms product in line 367 is recycled to the bottom of column 289 via interchanger 370 and line 371 . Bottoms product in line 368 is recycled to the bottom of column 289 via interchanger 372 and line 373 .

The present invention relates to a process for the production of methanol from a hydrocarbon feedstock comprising: contacting a vaporous mixture comprising the feedstock and steam in a steam reforming zone with a catalyst effective for catalysis of at least one reforming reaction; recovering from the reforming zone a synthesis gas mixture comprising carbon oxides, hydrogen and methane; supplying material of the synthesis gas mixture to a methanol synthesis zone charged with a methanol synthesis catalyst and maintained under methanol synthesis conditions; recovering from the methanol synthesis zone a product gas mixture comprising methanol and unreacted material of the synthesis gas mixture; supplying material of the product gas mixture to a methanol recovery zone maintained under methanol recovery conditions; recovering from the methanol recovery zone a crude methanol product stream and a vaporous steam comprising unreacted material of the synthesis gas mixture; separating material of the synthesis gas mixture into a first hydrogen-rich stream and a second hydrogen-depleted stream comprising carbon oxides and methane; supplying at least part of the first hydrogen-rich stream to the steam reforming zone as fuel; and recycling at least part of the second hydrogen-depleted stream to the steam reforming zone to form part of the mixture of the vaporous mixture comprising the feedstock and steam and to a plant constructed and arranged so as to be operable in accordance with the process.

TECHNICAL FIELD [0001] Embodiments of the present disclosure relate to a method and device for monitoring fatigue driving. BACKGROUND [0002] It is well-known that fatigue driving is one of the major factors that cause most traffic accidents, and so how to prevent fatigue driving has gradually become a focus of attention. [0003] A fatigue driving warning system in existing technologies can only give out a simple warning to a driver when it detects that the driver is in a fatigue driving state. However, when the driver is in an over-fatigue state, the warning may not be able to effectively help the driver to restore from the fatigue driving state to a clearheaded driving state, such that safety problems that may emerge when the driver is in the fatigue driving state still cannot be effectively avoided. SUMMARY [0004] Embodiments of the present disclosure provide a method and a device for monitoring fatigue driving, which can increase a probability that the driver restores from a fatigue driving state to a clearheaded driving state, and hence can reduce a probability of occurrence of safety problems when the driver is in the fatigue driving state. [0005] Embodiments of the disclosure provides a device for monitoring fatigue driving, which includes a processor, and a monitoring unit, an alarm unit and an inflating unit which are respectively connected with the processor. For example, the processor is configured to acquire a monitoring result, send an alarm instruction to the alarm unit according to the monitoring result, and send an inflating instruction to the inflating unit when acquiring the monitoring result again after sending the alarm instruction, where the monitoring result is used for indicating whether a driver is in a fatigue driving state, the alarm instruction is used for instructing the alarm unit to give out an alarm, and the inflating instruction is used for instructing the inflating unit to perform an inflation operation; the monitoring unit is configured to monitor the driving state of the driver in real time, and send data indicating the driving state of the driver to the processor; the alarm unit is configured to receive the alarm instruction sent by the processor, and give out the alarm according to the alarm instruction; and the inflating unit is configured to receive the inflating instruction sent by the processor, and perform the inflation operation according to the inflating instruction. [0006] For example, the inflating unit includes a microprocessor connected with the processor, a driving module connected with the microprocessor, and a cuff connected with the driving module. The microprocessor is configured to receive the inflating instruction sent by the processor, and send an inflating signal to the driving module according to the inflating instruction; and the driving module is configured to receive the inflating signal sent by the microprocessor, and inflate the cuff according to the inflating signal. [0007] For example, the inflating unit further includes a pressure sensor connected with both the microprocessor and the cuff. The pressure sensor is configured to detect a value of a pressure intensity of the cuff when the driving module inflates the cuff, and send the value of the pressure intensity to the microprocessor; the microprocessor is also configured to receive the value of the pressure intensity sent by the pressure sensor, and send a deflating signal to the driving module when the value of the pressure intensity is greater than or equal to a default threshold; and the driving module is also configured to receive the deflating signal sent by the microprocessor, and deflate the cuff according to the deflating signal. [0008] For example, the driving module is a miniature inflation motor; or the driving module includes a miniature pressure pump and a miniature exhaust valve. [0009] For example, the monitoring unit includes at least one of a face monitoring module or a brain monitoring module; the face monitoring module is configured to monitor eyes of the driver and send data indicating an eye state of the driver to the processor; and the brain monitoring module is configured to monitor a brain of the driver and send data indicating a brain state of the driver to the processor. [0010] For example, the face monitoring module is a miniature camera; and the brain monitoring module is an electroencephalogram (EEG) sensor. [0011] For example, the device for monitoring fatigue driving further comprises a power supply unit connected with the processor, the monitoring unit, the alarm unit and the inflating unit; and the power supply unit is configured to supply power for the processor, the monitoring unit, the alarm unit and the inflating unit. [0012] For example, the power supply unit is charged by a wireless charging approach. [0013] For example, the device for monitoring fatigue driving further comprises a switching unit connected with the processor; and the switching unit is configured to control the device for monitoring fatigue driving to switch on or off. [0014] For example, the switching unit is a mechanical switch or an acceleration sensor. [0015] For example, the alarm unit includes at least one of a voice alarm module or a vibrating motor alarm module. [0016] Embodiments of the disclosure provide a method for monitoring fatigue driving, applied in a device for monitoring fatigue driving described herein, which includes: monitoring, by the device for monitoring fatigue driving, a driving state of a driver in real time; providing, by the device for monitoring fatigue driving, an alarm if the driving state of the driver is determined to be a fatigue driving state; and performing, by the device for monitoring fatigue driving, an inflation operation if the driving state of the driver is still determined to be the fatigue driving state after providing the alarm. [0017] For example, performing, by the device for monitoring fatigue driving, the inflation operation if the driving state of the driver is still determined to be the fatigue driving state after providing the alarm includes: inflating a cuff of the device for monitoring fatigue driving if the driving state of the driver is still determined to be the fatigue driving state after providing the alarm. [0018] For example, the method further comprises: detecting, by the device for monitoring fatigue driving, a value of a pressure intensity of the cuff when the cuff is inflated; and deflating the cuff if the value of the pressure intensity is greater than or equal to a default threshold. [0019] For example, monitoring, by the device for monitoring fatigue driving, the driving state of a driver in real time includes: monitoring, by the device for monitoring fatigue driving, eyes of the driver and a brain of the driver in real time; and performing, by the device for monitoring fatigue driving, the inflation operation if the driving state of the driver is still determined to be the fatigue driving state after providing the alarm includes: providing, by the device for monitoring fatigue driving, the alarm if both the eyes of the driver and the brain of the driver are determined to be in a fatigue state. [0020] For example, monitoring, by the device for monitoring fatigue driving, the eyes of the driver and the brain of the driver in real time includes: extracting, by the device for monitoring fatigue driving, eye features of the driver in real time, and acquiring an EEG signal of the driver; determining, by the device for monitoring fatigue driving, whether the eyes of the driver are in the fatigue state according to the eye features; and determining, by the device for monitoring fatigue driving, whether the brain of the driver is in the fatigue state according to the EEG signal. BRIEF DESCRIPTION OF THE DRAWINGS [0021] In order to illustrate the technical solutions in the embodiments of the present disclosure or the existing arts more clearly, the drawings need to be used in the description of the embodiments or the existing arts will be briefly described in the following; it is obvious that the drawings described below are only related to some embodiments of the present disclosure, for one ordinary skilled person in the art, other drawings can be obtained according to these drawings without making other inventive work. [0022] FIG. 1 is a first schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0023] FIG. 2 is a second schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0024] FIG. 3 is a third schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0025] FIG. 4 is a fourth schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0026] FIG. 5 is a sixth schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0027] FIG. 6 is a sixth schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0028] FIG. 7 is a seventh schematic structural view of a device for monitoring fatigue driving provided by an embodiment of the present disclosure; [0029] FIG. 8 is a first flowchart of a method for monitoring fatigue driving provided by an embodiment of the present disclosure; [0030] FIG. 9 is a second flowchart of a method for monitoring fatigue driving provided by an embodiment of the present disclosure; [0031] FIG. 10 is a third flowchart of a method for monitoring fatigue driving provided by an embodiment of the present disclosure; [0032] FIG. 11 is a fourth flowchart of a method for monitoring fatigue driving provided by an embodiment of the present disclosure; and [0033] FIG. 12 is a fifth flowchart of a method for monitoring fatigue driving provided by an embodiment of the present disclosure. DETAILED DESCRIPTION [0034] Hereafter, the technical solutions of the embodiments of the present disclosure will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. It is obvious that the described embodiments are just a part but not all of the embodiments of the present disclosure. Based on embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making other inventive work should be within the scope of the present disclosure. [0035] Detailed description will be given below to a method and a device for monitoring fatigue driving, provided by embodiments of the present disclosure, with reference to the accompanying drawings. [0036] In some technical solutions, a device for monitoring fatigue driving (or a warning system for fatigue driving) comprises a central processing unit (CPU), a fatigue driving warning light, a voice reminder, a hand blood pressure sensor, a foot blood pressure sensor and a body temperature sensor which are electrically connected with the CPU respectively, and a power source for supplying power to the various power consumption components described above. The device (or the system) may monitor life parameters, including a time duration when a driver sits on a driver seat, a body temperature of the driver, a hand blood pressure and a foot blood pressure, etc., in real time. The life parameters may reflect a current physical status of the driver in real time. For instance, the hand blood pressure and the foot blood pressure may indicate whether the driver has insufficient blood pressure and whether hand and/or foot paralysis occurs. After the CPU collects and analyzes the life parameters, the fatigue driving warning light and the voice reminder may provide a warning message to the driver so that a warning indicating whether the driver has been in the fatigue driving state may be provided in time to the driver, and another warning indicating possible occurrence of paroxysmal diseases may also be provided to the driver. [0037] As illustrated in FIG. 1 , an embodiment of the present disclosure provides a device 1 for monitoring fatigue driving. The device 1 for monitoring fatigue driving may comprise a processor 10 , a monitoring unit 11 , an alarm unit 12 and an inflating unit 13 , where the monitoring unit 11 , the alarm unit 12 and the inflating unit 13 are respectively connected to the processor 10 . [0038] For instance, the processor 10 is configured to acquire a monitoring result, send an alarm instruction to the alarm unit 12 according to the monitoring result, and send an inflating instruction to the inflating unit 13 when acquiring the monitoring result again after sending the alarm instruction, in which the monitoring result indicates whether the driver is in the fatigue driving state, the alarm instruction is used for instructing the alarm unit 12 to provide an alarm signal; and the inflating instruction is used for instructing the inflating unit 13 to perform an inflating operation. [0039] The monitoring unit 11 is configured to monitor in real time or in near real time a driving state of the driver, and send data indicating the driving state of the driver to the processor 10 . [0040] The alarm unit 12 is configured to receive the alarm instruction sent by the processor 10 , and provide an alarm signal according to the alarm instruction. For instance, the alarm signal may include a voice prompt, a lighting alert or a vibrating alert. [0041] The inflating unit 13 is configured to receive the inflating instruction sent by the processor 10 , and perform an inflating operation according to the inflating instruction. [0042] The device for monitoring fatigue driving provided by embodiments of the present disclosure may monitor the driving state of the driver in real time, may prompt the driver through the alarm signal when the driver is in the fatigue driving state, and may also perform an inflating operation when the driver continues to be in the fatigue driving state. The inflating operation helps the driver to restore from the fatigue driving state to a clearheaded driving state. The device for monitoring fatigue driving provided by embodiments of the present disclosure can increase a probability that the driver restores from the fatigue driving state to the clearheaded driving state, and hence can reduce a probability of occurrence of safety problems when the driver is in the fatigue driving state. [0043] It is noted that the device for monitoring fatigue driving provided by the embodiments of the present disclosure may be worn on the driver's head. When the inflating unit 13 performs an inflating operation, gas introduced by the inflating unit may apply pressure on the driver's head and help to increase the amount of blood supply on the driver's head, which is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state. [0044] For instance, the device for monitoring fatigue driving provided by the embodiments of the present disclosure may be a small-sized monitoring device which can be worn on the driver's head, e.g., a hat, a headphone, a barrette and a hair lace, etc. [0045] For instance, a method of acquiring the monitoring result by the processor 10 in the embodiments of the present disclosure may include any of the following: [0046] (1) The processor 10 receives the monitoring result sent by the monitoring unit 11 . For instance, the data indicating the driving state of the driver, sent by the monitoring unit 11 to the processor 10 , is the monitoring result. For instance, the processor 10 directly receives the monitoring result sent by the monitoring unit 11 . In another instance, the monitoring unit 11 monitors the driving state of the driver in real time and may send the obtained monitoring result to the processor 10 when the driver is in the fatigue driving state, and the processor 10 may provide an alarm instruction according to the monitoring result after acquiring the monitoring result. [0047] (2) After receiving the data indicating the driving state of the driver sent by the monitoring unit 11 , the processor 10 analyzes and processes the data and obtains a processing result, and then acquires the monitoring result from the processing result. For instance, the data indicating the driving state of the driver, sent by the monitoring unit 11 to the processor 10 , is data relevant to the driver including, e.g., eye features, facial features and/or electroencephalograph (EEG) signals of the driver monitored in real time by the monitoring unit 11 . The processing result may include a first monitoring result indicating that the driver is in the fatigue driving state or a second monitoring result indicating that the driver is in the clearheaded driving state (is not in the fatigue driving state). In embodiments of the present disclosure, after the processor 10 obtains the processing result, if the processing result is the second monitoring result, the processor 10 may not take any action; and if the processing result is the first monitoring result, the processor 10 may provide an alarm instruction according to the first monitoring result after acquiring the first monitoring result. [0048] For instance, as shown in FIG. 2 , the inflating unit 13 may include a microprocessor 130 connected with the processor 10 , a driving module 131 connected with the microprocessor 130 , and a cuff 133 connected with the driving module 131 . [0049] For instance, the microprocessor 130 may be configured to receive the inflating instruction sent by the processor 10 , and send an inflating signal to the driving module 131 according to the inflating instruction. [0050] The driving module 131 may be configured to receive the inflating signal sent by the microprocessor 130 , and inflate the cuff 133 according to the inflating signal. [0051] In embodiments of the present disclosure, when the device for monitoring fatigue driving is adopted for monitoring, the cuff 133 may be wound around the driver's head. Thus, when the driving module 131 inflates the cuff 133 , along with the gradually increased pressure intensity of the gas in the cuff 133 , the cuff 133 may impose pressure on the driver's head, which is helpful for increasing the amount of blood supply on the driver's head. Therefore, it is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state. [0052] For instance, as shown in FIG. 3 , the inflating unit 13 may also include a pressure sensor 132 connected with both the microprocessor 130 and the cuff 133 . [0053] For instance, the pressure sensor 132 may be configured to detect a value of a pressure intensity of the cuff 133 when the driving module 131 inflates the cuff 133 , and send the value of the pressure intensity to the microprocessor 130 . [0054] The microprocessor 130 is also configured to receive the value of the pressure intensity sent by the pressure sensor 132 , and send a deflating signal to the driving module 131 when the pressure intensity is greater than or equal to a default threshold. [0055] The driving module 131 is also configured to receive the deflating signal sent by the microprocessor 130 , and deflate the cuff 133 according to the deflating signal. [0056] In embodiments of the present disclosure, the driving module 131 in the inflating unit 13 may inflate the cuff 133 , so that the pressure intensity in the cuff 133 can be gradually increased. That is, the cuff 133 can apply pressure to the driver's brain, which is helpful for increasing the amount of blood supply on the driver's head, and hence it is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state. [0057] Moreover, when the driving module 131 inflates the cuff 133 , in order to prevent the cuff 133 from applying too much pressure to the driver's head and prevent the driver's head from being overly oppressed, the pressure sensor 132 may detect a value of the pressure intensity of the cuff 133 in real time and send the value of the pressure intensity to the microprocessor 130 . The microprocessor 130 can compare the value of the pressure intensity with a default threshold (that is, a predetermined maximal pressure intensity applied to the cuff). If the microprocessor 130 determines that the value of the pressure intensity is greater than or equal to the default threshold, the microprocessor 130 may send the deflating signal to the driving module 131 and control the driving module 131 to deflate the cuff 133 , so as to reduce the pressure applied to the driver's head by the cuff 133 , and hence the brain of the driver may not be overly oppressed. [0058] For instance, the default threshold may be set according to actual design demands of the inflating unit. No specific limitation will be given here in embodiments of the present disclosure. [0059] For instance, in embodiments of the present disclosure, after the driving module 131 inflates the cuff 133 which is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state, the microprocessor 130 may also send the deflating signal to the driving module 131 after a preset time and instruct the driving module 131 to deflate the cuff 133 , so as to avoid the problem that the driver's head is overly oppressed due to overlarge pressure caused by the cuff 133 on the brain of the driver when the driver is in the clearheaded driving state. [0060] An implementation principle of the inflating unit 13 in embodiments of the present disclosure is similar to an implementation principle of inflating in a process of measuring blood pressure via an electronic sphygmomanometer; that is, a cuff being worn around an arm of a user to be tested is inflated, so that the cuff can impose certain pressure to the user's arm. For instance, the implementation principle of the inflating unit 13 may be understood with reference to the implementation principle of inflating in the process of measuring blood pressure via an electronic sphygmomanometer. No further description will be given here. [0061] For instance, in a feasible implementation, the driving module 131 in embodiments of the present disclosure may be a miniature inflation motor. As the miniature inflation motor not only can inflate the cuff 133 but also can deflate the cuff 133 , the driving module 131 may be implemented by one miniature inflation motor. [0062] For instance, in another feasible implementation, the driving module 131 in embodiments of the present disclosure may include a miniature pressure pump and a miniature exhaust valve. As the miniature pressure pump inflates the cuff 133 and the miniature exhaust valve deflates the cuff 133 , the driving module 131 may be implemented by one miniature pressure pump and one miniature exhaust valve together. [0063] It is noted that the miniature inflation motor, the miniature pressure pump and the miniature exhaust valve in embodiments of the present disclosure may all be selected as components with a small size, so as to prevent the inflating unit and the device for monitoring fatigue driving from interfering with normal driving of the driver. [0064] For instance, the monitoring unit 11 may include at least one of a face monitoring module 110 or a brain monitoring module 111 . [0065] For instance, the face monitoring module 110 may be configured to monitor the eyes of the driver, and send data indicating a state of the eyes of the driver to the processor 10 . [0066] The brain monitoring module 111 may be configured to monitor the brain of the driver, and send data indicating a brain state of the driver to the processor 10 . [0067] It is noted that: when the monitoring unit 11 includes the face monitoring module 110 , the data indicating the driving state of the driver sent by the monitoring unit 11 to the processor 10 includes data indicating a facial state of the driver (for instance, the data indicating the facial state may include data indicating the eye state). When the monitoring unit 11 includes the brain monitoring module 111 , the data indicating the driving state of the driver sent by the monitoring unit 11 to the processor 10 may include data indicating the brain state of the driver. When the monitoring unit 11 includes the face monitoring module 110 and the brain monitoring module 111 , the data indicating the driving state of the driver sent by the monitoring unit 11 to the processor 10 includes data indicating the facial state of the driver, data indicating the eye state of the driver, data indicating the brain state of the driver or any combination thereof. [0068] Correspondingly, the monitoring result includes a face monitoring result corresponding to the face monitoring module 110 and a brain monitoring result corresponding to the brain monitoring module 111 . The face monitoring result is used for indicating that the face and/or the eyes of the driver are in the fatigue state, and the brain monitoring result is used for indicating that the brain of the driver is in the fatigue state. [0069] For instance, when the monitoring unit 11 includes the face monitoring module 110 , the monitoring result which can be acquired by the processor 10 includes the face monitoring result; when the monitoring unit 11 includes the brain monitoring module 111 , the monitoring result which can be acquired by the processor 10 includes the brain monitoring result; and when the monitoring unit 11 includes the face monitoring module 110 and the brain monitoring module 111 , the monitoring result which can be acquired by the processor 10 includes the face monitoring result and the brain monitoring result. [0070] For instance, with reference to FIG. 1 , the monitoring unit 11 as shown in FIG. 4 in embodiments of the present disclosure may be implemented by the face monitoring module 110 and the brain monitoring module 111 together. For instance, the eye state of the driver may be monitored by the face monitoring module 110 and simultaneously the brain state of the driver may be monitored by the brain monitoring module 111 , so that whether the driver is in the fatigue driving state may be determined according to the driver's state monitored by the two monitoring modules including the face monitoring module 110 and the brain monitoring module 111 . Hence, the monitoring accuracy of the device for monitoring fatigue driving can be improved. [0071] For instance, the face monitoring module 110 may be a miniature camera, and the brain monitoring module 111 may be an EEG sensor. For instance, the miniature camera may monitor the eye state of the driver in real time by extracting eye features of the driver. The miniature camera may also monitor the facial state of the driver in real time by extracting facial features of the driver. The EEG sensor may monitor the brain state of the driver in real time by acquiring EEG signals of the driver. [0072] In some embodiments, the face monitoring module 110 may be implemented by a miniature camera and may also be achieved by other component/apparatus/devices capable of capturing the eye features of the driver. No specific limitation will be given in the present disclosure. An EEG sensor may also be selected according to actual design demands of the device for monitoring fatigue driving. No specific limitation will be given in the present disclosure. [0073] It is noted that the miniature camera, the EEG sensor and the like may be selected as components with small sizes, so as to prevent the monitoring unit and the device for monitoring fatigue driving from interfering with normal driving of the driver. [0074] In embodiments of the present disclosure, the miniature camera for implementing the face monitoring module 110 may capture the eye features of the driver by using camera-capture technologies, so that whether the eyes of the driver are in the fatigue state can be determined according to the eye features. For instance, the miniature camera may take pictures capturing eyes of the driver. The pictures may reflect physiological changes of the driver, that is, the changes of the eye features of the driver, e.g., an amplitude of wink, a frequency of wink, and an average eye closing time of the driver, etc. The miniature camera or the processor may determine whether the eyes of the driver are in the fatigue state by analyzing the eye features of the driver in the pictures. [0075] Of course, the miniature camera for implementing the face monitoring module 110 in embodiments of the present disclosure may also monitor the facial features, eye signals, head movement characteristics and the like of the driver, and can also determine whether the driver is in the fatigue driving state by synthesizing all the information. The specific monitoring method is similar to the method of monitoring the eye features of the driver via the miniature camera. No further description will be given here. [0076] It is noted that the implementation principle of the EEG sensor is similar to a general electrocardiogram (ECG) monitoring principle, and both utilize electrodes to monitor voltage variations. For instance, a neuronal activity of the brain is transmitted to a cerebral cortex through ions to form weak electric signals; after sensing the weak electric signals, the electrodes in the EEG sensor may perform differential amplification, filtering, digital-to-analog conversion and the like on the weak electric signals, so as to convert the weak electric signals into initial data of EEG Thus, the EEG sensor or the processor can determine whether the brain of the driver is in the fatigue state by analyzing the initial data of EEG. [0077] For instance, in embodiments of the present disclosure, the EEG sensor for implementing the brain monitoring module 111 or the processor may determine whether the brain of the driver is in the fatigue state by adoption of an EEG fatigue state determination method using independent component analysis (ICA). For instance, the EEG sensor may acquire EEG signals (that is, the initial data of EEG) by the above method, and the EEG sensor or the processor may perform ICA analysis on the acquired EEG signals, calculate a variety of power spectral densities in the EEG, and calculate a fatigue index according to the variety of power spectral densities. When the calculated fatigue index is greater than 1, the brain of the driver may be determined to be in the fatigue state. For instance, the fatigue index may be calculated by the following method. [0078] Illustratively, an EEG signal of a human being may be decomposed into 4 basic rhythms, e.g., a δ wave, a θ wave, an α wave and a β wave, and the 4 rhythms will change along with the change of the fatigue state of the human being. For instance, when the α wave and β wave dominate, it indicates that the consciousness of the human being is clearheaded; but when the δ wave and θ wave dominate, it indicates that the consciousness of the human being is blurred and even is in a slight sleep state. Therefore, whether the brain of the human being is in the fatigue state may be determined and estimated by calculation and analysis of the EEG signals of the human being. [0079] The frequency ranges corresponding to the δ wave, θ wave, α wave and β wave are respectively −3.8 Hz, 4-7.8 Hz, 8-12.8 Hz and 13-30 Hz. Supposing the power spectral density is P and the fatigue index is F, if: [0000] E δ =ΣP i , 1≦ f ( i )≦3.8; E θ =ΣP i , 4≦ f ( i )≦7.8; E α =ΣP i , 8≦ f ( i )≦12.8; E β =ΣP i , 13≦ f ( i )≦30, in which [0000] i = 1 , 2 , 3 , … , N 2 , and   f = ( i ) = f s  i N , [0000] then [0000] F = E δ + E θ E α + E β . [0080] For instance, as shown in FIG. 5 , the device 1 for monitoring fatigue driving provided by embodiments of the present disclosure may further comprise a power supply unit 14 connected with the processor 10 , the monitoring unit 11 , the alarm unit 12 and the inflating unit 13 respectively. [0081] In some embodiments, the power supply unit 14 is configured to supply power for the processor 10 , the monitoring unit 11 , the alarm unit 12 and the inflating unit 13 . [0082] In embodiments of the present disclosure, as the power supply unit 14 is adopted to supply power for the processor 10 , the monitoring unit 11 , the alarm unit 12 and the inflating unit 13 , it is ensured that the processor 10 , the monitoring unit 11 , the alarm unit 12 and the inflating unit 13 can all operate normally, so that the device for monitoring fatigue driving provided by embodiments of the present disclosure can accurately monitor the driving state of the driver and perform corresponding operations that match the driving state. [0083] For instance, the power supply unit 14 may be charged by a wireless charging approach, e.g., being charged by a power source mounted on a vehicle. As the power supply unit 14 in embodiments of the present disclosure is charged by a wireless charging approach, interference on the driving of the driver when the power supply unit is charged by a wired approach can be avoided. [0084] For instance, as shown in FIG. 6 , the device 1 for monitoring fatigue driving provided by embodiments of the present disclosure may further comprise a switching unit 15 connected with the processor 10 . The switching unit 15 may be configured to control the device 1 for monitoring fatigue driving to switch on or off. [0085] It should be understood that: in order to reduce the power consumption of the device for monitoring fatigue driving, the switching unit 15 may be adopted to control the device for monitoring fatigue driving to switch on when the device is used; and the switching unit 15 may be adopted to control the device for monitoring fatigue driving to switch off when the device is not used, so that controllability of the device for monitoring fatigue driving can be achieved. [0086] For instance, the switching unit 15 may be a mechanical switch or an acceleration sensor. [0087] When the switching unit 15 is a mechanical switch, the driver may control the device for monitoring fatigue driving to switch on or off by operating on the mechanical switch. When the switching unit 15 is an acceleration sensor, if the driver is driving a vehicle, the acceleration sensor may determine that the driver is in the driving state by detecting the acceleration of the vehicle, and automatically trigger and switch on the device for monitoring fatigue driving. In the above two ways, the mechanical switch can be easily implemented and also has a lower cost; but the acceleration sensor has better real-time performance and reliability. [0088] For instance, the alarm unit 12 may include at least one of a voice alarm module or a vibrating motor alarm module. For instance, the voice alarm module may be implemented by a loudspeaker; that is, the voice alarm module may provide a voice alarm signal through the loudspeaker. The vibrating motor alarm module may be implemented by a motor; that is, the vibrating motor alarm module may provide a vibrating alarm signal through motor rotation. [0089] For instance, as shown in FIG. 7 , the device 1 for monitoring fatigue driving provided by embodiments of the present disclosure may further comprise a Bluetooth unit 16 connected with the processor 10 . For instance, the Bluetooth unit 16 may be interactive with other devices. The Bluetooth unit 16 may also include a Bluetooth headset, so that the driver can answer a call during driving. In embodiments of the present disclosure, the Bluetooth unit 16 may be powered by batteries and/or may also be powered by the power supply unit 16 . No specific limitation will be given in the present disclosure. [0090] Embodiments of the present disclosure provide a device for monitoring fatigue driving. The device for monitoring fatigue driving comprises a processor and a monitoring unit, an alarm unit and an inflating unit which are respectively connected with the processor. The processor is configured to acquire a monitoring result, send an alarm instruction to the alarm unit according to the monitoring result, and send an inflating instruction to the inflating unit if acquiring the monitoring result again after sending the alarm instruction. The monitoring result is used for indicating that the driver is in the fatigue driving state; the alarm instruction is used for instructing the alarm unit to give out an alarm; and the inflating instruction is used for instructing the inflating unit to perform an inflation operation. The monitoring unit is configured to monitor the driving state of the driver in real time, and send data indicating the driving state of the driver to the processor. The alarm unit is configured to receive the alarm instruction sent by the processor, and give out an alarm according to the alarm instruction. The inflating unit is configured to receive the inflating instruction sent by the processor, and perform an inflation operation according to the inflating instruction. [0091] Based on the above technical solutions, the device for monitoring fatigue driving provided by the present disclosure may monitor the driving state of the driver in real time in the monitoring process, and give out an alarm when the driver is in the fatigue driving state, so as to prompt the driver that he/she is in the fatigue driving state. The device for monitoring fatigue driving may perform an inflation operation if it is detected that the driver continues to be in the fatigue driving state after giving out the alarm. As the inflating operation can result in an extrusion pressing with a certain intensity on the driver's body, it is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state, so that the probability that the driver restores from the fatigue driving state to the clearheaded driving state can be increased, and hence the probability of safety problems emerging when the driver is in the fatigue driving state can be reduced. [0092] For instance, as shown in FIG. 8 , embodiments of the present disclosure provide a method for monitoring fatigue driving. The method may be applied to the device for monitoring fatigue driving as shown in any one of FIGS. 1-7 . The detailed description on the device for monitoring fatigue driving may be with reference to with the relevant description as shown in FIGS. 1-7 . No further description will be given here. The method may comprise: [0093] S 101 : monitoring, by the device for monitoring fatigue driving, a driving state of a driver in real time. [0094] S 102 : providing, by the device for monitoring fatigue driving, an alarm if the driving state of the driver is determined to be a fatigue driving state. For instance, the device for monitoring fatigue driving may give out a voice, light or vibrating alarm signal. [0095] S 103 : performing, by the device for monitoring fatigue driving, an inflation operation if the driving state of the driver is still determined to be the fatigue driving state after providing the alarm. The inflating operation helps the driver to restore to a clearheaded driving state. [0096] In embodiments of the present disclosure, the device for monitoring fatigue driving may monitor the driving state of the driver in real time, give out an alarm to prompt the driver that he/she is in the fatigue driving state when the driving state of the driver is the fatigue driving state, and perform an inflation operation if it is continuously detected that the driver is still in the fatigue driving state after giving out the alarm. As the inflating operation can result in extrusion pressing with certain intensity on the driver's body, it is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state, so that the probability that the driver restores from the fatigue driving state to the clearheaded driving state can be improved, and hence the probability of safety problems emerging when the driver is in the fatigue driving state can be reduced. [0097] For instance, a specific form and structure of the device for monitoring fatigue driving and an implementation principle of the inflating operation of the device for monitoring fatigue driving may all be provided with reference to relevant description in the above embodiment. No further description will be given here. [0098] For instance, as shown in FIG. 9 , in the method for monitoring fatigue driving provided by embodiments of the present disclosure, the step S 103 may include: [0099] S 103 a : inflating, by the device for monitoring fatigue driving, a cuff of the device if the driving state of the driver is still determined to be in the fatigue driving state after providing the alarm. The detailed description on the cuff may be provided with reference to relevant description on the cuff in the above embodiments. No further description will be given here. [0100] For instance, as shown in FIG. 10 , the method for monitoring fatigue driving provided by embodiments of the present disclosure may further comprise: [0101] S 104 : detecting, by the device for monitoring fatigue driving, a value of a pressure intensity caused by the cuff when the cuff is inflated. [0102] S 105 : deflating, by the device for monitoring fatigue driving, the cuff if the value of the pressure intensity is greater than or equal to a default threshold. [0103] Moreover, in the process of inflating the cuff by the device for monitoring fatigue driving, in order to prevent the brain of the driver from being overly oppressed by an overlarge pressure of the cuff on the brain of the driver, the device for monitoring fatigue driving may detect a value of the pressure intensity of the cuff in real time, and deflate the cuff when the value of the pressure intensity is greater than or equal to the default threshold, so that the pressure of the cuff applied on the brain of the driver can be reduced, and hence the brain of the driver cannot be overly oppressed. [0104] The default threshold may be set according to actual design demands of the device for monitoring fatigue driving. No specific limitation will be given in the present disclosure. [0105] In embodiments of the present disclosure, the implementation principle of the deflating operation by the device for monitoring fatigue driving may be provided with reference to relevant description in the above embodiments. No further description will be given here. [0106] It should be noted that: in embodiments of the present disclosure, the steps S 104 -S 105 may be simultaneously executed when the step S 103 is executed, so as to avoid the problem that the brain of the driver is overly oppressed due to overlarge pressure of the cuff on the brain of the driver when the device for monitoring fatigue driving continuously inflates the cuff. [0107] For instance, with reference to FIG. 8 , as shown in FIG. 11 , in the method for monitoring fatigue driving provided by embodiments of the present disclosure, the steps S 101 and S 102 may include: [0108] S 101 a : monitoring, by the device for monitoring fatigue driving, eyes of the driver and the brain of the driver in real time. [0109] S 102 a : providing, by the device for monitoring fatigue driving, an alarm if both the eyes of the driver and the brain of the driver are determined to be in the fatigue state. [0110] The method for monitoring fatigue driving provided by embodiments of the present disclosure simultaneously monitors whether the eyes of the driver are in the fatigue state and whether the brain of the driver is in the fatigue state, can determine whether the driver is in the fatigue driving state according to the two monitoring results, and hence can improve the monitoring accuracy of the device for monitoring fatigue driving. [0111] For instance, as shown in FIG. 12 , in the method for monitoring fatigue driving provided by embodiments of the present disclosure, the step S 101 a may include: [0112] S 101 aa : extracting, by the device for monitoring fatigue driving, eye features of the driver in real time, and acquiring EEG signals of the driver. [0113] S 101 ab : determining, by the device for monitoring fatigue driving, whether the eyes of the driver are in the fatigue state according to the eye features of the driver. [0114] S 101 ac : determining, by the device for monitoring fatigue driving, whether the brain of the driver is in the fatigue state according to the EEG signals of the driver. [0115] For instance, the method of determining whether the driver is in the fatigue driving state by monitoring the eye features of the driver and the EEG signals of the driver, which is performed by the device for monitoring fatigue driving, and specific hardware to implement the method may be provided with reference to relevant description in the above embodiments. No further description will be given here. [0116] Embodiments of the present disclosure provide a method for monitoring fatigue driving, in which the device for monitoring fatigue driving is adopted to monitor the driving state of the driver in real time. If the driving state of the driver is the fatigue driving state, the device for monitoring fatigue driving gives out an alarm; and if the driving state of the driver is still in the fatigue driving state after giving out the alarm, the device for monitoring fatigue driving performs an inflation operation. [0117] Based on the above technical solutions, the device for monitoring fatigue driving provided by the present disclosure may monitor the driving state of the driver in real time in the monitoring process, and give out an alarm when the driver is in the fatigue driving state, so as to prompt the driver that he/she is in the fatigue driving state, and perform an inflation operation if it is continuously detected that the driver is still in the fatigue driving state after giving out the alarm. As the inflating operation can result in extrusion pressing with certain intensity on the driver's body, it is helpful for the driver to restore from the fatigue driving state to the clearheaded driving state, so that the probability that the driver restores from the fatigue driving state to the clearheaded driving state can be improved, and hence the probability of occurrence of safety problems when the driver is in the fatigue driving state can be reduced. [0118] The processor or microprocessor included in the device for monitoring fatigue driving in embodiments of the disclosure may include various computing architectures such as a complex instruction set computer (CISC) architecture, a reduced instruction set computer (RISC) architecture or an architecture for implementing a combination of multiple instruction sets. The memory may store instructions and/or data executed by the processor. The instructions and/or data may include codes which are configured to achieve some functions or all the functions of one or more devices in the embodiments of the present disclosure. For instance, the memory includes a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, an optical memory or other memories well known to those skilled in the art. [0119] It should be clearly understood by those skilled in the art that the foregoing is only illustrative for convenient and simple description, and other similar embodiments may also be provided in actual application. [0120] It should be understood that the functional modules disclosed in several embodiments of the application may be implemented by other means. For instance, the structural modules described above are only illustrative. Moreover, the displayed or discussed connection may be connection via some pins, and may be electrical connection. [0121] The units described as discrete components may be or may not be physically separate, and components displayed as units may be or may not be physical units, may be disposed at one place or may also be distributed on a plurality of units. Partial or all the units may be selected according to actual demands to achieve the objectives of the proposals of the embodiments. [0122] In addition, the functional units in the embodiments of the present disclosure may be integrated into a processing unit, or various units may be independently physically provided, or two or more than two units may be integrated into one unit. The integrated units may be implemented by hardware and may also be implemented by software functional units [0123] In the present disclosure, terms such as “first”, “second” and the like used in the present disclosure do not indicate any sequence, quantity or significance but only for distinguishing different constituent parts. Also, the terms such as “a,” “an,” or “the” etc., are not intended to limit the amount, but indicate the existence of at lease one. The terms “comprises,” “comprising,” “includes,” “including,” etc., are intended to specify that the elements or the objects stated before these terms encompass the elements or the objects and equivalents thereof listed after these terms, but do not preclude the other elements or objects. [0124] What are described above is related to the illustrative embodiments of the disclosure only and not limitative to the scope of the disclosure; any changes or replacements easily for those technical personnel who are familiar with this technology in the field to envisage in the scopes of the disclosure, should be in the scope of protection of the present disclosure. Therefore, the scopes of the disclosure are defined by the accompanying claims. [0125] The present application claims the priority of the Chinese Patent Application No. 201510170673.6 filed on Apr. 10, 2015, which is incorporated herein by reference in its entirety as part of the disclosure of the present application.

A method and device for monitoring fatigued driving. The device comprises a processor, a monitoring unit an alarm unit and an inflating unit connected to the processor. The processor is used to obtain a monitor result, transmit, according to the monitor result, an alarm instruction to the alarm unit, and transmit an air inflation instruction to inflating unit upon obtaining the monitor result again after transmitting the alarm instruction. The monitor unit is used to monitor, in real time, a driving state of the driver, and transmit data indicating the driving state of the driver; the alarm unit ( 12 ) is used to receive the alarm instruction, and provide the alarm according to the alarm instruction; and the inflating unit is used to receive the air inflation instruction, and fill air according to the air inflation instruction.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a plasma display panel (PDP). More particularly, the present invention relates to a PDP having connection passage units that facilitate exhaust and injection processes when manufacturing the PDP. [0003] 2. Description of the Related Art [0004] Recently, the use of PDPs as large flat display devices has been emphasized. A PDP may include two substrates with a space filled with a discharge gas therebetween, and a plurality of electrodes formed on the substrates. The PDP displays desired images using visible light emitted through a process of exciting a luminescent material, e.g., a phosphor, in a predetermined pattern with ultraviolet (UV) light generated from a discharge of the discharge gas in the space when a voltage is applied to the electrodes. [0005] PDPs may be classified into direct (DC) type PDPs and alternating current (AC) type PDPs according to discharge types. PDPs may also be classified into facing discharge type panels and surface discharge type panels according to electrode arrangement. [0006] FIG. 1A illustrates a cross-sectional view of a discharge cell having a field concentration groove 20 of an AC surface discharge type PDP, and FIG. 1B illustrates a schematic plan view of the discharge cell of FIG. 1A as seen from a first substrate 2 of the PDP. [0007] Referring to FIGS. 1A and 1B , the AC facing discharge type PDP may include a first panel and a second panel. The first panel may include the first substrate 2 , X and Y electrodes (common and scanning electrodes) 12 and 14 , each including a transparent electrode 12 a and 14 a and a bus electrode 12 b and 14 b , a first dielectric layer 9 a , a protective layer 10 , and the field concentration groove 20 . [0008] The second panel may include a second substrate 4 , address electrodes 16 , and a second dielectric layer 9 b . Barrier ribs 6 that partition the discharge cell may be interposed between the first and second panels. A phosphor layer 8 may be coated on the barrier ribs 6 and the first substrate 2 . [0009] The field concentration groove 20 concentrates an electric field in a groove. Although this groove increases a space between the X and Y electrodes 12 and 14 , a driving voltage applied to the electrodes is not increased. The discharge space can be increased by increasing the distance between the X electrodes 12 and the Y electrodes 14 , thus increasing the light emission efficiency. Also, the transmittance of visible light emitted from the discharge cell through the first panel can be increased in proportion to a depth of the groove in the field concentration groove 20 , i.e., how much of the first dielectric layer 9 a is removed. [0010] The barrier ribs 6 may be closed, and may not be connected to neighboring discharge cells, so that neighboring field concentration grooves formed in discharge cells neighboring the barrier ribs 6 may be separated from each other. [0011] Such closed barrier ribs do not cause cross talk that occurs with open shaped barrier ribs. However, closed shaped barrier ribs are not efficient in exhausting impurities of a discharge space of discharge cells or injecting a discharge gas necessary for generating a discharge into discharge cells during the manufacture of PDPs. SUMMARY OF THE INVENTION [0012] The present invention is therefore directed to a plasma display panel (PDP) and method of manufacturing the same, which substantially overcome one or more of the problems due to the limitations and disadvantages of the related art. [0013] It is therefore a feature of an embodiment of the present invention to provide a PDP having connection passage grooves connecting the field concentration grooves. [0014] It is another feature of an embodiment of the present invention to provide a method of manufacturing a PDP having connection passage units connecting the field concentration grooves. [0015] It is yet another feature of an embodiment of the present invention to provide a method of manufacturing a PDP that uses connection passage units to exhaust impurities during manufacture of the PDP [0016] It is still another feature of an embodiment of the present invention to provide a method of manufacturing a PDP that uses connection passage units to inject discharge gas during manufacture of the PDP. [0017] At least one of the above and other features and advantages of the present invention may be realized by providing a plasma display panel, including a first substrate, a second substrate facing the first substrate, the first and second substrates being spaced apart by a predetermined distance, barrier ribs for defining a plurality of discharge cells in a space between the first substrate and the second substrate, first and second electrodes extending parallel to each other on the first substrate, and a first dielectric layer covering the first and second electrodes, the first dielectric layer including a field concentration groove between the first and second electrodes within each discharge cell, and connection passage units for connecting field concentration grooves in adjacent discharge cells. [0018] The connection passage units may be parallel to the first and second electrodes. The connection passage units may have smaller widths than the field concentration grooves. [0019] The plasma display panel may include address electrodes on the second substrate, the address electrodes extending perpendicular to the first and second electrodes, a second dielectric layer covering the address electrodes, a luminescent layer in the discharge cells, and a discharge gas filling the discharge cells. [0020] The barrier ribs may be closed and have a cross-section parallel to the first substrate that is polygonal, circular or oval. The connection passage units may be grooves having a trapezoidal or a rectangular cross-section perpendicular to the first substrate and parallel to the address electrodes. The luminescent layer may be on the second substrate. The plasma display panel may include a protective layer on the first dielectric layer. [0021] The connection passage units may extend parallel to the first and second electrodes. The connection passage units may have smaller widths than widths of the field concentration grooves. The connection passage units are grooves may have a trapezoidal or rectangular cross-section perpendicular to the first substrate and parallel to the address electrodes. The connection passage units have a same cross-sectional shape as the field concentration grooves. [0022] At least one of the above and other features and advantages of the present invention may separately be realized by providing a method of manufacturing a plasma display panel, the method including providing a first substrate having first and second electrodes extending parallel to each other, providing a second substrate facing the first substrate, the first and second substrate being spaced apart by a predetermined distance, providing barrier ribs for defining a plurality of discharge cells in a space between the first and second substrates, and forming a first dielectric layer that covers the first and second electrodes, the first dielectric layer including a field concentration groove between the first and second electrodes within each discharge cell, and connection passage units for connecting field concentration grooves in adjacent discharge cells. [0023] The method may include securing the first and second substrates together, and exhausting impurities through the connection passage units. After exhausting, the method may include injecting discharge gas through the connection passage units. The method may include securing the first and second substrates together, and injecting discharge gas through the connection passage units. [0024] Forming the field concentration grooves and the connection passage units may include etching. The field concentration grooves may be wider than the connection passage units. BRIEF DESCRIPTION OF THE DRAWINGS [0025] The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: [0026] FIG. 1A illustrates a cross-sectional view of a discharge cell having a field concentration groove of an AC surface discharge type plasma display panel; [0027] FIG. 1B illustrates a schematic plan view of the discharge cell of FIG. 1A as seen from a first substrate of the AC surface discharge type plasma display panel; [0028] FIG. 2 illustrates a schematic partial plan view of a plasma display panel having connection passage units connected to field concentration grooves formed in every discharge cells, as seen from a first substrate according to an embodiment of the present invention; [0029] FIG. 3 illustrates a perspective view of a first panel of a plasma display panel having connection passage units according to an embodiment of the present invention; [0030] FIG. 4 illustrates an exploded perspective view of a plasma display panel according an embodiment of the present invention; and [0031] FIGS. 5A and 5B illustrate cross-sectional views of discharge cells having field concentration grooves of a plasma display panel according an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0032] Korean Patent Application No. 10-2005-0072007, filed on Aug. 6, 2005, in the Korean Intellectual Property Office, and entitled: “Plasma Display Panel,” is incorporated by reference herein in its entirety. [0033] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. [0034] In the figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being “under” another layer, it can be directly under, and one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout. [0035] FIG. 2 illustrates a schematic partial plan view of a plasma display panel (PDP) having connection passage units 122 connected to field concentration grooves 120 formed in each discharge cell as seen from a first substrate according to an embodiment of the present invention. [0036] Referring to FIG. 2 , the field concentration grooves 120 of discharge cells may be formed in a first dielectric layer 109 a corresponding to the center of X electrodes 112 , 112 a , and 112 b , and Y electrodes 114 , 114 a , and 114 b , and may be connected to each other through the connection passage units 122 . [0037] The connection passage units 122 may serve as passage spaces for connecting the field concentration grooves 120 of neighboring discharge cells, so that discharge spaces of neighboring discharge cells are connected to one another. [0038] The connection passage units 122 may be used to exhaust impurities of discharge spaces of discharge cells in an exhaust process during the manufacture of the PDP. The connection passage units 122 may also be used to inject discharge gas for generating a discharge into discharge cells in an injection process during the manufacture of the PDP. [0039] Discharge spaces of neighboring discharge cells of the PDP may be connected to one another, facilitating exhausting of impurities of discharge spaces and/or injecting the discharge gas into discharge cells during the process of manufacturing the PDP. Therefore, the PDP having the connection passage units 122 connected to the field concentration grooves 120 may solve problems that may arise during exhaust and/or injection processes used in the manufacture thereof. [0040] The connection passage units 122 may be disposed parallel to the X and Y electrodes 112 and 114 . That is, discharge spaces of neighboring discharge cells perpendicular to the X and Y electrodes 112 and 114 may not be connected. Alternatively or additionally, the connection passage units 122 may be disposed perpendicular to the X and Y electrodes 112 and 14 to connect adjacent discharge spaces via the field concentration grooves 120 . [0041] A width d 2 of the connection passage units 122 may be smaller than a width d 1 of the field concentration grooves 120 . If the width d 2 of the connection passage units 122 is too wide, cross talk may occur between neighboring discharge cells. Therefore, the width d 2 of the connection passage units 122 may be selected so as to prevent the cross talk between the neighboring discharge cells, while facilitating exhaust and/or injection processes during manufacture of the PDP. [0042] FIG. 3 illustrates a perspective view of a first panel of a PDP having connection passage units 122 according to an embodiment of the present invention. Referring to FIG. 3 , the first panel may include a first substrate 102 , a first dielectric layer 109 a , a protective layer 110 , X electrodes 112 , 112 a , and 112 b , and Y electrodes 114 , 114 a , and 114 b. [0043] The field concentration grooves 120 and the connection passage units 122 may be notches or indentations that may be formed in the first dielectric layer 109 a by patterning, e.g., etching, the first dielectric layer 109 a . Alternatively, the patterning of the first dielectric layer may include adding material to a dielectric layer to create indentations in the dielectric layer 109 a serving as the field concentration grooves 120 and the connection passage units 122 . Further, the connection passage units 122 may be holes in the dielectric layer 109 a , rather than the indentations shown in FIG. 3 . [0044] The field concentration grooves 120 may correspond to discharge cells in the first dielectric layer 109 a . The field concentration grooves 120 may be connected to one another via the connection passage units 122 . [0045] The connection passage units 122 may facilitate exhaust and/or injection processes during manufacture of the PDP. The width d 2 of the connection passage units 122 may be smaller than the width d 1 of the field concentration units 120 so as to prevent cross talk between neighboring discharge cells. [0046] FIG. 4 illustrates an exploded perspective view of a PDP according an embodiment of the present invention. Referring to FIG. 4 , a first panel may include the first substrate 102 , the X electrodes 112 , 112 a , and 112 b , the Y electrodes 114 , 114 a , and 114 b , the first dielectric layer 109 a , and the protective layer 110 . A second panel may include a second substrate 104 , address electrodes 116 , a second dielectric layer 109 b , barrier ribs 106 , and a luminescent material, e.g., a phosphor layer 108 . [0047] The barrier ribs 106 may form closed grid. Nine field concentration grooves 120 may be formed in spaces corresponding to nine discharge cells shown in FIG. 4 , and may be connected via connection passage units 122 . [0048] Referring to FIGS. 3 and 4 , the connection passage units 122 may be parallel to the X electrodes 112 , 112 a , and 112 b , and the Y electrodes 114 , 114 a , and 114 b , may connect discharge spaces of neighboring discharge cells, and the width d 2 thereof that may be smaller than the width d 1 of the field concentration grooves 120 to prevent the cross talk between neighboring discharge cells as illustrated in FIG. 2 . [0049] FIGS. 5A and 5B illustrate cross-sectional views of discharge cells including field concentration grooves of a PDP according an embodiment of the present invention. [0050] Referring to FIGS. 5A and 5B , the PDP may include the first substrate 102 , the second substrate 104 , the barrier ribs 106 , the phosphor layer 108 , the first dielectric layer 109 a , the second dielectric layer 109 b , the protective layer 110 , X electrodes 112 , 112 a , and 112 b , Y electrodes 114 , 114 a , and 114 b , and the address electrodes 116 . Patterning, e.g., etching, of the first dielectric layer 109 a may be performed to create the field concentration grooves 120 and connection passage units 122 interposed between the X electrodes 112 and the Y electrodes 114 . [0051] A discharge gas at a pressure lower than atmospheric pressure, e.g., approximately 0.5 atm, may fill the discharge cells. Plasma discharge may be generated by the collision of particles of the discharge gas with charges due to an electric field formed by a driving voltage applied to the electrodes located in each discharge cell, and, as a result of the plasma discharge, vacuum ultraviolet light may be generated. The discharge gas may be a gas mixture containing one or more of Ne gas, He gas, and Ar gas mixed with Xe gas. [0052] The barrier ribs 106 may define the discharge cells to be basic units of an image, and may prevent cross-talk between the discharge cells. According to an embodiment of the present invention, a horizontal cross-section of the discharge cells, i.e., a cross-section parallel to the first substrate 102 and the second substrate 104 , may be, for example, polygonal, e.g., rectangular, hexagonal, or octagonal, circular, or oval, and may vary within the PDP. In the current embodiment of the present invention, the barrier ribs 106 of the PDP are primarily closed, as illustrated in FIG. 4 . [0053] Electrons in the phosphor layer 108 are excited by absorbing vacuum ultraviolet light generated by discharge, resulting in photo luminescence. That is, visible light is generated when the excited electrons of the phosphor layer 108 return to a stable state. The phosphor layer 108 may include, e.g., red, green, and blue phosphor layers such that the plasma display panel can display a full color image. The red, green, and blue phosphor layers may constitute a unit pixel in the discharge cell. The red phosphor may be (Y,Gd)BO 3 :Eu 3+ , etc., the green phosphor may be Zn 2 SiO 4 :Mn 2+ , etc., and the blue phosphor may be BaMgAl 10 O 17 :Eu 2+ , etc., but the present invention is not limited thereto. [0054] The phosphor layer 108 may be formed in the second substrate 104 in the discharge cells. However, locations of the phosphor layer according to embodiments of the present invention are not limited thereto, and various arrangements can be used. [0055] The first dielectric layer 109 a may be used as an insulating film for insulating the X electrodes 112 and the Y electrodes 114 , and may be formed of a material having high electrical resistance and high light transmittance. Some charges generated by the discharge may form wall charges on the protective layer 110 near the first dielectric layer 109 a due to an electrical attractive force caused by the polarity of a voltage applied to each of the X and Y electrodes 112 and 114 . [0056] The second dielectric layer 109 b may be used as an insulating film for insulating the address electrodes 116 , and may be formed of a material having high electrical resistance. Since the second dielectric layer 109 b does not transmit visible light, a material having high light transmittance is not required. [0057] The protective layer 110 may protect the first dielectric layer 109 a , and may facilitate discharge by increasing the emission of secondary electrons. The protective layer 110 may be formed, e.g., magnesium oxide (MgO), etc. [0058] The X electrodes 112 and the Y electrodes 114 may respectively include the transparent electrodes 112 a and 114 a and the bus electrodes 112 b and 114 b . However, since the address electrodes 116 do not transmit visible light, they may not include a transparent electrode and a bus electrode, but may have a single body structure. [0059] The transparent electrodes 112 a and 114 a may be formed of a transparent material, e.g., indium tin oxide (ITO), which transmits visible light emitted from the discharge cells. The transparent electrodes 112 a and 114 a may have a relatively high electrical resistance, in which case the electrical conductivity of the transparent electrodes 112 a and 114 a may be increased by the inclusion of the bus electrodes 112 b and 114 b formed of a material having high electrical conductivity, e.g., a metal. [0060] The field concentration groove 120 may be a groove, and may be formed by patterning, e.g., by etching, the first dielectric layer 109 a . A discharge path between the X electrodes 112 and the Y electrodes 114 may be reduced by the field concentration groove 120 . In addition, the field concentration effects of the central portion of the groove of the field concentration groove 120 may increase the density of electrons (negative charges) and ions (positive charges) in the field concentration groove 120 , thereby facilitating discharge between the X electrodes 112 and the Y electrodes 114 . Consequently, the distance between the X electrodes 112 and the Y electrodes 114 may be increased so as to increase the discharge space. Thus, the light emitting efficiency may be improved. Also, the transmittance of visible light emitted from the discharge cell through the first panel may be increased in proportion to the amount of the first dielectric layer 109 a that is removed, i.e., etched away. [0061] The connection passage units 122 with the smaller width d 2 than the width d 1 of the field concentration grooves 120 connect the field concentration grooves with the neighboring field concentration grooves so that discharge spaces of neighboring discharge cells can be connected, thereby facilitating the exhaust and injection processes during the manufacturing process of the plasma display panel. [0062] In FIG. 5A , the cross-section of the connection passage unit 122 , i.e., a cross-section perpendicular to the first substrate 102 and parallel to the address electrodes 116 , is trapezoidal. In FIG. 5B , the cross-section of the connection passage unit 122 is rectangular. However, any suitable cross-section may be used. [0063] Further, while the cross-section of the field concentration grooves 120 , i.e., a cross-section perpendicular to the first substrate 102 and parallel to the address electrodes 116 , is shown FIGS. 5A and 5B as having the same cross-sectional shape, although wider than, that of the connection passage unit 122 , they are not limited thereto, and the cross-section of the field concentration grooves 120 can have shapes different from that of the connection passage unit 122 . [0064] Exemplary embodiments of the present invention have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.

A plasma display panel has connection passage units that facilitate exhaust and injection processes during manufacture of the plasma display panel. The plasma display panel includes a first substrate, a second substrate facing the first substrate, the first and second substrates being spaced apart by a predetermined distance, barrier ribs for defining a plurality of discharge cells in a space between the first substrate and the second substrate, first and second electrodes extending parallel to each other on the first substrate, and a first dielectric layer covering the first and second electrodes, the first dielectric layer including a field concentration groove between the first and second electrodes within each discharge cell, and connection passage units for connecting field concentration grooves in adjacent discharge cells

FIELD OF THE INVENTION [0001] The present invention relates to a method and a software system for configuring a system including at least one module (a modular system). BACKGROUND INFORMATION [0002] By systems including at least one module (modular systems), particularly microprocessor programs are to be understood, of the type described below. In this case, a module can be equated to a functional unit. The method is, however, not restricted to microprocessor programs, but can be used generally for configuring modular systems in which individual modules are configured and assembled. [0003] Microprocessors are used these days in all important technological fields. Their use is not limited to the usual personal computers (PC's), in this context, but rather extends beyond this to many different electronic devices, such as measuring devices, control devices, etc., particularly in the automotive industry. [0004] Modern microprocessor programs and computer programs are predominantly programmed in such a way that they are useable in as broad a range of application as possible. The range of application is determined, on one hand, by the functionalities made available, which in turn should cover as many desires of the user as possible, and, on the other hand, by the underlying hardware on which the microprocessor program is to run. In this context, the underlying hardware denotes different (computer) systems which are used in different areas, are constructed of different components (e.g., processors or bus systems), and/or have different peripheral devices. [0005] Different functionalities can result from different conditions of the underlying hardware or from different user desires. Adaptation, and therefore specialization, of a microprocessor program to an underlying hardware and to specific user desires includes a so-called configuration of the microprocessor program. [0006] For example, a configuration includes the activation or deactivation of individual functions of the microprocessor program, the setting of starting values for certain variables or the preselecting and specifying of certain variable types. [0007] It is well-known that one may declare the variables and functions used in a microprocessor program in a so-called header file, and that one may configure the microprocessor program by changing individual variables or function designators in the header file. For example, it is possible to assign a special function to a function designator used in the microprocessor program and declared in the header file, as a function of a specific configuration. [0008] Microprocessor programs are usually created in a so-called high-level programming language, e.g., C, C++, Scheme or JAVA. A microprocessor program created in a high-level programming language is usually referred to as source code. To permit execution of such a microprocessor program on a microprocessor, a so-called machine code must be generated from the source code, the machine code containing instructions which are executable by the processor. Machine code can be generated by so-called interpretation or compilation of the source code. [0009] Typically, a microprocessor program includes a plurality of functional units. The source code of one or more functional units is stored in a data file, in this instance. A header file is assigned to one or more such data files. Thus, a microprocessor program is typically made up of a plurality of data files. A configuration of such a microprocessor program, which is accomplished by changes within individual header files, is therefore very unclear and can often only be accomplished by the creator of the source code. In addition, a documentation must be created for all header files, which is very painstaking; even the documentation for the most part being very unclear. [0010] To configure a microprocessor program, it is also known to assign it a special functional unit by which it is possible to configure the entire microcomputer program, for instance, by modifying the values of predefined parameters. For example, the functional unit may be launched from within the microprocessor program running, and be executed for configuring the microprocessor program. However, such a functional unit provided for configuring the microprocessor program only allows a configuration within predefined range limits. A configuration of the microprocessor program, e.g., for adapting the computer program to new hardware or for adapting the microprocessor program to new desires of the user is not possible using such a functional unit. Moreover, the functional unit used for the configuration must be developed specially for the microprocessor program in question, and cannot be used for other microprocessor programs. [0011] German Published Patent Application No. 10 2004 005 730 describes that the configuration of a microprocessor program is improved, and a resource-optimized implementation is achieved, by providing, between a user (configurator) and the microprocessor program, an abstract description of the configuration to be executed in an implementation-independent configuration data file, which is made the basis for the configuration. With the aid of the implementation-independent configuration data file, an implementation-dependent configuration data file is automatically created which is then utilized for configuring the microprocessor program. In order to ensure that the configuration process, and eventually the microprocessor program, is error-free, multiple checking processes are carried out during the creation of the implementation-dependent configuration data files. The creation and attachment of these checking processes is difficult and costly, particularly since they are generated and programmed in program code. SUMMARY [0012] Thus, example embodiments of the present invention simplify the configuration of microprocessor programs, and design them as clearly as possible and as flexibly as possible. [0013] The data determining a configuration are stored independently of an intended, specific implementation, in one or more implementation-independent configuration data files. The implementation independence of this configuration data file permits, in particular, an abstract description of the stored information. This makes it possible to store the information relevant for the configuration of the microprocessor program so that it can be read particularly well, and therefore to markedly simplify the configuration. Because this configuration data file is implementation-independent, it is possible in particular to configure the microprocessor program in a simple manner so that, for instance, the microprocessor program is executable on a new computer system whose exact parameters were not even known yet when the computer program was created. [0014] The configuration data container makes it possible to centrally provide all data relevant for a configuration. [0015] The at least one module is configured automatically with the aid of the configuration data stored in the configuration data container. [0016] According to an example embodiment of the method according to the present invention, it is provided that, using the configuration data filed in the configuration data container, automatically at least one implementation-dependent configuration data file is created, the automatic configuration of the at least one module being carried out as a function of the information stored in the at least one implementation-dependent configuration data file. [0017] In each of the example embodiments of this step, a specification takes place of individual or several parameter values with regard to the implementation-independent configuration data file. In such a concretization, for example, relative values are replaced by absolute values. Specific data types or structures may be assigned to individual values or data areas, as well. [0018] The implementation-dependent configuration data file takes into account implementation-dependent properties, such as one or more programming languages used when programming the source code, or properties of the hardware on which the microprocessor program is intended to run. [0019] The setup or the updating of the configuration data container with the aid of the information stored in the implementation-independent configuration data files may be carried out using so-called scripts, for example. In this context, a script denotes a sequence of instructions which are executable by a special microprocessor program. Such special microprocessor programs are AWK or Perl, for example. These special microprocessor programs may also be used for creating implementation-dependent configuration data files, or the configuration of the module, from the configuration data stored in the configuration data container. [0020] Moreover, configuration rules are used in the method. In this context, one or more configuration rules are assigned to each configuration parameter. In the configuration rules it can be stipulated, for example, which data sources or groups of data sources for a certain configuration parameter are valid, necessary or prohibited. In using the method for complex software systems, one should understand by the term data sources especially the components of this software system, for instance, configuration data. In the motor vehicle field, possible data sources for configuration data are, for instance, lambda regulation, accelerator preparation, diagnosis system, etc. In citing the valid data sources, quantifying specifications such as “all sources without difference” or “component X with the addition of all subcomponents” may be provided. In particular, in the configuration rules, it should be strictly recorded how the individual configuration parameters are to be organized formally and as to content. Overall, this measure makes possible, in a particularly simple manner, avoiding costly and distributed checking processes, and instead implementing them centrally and uniquely, and thus consistently. [0021] The comparison of the configuration parameters to the configuration rules can also be carried out using suitable scripts. The use of central configuration rules offers inclusive possibilities for formal specification of the properties and restrictions of the configuration parameters. Consequently, many and detailed tests at a central location are made possible and brought about. In contrast to design approaches described up to now, in which test runs in the respective scripts had to be carried out and programmed separately, a processor or script can now carry out a rules test, a structure test and/or a cross-relationship test can be carried out at a central location. Because of the measure hereof, a transfer is carried out away from program code to rules. By treating the configuration rules as a part of the component interface, far-reaching interface tests are made possible, such as visibility restrictions. Thereby conflicts can be detected early and avoided in response to the exchange of individual components. [0022] An aspect hereof is thus the recognition that it is possible to decisively improve the configuration of a modular system, in particular a microprocessor program, by providing between a user (configurator) and the system an abstract description of the configuration to be implemented in the implementation-independent configuration data file, which is taken as the basis of the configuration. By the use of configuration rules, the configuration parameters can be checked at an early time in the method, which advantageously reduces the effort required for it. [0023] With the aid of the implementation-independent configuration data file, an implementation-dependent configuration data file can automatically be created which is then utilized for configuring the system. However, the system can also be configured without physically creating such data files. Since the configuration parameters are subject to specified configuration rules, a simple and flexible adaptation to specified external parameters can be achieved. The method thus makes it possible to indicate the information describing a configuration in an abstract and therefore particularly easily readable manner. Because of the independence of any implementation details, a particularly great flexibility is also attained, which remains easily comprehensible and manageable, on account of the configuration rules. [0024] Furthermore, there is the advantage of decentralized control. For instance, the properties of a multi-channel measuring system can be stored, not only centrally in a configuration data file assigned to this measuring system, but also centrally, specific as to channel, in a plurality of implementation-independent configuration data files assigned to the respective sensors/channels. These data are then gathered in the container and can be evaluated centrally by scripts. [0025] In addition, for instance, in a process in a mode of division of labor, the configuration rules data files lead to a secure handling of the implementation-independent configuration data files. In particular, in an implementation-independent configuration data file, there may be included configuration elements having different configuration rules data files, whereby the configuration requirements of various modules can be processed in bundled fashion. [0026] In an example embodiment of the method, the configuration rules are used in the automatic setup and/or the automatic updating of the configuration data stored in the configuration data container, and/or in the automatic configuration of the at least one module as a function of the configuration data stored in the configuration data container, and/or in the automatic generation of an implementation-dependent configuration data file as a function of the configuration data stored in the configuration data container. It may also be provided that one should use the configuration rules already during the creation of the implementation-independent configuration data files, as is described below using the example of a configuration data file editor. At the points named, bringing in the configuration rules is particularly easy to carry out. Accordingly, in this connection, a particularly favorable cost-utilization factor is achieved. [0027] It may be provided that the configuration rules are stored in at least one configuration rules data file. In this context, one has the choice of providing a plurality of configuration rules data files, for instance one configuration rules data file for each functional unit or one configuration rules data file for each configuration data file. In one such configuration rules data file, rules are stored for the configuration parameters of the assigned functional unit. Great clarity can be achieved by this. During the configuration method, the individual rules data files are expediently gathered to one central rules data file. It is clear that also only one configuration rules data file can be provided for all configuration parameters to be processed. [0028] In an example embodiment of the method, at least one configuration rule is assigned to a configuration parameter, the configuration rule describing an authorization to process the configuration parameters, a formal property, an existence-determining property or a value-determining property of the configuration parameter. As will be described below, a configuration by dependency information is provided. It is expedient if, in this context, configuration rules with respect to (processing) authorization are provided. One can thereby stipulate, in a simple manner, a hierarchy within the configuration parameters, which describes a mutual modification. In particular it is controllable which configuration parameter can be or is allowed to be described or modified by which other configuration parameters. It might be appropriate here to describe additional properties of configuration parameters by configuration rules, such as a default value that is used as an alternate value if no value has been given for a parameter; thereby all post-connected processes processing configuration data can rely on the existence of a configuration value; a specification of valid reference targets, if the assigned configuration parameter represents a list of numbers of configuration settings to be distinguished by identifiers; an admissible value range (e.g. minimum/maximum value, increment, minimum/maximum text length in the case of textual parameters, fixed, set text type (e.g. Iso date), a text satisfying a certain text pattern or a text identical to a plurality of specified texts); an instruction for the automatic conversion of a value to another representation; a conversion formula of an abstract/physical representation of a value to an internal representation and/or vice versa; a statement as to how a configuration value is, for instance, to be indicated on a display (e.g. format string in a print format); a connection to another system property, e.g. a variable in a software system or microprocessor program, or a hardware property or resource; a unit of the configuration value; a treatment of blank spaces and page breaks in the case of textual information. [0038] In this context, individual, several or all of the rules named, as well as additional ones can be provided for each configuration parameter. It is thereby possible to greatly increase the degree of automation, and to achieve a reliable configuration of the microprocessor program. If a module or a functional unit provides a recording of measured values, for example, it may be described in the associated rule which sensors are to be made available by the hardware, and what type of measuring accuracy is available. The parameter can only be set within these rules. [0039] In example embodiments of the method, at least one item of dependency information, which describes a dependency of at least two configuration data present in the configuration data container, is automatically generated. The at least one implementation-dependent configuration data file is generated as a function of the at least one item of dependency information. Dependency information may describe, for example, whether the modification of one configuration parameter has an effect on another configuration parameter. For instance, if a resource is reserved exclusively for one module, then it is not available to other functional units during the execution of the module/functional unit. With dependency information, it is possible to ascertain which functional units need a specific resource, and therefore cannot run simultaneously. Consequently, dependency information may also be used for resource management. The dependency information is used for forwarding configuration information. During forwarding, a configuration processing entity assigned to a certain component, because of configuration requirements posed to it or because of configuration fine tuning, conducts away configurations of other components by a freely selectable algorithm, and conducts these settings thus ascertained on to these other components. This advantageous measure can be used especially for the automatic configuration of subcomponents. [0040] One may also store the intention of the forwarding in configuration rules, in order to be able to check even before the time of the actual configuration whether, because of this conducting on of configuration data, possibly vicious circles might be created (parameter A configures parameter B which, in turn, configures parameter A). Furthermore, because of the storing in configuration rules, dependencies between the individual components are formally described and are therefore available to other processes that continue processing. [0041] Besides the described moving procedure, the forwarding can also provide a fetching procedure. In a fetching forwarding a specification takes place of a fine tuning of a certain configuration parameter not only from a constant datum but advantageously also from a (possibly more complex and/or conditioned) expression, which includes references to the fine tuning of other parameters. It is also advantageous to provide making a specification of a configuration parameter as a whole (that is, the existence of this specification), in turn a function the setting of other configuration parameters—or possibly of expressions of any complexity made up of such settings. By using configuration rules, an automatic establishment of the forwarding sequence can take place, whereby the detection of possible vicious circles is already made possible at the time of the interface testing. [0042] In an example embodiment of the method, a plurality of implementation-independent configuration data files is created, and each of the implementation-independent configuration data files is assigned to at least one module or functional unit. This allows a particularly simple configuration, because the configuration parameters stored as information in the implementation-independent configuration data files can be found especially easily and modified. For example, it is possible to sort the information determining a configuration, thus, the configuration parameters, according to the functionality influenced by it or hardware. Moreover, a particularly simple adaptation of the implementation-independent configuration data files to newly added functional units is thereby made possible. In the simplest case, a special implementation-independent configuration data file, as well as, for instance, a configuration rules data file are assigned to a newly added functional unit. A plurality of implementation-dependent configuration data files is advantageously generated, and each of the implementation-dependent configuration data files is allocated to at least one functional unit. Such a structuring of the implementation-dependent configuration data files increases the clarity of the implementation-dependent configuration data files generated. If the source code is structured in such a way that one or more functional units are located in different data files, then an implementation-dependent configuration data file can be allocated to each of the data files of the source code. A particularly lucid structuring may also be achieved by in each case assigning one implementation-dependent configuration data file to each implementation-independent configuration data file. [0043] The at least one implementation-dependent configuration data file is preferably generated as a function of at least one property of hardware on which an installation of at least one portion of the configured computer program is to be made possible. For instance, such a hardware property may be the number of processors available or the type and number of sensors connected to the hardware. If such hardware properties are taken into account when generating the implementation-dependent configuration data files, it is then possible to configure the computer program especially precisely. Particularly using dependency information, it is therefore possible, for instance, in this way to automatically create a configuration optimized with regard to execution speed and the use of resources. [0044] In an example embodiment, a documentation is created automatically. The documentation describes the information filed within the at least one implementation-independent configuration data file and/or the at least one implementation-dependent configuration data file and/or the configuration rules and/or the at least one configuration rules data file. Such automatically generated documentation increases the maintainability of the microprocessor program on the one hand, and makes it possible, especially simply, on the other hand to plan and prepare a configuration, and to comprehend a configuration that has been carried out. The automatic generation of the documentation ensures that it conforms with the actual configuration and the configuration rules. If a new configuration of the modular system is to be carried out, then with the aid of such a documentation, it is possible to determine particularly easily which parameter values must or may be modified, and to which rules they are submitted. [0045] In the method, it is expedient, for creating and/or modifying the at least one implementation-independent configuration data file, if a microprocessor program is used which takes into account the configuration rules. Such a computer program or microprocessor program can be designated, for example, as a configuration data file editor, which sufficiently describes the functionality to one skilled in the art. If the configuration rules are used already when the configuration data files are created, the agreement of the configuration parameters with the configuration rules can be ensured right from the beginning. One can then avoid a subsequent reworking. The at least one implementation-independent configuration data file and/or the at least one configuration data rules file are preferably created in an XML-based format. XML (Extensible Markup Language) is a standardized meta language which makes it possible to generate structured languages. If the at least one implementation-independent configuration data file and/or the at least one configuration rules data file is created in an XML-compliant, structured language, then a configuration is facilitated, because such a data file can be read particularly well. Moreover, a data file of this kind can also be read especially well by machine. In particular, there exists a plurality of software tools likewise standardized in part, by which it is possible to edit and process data files created in an XML-based format. [0046] In an example embodiment of the method, it is automatically ascertained as a function of the configuration data, whether a module included in the modular system is required by the modular system, and one configuration of this module is only executed if the module is required by the modular system. This facilitates an especially rapid configuration, because only those modules/functional units are actually configured which are really needed in an execution of the configured system. Furthermore, the configured system thereby takes up as little storage space as possible, when a microprocessor program is involved since, for example, a translation of source code into machine code is only brought about for those functional units which are actually intended to be used. [0047] The method may be used for the configuration of a microprocessor program. However, in principle it can be used for the configuration of any system made up of modules (such as text, data, mechanical components, etc.). [0048] The foregoing is also achieved by a software system of the type indicated at the outset. In this context, the software system, especially a computer program or a microprocessor program, has: at least one configuration rules data file; at least one implementation-independent configuration data file; a configuration data container including configuration data and/or means for creating a configuration data container as a function of information stored in the at least one implementation-independent configuration data file; device(s) for modifying and/or reading out configuration data from the configuration data container; device(s) for automatically configuring at least one module as a function of configuration data stored in the configuration data container. [0054] In an example embodiment, the device(s) for automatically configuring at least one module, as a function of configuration data stored in the configuration data container, have: device(s) for automatically generating at least one implementation-dependent configuration data file as a function of configuration data stored in the configuration data container; and device(s) for automatically configuring the at least one functional unit as a function of information stored in the implementation-dependent configuration data file. [0057] The software system preferably has device(s) for carrying out the method according, particularly if the software system is executed on a computer, a microprocessor or corresponding processor unit, particularly of the computer unit. [0058] The implementation in the form of a software system is of particular importance, in this instance. In this context, the software system is able to run on a computing device, particularly on a microprocessor, and is suitable for carrying into effect the method. In this case, therefore, an example embodiment of the present invention is implemented by the software system, so that the software system constitutes an example embodiment of the present invention in the same manner as the method for whose execution the software system is suitable. [0059] A further software system and computer program has program code device(s) for the purpose of creating or modifying implementation-independent configuration data files, while taking into account configuration data files (configuration data file editor). [0060] The software system is preferably storable in a memory element (storage medium, data carrier). The memory element may take the form of a random access memory, read only memory or flash memory. The memory element may also be in the form of a digital versatile disk (DVD), compact disk (CD) or hard disk. [0061] A software system product, especially a computer program product or a microprocessor program product, includes program code device(s) which are stored in a memory element, particularly a machine-readable or a computer-readable data carrier. Suitable data carriers are, particularly, diskettes, hard disks, flash memories, EEPROM's, CD ROMS, DVD'S, RAM, ROM and others. Downloading a program via computer networks (Internet, Intranet, etc.) is also possible. [0062] A processor unit, particularly a control device, has a microprocessor and is programmed for carrying out a method. [0063] It is expedient to use a method, a software system, a software system product or a processor unit in the auto industry. It should be understood that the use is not limited to this. [0064] Further advantages and aspects of example embodiments of the present invention will be apparent from the description and the accompanying drawings. [0065] It is understood that the aforementioned features and the features yet to be explained below may be used not only in the combination indicated in each instance, but also in other combinations or by themselves, without departing from the scope of the present invention. [0066] Example embodiments of the present invention are illustrated schematically in the drawings and will be described in detail below, with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0067] FIG. 1 shows an example embodiment of a software system for carrying out the method according to an example embodiment of the present invention; and [0068] FIG. 2 shows schematic flow chart of the method according to an example embodiment of the present invention. DETAILED DESCRIPTION [0069] FIG. 1 shows a software system for carrying out the method of example embodiments of the present invention. The software system has a plurality of implementation-independent configuration data files 1 . A file name is assigned to each configuration data file 1 . The implementation-independent configuration data files shown in FIG. 1 , for example, bear data file names conf — 1.xml, conf — 2.xml, conf — 3.xml, . . . to conf_n.xml. [0070] The software system also has a plurality of configuration rules data files 1 b . A file name is assigned to each configuration rules data file 1 b . The configuration rules data files shown in FIG. 1 bear, for example, data file names rule — 1.xml, rule — 2.xml, rule — 3.xml . . . to rule_x.xml. The data file ending xml points out that implementation-independent configuration data files 1 and the configuration rules data files 1 b are present in an xml-based format. A text data file present in an XML-based format makes it possible to structure the text data file according to specifiable rules. Such a structured text data file can be read and processed particularly well manually and by machine. [0071] Implementation-independent configuration data files 1 and configuration rules data files 1 b are fed to a script 2 . Script 2 is in the form of a so-called Perl script, for example. Perl is an interpreter language whose syntax is based on programming language C, and which uses utility programs made available by the specific operating system. [0072] Using script 2 , implementation-independent configuration data files 1 are read, and the information stored therein is extracted and stored in a configuration data container 3 . The extraction of the configuration information and configuration parameters takes place while taking into account the configuration rules from configuration rules data files 1 b . If the configuration parameters contradict the configuration rules, this can therefore be detected and faulted at an earlier stadium of the configuration. To do this, appropriate instruction texts or error texts may be included, for example, in the configuration rules data files or in script 2 , which can be output in response to the infraction of a corresponding rule or rule type. At the same time, possibly existing dependencies with respect to further configuration scripts 4 are also determined and stored (forwarding). The positioning of the configuration rules data files 1 b within the software system may be seen, for instance. Configuration rules data files 1 b may be assigned, for instance, to scripts 4 , in another specific embodiment of the software system. [0073] Additional configuration scripts 4 are also Perl scripts, for example. It is equally conceivable that one or more of further configuration scripts 4 is an executable microprocessor program (machine code), or exists in another script language, e.g., AWK. [0074] Implementation-dependent configuration data files are denoted by reference numeral 5 . For example, implementation-dependent configuration data files 5 are coded in the programming language in which the source code to be configured is also programmed. Such implementation-dependent configuration data files are able to be processed by a compiler 6 . [0075] Reference numeral 7 denotes a microprocessor program having a plurality of functional units 8 . The functioning method of the software system according to example embodiments of the present invention is described with reference to the flow chart shown in FIG. 2 . [0076] The flow chart shown in FIG. 2 , of a method, according to example embodiments of the present invention, for configuring a microprocessor program starts at step 100 . In a step 101 , implementation-independent configuration data files 1 are created or modified. Implementation-independent configuration data files 1 have the special distinction that, using the information stored there, it is possible to abstractly describe concrete configuration values or configuration parameters. For instance, concrete configuration values are able to define the measuring range of a sensor module for measuring an electric voltage. It is possible, for instance, to indicate a measuring range abstractly using the values 3-5 volts. However, the implementation-dependent values of the measuring range to be generated therefrom, in the manner functional unit 8 to be configured expects it, may lie between 10,000 and 20,000, for example. In this case, a functional unit 8 , of the microprocessor program, that controls the sensor module, would have to be configured using the concrete configuration values 10,000 and 20,000, for instance, to permit a measurement in a measuring range of 3-5 volts. [0077] In addition, configuration rules data files 1 b (rule — 1.xml to rule_x.xml in FIG. 1 ) are also available for the method. Usually, configuration rules data files 1 b are not created or modified in response to each performance of the method. Configuration rules data files 1 b describe the formal and content properties of the configuration parameters. [0078] Implementation-independent configuration data files 1 and configuration rules data files 1 b created or modified in step 101 are created, for example, in an XML-based format. Such a format makes it particularly easy to achieve a lucid structuring of implementation-independent configuration data files 1 and configuration rules data files 1 b . This increases the readability of implementation-independent configuration data files 1 and configuration rules data files 1 b , and simplifies the modification of implementation-independent configuration data files 1 , e.g., because configuration data to be modified can be quickly found. It is possible to provide only one single implementation-independent configuration data file or configuration rules data file, even for a particularly large microprocessor program requiring a multitude of configuration data for its configuration. In this context, the information stored in implementation-independent configuration data file 1 and the configuration rules stored in configuration rules data file 1 b are able to be structured using suitable XML structures. However, it is especially advantageous to provide a plurality of implementation-independent configuration data files and configuration rules data files. For instance, each of these implementation-independent configuration data files 1 and configuration rules data files 1 b may be assigned to one or more functional units 8 . It is thereby possible to create or modify the implementation-independent configuration data files and configuration rules data files in a particularly clear manner. In addition, reusability of individual implementation-independent configuration data files and configuration rules data files is thereby increased. This is especially advantageous for projects in which individual functional units 8 of the source code are also to be reused. [0079] In a step 102 the instructions listed in script 2 are processed. Script 2 causes independent configuration data flies 1 and configuration rules data files 1 b to be read in. If implementation-independent configuration data files 1 and/or configuration rules data files 1 b are based on a structured format, e.g., an XML-based format, then a syntactic and/or semantic analysis of the contents of implementation-independent configuration data files 1 and/or configuration rules data files 1 b may be carried out particularly well using script 2 . (Data file) errors in the detail of the configuration data can be detected thereby (missing symbols, too many symbols, wrong symbols, etc.). Preferably, the XML-based format of implementation-independent configuration data files 1 and configuration rules data files 1 b has a hierarchical structure that is advantageously oriented to the structure of functional units 8 themselves, their dependencies and/or their thematic closeness. Errors in the setup of this hierarchical structure, and therefore also in the setup of the source code itself may be recognized using script 2 . [0080] Errors found are advantageously handled in step 102 . This may be accomplished, for example, by the output of error information. It is equally possible to use stochastic methods to remove errors. [0081] The configuration parameters are also checked in step 102 , with the aid of the configuration rules. In this context what is particularly checked is whether the configuration parameters correspond formally and as to content to the associated configuration rules. If this is not the case, the method branches back to step 101 , in which a change is made in implementation-independent configuration data files 1 with the aim of eliminating errors. If no errors are detected in step 102 , the system branches to a step 103 , in which configuration data container 3 is set up or updated. [0082] In step 103 , script 2 extracts the configuration data present in implementation-independent configuration data files 1 and stores them in configuration data container 3 . Configuration data container 3 may be in the form of a database, for example, in this instance. It is likewise possible to implement configuration data container 3 as a data structure, provided in a storage area, within the software system of the present invention, in so doing, it being ensured that script 2 has writing and reading access to the configuration data stored in configuration data container 3 . [0083] In a step 104 , dependencies are ascertained. For example, one such dependency may describe which functional units 8 of the microprocessor program must actually be processed in the case of the present configuration. With the aid of these dependencies, it is possible to decide whether, in one of the following steps, it is necessary to generate an implementation-dependent configuration data file for a specific functional unit 8 at all. Dependencies may further describe which concrete configuration data are a function of which abstract configuration data. Thus, it is possible that the change of an abstract configuration datum in an implementation-independent configuration data file gives rise to a change in a plurality of concrete configuration data. [0084] Dependencies may also arise if further scripts 4 on their part modify configuration container 3 . Thus, the correct calling sequence (activation sequence) of scripts 4 must be ascertained and stored. Dependencies may also describe relationships between one or more hardware components and individual configuration data. This makes it possible to recognize, for instance, whether a configuration provided is actually executable on specific hardware. [0085] In step 105 , implementation-dependent configuration data files 5 are generated. To that end, first of all the configuration data stored in configuration data container 3 are retrieved with the aid of a script 4 or a plurality of scripts 4 . In the present exemplary embodiment, scripts 4 are in the form of Perl scripts. Abstract configuration data, stored in particular in configuration data container 3 , are converted by scripts 4 into concrete configuration data, which are then stored in implementation-dependent configuration data files 5 . In so doing, preferably the dependencies ascertained in step 104 are used as well. [0086] The implementation-dependent configuration data files 5 generated in step 105 may be, for example, header data files (file — 1.h, file — 2.h, file — 3.h in FIG. 1 ). In the same way, generated implementation-dependent configuration data files 5 may also contain source code (file — 2.c, file_k.c in FIG. 1 ). Typically, the concrete configuration data generated by scripts 4 from the abstract configuration data are implemented by value assignments for variables and/or function parameters, and as instructions in a programming language. In this context, the programming language corresponds to the programming language in which functional units 8 of microprocessor program 7 are coded. For example, if functional units 8 of microprocessor program 7 are coded in programming language C++, then the concrete configuration data may be implemented by so-called define instructions, for instance, or by the definition of constant variables. Depending on the configuration data stored in configuration data container 3 , with the aid of scripts 4 , it is also possible to generate functions which assume complex tasks—such as the initialization of hardware components, or checking for the presence of individual software components or hardware components—and are themselves implemented as source code in a higher programming language. This source code may then be stored in one or more implementation-dependent configuration data files (file — 2.c, file_k.c in FIG. 1 ). For that purpose, for example, a script 4 may contain a so-called template, made up, for instance, of instructions in C++, which are updated as a function of the configuration data stored in configuration data container 3 , and are stored in an implementation-dependent configuration data file 5 . [0087] In step 106 , functional units 8 of microprocessor program 7 are updated. For example, this may be accomplished by the automatic call-up of a compiler 6 which translates functional units 8 , existing in a source code, into a machine code. To that end, compiler 6 reads in implementation-dependent configuration data files 5 and controls the generation of the machine code as a function of the concrete configuration data stored in implementation-dependent configuration data files 5 . It is also conceivable that one or more functional units 8 already exist in machine code. In this case, the compiler may, for instance, translate the source code (file — 2.c, file_k.c in FIG. 1 ), generated by scripts 4 , into machine code, taking into account the header data files (file — 1.h, file — 2.h, file — 3.h), and link the machine code thus translated to the machine code representing functional units 8 with the aid of a so-called linker assigned to compiler 6 . [0088] The method ends in step 107 . In this step, microprocessor program 7 is configured in such a way that the concrete configuration data, stored in the implementation-independent configuration data files, are taken into account in the machine code generated. [0089] It is possible for script 2 and/or scripts 4 to be written in another script language, or to be developed as executable programs. It is also possible to use the configuration rules only in connection with scripts 4 . [0090] The execution steps shown in FIG. 2 may, of course, vary, and the processing sequence may be able to be partially modified. In particular, the method may also start out from one or more implementation-independent configuration data files; have one or more scripts 2 that, for instance, are carried out consecutively; have one or more scripts 4 , each generating one or more implementation-dependent configuration data files 5 ; and of course, microprocessor program 7 may have one or more functional units 8 . Using the method of the present invention, it is possible, in particular, to recognize whether one or more of functional units 8 actually come to be used in the configuration specified by the implementation-independent configuration data files. If this is not the case, it can be recognized by a software tool (not shown), assigned to configuration data container 3 . This makes it possible that such a functional unit 8 is not configured, and with the aid of implementation-dependent configuration data files 5 , compiler 6 is induced not to import functional unit 8 into the machine code to be generated. The method may thereby be carried out particularly rapidly. The machine code generated by a microprocessor program, which was configured using the method, may, in this instance, be especially compact and consequently may be able to save memory space. [0091] There is the possibility that script 2 itself is already brings about the generation of one or a plurality of implementation-dependent configuration data files 5 . The method may thereby be carried out particularly rapidly. For example, this may be advantageous for abstract configuration data that have no dependencies and differ from the concrete configuration data.

In order particularly easily and flexibly to configure a system including at least one module, a method has the following steps: creation of at least one implementation-independent configuration data file and/or modification of information stored in the at least one implementation-independent configuration data file; automatic setup and/or automatic update of configuration data, stored in a configuration data container, as a function of the information stored in the at least one implementation-independent configuration data file; automatic configuration of at least one module as a function of the stored in the configuration data container.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to a floor box of the type commonly installed into the floor of a facility for providing temporary connections to utilities, and more particularly to an improved utility connection floor box which may be removed and replaced without requiring either the demolition and subsequent reconstruction of the floor in which the floor box is installed or the replacement or repair of the utility lines located in the floor and connected to the floor box. Floor boxes are typically installed in locations at which connections to utilities such as electrical power, telephone, data, audio/visual, compressed air, water, and a drain will be required on a temporary or occasional basis. For example, convention and exhibition facilities require that connections to utilities be available at a large number of different locations throughout the facility, and that exhibitors be able to connect to utility connections located in the floor boxes. Since conventions or exhibitions are typically held for a matter of several days or a week, it will be appreciated that such connections are only used for short periods of time between setup and teardown of the displays or exhibitions. However, convention or exhibition facilities in most large cities will be in more or less continuous use throughout the year, with a large number of different shows or exhibitions coming and going in rapid succession. It will also be appreciated that the use of floor boxes offers ready connections to utilities in a manner which is unobtrusive, and which does not require a great deal of time to set up or run electrical and plumbing lines. However, in order to afford the maximum degree of flexibility in configuring exhibit areas, it will be appreciated that a relatively large number of such floor boxes will be installed throughout the convention or exhibition facility. Such floor boxes are installed at the time the facility is constructed, and are recessed into the concrete floors, which may be either slab on grade or structural floors. The floor boxes are typically made of either electro-galvanized steel, painted carbon steel, or stainless steel. The floor boxes are open on the top side thereof, and have a frame typically made of angle iron located at the top of the box. The floor boxes have covers which fit into the angle iron frame, with the covers typically being either steel plate or cast iron. More recently, cast aluminum has also been used as a material instead of steel plate or cast iron. The installation of the typical floor box is made by first attaching the angle iron frame to the top of the floor box. The floor box is then set place and temporarily supported on concrete blocks or 2"×4" blocks, with the angle iron frame being located at the level at which the floor surface will be when the slab or floor is poured. Holes are cut into the sides and bottom of the floor box for connections to utilities. The utility lines are then run and plumbed, and are permanently connected to the floor box through the holes which were cut therein in the conventional manner. Re-bar for the slab or floor is then installed, and the concrete for the slab or floor is then poured. The cement in the concrete permanently "glues" the floor box into the slab or floor, and the utility lines extending into the floor box serve as dowels to make the installation of the floor box permanent. The concrete completely surrounds the floor box, and is level with the angle iron frame. When the cover is placed on the floor box, it is at the same level as the concrete slab or floor. Thus, when the floor box is not being used, it serves as a part of the floor surface, and may be walked on or driven over. Since it is necessary for delivery trucks to drive onto the floor to deliver loads of materials for a convention or exhibit, the covers must be able to support heavy loads. The design criteria used for wheel loading is "highway" wheel loads, which are approximately 15,000 pounds over a 9 inch by 15 inch footprint. Some floor box covers are damaged or destroyed by the greater wheel loads imposed by forklifts, particularly hard-wheeled forklifts. Such loads can also damage a floor box to the point where it may require replacement. One of the most serious problems encountered with floor boxes is corrosion. Since the floor boxes are typically made of steel, they can and do rust, particularly in northern climates where they are exposed to salt-laden water from melted snow picked up by the trucks on the highways. The water drips into the floor boxes, where the salt tends to greatly accelerate the rusting process. Such corrosion eventually results in the floor box deteriorating to a point at which it must be replaced. Other problems which can result in the floor box needing to be replaced are fire, obsolescence, or physical damage caused by misuse. It will at once be appreciated by those skilled in the art that when the floor box is either unusable or when it has deteriorated to a certain point, it must be replaced. In addition, the facility may decide to upgrade their exhibitor services, but to do so means that the floor box would have to be replaced. In order to replace a floor box, the concrete slab or floor must be jackhammered to remove the box and to obtain access to the supply lines and plumbing. Frequently, the supply lines and plumbing are damaged in the process of removing the floor box, further exacerbating the replacement process. Replacement of a floor box is a difficult, time consuming, and expensive process, to say the least. It is accordingly the primary objective of the present invention that it provide a floor box which may be relatively easily removed from the concrete slab or floor and the cover frame without requiring the slab or floor to be broken. It is a closely related objective of the removable floor box of the present invention that it may be reinstalled in the slab or floor and the cover frame without requiring any cement to be poured and with a similar degree of ease to that associated with its removal. It is a further primary objective of the present invention that the fittings connected to the removable floor box can be removed from the old floor box and reconnected to the new floor box easily and without necessitating the replacement of any of the lines or plumbing. It is a further objective of the removable floor box of the present invention that it be provided with a cover which fits on the floor box in a water resistant manner, even though there are access doors which are located in the cover. It is a still further objective of the removable floor box of the present invention that the cover be designed so that it can support even large loads (such as a forklift with its maximum load, about to tip over so that most of its weight is on its front wheels) without damage to either the cover or the floor box. It is yet another objective of the removable floor box of the present invention that it may be made of a material which is completely resistant to corrosion. The removable floor box of the present invention must be of a construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the removable floor box of the present invention, it should also be of relatively inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the removable floor box of the present invention be achieved without incurring any substantial relative disadvantage. SUMMARY OF THE INVENTION The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a removable floor box having four main components is disclosed and taught. The four components of the removable floor box of the present invention are a floor box of unique design, a rim member which may be mounted onto the open top of the floor box, a cover frame fitting into the rim member in a manner which is flush to the floor, and covers which fit into apertures in the cover frame. The floor box is open only on the top side thereof (as is conventional), and has four vertically oriented guide tubes which are respectively installed in the four corners of the box on the inside thereof. The four guide tubes are each sealed at the top end thereof and are open at the bottom end thereof. The open bottom ends of the four guide tubes respectively communicate with four axially oriented apertures located in the bottom of the box beneath the guide tubes. Four threaded rods are used to support the floor box of the present invention in place, with a nut and washer being mounted on each of the four threaded rods to adjust the height of the floor box. The top ends of the four threaded rods are respectively inserted into the four guide tubes, with the floor box thereby resting on the washers and nuts mounted on the four threaded rods. The sides and the bottom of the floor box of the present invention are wrapped with 1/8 inch thick sheets of extruded polystyrene expanded foam material, such as the material marketed by Dow Chemical Company under the trademark STYROFOAM. The sheets of extruded polystyrene expanded foam material may be retained in place on the sides and the bottom of the floor box by pieces of string wrapped around the floor box. The sheets of extruded polystyrene expanded foam material will act to prevent the concrete from gluing the floor box in place when the concrete is poured. The utility lines and plumbing are run to the floor box, and are connected thereto through holes in the sides and bottom of the floor box. In a significant departure from the prior art, the connections to the utilities are all made from the inside of the floor box of the present invention. By so doing, the floor box of the present invention will be able to be disconnected from the fittings of the utility lines and plumbing from the inside thereof, thereby making it possible to remove the floor box from the utilities in order to remove it. In another departure from the prior art, the floor box of the present invention is made of a corrosion resistant material such as PVC. As such, the guide tubes may be molded into the floor box if desired. In the preferred embodiment, the floor box of the present invention is made of white PVC (rather than gray, which is the standard color for floor boxes), which substantially improves visibility in the floor box. Since in normal use the floor box of the present invention will never be exposed to sunlight, it need not have the gray pigmentation normally used for PVC pigmentation to resist ultraviolet breakdown due to exposure to sunlight. The rim member fits around the outer periphery of the floor box adjacent the top end thereof, and in cross section is shaped like a stretched "Z" rather than a simple "L" (which is the shape of conventional angle iron). The rim member is preferably made of steel, and in the preferred embodiment it is galvanized to make it resistant to corrosion. The top edge of the floor box thus fits inside the rim member, and is attached to the rim member by self-tapping bolts installed from the inside of the floor box. The concrete is poured around the floor box, and is leveled with the top of the rim member. The sheets of extruded polystyrene expanded foam material prevent the concrete from gluing the floor box in place when the concrete is poured. The sheets of extruded polystyrene expanded foam material and the string holding them in place around the floor box will disintegrate over time, leaving a 1/8 inch thick gap between the floor box and the concrete, and making removal of the floor box an easy task. The cover frame is designed to transfer the load from wheels on the surface thereof to the concrete. As such, in the preferred embodiment it has a thick center beam (at least in larger sizes) to effectively carry loads as large as 16 tons on a 1 inch by 16 inch footprint. The cover frame of the preferred embodiment has two apertures therein which are used to support the covers. The cover frame is made of cast aluminum alloy in the preferred embodiment. A gasket placed into the rim effectively seals between the cover frame and the rim when the cover frame is installed onto the rim. The covers are designed to provide access to the interior of the floor box, and as such have doors mounted therein on hinges. The doors in the covers may be swung downwardly into the interior of the floor box to allow for wires and hoses to extend from the floor box. The covers and doors are also designed to carry a load, in the preferred embodiment a load of as much as 32,000 pounds. Since they are smaller than the cover frame, they are also thinner and lighter (typically weighing about twenty pounds). In the preferred embodiment, the covers also have handles which are retractable into a flush position on the covers. The handles are biased into this retracted position by springs, and may be opened by pressing at one end thereof to pop the other end up sufficiently to permit it to be grasped. Gaskets located in the cover under the handles effectively seal them when they are in their retracted position. No holes are exposed on the covers when the doors are closed and the handles are retracted. It may therefore be seen that the present invention teaches a floor box which may be relatively easily removed from the concrete slab or floor and the cover frame without requiring the slab or floor to be broken. The removable floor box of the present invention may also be reinstalled in the slab or floor and the cover frame without requiring any concrete to be poured and with a similar degree of ease to that associated with its removal. The fittings connected to the removable floor box of the present invention can be removed from the old floor box and reconnected to the new floor box easily and without necessitating the replacement of any of the lines or plumbing. The removable floor box of the present invention is provided with a cover which fits on the floor box in a water resistant manner, even though there are access doors which are located in the cover. The cover of the removable floor box of the present invention is designed so that it can support even large loads (such as a forklift with its maximum load, about to tip over so that most of its weight is on its front wheels) without damage to either the cover or the floor box. If so desired, the removable floor box of the present invention may be made of a material which is completely resistant to corrosion. The removable floor box of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The removable floor box of the present invention is also of relatively inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the removable floor box of the present invention are achieved without incurring any substantial relative disadvantage. DESCRIPTION OF THE DRAWINGS These and other advantages of the present invention are best understood with reference to the drawings, in which: FIG. 1 is a cross-sectional view from the side of a drain plumbing connection as customarily made on the bottom of a prior art floor box; FIG. 2 is a cross-sectional view from the side of an electrical conduit connection as customarily made on the side of a prior art floor box; FIG. 3 is a cross-sectional view from the side of a water or air supply plumbing connection as customarily made on the bottom of a prior art floor box; FIG. 4 is a top plan view of the removable floor box of the present invention, showing four guide tubes which are respectively installed in the four corners of the box on the inside thereof, two apertures located in the bottom of the removable floor box, and the location of an aperture located in a side wall of the removable floor box, and also showing four sheets of extruded polystyrene expanded foam material placed on the exterior of the removable floor box on the sides thereof; FIG. 5 is a side view of the removable floor box illustrated in FIG. 4, showing the location of the aperture located in the side wall of the removable floor box, the sheet of extruded polystyrene expanded foam material placed on the side of the removable floor box, and also showing another sheet of extruded polystyrene expanded foam material placed on the exterior of the removable floor box on the bottom thereof; FIG. 6 is a partial cross-sectional view of the removable floor box illustrated in FIGS. 4 and 5, showing one of the four guide tubes as being sealed at the top thereof and open at the bottom end thereof, the open bottom end of the guide tube being in communication with an aperture extending through the bottom of the removable floor box; FIG. 7 is a cross-sectional view from the side of a drain plumbing connection as made on the bottom of the removable floor box illustrated in FIGS. 4 and 5; FIG. 8 is a cross-sectional view from the side of an electrical conduit connection as made on the side of the removable floor box illustrated in FIGS. 4 and 5; FIG. 9 is a cross-sectional view from the side of a water or air supply plumbing connection as made on the bottom of the removable floor box illustrated in FIGS. 4 and 5; FIG. 10 is a partial cross-sectional view of the removable floor box similar to the view illustrated in FIG. 6, showing a threaded rod extending through the aperture in the bottom of the removable floor box and into the open bottom end of the guide tube, and also showing a washer and nut located on the threaded rod at an intermediate location thereon to support the corner of the removable floor box thereupon; FIG. 11 is an exploded view showing a rim member which will fit around the outer periphery of the floor box illustrated in FIGS. 4 and 5 adjacent the top end thereof, a cover frame which will fit into the rim member above the removable floor box, and two covers which will fit into two corresponding apertures located in the cover frame; FIG. 12 is a top plan view of the rim member illustrated in FIG. 11; FIG. 13 is a bottom plan view of the rim member illustrated in FIGS. 11 and 12, showing two angle iron segments located on the bottom side thereof; FIG. 14 is a cross-sectional view of a portion of the rim member and one of the angle iron segments; FIG. 15 is a top plan view of the cover frame illustrated in FIG. 11, showing two large apertures located therein to receive the covers; FIG. 16 is a first cross-sectional view of the cover frame illustrated in FIGS. 11 and 15, showing the configuration of the center beam of the cover frame; FIG. 17 is a second cross-sectional view of the cover frame illustrated in FIGS. 11, 15, and 16, showing the configuration of the large apertures located therein as well as the cross-sectional configuration of the center beam; FIG. 18 is a top plan view of one of the covers illustrated in FIG. 11, showing two notches located in the sides thereof for receiving two doors respectively therein, and also showing two recesses for containing two handles respectively therein; FIG. 19 is a bottom plan view of the cover illustrated in FIG. 18; FIG. 20 is a first cross-sectional view of the cover illustrated in FIGS. 18 and 19, showing the cross-sectional detail of one of the notches located in a side edge of the cover for receiving a door therein; FIG. 21 is a second cross-sectional view of the cover illustrated in FIGS. 18 and 19, showing the cross-sectional detail of one of the recesses located in the top side thereof for receiving a handle therein; FIG. 22 is an exploded plan view of a handle for installation into one of the recesses located in the top side of the cover illustrated in FIGS. 18 and 21, showing a shaft mounted onto the bottom side of the handle, and a spring, a washer, and a nut for installation onto the threaded end of the shaft opposite the handle; FIG. 23 is a side view of the handle illustrated in FIG. 22; FIG. 24 is a top plan view of one of the doors for installation into one of the notches located in the top side of the cover illustrated in FIGS. 18 and 21; FIG. 25 is a side plan view of the door illustrated in FIG. 24; FIG. 26 is a bottom plan view of the door illustrated in FIGS. 24 and 25, also showing a hinge mounted onto the bottom side of the door; and FIG. 27 is a partial cross sectional view of the removable floor box of the present invention from the side, showing the top end of the floor box illustrated in FIGS. 4 and 5 attached to the rim member illustrated in FIGS. 11 through 14 with a self-tapping bolt, and also showing the cover frame mounted in the rim member with a gasket located therebetween and one of the covers mounted in the cover frame with a gasket located therebetween. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before discussing the removable floor box of the present invention, it is helpful to briefly discuss the prior art. Specifically, in order to fully understand the advantages offered by the present invention, the manner in which the prior art floor box, which was simply a steel box that was open on the top side thereof, was installed, and specifically how it was hooked up to electrical and plumbing lines, will be briefly discussed with reference to FIGS. 1 through 3. Referring first to FIG. 1, a portion of the bottom of a floor box 40 is illustrated with plumbing for a drain connection installed. A drain fitting 42 having a cylindrical segment 44 projecting downwardly therefrom is installed in an aperture 46 in the floor box 40. The cylindrical segment 44 of the drain fitting 42 is threaded on the outside surface thereof. An annular gasket 48 is installed on the cylindrical segment 44 of the drain fitting 42 underneath the bottom of the floor box 40. A locking ring 50 of cylindrical configuration having the interior threaded on the top portion thereof is screwed onto the threaded cylindrical segment 44 of the drain fitting 42. When the locking ring 50 is tightly secured on the cylindrical segment 44 of the drain fitting 42, the annular gasket 48 will be compressed to provide a watertight seal. A drain pipe 52 is inserted into the bottom of the locking ring 50, where it is retained in place by solvent bonding. Alternately, the bottom portion of the locking ring 50 may also be threaded on the inside thereof, and the top end of the drain pipe 52 may be threaded on the outside thereof, thereby allowing the drain pipe 52 to be screwed into the locking ring 50. Referring next to FIG. 2, a portion of the side of the floor box 40 is illustrated with fittings for an electrical connection installed. An electrical conduit segment 54 is inserted into one end of a box connector 56, where it is retained in place by solvent bonding. Alternately, the end of the box connector 56 may be threaded on the inside thereof, and the end of the electrical conduit segment 54 may be threaded on the outside thereof, thereby allowing the electrical conduit segment 54 to be screwed into the box connector 56. The other end of the box connector 56 has a cylindrical segment 58 extending therefrom which is threaded on the outside thereof. The cylindrical segment 58 of the box connector 56 extends through an aperture 60 in the side of the floor box 40. A bonding locknut 62 is screwed onto the threaded cylindrical segment 58 of the box connector 56. If the conduit system running to the location of the floor box 40 is continuously metallic, then metal fittings would be used instead of plastic fittings, and a grounding bushing would be used instead of the bonding locknut 62. Referring now to FIG. 3, a portion of the bottom of the floor box 40 is illustrated with plumbing for a water or air supply connection installed. The water or air is supplied from a supply pipe 64, the end of which is threaded on the outside. One end of a connecting sleeve 66 which is threaded on the inside thereof is screwed onto the threaded end of the supply pipe 64. A threaded nipple 68 has one end thereof screwed into the other end of the connecting sleeve 66. A nut 70 is screwed onto the threaded nipple 68, and a washer 72 is then placed onto the threaded nipple 68. The free end of the threaded nipple 68 is then inserted through an aperture 74 in the bottom of the floor box 40. A washer 76 is then placed onto the threaded nipple 68, and a nut 78 is screwed onto the threaded nipple 68 to retain it in place in the aperture 74 in the floor box 40. Finally, a valve body 80 is screwed onto the top end of the threaded nipple 68. It will be appreciated by those skilled in the art that when the drain, electrical, and water or air supply connections illustrated in FIGS. 1 through 3 are installed, they will effectively secure the floor box 40 in place. The concrete (not shown herein) will secure the conduit and pipes in place, and the only way that the floor box 40 may be removed is by removing the concrete around the sides and the bottom of the floor box 40. In addition, of course, the concrete will also act as glue to retain the floor box 40 is place, making its removal impossible without breaking the concrete. The preferred embodiment of the removable floor box of the present invention has four primary components: a floor box of unique design, a rim member which may be mounted to the open top of the floor box, a cover frame fitting into the rim member in a manner which is flush to the floor, and covers which fit into apertures which are located in the cover frame. The first of these components is illustrated in FIGS. 4 through 6, which show a removable floor box 82. The removable floor box 82 has four sides and a bottom, and is open on the top side thereof. As shown in FIG. 4, the removable floor box 82 has four vertically oriented guide tubes 84, 86, 88, and 90 which are respectively installed in the four corners of the removable floor box 82 on the inside thereof. The four guide tubes 84, 86, 88, and 90 are approximately half as tall as the removable floor box 82, and are located in the removable floor box 82 with their bottom ends on the bottom of the removable floor box 82, as best shown in FIG. 6. The four guide tubes 84, 86, 88, and 90 are each sealed at the top end thereof, and are each open at the bottom end thereof. The open bottom ends of the four guide tubes 84, 86, 88, and 90 are sealed to the bottom of the removable floor box 82 and respectively communicate with four axially oriented apertures located in and extending through the bottom of the removable floor box 82 beneath the guide tubes. One of these four apertures, which is illustrated in FIG. 6, is identified by the reference numeral 92, and is in communication with the guide tube 84. The other three apertures, although not illustrated in the figures, are identical in size and configuration to the aperture 92. In the preferred embodiment, the removable floor box 82 is made of PVC rather than of metal. While floor boxes have in the past been made of PVC, the standard color used has typically been ANSI 70 gray, or battleship gray. As mentioned above, this color has been used because there is a pigment in it that resists ultraviolet breakdown of the PVC when exposed to sunlight. Since floor boxes are never exposed to sunlight in that they are located below the floor, they need not be gray. Accordingly, in the preferred embodiment, the removable floor box 82 is made of white PVC to substantially improve visibility therein. The removable floor box 82 may be made of slabs of PVC which are welded together. In this case, the four guide tubes 84, 86, 88, and 90 are also welded into place inside the removable floor box 82, with the bottom ends sealed around the apertures in the bottom of the removable floor box 82. For example, the open bottom end of the guide tube 84 is welded to the removable floor box 82 around the aperture 92 in the removable floor box 82. Alternately, the removable floor box 82 together with the four guide tubes 84, 86, 88, and 90 may be molded in a single piece. An aperture 94 which is shown as being centrally located in the bottom of the removable floor box 82 will be used to install fittings for a drain therein. It should be noted that drains in floor boxes are typically installed in a corner of the floor box. In some applications, the floor box may have multiple compartments located therein, e.g. separate compartments for the air and water supplies as well as a separate electrical compartment. In such applications, each compartment would have its own drain. It will be appreciated by those skilled in the art that the example shown herein is equally applicable to such multiple drain applications, with the drains varying only in size and placement. Located in the bottom of the removable floor box 82 on the inside thereof is a circular recess 96 which surrounds the aperture 94. This recess will be used to receive a strainer which is mounted over the drain, as will become evident below in conjunction with the discussion accompanying FIG. 7. Also located in the bottom of the removable floor box 82 is an aperture 98 which will be used to install fittings for a water or air supply line. Located in one side of the removable floor box 82 is an aperture 100 which will be used to install fittings for an electrical supply line. The four sides of the removable floor box 82 are covered on the outside thereof with four sheets of 1/8 inch thick sheets of extruded polystyrene expanded foam material 102, 104, 106, and 108, which may be, for example, the material marketed by Dow Chemical Company under the trademark STYROFOAM. Similarly, the bottom of the removable floor box 82 is covered on the outside thereof with a sheet of extruded polystyrene expanded foam material 110. The sheets of extruded polystyrene expanded foam material 102, 104, 106, 108, and 110 may be retained in place by segments of string 112, 114, 116, and 118. It will be appreciated by those skilled in the art that other means may be used to retain the sheets of extruded polystyrene expanded foam material 102, 104, 106, 108, and 110 in place. For example, masking tape (not illustrated herein) may be used instead of the segments of string 112, 114, 116, and 118. When the removable floor box 82 is installed in a floor and concrete is poured around the removable floor box 82, the sheets of sheets of extruded polystyrene expanded foam material 102, 104, 106, 108, and 110 will act to prevent the cement in the concrete from gluing the floor box 82 in place when the concrete is poured. Over time following the installation of the removable floor box 82 in the concrete floor, the sheets of sheets of extruded polystyrene expanded foam material 102, 104, 106, 108, and 110 and the segments of string 112, 114, 116, and 118 will disintegrate, leaving a 1/8 inch thick air gap around the removable floor box 82. This air gap will ensure that the removable floor box 82 is easily removable from the concrete. Referring particularly to FIG. 5, it may be seen that the sheet of extruded polystyrene expanded foam material 104 on the side of the removable floor box 82 has an aperture 120 which is coaxial with the aperture 100 in the removable floor box 82. There are four apertures in the sheet of extruded polystyrene expanded foam material 110 on the bottom of the removable floor box 82 which are coaxial with the four apertures in the bottom of the removable floor box 82 which are in communication with the interiors of the guide tubes 84, 86, 88, and 90. One of these apertures which is shown in FIG. 6 is identified with the reference numeral 122, and is coaxial with the aperture 92 in the bottom of the removable floor box 82. Referring next to FIG. 7, the installation of the drain plumbing connection to the removable floor box 82 is illustrated. It may be seen that the sheet of extruded polystyrene expanded foam material 110 on the bottom of the removable floor box 82 has an aperture 124 located there which is coaxial with the aperture 94 in the bottom of the removable floor box 82. A segment of PVC pipe 126 is welded to the bottom of the removable floor box 82 around the aperture 94 therein. A PVC coupling 128 fits over the segment of PVC pipe 126, thereby engaging it. The PVC coupling 128 is not glued to the segment of PVC pipe 126, thereby enabling the segment of PVC pipe 126 to be pulled out of the PVC coupling 128 to disengage it from the PVC coupling 128. The PVC coupling 128 is connected to the drain pipe 52, which is of conventional design (see FIG. 1). It will be appreciated by those skilled in the art that the drain plumbing connection of the removable floor box 82 will not inhibit the easy removal of the removable floor box 82 once it has been installed in a concrete floor, since the concrete will surround only the PVC coupling 128, and not the segment of PVC pipe 126. Completing the drain plumbing is a PVC domed strainer 130 which fits into the circular recess 96 in the removable floor box 82 surrounding the aperture 94. Since the PVC domed strainer 130 is installed in this manner into the circular recess 96, all water located in the removable floor box 82 will immediately drain out, leaving no pools in the bottom of the removable floor box 82. Alternately, a flat strainer (not illustrated herein) may be used in some drain applications. Referring now to FIG. 8, the installation of an electrical conduit connection to the removable floor box 82 is illustrated. The electrical conduit segment 54, which is of conventional design (see FIG. 2), is inserted into one end of a coupling member 132, where it is retained in place by solvent bonding. Alternately, the end of the coupling member 132 which is connected to the electrical conduit segment 54 may be threaded on the inside thereof, and the end of the electrical conduit segment 54 may be threaded on the outside thereof, thereby allowing the electrical conduit segment 54 to be screwed into the coupling member 132. The other end of the coupling member 132 is threaded on the inside thereof, and abuts the outside wall of the removable floor box 82. A chase nipple 134 which is threaded on the outside thereof at one end thereof is then inserted from the inside of the removable floor box 82 through the aperture 100 in the side wall of the removable floor box 82, and then is screwed into the threaded end of the coupling member 132. Alternately, a close nipple (not shown herein) and a locknut (not shown herein) could be used instead of the chase nipple 134. It will be appreciated by those skilled in that art that although only a single electrical conduit connection to the removable floor box 82 is illustrated herein, typical floor boxes will have several connections. For example, electrical connections for telephone, data, and audio/visual services are made in addition to electrical power connections. All of these connections are typically run through electrical conduit. In order to remove the removable floor box 82, only the chase nipple 134 need be removed to free the removable floor box 82 from the electrical conduit connection. Thus, it will be appreciated by those skilled in the art that the electrical conduit connection of the removable floor box 82 will not inhibit the easy removal of the removable floor box 82 once it has been installed in a concrete floor, since the concrete will surround only the electrical conduit segment 54 and the coupling member 132, which both remain in the concrete when the removable floor box 82 is removed. Referring now to FIG. 9, the installation of a water or air supply plumbing connection to the removable floor box 82 is illustrated. The supply pipe 64, which is of conventional design but which is oriented horizontally rather than vertically as in FIG. 3, has an end which is threaded on the outside thereof. An elbow 136 has both ends threaded on the inside thereof. The threaded end of the supply pipe 64 is inserted into one end of the elbow 136, and the elbow 136 is then screwed onto the supply pipe 64. If the supply pipe 64 is PVC, the elbow 136 may also be PVC with a socket on one end for adhesive installation onto the PVC supply pipe. A threaded nipple 138 is then screwed into the other end of the threaded nipple 138. It may be seen that the sheet of extruded polystyrene expanded foam material 110 on the bottom of the removable floor box 82 has an aperture 140 located there which is coaxial with the aperture 98 in the bottom of the removable floor box 82. The threaded nipple 138 is inserted through the aperture 98 in the bottom of the removable floor box 82. Note that no nut is mounted on the threaded nipple 138 below the removable floor box 82. This enables the threaded nipple 138 to be removed from the socket elbow 136 without first removing the removable floor box 82, should it even become necessary to do so. A washer 142 is then placed onto the threaded nipple 138, and a nut 144 is screwed onto the threaded nipple 138 to retain it in place in the aperture 98 in the removable floor box 82. Finally, the valve body 80 is screwed onto the top end of the threaded nipple 138. In order to remove the removable floor box 82, only the valve body 80, the nut 144 and the washer 142 need be removed from the threaded nipple 138 to free the removable floor box 82 from the water or air supply connection. Thus, it will be appreciated by those skilled in the art that the water or air supply connection of the removable floor box 82 will not inhibit the easy removal of the removable floor box 82 once it has been installed in a concrete floor, since the concrete will surround only the supply pipe 64 and the socket elbow 136, which both remain in the concrete when the removable floor box 82 is removed. Referring now to FIG. 10, the manner in which the removable floor box 82 is installed is illustrated. This would be done prior to making the final electrical and water and/or air supply connections, which have been illustrated in FIGS. 4 through 6. A threaded rod 146 has a nut 148 and a washer 150 mounted thereupon. An end of the threaded rod 146 is inserted into the aperture 92 in the bottom of the removable floor box 82, and into the open bottom end of the guide tube 84. The corner of the removable floor box 82 in which the guide tube 84 is located rests upon the washer 150, which in turn rests upon the nut 148 on the threaded rod 146. Note that the end of the threaded rod 146 extending into the guide tube 84 does not extend to the closed end of the guide tube 84. This allows the nut 148 to be used to adjust the height of the corner of the removable floor box 82 in which the guide tube 84 is located. Three additional threaded rod 146, nut 148, and washer 150 assemblies (not shown herein) will be used to support the other three corners of the removable floor box 82 in similarly adjustable fashion. The four threaded rod 146, nut 148, and washer 150 assemblies may be used to level the removable floor box 82. Following the position of the removable floor box 82 being properly set, the final electrical conduit and plumbing connections may be made as illustrated in FIGS. 4 through 6, securing the removable floor box 82 in position prior to the concrete being poured. Referring next to FIG. 11, the remaining components of the removable floor box of the present invention are illustrated. First, a rim member 152 which will fit around the outer periphery of the floor box 82 (which is illustrated in FIGS. 4 and 5) adjacent the top end thereof is illustrated. The lower portion of the rim member 152 is formed by four angle iron segments 153, 154, 155, and 156 which are welded together with the downwardly extending ones of each of their respective sides being located at the inside of the rim member 152. Two U-shaped flanges 157 and 158 made of flat bar stock which is bent into the U-shaped configuration are welded together at the ends thereof to form a flange having a rectangular configuration with rounded corners. The U-shaped flanges 157 and 158 are located immediately above the most outwardly extending portions of the four angle iron segments 153, 154, 155, and 156, and are welded onto the top side of the four angle iron segments 153, 154, 155, and 156. The U-shaped flanges 157 and 158 thereby form the upper portion of the rim member 152. The longer opposite sides of the rim member 152 are defined by the two angle iron segments 153 and 154, which extend slightly beyond the ends of the angle iron segments 155 and 156. Located at each end of the angle iron segment 153 is an aperture 159 (one of which is illustrated in FIG. 11). Similarly, located at each end of the angle iron segment 154 is an aperture 160 (one of which is illustrated in FIG. 11). The apertures 159 and 160 will be used to thread re-bar (not shown herein) through, which will assist in retaining the rim member 152 (and the removable floor box 82 which will be fastened to the rim member 152) in place when concrete is poured. All of the components of the rim member 152 are made of galvanized steel to make them resistant to corrosion. This is essential, since the rim member 152 is not removable from the concrete once it has been installed. Shown above the rim member 152 is a cover frame 162 forming part of a cover apparatus which will fit into the rim member 152 above the removable floor box 82. Two apertures 164 and 166 which are located in the cover frame 154 are illustrated. Finally, two covers 168 which will fit into the two apertures 164 and 166 which are located in the cover frame 162 are illustrated. Located in each of the covers 168 are two doors 170 and two handles 172. Referring now to FIGS. 12 through 14, the rim member 152 is illustrated in greater detail. It may be seen that in cross section, the rim member 152 is shaped like a stretched "Z" with two right angle bends therein. The outer portion of the rim member 152 is formed by the U-shaped flanges 157 and 158, and is the portion which will surround the cover frame 162 (illustrated in FIG. 11) when it is installed. The portion of the rim member 152 defined by the U-shaped flanges 157 and 158 is rectangular in configuration with rounded corners. The inner portion of the rim member 152 is defined by the angle iron segments 153, 154, 155, and 156 to be rectangular in configuration, and will surround the top portions of the sides of the removable floor box 82 (illustrated in FIGS. 4 and 5), as will become evident below in conjunction with the discussion of FIG. 27. Located on the upper surfaces of the angle iron segments 153, 154, 155, and 156 of the rim member 152 upon which the cover frame 162 will sit is a gasket 174, best shown in FIG. 14. Referring next to FIGS. 15 through 17, the cover frame 162 is illustrated in greater detail. The function of the cover frame 162 is to transfer the load from the covers 168 (illustrated in FIG. 11) to the rim member 152 (illustrated in FIGS. 12 through 14) and thereby to the concrete in which the rim member 152 is mounted. Accordingly, the cover frame 162 has a crossbar 176 which extends between opposite sides of the cover frame 162 and is located between the apertures 164 and 166 to support very heavy loads. Note that the aperture 164 in the cover frame 162 has a recessed ledge 178 extending inwardly therefrom to support one of the covers 168 (illustrated in FIG. 11) thereupon when the cover 168 is installed into the aperture 164. Similarly, the aperture 166 in the cover frame 162 has a recessed ledge 180 extending inwardly therefrom to support the other one of the covers 168 thereupon when the cover 168 is installed into the aperture 166. The apertures 164 and 166 are rectangular in configuration with rounded corners, and the apertures defined by the ledges 178 and 180 are also rectangular in configuration with rounded corners. Located on top of the ledge 178 in the aperture 164 is a gasket 182. Similarly, located on top of the ledge 180 in the aperture 166 is a gasket 184. When the covers 168 are installed in the apertures 164 and 166, they fit in a flush manner thereupon. Similarly, when the cover frame 162 is installed in the rim member 152 (illustrated in FIGS. 12 through 14), it will fit flush with the concrete floor which is poured around the rim member 152. Referring now to FIGS. 18 through 21, one of the covers 168 is illustrated with the doors 170 and the handles 172 removed therefrom. It may be seem at once that the cover 168 has a recessed area 186 extending around the entire periphery thereof on its bottom side. The upper portion of the cover 168 thereby extends outwardly further than does the lower portion of the cover 168. Both the upper portion of the cover 168 and the lower portion of the cover 168 have rounded corners, as best shown in FIG. 19. When the cover 168 is installed in one of the apertures 164 and 166 in the cover frame 162 (best illustrated in FIGS. 11, 15, and 17), the upper portion of the cover 168 will rest upon one of the ledges 178 and 180 in the apertures 164 and 166 (FIGS. 11, 15, and 17), respectively, and the lower portion will extend through the aperture defined by the ledges 178 and 180, respectively, which is rectangular with rounded corners. In this manner, the cover 168 will fit flush with the upper surface of the cover frame 162. Located in two adjacent sides of the cover 168 are two rectangular notches 188 and 190 into which the doors 170 (illustrated in FIG. 11) will fit. Located in the cover 168 and surrounding the rectangular notches 188 and 190 on the bottom side of the cover 168 are recessed areas 192 and 194, respectively. The recessed area 192 extends around the entire periphery of the rectangular notch 188 on the bottom side of the cover 168. Similarly, the recessed area 194 extends around the entire periphery of the rectangular notch 190 on the bottom side of the cover 168. The upper portion of the cover 168 around the rectangular notches 188 and 190 thereby extends outwardly further than does the lower portion of the cover 168 around the rectangular notches 188 and 190. Located in the top side of the cover 168 as shown in FIGS. 18 and 21 are two elongated rectangular recesses 196 and 198 into which the handles 172 (illustrated in FIG. 11) will fit. The elongated rectangular recess 196 has an aperture 200 located centrally therein, which aperture 200 extends through the cover 168. Similarly, the elongated rectangular recess 196 has an aperture 202 located centrally therein, which aperture 202 extends through the cover 168. Located in the bottom of the elongated rectangular recess 196 around the aperture 200 is a gasket 204. Similarly, located in the bottom of the elongated rectangular recess 198 around the aperture 202 is a gasket 206. Referring next to FIGS. 22 and 23, the handle 172 is illustrated, together with its mounting hardware (the latter is shown only in FIG. 23). The handle 172 has a handgrip member 208 which is sized to removably fit within one of the elongated rectangular recesses 196 and 198 in the cover 168 (illustrated in FIGS. 18 and 21). For purposes of example herein, the fit of the handle 172 into the elongated rectangular recess 196 will be discussed. The handle 172 fits into the elongated rectangular recess 196 in a manner such that the handgrip member 208 of the handle 172 is flush with the top surface of the cover 168. Extending from the bottom of the handgrip member 208 in the center thereof is a shaft 210 which is threaded at the end opposite its point of attachment to the handgrip member 208. The diameter of the shaft 210 is substantially smaller than the diameter of the apertures 200 and 202 (illustrated in FIGS. 18 and 21) which are respectively located in the elongated rectangular recesses 196 and 198 in the cover 168. This allows the shaft 210 to pivot slightly when the shaft 210 is installed, for example, in the aperture 200 in the elongated rectangular recess 196 in the cover 168. In the preferred embodiment, the diameter of the shaft 210 is 1/4 inch, the diameter of the aperture 200 is 3/8 inch, and the aperture 200 is 1/2 inch deep. When installed, the handgrip member 208 lies for example in the elongated rectangular recess 196 with its top surface flush with the top surface of the cover 168, and with the shaft 210 extending through the aperture 200 at the bottom of the elongated rectangular recess 196 in the cover 168. The gasket 204 (illustrated in FIGS. 18 and 21) provides a water resistant seal. A spring 212 is mounted on the portion of the shaft 210 which extends below the cover 168, and a washer 214 and a nut 216 are used to retain the spring 212 on the shaft 210. The force of the spring 212 will act to retain the handle 172 in place in the elongated rectangular recess 196 in the cover 168. By pressing one end of the handgrip member 208, the gasket 204 will compress slightly, causing the other end of the handgrip member 208 to move up above the surface of the cover 168 just enough to allow it to be grasped to pull the handgrip member 208 up out of the elongated rectangular recess 196. By pulling the handle 172 to compress the spring 212, the handle 172 may be used to support one end of the cover 168 to lift it out of its position on the cover frame 162 (illustrated in FIG. 11). In the preferred embodiment, a recess 218 is machined into each end of the handgrip member 208 just below the top surface of the handgrip member 208. These recesses provide a place to get a grip on one end of the handgrip member 208 when the other end is depressed, thereby facilitating lifting the handgrip member 208 out of the elongated rectangular recess 196 in the cover 168. Referring now to FIGS. 24 through 26, one of the doors 170 is shown in detail. The upper portion of the cable access door 170, which is referred to by the reference numeral 220, is of a size to fit into one of the rectangular notches 188 or 190 in the cover 168. For purposes of example herein, the fit of the upper portion 220 of the cable access door 170 into the rectangular notch 188 in the cover 168 will be discussed. The lower portion of the cable access door 170, which is referred to by the reference numeral 170, extends beyond the surface of the upper portion 220 of the cable access door 170 on three sides thereof, and is designed to be received into the recessed area 192 surrounding the rectangular notch 188 in the cover 168. When the cable access door 170 is installed, the upper portion 220 of the cable access door 170 will fit into the rectangular notch 188 of the cover 168 and the lower portion 222 of the cable access door 170 will fit into the recessed area 192 of the cover 168. A gasket 224 is located upon the upper side of the portion of the lower portion 222 of the cable access door 170 which extends beyond the upper portion 220 of the cable access door 170. The gasket 224 will provide a seal between the cable access door 170 and the cover 168 when the cable access door 170 is in its closed position (as the doors 170 are illustrated in FIG. 11). The cable access door 170 is mounted onto the cover 168 using a hinge 226 as shown in FIG. 26. One side of the hinge 226 is mounted onto the bottom side of the lower portion 222 of the cable access door 170, and the other side would be mounted onto the bottom side of the cover 168 when the cable access door 170 is in position. The hinge 226 will allow the cable access door 170 to swing downwardly to open. In the preferred embodiment, the hinge 226 is a friction hinge, in which the ease of movement of the hinge may be adjusted with a screw 228. The hinge 226 may thus be adjusted to be sufficiently tight to maintain the position of the cable access door 170 against gravity. Thus it will be appreciated that the cable access doors 170 open downwardly, which will be into the removable floor box 82 (illustrated in FIGS. 4 and 5). To open the cable access doors 170, the cover 168 (illustrated in FIG. 11) must first be removed from the cover frame 162. Since the cover 168 must be removed to make connections inside the removable floor box 82, this is not an unreasonable restriction. Referring finally to FIG. 27, the assembly of several of the various components of the removable floor box of the present invention are illustrated. First, the removable floor box 82 is secured to the rim member 152 with a plurality of bolts 230, one of which is illustrated in FIG. 27. The bolts 230 are screwed into threaded apertures 232 located in at least two of the angle iron segments 153, 154, 155, and 156 (illustrated in FIG. 13). One such threaded aperture 232 is shown in FIG. 27 as being located in the angle iron segment 154. The bolts 230 are installed from the interior of the removable floor box 82, thus presenting no impediment to the removal of the removable floor box 82 from the rim member 152 should it become necessary to remove it. In the preferred embodiment, the bolts 230 are made of stainless steel. In an alternate embodiment, self-tapping bolts (not illustrated herein) could be used instead of the bolts 230, with non-threaded apertures (also not illustrated herein) being used instead of the threaded apertures 232. The cover frame 162 fits into the rim member 152 on top of the gasket 174, which is mounted in the rim member 152. The rim member 152 (including the angle iron segment 154 and the U-shaped flange 158 which are shown in FIG. 27), of course, is permanently secured in the concrete (not shown herein). The cover 168 fits into the aperture 164 in the cover frame 162, and rests on top of the gasket 182, which in turn is seated on the ledge 178 in the aperture 164 in the cover frame 162. If desired, the cable access doors 170 and the cover frame 162 may have a recessed pattern located in the top surfaces thereof, to increase friction to foot traffic. Such a recessed pattern will, of course, not be so deep that it will allow one's shoe to become caught in it. For example, grooves may be located in the top surfaces of the cable access doors 170 and the cover frame 162 in a configuration which may be, for example, square-shaped or diamond-shaped. Such grooves may be, for example, 1/32 of an inch in depth. It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it teaches a floor box which may be relatively easily removed from the concrete slab or floor and the cover frame without requiring the slab or floor to be broken. The removable floor box of the present invention may also be reinstalled in the slab or floor and the cover frame without requiring any concrete to be poured and with a similar degree of ease to that associated with its removal. The fittings connected to the removable floor box of the present invention can be removed from the old floor box and reconnected to the new floor box easily and without necessitating the replacement of any of the lines or plumbing. The removable floor box of the present invention is provided with a cover apparatus, such as a cover which fits on the floor box in a water resistant manner, even though there are access doors which are located in the cover. The cover of the removable floor box of the present invention is designed so that it can support even large loads (such as a forklift with its maximum load, about to tip over so that most of its weight is on its front wheels) without damage to either the cover or the floor box. If so desired, the removable floor box of the present invention may be made of a material which is completely resistant to corrosion. The removable floor box of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The removable floor box of the present invention is also of relatively inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the removable floor box of the present invention are achieved without incurring any substantial relative disadvantage. Although an exemplary embodiment of the removable floor box of the present invention has been shown and described with reference to particular embodiments and applications thereof, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. All such changes, modifications, and alterations should therefore be seen as being within the scope of the present invention.

An improved floor box of the type commonly installed into the concrete floor of a facility for providing temporary connections to utilities is disclosed which may be removed and replaced without requiring either the demolition and subsequent reconstruction of the floor in which the improved floor box is installed or the replacement or repair of the utility lines located in the floor and connected to the improved floor box. The improved floor box is secured within a rim member mounted into the concrete floor by bolts mounted from the inside of the improved floor box, and the outside of the improved floor box is wrapped with sheets of extruded polystyrene expanded foam material to prevent poured concrete from encasing the improved floor box itself, thereby permitting easy removal of the improved floor box from the concrete floor. The connections to the improved floor box to electrical and plumbing lines are made in a manner allowing them to be disconnected from the improved floor box from the inside thereof. A cover frame which fits into the rim member in a flush manner has removable covers mounted therein, with each cover having access doors located therein as well as pop-up handles to facilitate removal of the covers.

This application is a continuation under 35 U.S.C. 120 of U.S. application Ser. No. 09/547,171, entitled Dual Function Suturing Device and Method, filed on Apr. 11, 2000, now U.S. Pat. No. 6,533,795. BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for placing sutures in tissue, and more particularly to a method and device for arthroscopic repair of a torn rotator cuff. Suturing of body tissues is a time consuming aspect of most surgical procedures. Many surgical procedures are currently being performed where it is necessary to make a large opening to expose an area of the body that requires surgical repair. Endoscopes are available for viewing certain interior regions of the body through a small puncture wound without exposing the entire body cavity. These instruments can be used in conjunction with specialized surgical instrumentation to detect, diagnose, and repair areas of the body that were previously only able to be repaired using traditional “open” surgery. In the past, there have been many attempts to simplify the surgeon's task of driving a needle carrying suture material through body tissues to approximate, ligate and fixate them. Many prior disclosures, such as described in U.S. Pat. No. 919,138, to Drake et al., issued Apr. 20, 1909, employ a hollow needle driven through the tissue with the suture material passing through the hollow center lumen. The needle is withdrawn leaving the suture material in place, and the suture is tied, completing the approximation. A limitation of these types of devices is that they are particularly adapted for use in open surgical procedures where there is room for the surgeon to manipulate the instrument. Others have attempted to devise suturing instruments that resemble traditional forceps, such as U.S. Pat. No. 3,946,740 to Bassett, issued Mar. 30, 1976. These devices pinch tissue between opposing jaws and pass a needle from one jaw through the tissue to the other jaw, where grasping means pull the needle and suture material through the tissue. A limitation of these designs is that they also are adapted primarily for open surgery, in that they require exposure of the tissues to be sutured in order that the tissue may be grasped or pinched between the jaws of the instrument. This is a severe limitation in the case of endoscopic surgery. The term “endosurgery” means endoscopic surgery or surgery performed using an endoscope. In conjunction with a video monitor, the endoscope functions as the surgeon's surrogate eyes for the purpose of performing the surgical procedure. Operations using an endoscope are significantly less invasive when compared to traditional open surgery. Patients usually return home the next day or in some cases, the same day of the endosurgical procedure. This is in contrast to standard open surgical procedures where a large incision divides the muscle layers and allows the surgeon to directly visualize the operative area. Patients may stay in the hospital for 5 to 6 days or longer following open surgery. In addition, after endosurgical procedures, patients often return to work within a few days versus the traditional 3 to 4 weeks recuperative period following open surgery. Access to the operative site using endosurgical or minimally invasive techniques is accomplished by inserting small tubes called trocars into a body cavity. These tubes have a diameter of, for example, between 3 mm and 30 mm and a length of about 150 mm (6 inches). There have been attempts to devise instruments and methods for suturing within a body cavity through these trocar tubes. Such an instrument is disclosed in U.S. Pat. No. 4,621,640 to Mulhollan et al., issued Nov. 10, 1986. Mulhollan et al. describe an instrument that may be used to hold and drive a needle, but make no provision for retrieval of the needle from the body cavity, nor the completion of the suture by tying. The instrument disclosed in the Mulhollan et al. patent is limited, in that the arc through which the needle must be driven is perpendicular to the axis of the device. Another such instrument intended for endoscopic use is described by U.S. Pat. No. 4,935,027 to Yoon, issued Jun. 19, 1990. This instrument uses oppositional hollow needles or tracks pushed through the tissue and coapted to create a tract through which the suture material is pushed. It is not clear from the disclosure how these curved tracks would be adapted to both be able to pierce the tissue planes illustrated, parallel to the tips of the tracks, and be curved toward each other to form the hollow tract. Yet another instrument and method is shown in U.S. Pat. No. 4,923,461 issued May 8, 1990 and U.S. Pat. No. 4,957,498 issued Sep. 18, 1990, both to Caspari. Caspari discloses an endoscopic instrument suitable for use through a trocar, that resembles the Yoon approach, but with a single hollow needle on one of a set of oppositional jaws. The jaws simultaneously close, grasping the tissue. The jaw opposite the hollow needle has a window through which the hollow needle passes as the jaws close, freeing the lumen of the hollow needle from the tissue. Much like the Yoon patent, a suture or suture snare is pushed down through the lumen and retrieved from the suture site, the jaws released, and the suture pulled back out through the trocar. This device may be used to place simple stitches in tissues that have been mobilized and have an edge accessible to the jaws. A limitation of the device is the manipulation that must be done with the snare if a suture other than a monofilament is used. Another instrument specifically adapted for the repair of a torn anterior cruciate ligament or for meniscal repair is disclosed in U.S. Pat. No. 4,836,205 to Barrett. The Barrett patent combines in a single instrument the functions of grasping the tissue to be sutured and the passing of the needles through that tissue. It is to be understood that this instrument is designed for use specifically under endoscopic view, and through trocars as previously described. A fairly generic endoscopic grasper is disclosed that has been adapted to allow for a hollow lumen from the handle of the grasper down to the distal tip of the grasper jaws. An elongate needle of 8 to 10 inches in length may be passed through this hollow lumen. The needle, being significantly longer than the grasper, is introduced through the handle of the grasper, and may be driven through the tissue being held in the grasping jaws of the device. The needle is then retrieved from the tissue via a trocar port placed substantially opposite the port through which the grasper is introduced. If a mattress stitch is desired, two needles attached to opposite ends of a suture are both passed through the tissue and retrieved. A limitation of this device is that there must be both visual and physical access to both sides of the tissue flap to be sutured. This requires trocars to be placed opposite each other and roughly on a line intercepting the tissue. This is a severe limitation in the instance of shoulder repair, and specifically in repair of the rotator cuff. There have been other attempts to improve the methods of tissue repair. These include the development of staplers and anchoring devices. In response to some of the aforementioned problems in placing sutures in tissues endoscopically, manufacturers have developed tissue staplers. These devices utilize stainless steel or titanium staples that are constructed much like the staples used to hold papers together. The major disadvantage of these kinds of staplers is that they leave metal in the body. For some tissues this is not a problem; however in some procedures, metal staples left within the tissues can be a major hindrance to the healing process. In orthopedic surgery, many different designs for bone anchors have been developed. These anchors allow soft tissues to be reattached to bone, and simplify the process by removing the need to create a trans-osseous tunnel. Trans-osseous tunnels are created in bones to allow suture material to be threaded through and tied across the bony bridge created by tunnels after it has been placed through the soft tissues and tied with conventional knots. Anchors fabricated from stainless steel or titanium are commonly used in joint reconstructions, and because the metal is contained in the bone, it does not typically cause a problem with healing. While endoscopy has certainly found favor with many physicians as an alternative operative modality, the advanced skill set and operative time necessary to become an efficient and practiced endoscopist have proven to be a challenge for a large portion of the surgical community. The cost pressures brought about by large scale patient management (the continued rise and success of health maintenance organizations or HMO's) have also caused the surgical community to carefully evaluate the overall costs and long-term outcomes of some of the procedures that have been tried via an endoscopic approach. While the laparoscopic cholecystectomy (gall bladder removal) has well proven its worth in the past 8-10 years, many other procedures have not shown similar cost effectiveness and positive long-term outcomes. Hence, alternatives have been sought to bridge the gap between skill and equipment intensive endoscopic surgery and more familiar open surgery. As such, under the broad umbrella of “minimally invasive surgery” which would include endoscopic surgery, a relatively new approach called “mini-incision surgery” has begun to emerge. This approach uses the principles of traditional open surgery, along with some of the equipment advances of endoscopy in an attempt to provide the patient with the best of both worlds. Perhaps the most visible of these new approaches is the emergence of minimally invasive heart surgery, both for coronary bypass and for valve replacement. Techniques and tools for cardiovascular surgery have begun to be used that allow the heart surgeon to perform procedures through small incisions between the ribs that previously required a massive incision and splitting of the sternum to gain access to the heart. In a similar way, orthopedic surgeons have begun to explore alternatives to the traditional open approach for the many indications requiring reconstruction of some aspect of the shoulder. As they did in adopting minimally invasive approaches to knee repair and re-construction, the use of either an endoscope or a “mini-open” approach is gaining in popularity with surgeons, patients and third party payers. It is an increasingly common problem for tendons and other soft, connective tissues to tear or to detach from associated bone. One such type of tear or detachment is a “rotator cuff” tear, causing pain and loss of ability to elevate and externally rotate the arm. Complete separation can occur if the shoulder is subjected to gross trauma, but typically, the tear begins as a small lesion, especially in older patients. The rotator cuff of a shoulder joint is made up of a combination of the distal tendinous portion of four muscles, supraspinatus and subspinatus, subscapularis and teres minor. The cuff is attached to the upper, anterior and posterior faces of the trochiter by covering the upper pole of the humeral head. Proper functioning of the tendinous cuff, 3 to 4 millimeters thick, depends on the fundamental centering and stabilizing role of the humeral head with respect to sliding action during anterior and lateral lifting and rotation movements of the arm. The musculotendinous cuff passes under an osteofibrous arch, which is made up from the front to the rear by a portion of the acromion, the coracoacromial ligament and the coracoid process, thereby forming a canal. A sliding bursa passes between the musculotendinous cuff and the walls of the osteofibrous arch. Therefore, there is a potential and sometimes detrimental interaction between the musculotendinous cuff and the acromiocoracoidian arch, particularly during lateral and anterior lifting movements of the arm. The repeated rubbing of the cuff against the walls of the osteofibrous arch results in wearing of the tendinous cuff by progressive abrasion. The rubbing can be increased, inasmuch as arthosis lesions with severe osteophytes may thicken the walls of the aforementioned arch, becoming more aggressive as the cuff gets older. With time, gradual thinning is brought about, often resulting in a trophic perforation (less than 1 cm 2 ) of the cuff, particularly in the hypo-vascularized and fragile area where the supraspinatus muscle is joined. A fall may provide a more extensive rupture by disjunction of the supraspinatus muscle, with extension towards the front (subscapularis muscle) or the rear (subspinatus muscle). The degenerative rupture of the rotator or musculotendinous cuff may be of a varied size: grade 1—perforation (less than 1 cm 2 ) reaching the supraspinatus muscle; grade 2—supraspinatus rupture (greater than 1 cm 2 ); grade 3—massive rupture concerning the supraspinatus, subspinatus, subscapularis muscles and sometimes the teres minor muscle. It is possible to carry out surgery to reconstruct the rotator cuff. This is done by re-covering the humeral head, giving back to the cuff its capturing and stabilizing role and re-establishing a harmonious scapulohumeral rhythm. Reconstruction requires excision of the coracoacromial ligament and cleaning of the subacromial space, including suppression of the arthrosis legions and thinning of the anterior portion of the acromion. The typical course for repair of a torn rotator cuff today is to do so through an open incision. This approach is presently taken in almost 99% of rotator cuff repair cases. Two types of open surgical approaches are employed for repair of the rotator cuff, one known as the “classic open” and the other as the “mini-open”. The classic open approach requires a large incision of 6 to 9 centimeters (cm) and complete detachment of the deltoid muscle from the acromion to facilitate exposure. Following the suturing of the rotator cuff to the humeral head, the detached deltoid is surgically reattached. Because of this maneuver, the deltoid requires postoperative protection, thus retarding rehabilitation and possibly resulting in residual weakness. Complete rehabilitation takes approximately 9 to 12 months. The mini-open technique, which represents the current growing trend and the majority of all surgical repair procedures, differs from the classic approach by gaining access through a smaller incision of 3 to 5 cm and splitting rather than detaching the deltoid. Additionally, this procedure is typically used in conjunction with arthroscopic acromial decompression. Once the deltoid is split, it is retracted to expose the rotator cuff tear. The cuff is debrided and trimmed to ensure suture attachment to viable tissue and to create a reasonable edge approximation. In addition, the humeral head is abraded or notched at the proposed soft tissue to bone reattachment point, as healing is enhanced on a raw bone surface. A series of small diameter holes, referred to as trans-osseous tunnels, are “punched” through the bone laterally from the abraded or notched surface to a point on the outside surface of the greater tuberosity, commonly a distance of 2 to 3 cm. There are a few different methods for placing the suture material in the supraspinatus tendon. Because one of the most common failure modes for rotator cuff repair lies in the sutures pulling out of the soft tissue, much care is taken to place the sutures such that the most security possible is achieved. This is typically done by using either a mattress stitch or a more complex stitch called a “modified Mason-Allen”. The goal of both of these stitches is to spread the forces imparted by the sutures on the tissues by involving a pledget of tissue between the entry and exit points of the suture ends. The mattress stitch incorporates essentially a “down, over and back up” path for the suture. Finally, the cuff is secured to the bone by pulling the suture ends through the trans-osseous tunnels and tying them together using the bone between two successive tunnels as a bridge, after which the deltoid muscle must be surgically reattached to the acromion. Although the above described surgical technique is the current standard of care for rotator cuff repair, it is associated with a great deal of patient discomfort and a lengthy recovery time, ranging from at least four months to one year or more. It is the above described manipulation of the deltoid muscle together with the large skin incision that causes the majority of patient discomfort and an increased recovery time. Less invasive arthroscopic techniques are beginning to be developed in an effort to address the shortcomings of open surgical repair. Working through small trocar portals that minimize disruption of the deltoid muscle, a few surgeons have been able to reattach the rotator cuff using various bone anchor and suture configurations. The rotator cuff is sutured intracorporeally using instruments and techniques such as the Caspari punch previously described. This creates a simple stitch instead of the more desirable mattress or Mason-Allen stitch. Rather than thread the suture through trans-osseous tunnels which are difficult or impossible to create arthroscopically using current techniques, an anchor is driven into bone at a location appropriate for repair. The repair is completed by tying the cuff down against bone using the anchor and suture. Early results of less invasive techniques are encouraging, with a substantial reduction in both patient recovery time and discomfort. However, as mentioned, this approach places only one loop of suture in the cuff for each anchor, reducing the fundamental strength of the repair. The knots in the tendon can be bulky and create a painful impingement of the tendon on the bone. This is because the knots end up on top of the cuff, in the sub-acromial space, and have the opportunity to rub on the acromion as the arm is raised. Because non-absorbable suture materials are used for these types of repairs, the suture and associated knots are not absorbed into the body, and hence provide a constant, painful reminder of their presence. None of the prior art devices are adaptable to effect the placement of a mattress stitch in grasped tissues, nor are they adaptable to place sutures precisely and controllably while making provision for needle retrieval when using endoscopic techniques. None of the prior art devices make it possible to place a mattress stitch into, for example, the supraspinatus tendon utilizing an endoscopic approach. Accordingly, it would be desirable to provide a family of novel suturing devices that overcomes the above set out disadvantages of prior known devices in a simple and economical manner. In particular, a system which would be capable of creating a mattress stitch in the tendon, using endoscopic techniques, to increase the soft tissue pullout strength would be advantageous, as would a system that does not require the traditional knots to secure the suture to the tendon. SUMMARY OF THE INVENTION Accordingly, a new and novel approach to securing a mattress stitch in a tissue flap has been developed. An instrument that combines the function of both grasping the tissue and passing sutures through the tissue to form a mattress stitch, in an endoscopic environment, is herein described. In the method of the present invention the instrument is inserted through a portal known as a trocar cannula. The portal is created by first making an incision in the skin and then inserting a cannula through the incision to the repair site. The distal end of the instrument is inserted through the cannula under direct visualization from a second trocar cannula that has been previously inserted. The visualization is accomplished via an endoscope, which is well known in the art. The instrument is inserted until the jaws reach, for example, torn rotator cuff tissue. In operation, the distal end of the grasper aspect of the instrument is positioned at the repair site against the tissue to be grasped. The moveable jaw is pivoted toward the stationary jaw by squeezing the handle lever. As the handle lever moves inwardly by pivoting about a pivot pin, a cable attached to the top of the handle lever is drawn rearwardly, proximal of the handle. When the cable is drawn rearwardly, the movable jaw pivots towards the stationary jaw to close the jaws. Once the appropriate section of tissue is isolated and grasped by the jaws, the lever may be locked in its closed position using a latch mechanism. Once the surgeon is satisfied with the placement of the grasper on the grasped tissue, the surgeon can then deploy the suture needles to create a mattress stitch in the tissues, for example, a torn rotator cuff. In operation, the suture needles may be advanced through the grasped tissues by pulling on a trigger. The trigger is attached to a slide cable, and pulling on the trigger draws the slide cable rearwardly towards the proximal end of the instrument, pulling against the force of a return spring. In turn, the slide cable pulls a needle carriage with suture needles releasably held in the carriage. The needle carriage resides within the lower stationary jaw of the instrument, and at the urging of the trigger via the slide cable, is able to move from distal to proximal locations within the jaw. As the carriage moves proximally, the tips of the suture needles begin to clear the distal edge of an aperture created in the lower stationary jaw and begin to penetrate through the underside of the grasped tissue and advance upwardly towards the movable jaw. In one preferred embodiment, the needle carriage is coupled to the needles by a set of tabs that engage shoulders on the needles. The shoulders of the needles are formed by the proximal end of the needle holding the suture, and an outer sleeve that is slidably disposed about a flexible inner ribbon affixed to the proximal end. The ribbon has attached to its distal end a needle tip which limits the distal travel of the outer sleeve and creates the second shoulder at the proximal end of the outer sleeve. In the aforementioned embodiment, the moveable jaw incorporates a passive needle catch. The jaw is constructed with a window in the face of the jaw to allow the needles to penetrate through to a passive catch that incorporates a thin stainless steel membrane with slots configured to capture the tips of the needles. As the suture needles approach the end of the ejection stroke, the distal ends of the needles pass through the upper movable jaw and the capture member. As the needles pass through the upper jaw they begin to separate from the needle carriage. The proximal end of the needles' curved outer sleeve separates from the first tab on the needle carriage, in such a manner that there is no further force pushing on the sleeve to force it through the tissues. The force now pushing on the suture needles is concentrated on the proximal end of the needles. As the needle carriage is advanced further, the needles' curved outer sleeves stay stationary due to the resistance caused by their contact with the tissues. However, the flexible inner ribbon of each needle is free to advance further. The gap between the needles' curved outer sleeves and the proximal end of each needle begins to close until there is no gap at all. At this point the penetrating tip of each needle has extended beyond the distal end of the needle's curved outer sleeve, exposing the flexible inner ribbon. Once the gap is closed between the proximal end of the needle and the outer sleeve, the needle assembly will again continue to advance as one unit through the grasped tissues. As the needle carriage advances further, it pushes on the needle assembly until each needle has been pushed beyond the point of contact with the needle carriage. At this point the suture needles are through the grasped tissues and protruding through the upper movable jaw and into the needle catch. Due to a pre-defined curve in the flexible inner ribbon, the penetrating tip remains extended from the distal end of each needle's curved outer sleeve. At this point, any pull force being applied by the grasper on the grasped tissues is relaxed. Once the tissue is in a relaxed state, the jaws of the grasper are then opened. The handle lever is unlocked from the locking mechanism and returns to an open position due to the pull force exerted on it by means of a return spring. As the return spring pulls on the lever, it pivots about a pin. As handle lever pivots, it pulls on the jaw cable coupled to the handle lever by means of a pin. This advances the jaw cable towards the distal end of the barrel. As the jaw cable advances, it pushes on a linkage which then pushes on the movable upper jaw, causing the upper jaw to pivot about a pin. This pivoting motion causes the moveable jaw to open and separate away from the stationary jaw. As the movable upper jaw begins to open, the suture needles for the most part remain stationary due to resistance caused by their contact with the tissues through which they have been driven. At a point just beyond the distal end of the suture needle's curved outer sleeve, the needle catch on the upper jaw will trap the suture needles at a point between the curved outer sleeve and the penetrating tip, grasping the flexible inner ribbon and securing the needles by interference with the shoulder created between the inner ribbon and the penetrating tip. As the upper jaw slips past the needle's outer sleeve, the small slit in the needle catch closes down around the needle's ribbon. The slit is large enough so as not to restrict the movement of the ribbon, but is too small to allow the penetrating tip to pass back through. This is because the needle catch on the upper jaw can only be deflected in an outward direction, away from the outer surface of the upper jaw. Since the distal end of the suture needles are trapped in the needle catch on the upper jaw, they are pulled through the tissues as the upper jaw is opened further. When the jaws of the grasper are fully extended, the suture needles are nearly pulled through the tissue. To complete the pullout of the suture needles, it is necessary to pull on the grasper, and begin to remove it from the repair site. Once the suture needles are through the tissue, they can be secured by closing down the jaws of the grasper. After closing the grasper jaws, the instrument can be retracted back through the portal via the trocar cannula. As the instrument is removed from the suture site, the free ends of the suture are retrieved as well. This causes the suture to pass through the tissues at the puncture sites. As the suture is pulled through, the loop end of the suture is pulled snug against the underside of the tissues to form what is referred to as a mattress stitch. This process may be repeated as necessary, depending on the number of sutures required for the particular procedure being undertaken. The instrument may be reloaded with new suture needles by removing an end cap covering the distal end of the lower stationary jaw. After the end cap is removed, the needle carriage may be advanced beyond the distal end of the lower jaw to be reloaded. To advance the needle carriage in this manner simply requires advancing the handle trigger towards the distal end of the grasper. Once new suture needles are reloaded, end cap may be replaced. The excess suture loop that will form the next stitch passes through the lower stationary jaw through a small notch. This extra length of suture is left outside the body as the grasper is inserted back through the portal to the repair site as previously described. Another embodiment of the grasper/suturing device modifies the needle and suture interface. Instead of the needle carrying the suture by an attachment point at the distal end of the needle, this embodiment releasably attaches the suture to the needle at nearly the proximal end. The major elements of the above described instrument remain the same; i.e. the grasper function with a lower fixed jaw and an upper moveable jaw, and a needle carriage coupled to a trigger for actuation of the stitching function. However, in this second embodiment, the needles are non-releasably attached to the needle carriage; that is to say that they are permanently attached to the carriage. The suture, which is of a braided configuration that is known in the art, and has a hollow core, is configured to have a ferrule attached to its ends. This ferrule is constructed such that the hollow braided suture is crimped or otherwise mechanically or adhesively attached to the ferrule. The ferrule includes an interior lumen which is dimensioned such that it is able to be slidably disposed over the end of the needles which are attached to the needle carriage. The needles are configured to have a step, preferably a radiused step, that functions as a stop for the ferrule over which the interior lumen may not pass. Both ends of the suture are loaded onto individual needles, with the excess suture between the ends contained within the bounds of the device. Functionally, as the aforementioned driver trigger is pulled by the surgeon, the needles are disposed to exit from the window in the stationary lower jaw and to transit a curved path through the grasped tissues until reaching a suture catch disposed upon the upper surface of the moveable upper jaw. The needles, carrying the ferrule and attached suture, pass through the suture catch. Since the ferrule is slidably disposed upon the needle, as the trigger is released, the needle carriage withdraws and the needles attached to the carriage are withdrawn through the tissue, leaving the ferrule and attached suture deposited within the suture catch. As described previously, the tension on the grasper is released, and the instrument is withdrawn from the operative trocar, trailing the suture behind, and creating a mattress stitch in the grasped tissues. Now it may be seen by those skilled in the art, the combination of grasping tissues to be sutured and precisely placing a mattress stitch in the grasped tissues while working through a trocar port effects a significant advance in the art. It is therefore an object of the present invention to provide an endoscopic instrument adapted for the grasping of tissues and creating a mattress stitch within those tissues. It is a further object to provide an instrument that allows for the reloading of additional sutures and suture needles for placement of subsequent stitches. The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a torn rotator cuff; FIGS. 2A through 2E are schematic plan views illustrating one embodiment of the invention, and a method, in sequence, for using same; FIG. 3 is a detail perspective view of the jaws of the grasper portion of the present invention; FIG. 4 is a detail perspective view, in isolation, of the underside of the needle guide portion of the present invention; FIG. 5 is a detail perspective view, similar to FIG. 3 , of the jaws of the grasper portion of the present invention, with the needle guide removed for clarity; FIGS. 6A through 6D are sequential cross-sectional views illustrating certain steps of an inventive method for deploying suture needles through grasped tissue, using an embodiment of the apparatus of the present invention; FIG. 7 is a perspective view of the internal needle ribbon of the present invention; FIG. 8 is a side, partial cross-sectional view of the jaws of the apparatus of the present invention, clamping down on a portion of a patient's rotator cuff; FIG. 9 is a side, partial cross-sectional view of the handle of the present invention; FIGS. 10A through 10C are sequential diagrammatic views, in cross-section, illustrating certain steps of an inventive method for capturing suture needles in the movable upper jaw of the inventive apparatus; FIG. 11 is an enlarged perspective view of the jaws of the present invention, wherein suturing material has been grasped therein; FIG. 12 is a schematic perspective view illustrating a mattress stitch which remains in a portion of the rotator cuff of a patient after a suturing procedure has been completed in accordance with the principles of the present invention; FIG. 13 is an enlarged perspective view of the jaws of the present invention, illustrating the reloading of the suture needles; FIG. 14 is a detail perspective view of the interior of the distal end of an alternate embodiment of the suturing device of the invention; FIGS. 15A through 15C are detail cross-sectional views, in sequence, illustrating constructional details and a method for using the alternate embodiment shown in FIG. 14 ; FIG. 16 is an enlarged detail view, in cross-section, of the tip of the needle illustrated in FIGS. 14 through 15C ; and FIG. 17 is a detail perspective view of the inventive embodiment shown in FIGS. 14-16 . DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention relates to a method and apparatus for the arthroscopic repair of torn tissue and bone at a surgical repair site using a device, which is a combination tissue grasper and suture placement device. Although the present invention is described primarily in conjunction with the repair of a torn rotator cuff, the apparatus and method could also be used in arthroscopic repair at other sites, such as the knee, elbow, or hip, for example, as well as in conjunction with other surgical techniques. Referring now to FIG. 1 , there is shown representative shoulder musculature 1 , including a supraspinatus muscle 2 , a deltoid muscle 4 , a biceps tendon 6 , a torn rotator cuff 8 , and a humeral head 10 . The humeral head 10 is not normally visible, as it is typically covered by the rotator cuff. However, in the illustration, the torn rotator cuff 8 has pulled away from the head 10 of the humerus, exposing it to view. Referring now particularly to FIGS. 2A through 2E , there is illustrated the general structure and function of an embodiment constructed and operated in accordance with the principles of the present invention. A trocar port 12 has been inserted into the shoulder joint, providing a conduit through which a grasper/stitcher 14 may be passed. The grasper/stitcher 14 is provided with pivotable jaws 16 for grasping the torn rotator cuff 8 . The jaws 16 are disposed at a distal end 17 of a hollow barrel 18 . A handpiece 20 is disposed at a proximal end 21 of the hollow barrel 18 , and is adapted to open and close the jaws 16 . In the present preferred embodiment, the handpiece 20 comprises a handle grip 22 and a handle lever 23 , which pivots about a pivot pin. In a manner to be fully described below, the handle lever 23 is suitably connected to the jaws 16 to actuate the jaws 16 between an open and a closed position, depending upon the position of the handle lever 23 . A spring 25 biases the pivotal handle portion to an extended position, as shown in FIG. 2B , wherein the jaws are disposed in an open configuration. Of course, the actuating mechanism which is illustrated for moving the jaws 16 between their open and closed positions, though presently preferred, is only exemplary. Many other types of similar actuating mechanisms are known to those skilled in the art, and any of those would be suitable for the present application. In FIG. 2A , the grasper/stitcher 14 is shown with the jaws 16 closed, trailing a suture 26 , ready to be placed into the shoulder joint through the trocar port 12 . To maintain the jaws 16 in their closed position, the operator holds the two handpiece portions 22 and 23 together, against the biasing force of spring 25 , using a squeezing action. FIG. 2B illustrates the grasper/stitcher 14 having been inserted through the trocar port 12 into the shoulder joint, and the jaws 16 having been opened by releasing the handle lever 23 of the handpiece 20 , so that the handle lever 23 becomes biased away from the handle grip 22 , thereby actuating the jaws 16 to an open position. The jaws 16 are oriented such that the torn rotator cuff 8 is situated between the jaws 16 . As shown in FIG. 2C , the hand piece 20 is again actuated to pivot and close the jaws 16 , to thereby grasp the tissues of the torn rotator cuff 8 . Referring now to FIG. 2D , it is seen that needles 27 have been drawn through the tissues of the torn rotator cuff 8 by rearward movement of a trigger 28 . The needles 27 are captured by the jaws 16 , and, as the grasper/stitcher 14 is withdrawn proximally from the operative site, the suture 26 is drawn along with the grasper/stitcher 14 and through the tissues of the torn rotator cuff 8 , forming a mattress stitch in the torn tendon 8 ( FIG. 2E ). Referring now to FIG. 3 , the construction and operation of the grasper/stitcher 14 will be more particularly discussed. The jaws 16 , disposed at the distal end 17 of the hollow barrel 18 , include a stationary lower jaw 29 and a moveable upper jaw 30 . Both jaws 16 include teeth 31 which are configured to atraumatically grip tissue such as the torn rotator cuff 8 shown in FIGS. 1 and 2 A– 2 E. Referring now to both FIGS. 3 and 4 , it may be seen that the stationary lower jaw 29 is comprised of several elements, including a jaw plate 32 which includes the teeth 31 and needle guides or channels 33 a,b which are best seen in FIG. 4 . The needle guides 33 a,b are disposed on the bottom edge of an enclosed aperture 34 . The enclosed aperture 34 allows passage of suture needles 27 a,b therethrough. The needle guides 33 provide a track for the suture needles 27 to ride in, thereby correctly orienting the needles. The stationary lower jaw 29 also includes a removable end cap 36 which will be discussed in further detail below. Referring now to FIG. 5 , the jaw plate 32 has been removed in order to show a needle carriage 38 , which is slidably disposed within the stationary lower jaw 29 formed at the distal end of the hollow tube 18 . The needle carriage 38 has capture tabs 40 a,b,c,d located on its distal end. The capture tabs 40 are used to couple the needle carriage 38 with the suture needles 34 . The proximal end of the needle carriage 38 is affixed to a slide cable 42 a,b . Slide cable 42 is forked on its distal end to allow it to pass on either side of a linkage 44 , which is used to activate the movable upper jaw 30 . Referring to FIG. 6A it may be understood that for clarity only one suture needle 27 is shown, but that any description of the single needle is understood to apply to both suture needles 27 a,b . Accordingly, there may be seen a suture needle 27 which includes a curved outer sleeve 46 tapered from a larger diameter at its proximal end to a smaller diameter at its distal end. A ribbon 48 is slidably and coaxially disposed within the curved outer sleeve 46 . Referring to FIG. 7 , it may be seen that the flexible inner ribbon 48 is circular at its proximal end 50 , and transitions into a rectangular shape at its distal end 52 . The flattened ribbon shape disposes the flexible inner ribbon 48 to bend in a pre-defined orientation suitable for this application. Referring back now to FIGS. 6A–6D , the distal end 52 of the flexible inner ribbon 48 is permanently attached to a penetrating tip 54 . The penetrating tip 54 is tapered to a sharp point 56 at its distal end, to facilitate penetration into tissue. As it may be appreciated by those skilled in the art, there are many different designs and configurations of needles adapted for passing through tissue, including both sharp and blunt tips. It is to be understood that any of these tip designs may be accommodated in the present invention. A needle stop 58 is affixed to the flexible inner ribbon 48 at a predetermined distance from the proximal end of the curved outer sleeve 46 . A needle shoulder 60 is affixed to the flexible inner ribbon 48 at a predetermined distance from the proximal end of the needle stop 58 . A length of suture 26 , which may be constructed from any material known in the art as suture material, for example braided polyester, is permanently attached to the proximal end of the needle shoulder 60 . Now with reference back to FIG. 5 , it may be seen that the movable upper jaw 30 includes a needle catch 64 attached to its outer surface. The needle catch 64 further comprises elongated apertures 66 a,b , which are formed by a tab 68 . When the jaws 16 are in a position of grasping tissue as shown in FIG. 8 , the movable upper jaw 30 and the stationary lower jaw 29 are aligned to allow for the suture needles 34 to pass through the apertures 66 a,b in the needle catch 64 . How the needle catch 64 captures the suture needles 27 will be explained in more detail below. As illustrated in FIG. 8 , the linkage 44 includes a pin 70 , a link 72 , a pin 74 , a jaw cable 76 , and a second pin 78 . The movable upper jaw 30 is rotatably attached to the hollow barrel 18 by means of the pin 70 . The proximal end of the movable upper jaw 30 is rotatably attached to the distal end of the link 72 using the pin 74 . The proximal end of the link 72 is then rotatably attached to the jaw cable 76 using the pin 78 . The movable upper jaw 30 pivots about the pin 70 when activated by the jaw cable 76 . The actuation mechanism that causes the jaw cable 76 to move will now be described in greater detail. As shown particularly in FIG. 9 , the jaw cable 76 passes through the proximal end of hollow barrel 18 to the handpiece 20 . The proximal end of the jaw cable 76 is attached to the handle lever 23 by means of a pin 82 which is slidably disposed within a slot 84 at the top of the handle lever 23 . The handpiece 20 includes the handle lever 23 , the handle grip 22 and a pivot pin 88 . The handle lever 23 is pivotally attached to the handle grip 22 using the pivot pin 88 . The extension spring 25 is attached to the handle lever 23 by way of a pin 92 . The other end of the extension spring 25 is attached to the handle grip 22 by way of a pin 94 . The handle lever 23 is normally in an open position, due to force pulling on it by way of the extension spring 25 . This means that the movable upper jaw 30 , located at the distal end of the device, is in a normally open position due to the spring force. As shown in FIG. 9 , the slide cable 42 , previously described in reference to FIG. 5 , passes through the proximal end of the hollow barrel 18 to the handle 20 . The proximal end of the slide cable 42 is attached to the trigger 28 , using a pin 98 . An outer sleeve 100 is slidably and co-axially placed over the slide cable 42 . A compression spring 102 is slidably and co-axially placed over the slide cable 42 and abuts the outer sleeve 100 on one end, and a spring land 104 on the other end. The compression spring 102 provides a return force to the trigger 28 and consequently to the needle carriage 38 after deployment of suture needles 34 . In a preferred method of the present invention the grasper/stitcher 14 is inserted through a portal in the shoulder, as shown in FIG. 2B . The portal is opened by first making an incision in the skin then inserting the trocar port 12 through the incision to the repair site. The distal end of the hollow barrel 18 is inserted through the cannula until the jaws 16 reach the torn rotator cuff tissue 8 . In operation, the distal end of the grasper is positioned at the repair site against the tissue to be grasped. Moveable jaw 30 is advanced toward the stationary jaw 29 by squeezing handle lever 23 . As lever 23 moves inwardly by pivoting about pivot pin 88 , the jaw cable 76 is drawn rearwardly, proximal of the handpiece 20 . When the jaw cable 76 is retracted rearwardly, the movable jaw 30 pivots toward the stationary jaw 29 to close the jaws. Once the appropriate section of tissue is isolated and grasped by jaws 16 , the lever 23 may be locked in its closed position, using a latch mechanism (not shown). Once the surgeon is satisfied with the placement of the grasper 14 , the surgeon can then deploy the suture needles to create a mattress stitch in the torn rotator cuff 8 . In operation, the suture needles 27 are advanced through the rotator cuff by pulling on the trigger 28 . This action draws the slide cable 42 rearwardly towards the proximal end of the grasper. As the slide cable 42 is pulled rearwardly, it is pulled against the force of return spring 102 . As the slide cable 42 moves rearwardly, it pulls the needle carriage 38 and suture needles 27 proximal to the needle guide aperture 33 ( FIG. 6A ). The suture needles 27 , as they clear the distal edge of the aperture 34 , begin to penetrate through the underside of the rotator cuff 8 and advance upwardly towards the movable jaw 30 . Referring now again to FIGS. 6A–6D , the needles are illustrated at various stages of advancement through the rotator cuff. In FIG. 6A , the proximal end of the suture needles 27 are fully engaged in the locking tabs of the needle carriage 38 . As the suture needles 27 near the end of the ejection stroke, the distal end of the needles 27 pass through the upper movable jaw 30 and the needle catch 64 . As the needles pass through the upper jaw 30 , they begin to separate from the needle carriage 38 ( FIG. 6B ). As the proximal end of the needle's curved outer sleeve 46 separates from the first tab on the needle carriage 38 , there is no further force pushing on it to force it through the rotator cuff 8 . The force now pushing on the suture needle 27 is concentrated on the needle stop 58 . As the carriage 38 is advanced further, the needle's curved outer sleeve 46 remains stationary due to the resistance caused by contact with the tissue of the rotator cuff 8 . However, the needle ribbon 48 is free to advance further. As shown in FIG. 6C , the gap between the needle's curved outer sleeve 46 and the needle stop 58 begins to close until there is no gap at all. At this point the penetrating tip 54 has extended beyond the distal end of the needle's curved outer sleeve 46 . Once the gap is closed between the needle stop 58 and the outer sleeve 46 , the needle will again continue to advance as one unit through the rotator cuff 8 . As the needle carriage 38 advances further, it pushes on the suture needle 27 until the needle has been pushed beyond the point of contact with the needle carriage 38 ( FIG. 6D ). At this point the suture needles 27 extend through the torn rotator cuff 8 and protruding through the upper movable jaw 30 and needle catch 64 . Due to a pre-defined curve in the needle's ribbon 48 , the penetrating tip 54 remains extended from the distal end of the needle's curved outer sleeve 46 . At this point, any pull force being applied by the grasper 14 on the rotator cuff 8 is relaxed. Once the rotator cuff is in a relaxed state, the jaws of the grasper 14 are then opened. The handle lever 23 is unlocked from the locking mechanism (not shown) and returns to an open position due to the pull force exerted on it by means of the return spring 25 . As the return spring 25 pulls on the lever 23 , the handle lever 23 pivots about the pin 88 . As the handle lever 23 opens, it pulls on the jaw cable 76 by means of the pin. This advances the jaw cable 76 towards the distal end of the barrel 18 . As the jaw cable 76 advances, it pushes on the linkage segment 44 , which then pushes on the movable upper jaw 30 , causing the upper jaw 30 to pivot about the pin 70 to open and separate away from the stationary jaw 29 ( FIG. 8 ). As shown in FIG. 10 a , as the movable upper jaw 30 begins to open, the suture needles 27 for the most part remain stationary due to resistance caused by their contact with the tissue of the rotator cuff 8 . As the upper jaw 30 is opened, it slips pass the suture needles 27 . At a point just beyond the distal end of the suture needle's curved outer sleeve 46 , the needle catch 64 on the upper jaw 30 trap the suture needles 27 at a point between the curved outer sleeve 46 and the penetrating tip 54 . Now, with reference to FIG. 10 b , it is seen that the upper jaw 30 slips pass the needle's outer sleeve 46 . The aperture or slit 66 in the needle catch 64 is allowed to close down around the needle's ribbon 48 . The slit 66 is large enough that it does not restrict the movement of ribbon 48 , but is sufficiently small so that it does not allow the penetrating tip 54 to pass back through. This is because the needle catch 64 on the upper jaw 30 can only be deflected in an outward direction, away from the outer surface of the upper jaw 30 . Thus, now that the distal end of the suture needles 27 are trapped in the needle catch 64 on the upper jaw 30 , they are pulled through the rotator cuff as the upper jaw 30 is opened further. As shown in FIG. 10 c , when the jaws 16 of the grasper 14 are fully extended, the suture needles 27 are nearly pulled through the rotator cuff 8 . To complete the pull out of the suture needles 27 , it is necessary to pull on the grasper 14 , and to begin to remove it from the repair site. Now with reference particularly to FIG. 11 , once the suture needles 27 are extended through the rotator cuff 8 , they can be secured by closing down the jaws 16 of the grasper 14 . Then, the graspers can be retracted back through the portal via the trocar cannula 12 ( FIGS. 2D and 2E ). As shown in FIG. 12 , the next step in the preferred method is to pull on the free ends 105 of the suture 26 . This causes the suture to pass through the rotator cuff 8 at puncture sites 106 a and 106 b . As the suture is pulled through, the loop end 107 of the suture is pulled snug against the underside of the rotator cuff 8 to form what is referred to as a mattress stitch. This process is repeated as necessary, depending on the number of bone anchors required to repair the rotator cuff for a given surgical procedure. To reload the inventive instrument with new suture needles 27 , the end cap 36 is pulled off to provide necessary access, as shown in FIG. 13 . After the end cap 36 is removed, the needle carriage 38 can be advanced beyond the distal end of the barrel 18 to be reloaded. To advance the needle carriage 38 in this manner simply requires advancing the handle trigger 28 towards the distal end of the grasper 14 . Once new suture needles are reloaded, the end cap 36 can be replaced. The remaining suture to form the next stitch passes through the lower stationary jaw 29 through a small notch abutting the end cap (not shown). This extra length of suture may be left outside the body as the grasper 14 is inserted back through the portal 12 to the operative site. A second, modified embodiment of a suturing instrument constructed in accordance with the principles of the present invention is illustrated in FIGS. 14-17 . With respect to this embodiment, it is to be understood that the proximal portion of the device is substantially the same as that illustrated with respect to the earlier embodiment, and is therefore not shown. Thus, in FIG. 14 , there is seen a distal end 108 of the inventive suturing device, which includes a moveable upper jaw 109 , a stationary lower jaw 110 , and a body 112 . The moveable upper jaw 108 is pivotally attached to the body 112 via a pin 114 , and includes a ferrule catch 116 which further includes slits 118 a,b . The ferrule catch 116 is preferably constructed of a high temper spring steel suited for tissue contact. By way of example only, ANSI 301 spring temper steel is suitable for this application. A needle carriage 120 is slidably disposed on the lower stationary jaw 110 . The needle carriage 120 is permanently affixed to slide cables 122 a,b , and moves proximally from a distal position to a proximal position within the lower stationary jaw 110 when urged by the slide cables 122 . The needle carriage 120 includes tabs 124 a,b to which are coupled needles 126 a,b . The needles 126 may be constructed, as is well known in the art, of 300 or 400 series stainless steel. As shown in FIGS. 15-17 , each needle 126 includes a sharpened tip 128 , a bulge 130 , and a body 132 . The bulge 130 may be best seen by referring to FIG. 16 , where a suture 134 comprising a hollow inner lumen 136 and a distal end 138 may also be seen. The distal end 138 is encapsulated by a ferrule 140 . The ferrule 140 is further comprised of an outside diameter 142 , an inside diameter 144 , and a shoulder 146 . The distal end 138 of the suture 134 is passed into the ferrule 140 and crimped or otherwise mechanically or adhesively attached to the ferrule 140 . In operation, the body 132 of the needle 126 is threaded into the hollow inner lumen 136 of the suture 134 and through the inside diameter 144 of the ferrule 140 . The bulge 130 interferes with the shoulder 146 of the ferrule, thereby preventing the ferrule 140 , and concomitantly the suture 134 , from sliding further along the body 132 . Referring now to FIGS. 15A-15C , in particular, the function of the combination of the needles 126 and the suture 134 is illustrated. In FIG. 15A , the needles 126 and the ferrule 140 are enclosed by a housing cap 148 . It is to be understood that, for clarity, the tissue that would normally be grasped between the moveable upper jaw 109 and the stationary lower jaw 110 is not shown. It is also to be understood that FIGS. 15A-15C depict a cross-sectional view showing only one of the two needles 126 . Accordingly, and with reference now to FIG. 15B , it may be seen that, as the slide cables 122 are withdrawn as previously described in connection with the prior embodiment, the needle carriage 120 is drawn along a path from the distal to the proximal end of the stationary lower jaw 110 . The needles 126 , being fixedly attached to the needle carriage 120 , are urged to exit the stationary lower jaw 110 and to transit along a curved path described by the pre-configured ben in the needles 126 until penetrating the catch 116 at the slits 118 . The ferrule 140 is forced to traverse the slits 118 by the urging of the bulge 130 on the shoulder 146 . As the tension on the slide cables 122 is released, the needle carriage 120 is permitted to return to its original position by reversing its motion so that it travels distally. As shown in FIG. 15C , the transition of the needle carriage 120 back to its original position functions to cause the needles 126 from the hollow inner lumen 136 of the suture 134 and from the inside diameter 144 of the ferrule 140 , leaving the ferrule 140 trailing the suture 134 to be captured by the ferrule catch 116 . This may be seen most advantageously by reference to FIG. 17 . At this point, with the suture 134 and the ferrules 140 captured, the tissue grasped by the moveable upper jaw 109 may be released, and the instrument withdrawn from the operative site, trailing the suture loop stored within its bounds. The result of the execution of these method steps is the creation of a mattress stitch in the grasped tissues in a manner similar to that described with respect to the embodiment illustrated in FIGS. 2-13 . The apparatus and method of the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

A suturing instrument and method for placing mattress stitches in soft tissues is described. An elongate shaft with a stationary jaw and a moveable jaw disposed at the distal end is coupled to a handle grip at the proximal end configured to manipulate the jaws into open and closed positions. The jaws are configured to allow for atraumatic grasping of soft tissues. The stationary jaw is comprised of a serrated face incorporating apertures through which needles attached to opposite ends of a single strand of suture material may be driven out into and through grasped tissue. The serrated upper jaw is configured with needle catch adapted to accept and capture the needles and suture. The handle is released to open the moveable jaw, the instrument may be withdrawn, trailing the suture, and leaving a mattress stitch in the grasped tissue.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an automatic loading mechanism for weapons, of the type in which a spring must be put under tension for firing a shot. In a particular embodiment, this mechanism will be utilized on air rifles. 2. Brief Description of the Related Art Automatic loading mechanisms for weapons are already known, in which an electric motor implements the tension of a spring, which is necessary for firing a shot. This is described in the Belgian patent application no. 905.904, in which an electric motor, a battery, a reduction gear and a motor mechanism implement the tension of a spring for driving a piston in order to be able to compress air to a high pressure. This known loading mechanism consists of an electric motor which drives a threaded rod, and a non-rotating nut, which can nevertheless be displaced axially, mounted on this rod and provided with a hammer, which hooks behind a piston, or a part connected to this piston in order to move it with a turning movement of the rod. This prior mechanism has the disadvantage, however, that the nut must continually effect a to and fro movement in order to region its initial position after the loading of the shot therefore the replacement of the nut is an action which requires energy and time. Another disadvantage of this known mechanism is that a motor capable of driving in both directions must be provided. To achieve case end switches must be utilized which increase the cost price of the control mechanism. OBJECTS AND SUMMARY OF THE INVENTION The present invention relates to a loading mechanism for weapons which utilizes a double action loading system can immediately effect a new loading action without having to effect a return action beforehand. The improved loading mechanism of the present invention for weapons comprises a piston drive by a spring and an electric motor with reduction gear, characterized in that the spring is compressed by the piston where the recoil displacement which has the result that the tension of the aforementioned spring is controlled by the piston working together with a continuous traction device. The traction device, in a red embodiment is comprised by a a continuous chain, driven and supported by toothed wheels. This chain is preferably provided with two protruding shafts, on two opposite locations which, alternatively, continually return to the same start and stop positions whether or not a loading operation is effected. In this manner an unnecessary return action of the traction device will be avoided which will considerably increase the efficiency regarding time and energy. Since less energy is used by the loading mechanism the more loading actions may be effected with the same charge contained in the portable battery, or for an equal number of loading actions a smaller and lighter battery may be utilized. The use of a smaller and lights battery is especially important with weapons, because a light construction is preferred. Instead of two protruding parts or shafts, the traction device may be provided with several such parts or shafts. Other sources of energy may replace the electrical sources. For example, a manual system could be envisaged utilizing a small crank installed on the side of the rifle. It is also known that, when a spring is put under tension more energy is necessary the more the end of the stroke of the spring is approached which, among others, results in an increase of forces which, certainly in relation to the average force applied, will lead to an over dimensioning of the materials and motor. An additional advantage of the present invention is that a hook shaped element capable of being pulled by a shaft, preferably provided on a continuous chain, is connected to the piston, so that when the spring is practically at the end of its tension stroke, i.e. it is in its compressed position the shaft positions itself exactly there where it will describe a circular path. Consequently, this shaft, during the first 90 degrees of the circular path described, will have a horizontal component of velocity from the initial (0 degrees) until zero (90 degrees). This component of velocity can be calculated for each position by multiplying the initial horizontal component of velocity with the sine of the angle in which the shaft is situated. It is clear that the horizontal component of velocity will have a sinusoidal progression. The motor, while putting the spring under tension, practically at the end of the tension stroke, will simultaneously compress the spring over a shorter distance, and therefore have to develop less power than, for example, in an ordinary linear system. This just at the moment where the compression of the aforementioned spring requires the greatest power. The torque, effected by the motor, will decrease according to a similar sinusoidal progression. With the traction device of the present invention, the over dimensioning, required with linear traction devices is no longer necessary and an economy both in material and in motor can be realized. It is equally evident that instead of a chain other endless elements, such as a cable, a toothed belt with protuberances, a band or similar means be utilized. BRIEF DESCRIPTION OF THE DRAWINGS This objects, advantages and features of present invention described above will be more fully understood when considered in conjunction with the accompanying drawings in which: FIG. 1, shows a weapon on which the loading mechanism is applied; FIG. 2 shows on a larger scale and in cross-section that which is indicated by F2 in FIG. 1; FIG. 3 shows a view according to line III--III in FIG. 2; FIG. 4 and 5 show similar views to those from FIG. 2 but in which the traction device has practically terminated the loading action, respectively where the weapon is ready to be fired. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In order to better show the characteristics of the loading mechanism for weapons of the present invention, a preferred embodiment is described hereafter, with reference to the accompanying drawings. FIG. 1 shows a weapon, in this case an air rifle, in which the improved mechanism is indicated by the block marked F2 and in which the energy for this loading mechanism is, for example, supplied by a battery 2 installed in the butt. In FIG. 2, the motor 4 and the reduction gear 5 are shown in a schematic manner, mounted in the housing 3. The motor 4 produces a rotative movement transmitted to the reduction gear 5 by means of a shaft 6. The reduction gear then transmits the rotative movement by means of the shaft 7 provided with a bevel gear 8 which can work together with a second bevel gear 9 on which an additional chain wheel 10 is provided. Chain wheel 10 is connected to a similar chain wheel 11 by means of a chain 12, on which two protruding shafts 13-14 are provided in this case. The toothed wheels and chain wheels 9, 10 and 11 are mounted on the shafts which are mounted on bearings that rotate freely in the housing 3. A piston 15 with drive spring 16 is provided and installed in a chamber 17 around a rod. A supple forked element 18 made for example of spring steel, which is curved downward and has a hook shaped fold 19 at its free extremity, is also provided on piston 15. The element 18 extends, through a groove 20, into the chamber 21 where the control mechanism is located. The toothed wheel 9 and a chain wheel 10 are located on a shaft 22 while the chain wheel 11 is located on the shaft 23. The parts of the shaft 23 next to the chain 12, that is, the parts of the shaft 23 which can be under the arms of the element 18 at a determined moment, are only constituted by a segment 24, the purpose of which will be described below. The operation of the loading mechanism according to the invention is very simple and is described below. In the resting position the loading mechanism is in position, as shown in FIG. 2. By the control of an electric switch not shown in the drawings, the motor 4 can be provided with current. When the motor rotates, the chain wheel 10 will drive the chain, through suitable means of transmission 6 to 9, accordion to arrow P. The protruding shaft 13 will engage the hook shaped fold 19 of the element of at a determined moment and, as a result, pull along element 18. In this manner the piston 15, to which the element 18 is attached, will also be pulled along and will compress the spring 16. The shaft 13 will then continue to effect a horizontal rectilinear movement until the chain wheel 11 reaches the position A. From position A, the shaft 13 will deviate from its initial horizontal rectilinear movement and start a circular movement from position A until position C is reached. In this manner, the original horizontal component of movement while in position A, will be partially converted between positions A and C, into a vertical movement. Between positions A and B, the horizontal component of movement can be calculated by multiplying the initial horizontal component of movement in position A with the sine of the angle formed by the shaft 13 in relation to the shaft of the chain wheel 11 (A=0 degrees and B=90 degrees). In the position B, spring is completely compressed and the piston 15 will be able to be locked by a suitable locking not shown. The chain 12 will pull along the shafts 13 until a position, as shown in FIG. 4, following which the hook 19 is released from the shafts in order that the element 18 returns toward the segments 24, more especially their edges 25 also act on this element 18 in order to ensure its release in relation to the shafts 13. From this moment the motor will cease to rotate. This can be applied by the installation of an end switch not shown in the drawings at a suitable location and driven either by the chain 12, or by the element 18. The unlocking of the piston 15 will be possible afterward, for example, by a release mechanism also not shown which can be controlled from the trigger 22. During the loading action described above, the shaft 13 has been placed at the position of the shaft 14 in FIG. 2 and the shaft 14 has taken the starting position of the shaft 13 in order to be ready to effect a new loading. FIG. 5 shows the loaded position which, after a command to fire, will change to be take the position as shown in FIG. 2, with this difference nevertheless that, now, the shafts 13 and 14 have changed place. The embodiment described above is a system which is especially applicable for air rifles. It is obvious that this improved loading mechanism can be also be used on other types of weapons and for other purposes. The above description and accompanying drawings are merely illustrative of the application of the principles of the present invention and are not limiting. Numerous other arrangements which embody the principles of the invention and which fall within its spirit and scope may be readily devised by those skilled in the art. Accordingly, the invention is not limited by the foregoing description, but is only limited by the scope of the appended claims.

Improved loading mechanism for weapons which principally consists of a piston (15), driven by a spring (16) and an electric driving motor (4) with reduction gear, characterized in that the spring (16) is compressed by the piston (15) of which the compression movement which results in putting the aforementioned spring (16) under tension is controlled by the piston (15) working together with a continuous traction device.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of prior application Ser. No. 11/672,253 filed Feb. 7, 2007 now abandoned and also claims the benefit of priority to U.S. application Ser. No. 60/771,281 filed Feb. 8, 2006, the contents of which are hereby incorporated by reference in its entirety for all purposes. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable. THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT Not applicable. INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC Not applicable. BACKGROUND OF THE INVENTION Field of Invention There are many examples of computer systems in which it is useful to be able to analyse symbols passing through or stored in the computer system. As will be appreciated from the following, the term “symbols” in this context is to be construed broadly. In general, the term “symbols” is used herein in the broad sense as used in the field of Universal Turing Machines. For example, “symbols” includes computer messages, which term is also to be construed broadly and includes for example computer messages in a computer language (including computer instructions, such as executable programs), natural languages in computer-readable form (such as in documents, emails, etc.). “Symbols” also includes computer data in the conventional sense, i.e., typically, abstractions of real world artefacts, etc. In one example of computer systems in which it is useful to be able to analyse symbols passing through or stored in the computer system, third parties can attempt to take control of a computer system by “hacking” the computer system. Such hacking can be carried out by exploiting the well known buffer overflow weaknesses of some computer operating systems. In another example, hacking can take place by the third party sending commands to the computer system in which the commands are correctly structured in the context of the language of the computer system, but which are intended to cause the computer system to return an error message that can be used by the third party to gain illegal access to the computer system. Attacks of this type on SQL (Structured Query Language) databases are well known and yet are difficult to defend against. SQL databases are widely used, and are used for example by e-commerce and many other websites to hold user data (such as login name and password, address and credit card details, etc.). In another example, it may be desirable to monitor computer symbols or messages to ensure that the computer system is being used properly and that for example it is not being used inappropriately. For example, in an organisation, a user may be using a computer system inappropriately, for example by using the computer system for purposes for which the user is not authorised, and yet which is not intended by the user to be an “attack” on the computer system as such. Known measures to prevent such inappropriate use of the computer system include the use of firewalls, virus scanning software and intrusion detection systems. Firewalls are effective but have many limitations. For example, in e-commerce or the like, it is inevitable that third parties must have access to a web server so that for example the third parties can enter login and password details and obtain appropriate responses from the web server. In such cases, the firewall must allow users access to the computer system. Virus scanning software is again effective, but only in respect of viruses that are already known or that have signatures that are similar to known viruses. This is because virus checkers typically monitor files to look for “signatures”, i.e. known strings of bytes, which are stored in a library. In other words, virus checkers look for syntax (e.g. strings of bytes in a file) and not semantics (i.e. the content and meaning of a message or file). Intrusion detection systems are becoming increasingly effective. However, typically these operate by analysing computer messages to determine whether they fit a set of known rules that are deemed to apply to messages that are to be accepted. A problem with this approach arises in the generation of the rules and when the intrusion detection system faces a new message that has not been seen previously. In WO-A-2003/090046, an intrusion detection system is disclosed that uses inductive logic programming to generate new rules for new messages so as to update the knowledge base of the intrusion detection system. Another example of an intrusion detection system that is similar in concept, though different in detail, is disclosed in U.S. Pat. No. 6,311,278. A problem with these known intrusion detection systems that effectively generate new rules, which allow the intrusion detection system to determine whether or not to accept the computer message, is that the time taken to generate the new rules is generally prohibitive. For example, even a modest e-commerce site can process 10,000 SQL statements per minute. It is not possible for these known intrusion detection systems to handle that amount of traffic in a reasonable time. It will be understood that any significant delay for a user in accessing an e-commerce site will generally not be acceptable to the user, who will typically require access within seconds of attempting to log in to a website. Similarly, within for example an organisation, users will not accept any significant delays in processing their traffic across the network. There are also many applications where it would be useful to be able to analyse symbols, including for example data and other computer messages, into patterns that can be recognised by humans. The message analysis can be used to monitor usage by users of a computer system to allow the users to be invoiced according to the amount and/or type of usage of the computer system, and generally to permit effective monitoring of usage of the computer system so that, in turn, the computer system can be managed in terms of availability and resources to meet usage requirements. BRIEF SUMMARY OF INVENTION According to a first aspect of embodiments of the invention, there is provided a computer-implemented method of analysing symbols in a computer system, the symbols conforming to a specification for the symbols, the specification having been codified into a set of computer-readable rules, the method comprising: analysing the symbols using the computer-readable rules to obtain patterns of the symbols by: determining a path that is taken by the symbols through the rules that successfully terminates, and grouping the symbols according to said paths. As mentioned above, “symbols” in this context is to be construed broadly. In general, the term “symbols” is used herein in the broad sense as used in the field of Universal Turing Machines. For example, the term “symbols” includes computer messages, which term is also to be construed broadly and includes for example computer messages in a computer language (including computer instructions, such as executable programs), natural languages in computer-readable form (such as in documents, emails, etc.). “Symbols” also includes computer data in the conventional sense, i.e., typically, abstractions of real world artefacts, etc. By analysing the symbols into patterns (which can be regarded as partitioning a data set of sequences of symbols into subsets, which are also sometimes referred to herein as “patterns” or “clusters”), new symbols can be analysed more efficiently than in prior art techniques, which makes it possible to implement the method in real-time with relatively little computational overhead. In an embodiment, the method is carried out on new symbols to determine whether the new symbols fit a pattern of symbols that is known or constitute a new pattern of symbols. In practice, in one embodiment, if the new symbols fit a pattern that is known, then a decision will already have been made as to whether symbols fitting that known pattern are to be deemed acceptable or not. If the symbols constitute a new pattern, in practice a decision will have been made what to do with symbols that constitute a new pattern, such as “always deem not acceptable” or “send error report”, etc. In an embodiment, the method is initially carried out on training examples of symbols. This allows a base set of patterns of symbols to be built up. This base set can be analysed by a human domain expert who can for example determine which of the patterns of symbols relate to acceptable or normal behaviour, so that new symbols can be classified accordingly (e.g. that the new symbols fit a pattern that is known and can therefore be deemed acceptable or not, or the new symbols constitute a new pattern and should therefore for example be deemed not acceptable). In principle, the training examples may be examples of symbols that are known to be acceptable thereby to obtain patterns of symbols that are known to be acceptable. However, more likely in practice is that the training examples will be general and a decision will be made later, after the patterns of symbols have been produced and based on the patterns of symbols, as to which patterns of symbols are to be deemed acceptable or not. In an embodiment, it is determined to be sufficient to take only a single said path that successfully terminates. As will be explained further below, this improves the efficiency of the method. In a preferred embodiment, the specification is codified by defining a first order logic that describes the specification; and, the symbols are analysed using the first order logic to obtain patterns of the symbols by: determining a path that is taken by each symbol through the first order logic that successfully terminates, and grouping the symbols according to said paths. The use of first order logic provides for a particularly efficient method and one that is comparatively easy to implement. In a preferred embodiment, the first order logic has clauses at least some of which are parameterised. In other words, some of the clauses have labels applied thereto, the labels relating to the probability of the clause being “true” in the context of the computer system in which the symbols are passing. Preferably, at least some of the clauses have a head that is parameterised, the determining step in the analysing step being carried out by determining a path of clauses having a parameterised head through the first order logic that is taken by each symbol that successfully terminates. As will be explained further below, this improves the efficiency of the method. In a most preferred embodiment, the first order logic is a stochastic logic program having at least some clauses that are instrumented, the determining step in the analysing step being carried out by determining a path of said instrumented clauses through the first order logic that is taken by each symbol that successfully terminates. In another embodiment, the specification is codified into a Java program; and, the symbols are analysed using the Java program to obtain patterns of the symbols by: determining an execution path that is taken by each symbol through the Java program that successfully terminates, and grouping the symbols according to said execution paths. In an embodiment, the symbols are messages of a computer language, said specification being the computer language, and wherein the codifying the specification into a set of computer-readable rules comprises defining computer-readable rules that describe the grammar of the computer language. In another embodiment, the symbols are data. In an embodiment, the method comprises generalising the symbols by generalising to the paths. This allows generalisation to be tractable. In this context, generalisation means that the sequences of symbols with the same path are considered to belong to a generalised group of sequences. In an embodiment, the method comprises, prior to the analysing, codifying the specification into the set of computer-readable rules. According to a second aspect of embodiments of the invention, there is provided a computer program for analysing symbols in a computer system, the symbols conforming to a specification for the symbols, the specification having been codified into a set of computer-readable rules, the computer program comprising program instructions for causing a computer to carry out a method of: analysing the symbols using the computer-readable rules to obtains patterns of the symbols by: determining the path that is taken by the symbols through the rules that successfully terminates, and grouping the symbols according to said paths. There may also be provided a computer programmed to carry out a method as described above. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: FIG. 1 shows an example of a cluster obtained in accordance with an embodiment of the invention; FIG. 2 shows a cluster as portrayed by its annotated parse tree; FIG. 3 shows a cluster as portrayed graphically by way of a parse map; FIG. 4 shows another example of portrayal of clusters; and, FIG. 5 shows a flow chart that indicates schematically an example method of analysing SQL statements according to an embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION In the immediately following specific description, reference will be made principally to computer messages written in a computer language, and to the use of first order logic including stochastic logic programs in particular. However, as will be appreciated from the foregoing and as explained further below, the symbols that are analysed can in general be of any type that conforms to a specification and that techniques other than first order logic may be applied. In a computer system, messages are used to specify the desired operational behaviour of components in the computer system. Thus, messages are used between components within the computer system, and messages are used by users to gain access to the computer system. High level or “scripting” languages are used to facilitate the use of messages in a computer system. The computer language is defined by a grammar so that the messages conform to a known syntax. The grammar of such computer languages is published so that software developers can ensure that the messages of the software conform to the correct syntax. By way of example only, the syntax for the SQL language is published as an ISO standard (for example the document series ISO/IEC 9075). The preferred embodiments of the invention operate by analysing new messages to determine whether the new messages fit a pattern of messages that is deemed to be acceptable. In this context, a message is “new” if it has not been seen by the system previously. In contrast to the prior art briefly discussed above, the preferred embodiments are not concerned with generating new rules for new messages, and instead, as stated, are concerned with determining patterns for computer messages. The patterns that are obtained can then be considered, for example by visual inspection, “manually” by a human user, to determine for example whether a computer system has been compromised or could be compromised. In this context “compromised” includes, but is not limited to, virus infections or unauthorised access of data. Alternatively, the patterns can be automatically analysed by a computer-implemented method, so that messages can be accepted or rejected, preferably effectively in real time and therefore “on the fly”. In the preferred embodiment, the grammar of the computer language of the messages that are to be analysed is defined using first order logic. This may be carried out in a manner that is known per se. For example, the programming language Prolog can be used to describe the grammar of the computer language as a set of first order logic. This grammar as first order logic is then applied initially to a set of training examples of messages. Such training examples of messages are defined so as to be correct syntactically in the context of the computer language and appropriate in the sense that they are messages that are deemed to be “acceptable” in the context of usage of the computer system around which the messages pass. The formal language term “acceptable” in this context means that the messages are grammatically correct rather than necessarily being safe for the computer system. The first order logic contains clauses. When the first order logic is applied to the messages, a series of the clauses (termed a “path”) analyses the messages. The identity of the clauses along a success path is noted. A success path is a path of clauses that terminates in the process of accepting the message in the grammar. In this way, the success paths of acceptable messages through the first order logic are obtained. These success paths can then be grouped (or “clustered”) according to similarity. In turn, the messages that follow the respective success paths can be grouped according to similarity in this sense, so that patterns of similar messages can be discerned. This means that new messages, which are different from messages used in the training, can then be allocated to patterns of messages that are known to be acceptable, or rejected. The success paths taken by different computer messages are determined to be similar when, for example, the success path taken by the different computer messages are identical. Furthermore, in a preferred embodiment, an indication of a further level of similarity may be obtained by determining which of the success paths can themselves be considered to be similar to each other. This may be achieved by for example using a Least General Generalisation (LGG) technique on the success paths, this method being known from for example G. D. Plotkin: “Automatic Methods of Inductive Inference”, PhD Thesis, Edinburgh University, 1971, in which the values of symbols occurring in the same part of a logical structure can be abstracted into a reference for any symbol value. In the preferred embodiment, some of the clauses of the program logic are annotated with probabilities of the clauses being true in the context of the messages in the computer system. By appropriate labelling of these annotated clauses, a very efficient system for analysing the messages into patterns can be obtained. The preferred embodiment uses logic in the form of a stochastic logic program. In general, for an arbitrary stochastic logic program, it is non-trivial to calculate the correct labels to be applied to the annotated clauses based on the stochastic logic program and a set of training examples so that the population that the stochastic logic program represents has the same probability of being generated as the original training examples. For example, a naïve way to build up the labels on the annotated clauses in the stochastic logic program is to count every time that each clause “fires” (i.e. the clause is determined to be “true”) when applying the training examples. There are however two immediate problems with this simple approach. First, it may be that there are several success paths through the logic when applying the logic to a particular example, which can cause multiple counting of the same clauses and/or undercounting of the same clauses. Secondly, some clauses will still fire and therefore be counted even when the final derivation of the goal along a path of clauses fails (i.e. the path is not terminated and there is no success path for this example). Whilst techniques are available for minimising these problems, this naïve method is still nevertheless computationally intensive and therefore cannot successfully be used in practice. Before discussing specific examples of embodiments of the invention in more detail, a more formal discussion of some aspects of the preferred embodiment will now be given. A logic program P is a conjunction of universally quantified clauses C 1 , . . . , C n . Each clause is a disjunction of literals L k . A goal G is a disjunction of negative literals ←G 1 , . . . , G m . A definite clause is a clause with at most one positive literal (which is known as the head). A definite logic program contains only definite clauses. All clauses in a logic program with heads having the same predicate name and arity make up the definition of the clause. A stochastic logic program (SLP) is a definite logic program where some of the clauses are parameterised with numbers. In other words, an SLP is a logic program that has been annotated with parameters (or labels). A pure SLP is an SLP where all clauses have parameters, as opposed to an impure SLP where not all clauses have parameters. A normalised SLP is one where parameters for clauses that share the same head predicate symbol and arity sum to one. If this is not the case, then it is an un-normalised SLP. Clauses having parameters are sometimes referred to herein as “parameterised clauses”. As will be understood from the following more detailed description, the preferred embodiments can be regarded as a parser that is an un-normalised stochastic logic program, i.e. only a subset of the definitions or clauses have parameters, and the parameters for any definition do not sum to one. As has been mentioned, typical approaches to fitting an SLP to a group of examples call each example in the presence of the SLP. Fitting is the process of determining the correct values to assign to the clauses that have parameters. Each time a parameterised clause is called by the example, its firing count is incremented. Once all of the examples have been processed, the firing counts for each of the parameterised clauses are then summed and the labels that are given to the parameterised clauses are normalised versions of the firing counts. (In particular, for predicate definition Pi with parameterised clauses C 1 . . . CN, with firing counts F 1 , . . . , FN, the label for Cj is Fj/sum(F 1 , . . . , FN).) However, again as mentioned, the runtime overhead of keeping track of the parameterised predicate definitions is significant, particularly given the problem of what to do when the firing clauses do not lead to a successful derivation for the example. This is overcome in the preferred embodiment by making the assumption that only single success paths are important in accepting a particular message. This means that only the first successful derivation path through the SLP needs to be recorded. It is not necessary to take into account any other or all other successful derivation paths when calculating the parameters to be applied to the clauses of the SLP. This assumption of using single success paths through the SLP contributes to making the method more efficient. Taking only a single (the first) success path is sufficient in the present context because the principal purpose is to cluster the messages with respect to the grammar. Another contributor to the efficiency of the preferred embodiment is the use of so-called “instrumentation”. In particular, the heads of certain clauses are parameterised, which is referred to herein as “instrumented”. This instrumentation can be performed at compile time. In an example, each clause that is part of a definition to be labelled is expanded at compile time, and an additional instrumentation literal slp_cc/1 is placed immediately after the head of the clause. The additional literal is also termed the “clause identifier”. For example the clause p(X):-r(X). will be compiled to p(X):-slp_cc(5), r(X). say (where it is the fifth clause to be instrumented by the compiler). An example of a relevant compiler code snippet for producing the instrumentation and written in Prolog is shown below: slp_clause(File, ‘$source_location’(File, Line):Clause) :- slp_clause(File, Line, Label, Clause0), expand_term(Clause0, Clause1), gen_cid(File, N), assert_label(Label, N, File), ( Clause1 = (Head :- Body0) −> Clause = (Head :- slp_cc(N), Body), slp_body(Body0, Body, File) ; Clause = (Clause1 :- slp_cc(N)), Clause1 = Head ), general_term(Head, Def), assert(cid_def(N, File, Def)). Data structures for keeping track of compiled clauses, their Prolog modules, and the context in which they are being called at runtime are initialised by the compiler. The main objective of this aspect of the preferred embodiment is to collect the sequence of all instrumented predicates (by noting the firing of clause identifiers) that were used in the successful derivation of a goal G. (In this context, the goal G corresponds to the message or other symbol that is to be analysed. When the goal G is called with respect to the SLP, either the goal G will be successfully derived (i.e. the message or other symbol is a “valid” message or symbol) or not. Any non-deterministic predicates that were tried and failed in the process are ignored: only the first successful derivation is used in accordance with the assumption discussed above (though backtracking is not prohibited by the methods described herein). The term non-deterministic in this context is known in logic programming and means that a goal can possibly be derived in more than one way. The preferred runtime system makes use of extensions to the standard Prolog system called global variables. Global variables are efficient associations between names (or “atoms”) and terms. The value of the global variables lives on the Prolog (global) stack, which implies that lookup time for the value of global variables is independent of the size of the term. The global variables support both global assignment (using nb_setval/2) and backtrackable assignment using (b_setval/2). It is the backtrackable assignment of global variables that are most useful for the present preferred runtime system. The runtime system (being the program compiled into an executable form) with the instrumentation works as follows. When a goal G is called using slp_call/1, a global variable slp_path is created to store the sequence of successful instrumented predicates. When an instrumentation literal or “clause identifier” slp_cc/1 is called, the path so far is retrieved from the global variable slp_path to which the clause identifier is added before the global variable slp_path is updated. The clause identifier identifies the successful instrumented clause. All of the additions of the clause identifiers are backtrackable should any subsequent sub-goal fail. An example of the kernel of the runtime system is shown below: /******************************* * CALLING * *******************************/ % slp_call(:Goal, -Path) slp_call(Goal, Path) :- b_setval(slp_path, [ ]), Goal, b_getval(slp_path, Path). /******************************* * INSTRUMENTATION * *******************************/ slp_cc(Clause) :- b_getval(slp_path, PO), b_setval(slp_path, [Clause|P0]). slp_id(SetID, IdentifierValue) :- b_getval(slp_path, P0), b_setval(slp_path, [id(SetID, IdentifierValue)|P0]). (The slp_identifier/2 literal will be discussed below.) For example, consider a parser expressed as an SLP in accordance with a preferred embodiment of the invention that is written to accept SQL statements as a Prolog module sql. The SQL grammar as published has several hundred clausal definitions. In one example of the preferred method, the following eleven clausal definitions of the SQL grammar are defined (by a human operator) as being worthy of instrumenting: :-slp select_list//0, derived_column//0, join//0, expression//0, query_specification//0, derived_column//0, set_quantifier//0, column_name_list//0, expression_list//0, show_info//0, cmp//0. The SLP can be used to determine the path of the derivation of the parse of a message in the following manner: ?- slp_call(parse( “select * from anonData where anonID = ‘nX19LR9P’” ), Path). Path = [21, 26, 17, 20, 19, 13, 12, 4] The numbers returned in the path sequence are the clause identifiers for the instrumented predicate (given in reverse order). In other words, by applying the SLP to the message, the identity of the clauses along the success path through the SLP can be obtained (and are written to the variable “Path”). This allows the path to be clustered with other similar paths. During training time, when the messages to which the system is applied are training examples, this “clusters” the messages into groups or sets of syntactically similar messages, irrespective of the semantics or content of the messages. (It will be understood that the patterns or clusters of any particular example will depend on the precise training examples that are given to the system during the training period and the instrumentation given to the program during compile time.) During runtime, messages are similarly analysed and effectively allocated to the patterns obtained during the training stage at training time. Significantly in the present context, even new messages, which literally have not been seen by the system previously, are allocated to the patterns obtained during the training stage. Thus, this provides the important feature of analysing messages in the computer system into patterns, even if the messages are new. In a practical example, the overhead of the instrumentation on the runtime system has been found to be low compared with prior art approaches. One weakness of associating normalised firing counts with probability distributions is that of “contextualisation”. A good “fit” of probabilities would be when the observed path frequencies match that of the so-called Markov chain probabilities of the success paths, where the Markov chain probabilities are calculated by the product of the observed individual clause labels in a path. For example, consider a parser with a “terminal” that is an integer, that is being used in accepting log items from syslog that records DHCPD messages. (A terminal symbol is a symbol that actually occurs in the language concerned.) The integer terminal could appear in any of the date, time, and IP address portions of the messages, all of which in general end in an integer. It has been found that the fit between firing counts and calculated Markov chain probabilities is poor in such circumstances where instrumented terminals belong to different contexts. It has also been found that the Markov chain probabilities fit the observed path probabilities in situations where there are no such context ambiguities. The context of the particular terminal is “lost”. To at least partially remedy these effects, the preferred embodiment uses set identifiers. These are terms that are defined to belong to a particular set. For example, consider a portion of an SQL parser (written as a Definite Clause Grammar or DCG) where it is determined that elements of the sets “table” and “column” are of interest. The slp_identifier/2 literal specifies the set name (either “table” or “column” in this case), and the value to associate with the set. table_name --> [ delimited(TName), period, delimited(CName) ], { concat_atom([TName, ‘.’, CName], Name), slp_identifier(table, Name) } !. table_name --> [ identifier(Name) ], { slp_identifier(table, Name) }. column_name --> [ identifier(Name) ], { slp_identifier(column, Name) }. In the same manner as clause paths are generated using firing clauses as described above, such paths are augmented with their set name-value pair when set identifiers are used. The runtime system for this again uses backtrackable global variables to keep track of the set name-value pairs for successful derivations. (The use of a slp_identifier/2 literal is shown in the example of the kernel of the runtime system given above.) If the previous SQL example is run again but with the slp_identifiers above installed, the following is obtained: ?- slp_call( parse( “select * from anonData where anonID = ‘nX19LR9P’” ), Path). Path = [21, 26, id(3, anonID), 17, 20, 19, id(2, anonData), 13, 12, 4] The element id(3, anonID) says that the set number 3 (corresponding to items of type “column”) contains the set value anonID. It will be understood that the clause paths that are obtained represent a form of generalisation from the training examples. From a textual parsing perspective, in this example this generalisation can be seen to provide a mapping from a string of ASCII characters (the SQL statement) to tokens and, with respect to a background-instrumented parser, a mapping to clause paths. In the preferred embodiment, the clause paths may include SLP identifier set name-value pairs as discussed above. Each clause identifier maps to a predicate name/arity. In this sense, a predicate is a family of clauses. A clause path can be further generalised to a variable “predicate path” where clause identifiers are replaced with the name/arity of the predicate to which they belong. It will be obvious to someone skilled in the art that this is only one form of generalisation or mapping and that this invention is not limited only to this possibility. Given that the messages in their raw textual form are reduced to sequences in the preferred embodiment, it is then possible to perform traditional generalisation techniques more efficiently because it is possible to generalise to the paths rather than to the whole Prolog program that describes the computer language. For example, the known “least general generalisations” method according to Plotkin (referred to above) can be used. Given that in the preferred embodiment the messages are represented as simple “atoms”, the least general generalisations can be carried out in a time that is proportional to the length of the sequence. In general, the maximum time required to carry out this known least general generalisation is proportional to the maximum sequence length and exponential in the number of examples. In summary, the preferred embodiments allow messages to be analysed to cluster the messages into patterns. A human domain expert can then inspect the patterns of messages to decide which are to be regarded as “normal” and therefore acceptable, and which are to be regarded as “abnormal” and therefore not acceptable. To simplify this analysis by humans, and given that the paths in the respective clusters are not particularly understandable to humans, the clusters can be portrayed with a single exemplar, and the user given the ability to drill down into the examples that belong to the cluster. This has been shown to communicate the cluster and its properties effectively to human users. An example of this is shown in FIG. 1 where a cluster is portrayed by an exemplar (at the top of the list), with further examples belonging to the cluster being shown below. The paths behind the clusters can also be shown to users. For example, FIG. 2 shows a cluster as portrayed by its annotated parse tree. In another example, the paths behind the clusters can be shown graphically by way of a parse map, an example of which is shown in FIG. 3 . It is possible to extend the mappings described above, particularly the use of set identifiers for contextualisation. For example, generalisations of interesting or key predicates can be defined. To illustrate this, the example given below considers how query specifications interact with particular tables: :- classify query specification//0, id(table). The result of this is shown in FIG. 4 , where different access methods to a table called “PersonalInfo” are shown in their clusters. With reference to FIG. 5 , a detailed description will now be given of an example of an embodiment of the invention that concerns the analysis of messages written in the computer language Structured Query Language (SQL). In short, messages (which, in the context of SQL, are more typically referred to as “SQL statements”) are either grammatically correct or not. In step 0, the SQL grammar is provided as an executable form of a BNF (“Backus-Naur Form”) specification written as a definite clause grammar (a form of Prolog syntax). The following block provides an example of code to parse the statement from a sequence of tokens extracted from the statement: statement --> query_specification, ( [ semicolon ] ; [ ] ). query_specification --> [ keyword(select) ], !, select_body. query_specification --> [keyword(insert), keyword(into) ], !, table_reference, insert_columns_and_source. query_specification --> [ keyword(update) ], !, table_reference, [ keyword(set) ], update_set, where. query_specification --> [ keyword(delete) ], !, table_expression. The executable parser from step 0 is then instrumented with the following compiler directives: :- slp select_list//0, derived column//0, join//0, expression//0, . query_specification//0, derived_column//0, set_quantifier//0, column_name_list//0, expression list//0, show_info//0, cmp//0. The compiled form of the instrumented parser specification results in an instrumented ISO SQL grammar, which is executable and will process SQL statements as inputs (step 2A) resulting in outputs of a successful parse or not (step 2B). Bearing in mind that a training phase using training examples of messages is initially employed in the preferred embodiment, an example of a training message or statement is “select * from anonData where anonID=‘nX19LR9P’”. The example training message is executed by the instrumented ISO SQL grammar (step 1) to produce a successful parse (step 2B) and also to emit the firing sequence (i.e. the “path”) (step 3) of the instrumentation points in the instrumented ISO SQL grammar (step 1). ?- slp_call(parse( “select * from anonData where anonID = ‘nX19LR9P’” ), Path). Path = [21, 26, 17, 20, 19, 13, 12, 4] As mentioned above, the numbers returned in the path sequence are the identifiers of the clauses for the instrumented predicate (given in reverse order). The path (step 3) is then further generalised to produce a cluster (step 4). All statements that produce the same cluster when parsed by the instrumented ISO SQL grammar (step 1) are then presented to the human domain expert. Reference may be made to FIG. 1 for an illustration of what the human domain expert is presented with in one embodiment of the present invention. The human domain expert can further select (step 5) other attributes of the SQL statements that are in the same cluster in order to specify an action policy (step 6). Such attributes may include (but are not limited to): User ID, IP Address, Time of Day. Subsequent SQL statements when they arrive can have the appropriate action taken as determined by the action policy (step 6). Actions might be (but are not limited to): pass the SQL statement to the database, block the SQL statement from the database, send an alert to another system whilst sending the SQL statement to the database, replace the SQL statement with an alternative SQL statement and send the alternative SQL statement to the database. So, for example, a known mode of attack on databases is by use of a technique known as “SQL injection”. In this, a hacker or the like, who is attempting illegitimately to access an e-commerce database or the like, instead of sending for example a statement “select * from anonData where anonID=‘nX19LR9P’”, sends a statement like “select * from anonData where anonID=‘'union select * from creditcards--’” (which is intended to cause the database to return details of credit cards held by the database). As noted above, processing the statement “select * from anonData where anonID=‘nX19LR9P’” using the instrumented parser produces a particular output path, say Path1: ?- slp_call(parse( “select * from anonData where anonID = ‘nX19LR9P’” ), Path1). Path1 = [21, 26, 17, 20, 19, 13, 12, 4] On the other hand processing the statement “select * from anonData where anonID=‘'union select * from creditcards--’” using the instrumented parser produces a different output path, say Path2: ?- slp_call(parse( “select * from anonData where anonID = ‘’ union select * from creditcards --’” ), Path2). Path2 = [19, 13, 12, 4, 33, 21, 26, 17, 20, 19, 13, 12, 4] Thus, the grammatical cluster to which the first statement belongs is denoted by Path1 and the grammatical cluster to which the second statement belongs is denoted by Path2. As can be seen, Path1 and Path2 are easily determined as being unequal. Such an inequality may be configured by the human domain expert to trigger an action, such as: alert, block the statement from passing to the database, or replace the statement that generates Path2 with an acceptable statement before passing the acceptable statement to the database. Another application of the preferred methods is to monitor usage by users of a computer system to allow the users to be invoiced according to the amount and/or type of usage of the computer system, and/or generally to permit effective monitoring of usage of the computer system so that, in turn, the computer system can be better managed in terms of availability and resources to meet usage requirements. For example, components of distributed computer systems interact with one another by passing messages between each component. Messages can be for example requests for the component receiving the message to perform some process or activity on behalf of the component from which the message originated. The messages can contain commands or carry data or both. In a particular example, the adoption of massively mobile and distributed computing components are known as “cloud computing”, which can be regarded as an automatically managed, flexible shared computing infrastructure where consumers of computing services interact via an application programming interface (API) with a pay-per-use model. The economics of cloud computing are favourable, but there are numerous challenges. Two key challenges are security and charging on a pay-per-use model. The specification of the APIs used by cloud computing are published in advance in the form of a language specification. Users or consumers of the “cloud” will interact with the API by sending and receiving messages to/from the cloud. By analysing the messages using the presently preferred methods, it is possible to build accurate usage patterns of consumers of the cloud computing services. Such patterns can be used to provide security by insisting that only messages that conform to policy are allowed into the cloud environment, as discussed generally above. Such patterns can also be used to monitor and meter usage by the consumers. Accurate metering allows accurate accounting and charging to be provided to the consumer on a pay-per-use model. Thus, in an example, the consumer and the service provider monitor the consumer's usage of the API and use the methods described herein to build a payment model. The payment model may be simply specified for differential payment terms. For example, when a purchase order is inserted into the cloud service, the agreed charge might be one unit. As described above, the parsing of the symbols used when calling the API uniquely identifies which of the grammatical clusters has been determined. Instead of block/alert/warn as in the context of a security system, such as an intrusion detection system as described above, the action on the next appearance of a request that fits the cluster will be of the type “bill consumer 1 unit”; “reduce remaining quota level by one”; “redirect the consumer's request to another (possibly cheaper) service provider)”; “replace the consumer's request with an alternative request”; etc. Usage metering can be applied by recording the precise cluster of functionality requested and received with respect to the API requests and responses. Quotas can be enforced by alerting users when sending/receiving messages. When clusters of requests have been fully utilized, then the service availability would cease. A natural extension to this is that if the cost per use for a service is accurately known, then the resources to provide the service are also accurately known. Thus, the run-time usage of the entire cloud can then be used to forecast peaks and troughs in load, in turn enabling better use of the cloud's virtualisation to provision more resources or free up resources for other tasks. It will be understood that the application of the invention to usage monitoring is not restricted to its use in cloud computing and that it has many varied applications, including for example to “software-as-a-service” and the more generic concept of “everything-as-a-service”. In summary, given the language or similar definition of the specification for the data, the preferred embodiments initially use training examples to cluster computer messages or other data into groups or patterns of the same or similar type. New messages can then be clustered to determine whether they fit one of the patterns. A human expert will for example decide which of the patterns are regarded as normal and which are abnormal. In an intrusion detection or prevention system, this can then be used to accept or reject new messages accordingly. In another example, the message analysis can be used to build models of normal usage behaviour in a computer system. This can be used to audit past behaviour, as well as to provide active filters to only allow messages into and out of the system that conform to the defined model of normality. The message analysis can be used to monitor usage by users of a computer system to allow the users to be invoiced according to the amount and/or type of usage of the computer system, and generally to permit effective monitoring of usage of the computer system so that, in turn, the computer system can be managed in terms of availability and resources to meet usage requirements. The techniques can be applied to obtain patterns from any type of data that conforms to a known specification. This includes for example data such as financial data, including data relating to financial transactions, which allows models of usage patterns to be obtained; so-called bioinformatics (e.g. for clustering sub-sequences of DNA); natural language messages, which can be used in many applications, e.g. the techniques can be used to form a “spam” filter for filtering unwanted emails, or for language education; design patterns for computer programs, engineering drawings, etc. The use of stochastic logic programs that are instrumented as described herein for the preferred embodiments leads to very efficient operation, making real time operation of the system possible with only minimum overhead. However, as mentioned, other techniques are available. It will be understood that the methods described herein will typically be carried out by appropriate software running on appropriate computer equipment. The term “computer” is to be construed broadly. The term “a computer” or similar may include several distributed discrete computing devices or components thereof. The computer program may be in the form of source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other form suitable for use in the implementation of the processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a ROM, for example a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example a floppy disk or hard disk. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via electrical or optical cable or by radio or other means. Embodiments of the invention have been described with particular reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made to the examples described within the scope of the present invention.

A computer-implemented method of analyzing symbols in a computer system, and a computer program and apparatus therefor are provided. The symbols conform to a specification for the symbols. The specification is codified into a set of computer-readable rules. The symbols are analyzed using the computer-readable rules to obtains patterns of the symbols by: determining the path that is taken by the symbols through the rules that successfully terminates, and grouping the symbols according to said paths.

This application is a continuation-in-part of application Ser. No. 07/996,806 filed on Dec. 23, 1992 and entitled "Workpiece Positioning and Drilling End Effector," now U.S. Pat. No. 5,299,894 issued on Apr. 5, 1994. BACKGROUND OF THE INVENTION This invention relates to automated drilling of coordination holes in parts for later assembly in a configuration determined by the location of the coordination holes, and more particularly to a method and apparatus for drilling coordination holes in stringers and stringer clips used in fabrication of transport airplanes. A recent development in fabrication and assembly of commercial airplanes is the concept of "virtual tooling" in which the positions of parts and even the shape of the final assembly is determined by the shape and locations of parts relative to each other, and those positions are determined exclusively by the use of coordination holes drilled precisely in the parts at locations specified in the original engineering parts definitions. The set-up of the machines used to drill the coordination holes in the parts is done automatically using digital inputs from the original engineering parts definitions as the sole authority, so the possibility of error caused by misadjustment or manufacturing errors in hard tooling, as was experienced in the past, is eliminated. These hard tooling jigs and fixtures were always subject to errors during initial fabrication which, because of the complexity of the tooling design, might escape detection and produce defective parts from the beginning, or were subject to damage by rough use in the factory. A breakthrough was made in the "virtual tooling" technology in a system disclosed in the following patent applications: ______________________________________Appln S/N Title Filed Patent No.______________________________________07/682,622 Stringer Clip End April 8, 1991 5,127,139 Effector07/871,321 Reconfigurable Holding April 20, 1992 5,249,785 Fixture07/964,533 Panel and Fuselage Oct. 13, 1992 Assembly07/996,806 Workpiece Positioning & Dec. 23, 1992 5,299,894 Drilling End Effector08/002,364 Part Positioning and Jan 6, 1993 Drilling End Effector______________________________________ The system disclosed in these applications and patents uses a central robot which routes the edges of the panel held on a configurable fixture, and uses several different end effector to pick up parts from a parts presentation station and hold them in position against the panel while coordination holes are drilled through the part and the panel. The results obtained from use of this system has exceeded expectations in terms of consistent accuracy, but the capacity of the system is limited and adding additional systems to increase capacity was disfavored because of the cost of the central robot. Moreover, the amount of load that the robot can accurately carry and position in space places physical restrictions into the design considerations for the end effectors, resulting in use of light duty mechanisms that requires rigerous maintenance to ensure their accurate operation. However, despite and because of these problems, sufficient confidence in the virtual tooling concept was developed from experience with the original system that it was decided that the an expansion of the system would be warrented. The expansion concept is to remove the function of pads drilling from the panel cell and perform that function on machines dedicated solely to that purpose, thereby fleeing the robot from the time-consuming tasks of picking up pads and holding them against the panel while coordination holes were drilled, and changing end effectors needed for different tasks. The same original engineering parts definition will be used to program the machine controller of the machine that drills the coordination holes in the parts. If the machine is designed with sufficient accuracy and set-up checks, the coordination holes in the panel and the parts will line up perfectly when the part is at the correct position on the panel, resulting in a fabricated part that is within specifications and requires no shims. Dedicated machines designed in accordance with this expansion of the concept can be Much less costly to build and operate that the panel cell, and they can be designed to require little maintence and with even greater precision than was possible in the panel cell. Freed from the time consuming tasks required for drilling the parts, the panel cell would now be able to concentrate on routing the panel edges and drilling the coordination holes in the panel, thereby increasing the panel cell throughput. SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide an improved machine for precisely and consistently drilling coordination holes in stringers and stringer clips in accordance with the original engineering part definition. Another object of this invention is to provide a stringer and stringer clip drilling machine that is self-checking to ensure that the machine is properly set-up before the parts are loaded into it. Yet another object of the invention is to provide a method of drilling holes in a stringer and stringer clip that are so accurate and repeatable that the holes can be used, without hard tooling, to position the parts accurately on a fuselage panel so that the stringer clips align within tolerance on a plane coinciding with the selected airplane fuselage frame so that the frame can be riveted to the clips without the use of shims. The machine includes an elongated bed for supporting the stringer, and a stop block against which the end of the stringer is abutted and fastened to establish the position of one end of the stringer. The machine touches a probe against various key items on the machine, including the abutting face of the stop block, to confirm the position of those key items, and automatically adjusts the position feedback signals to accommodate errors in the positions of those key items. Two longitudinally spaced, vertically movable spreaders descend into the stringer channel and rotate to center the stringer laterally, and a vertically oriented drill descends and drills a coordination hole in the floor of the stringer channel. The machine travels axially along the bed to the next position and repeats the drilling procedure at the next channel floor hole position. After all the floor coordination holes are drilled, the machine begins placing stringer clips and drilling coordination holes in the stringer side walls and the stringer clips. A stringer clip is fed from a magazine into a presenter and lifted by the presenter to a position to be gripper and held by a vertically movable gripper for drilling of a frame coordination hole, and is then placed by the gripper into the channel of the stringer. The sides of the stringer are clamped and two pairs of opposed drills drill rivet holes through the sides of the stringer and the stringer clip. After all the clips are placed and drilled, the machine cycles back to the home position and the drilled stringer with the placed and drilled clips is removed from the bed and the next stringer is installed. DESCRIPTION OF THE DRAWINGS The invention and its many attendant objects and advantages will become more apparent upon reading the following description of the preferred embodiment in conjunction with the following drawings, wherein: FIG. 1 is a perspective view of a stringer and stringer clip drilling machine in accordance with this invention; FIG. 1A is a perspective view of a section of a stringer and a stringer clip placed and drilled by the machine shown in FIG. 1; FIG. 2 is a perspective view of the upper carriage assembly of the machine shown in FIG. 1; FIG. 3 is an exploded perspective view of the two main structural elements of the frame for the machine shown in FIG. 1; FIG. 4 is a perspective view of the assembled frame for the machine shown in FIG. 1; FIG. 5 is an end elevation of the machine shown in FIG. 1; FIG. 6 is a front elevation of the carriage and a portion of the bed of the machine shown in FIG. 1; FIG. 7 is a plan view of the carriage of the machine shown in FIG. 1; FIG. 8 is an enlarged end elevation of the truck of the carriage of the machine shown in FIG. 1; FIG. 9 is an end elevation of the truck shown in FIG. 8 mounted on the bed of the machine shown in FIG. 1; FIG. 10 is an enlarged front elevation of the centering and channel floor drilling module on the machine shown in FIG. 1; FIG. 11 is a plan view of the centering and channel floor drilling module shown in FIG. 10; FIG. 12 is an enlarged end elevation of the centering and channel floor drilling module shown in FIG. 10; FIG. 13 is an enlarged end elevation of the drilling guide for the lower end of the centering and channel floor drilling module shown in FIG. 10; FIG. 14 is an end elevation of the gripper module shown in FIG. 1; FIG. 15 is a front elevation of the gripper module shown in FIG. 14; FIG. 16 is an enlarged sectional end elevation of the main body portion of the gripper module shown in FIG. 14, viewed from the opposite side from FIG. 14; FIG. 17 is an enlarged sectional elevation of the jaw portion of the gripper module shown in FIG. 16, showing the jaw in its open position; FIGS. 18 and 19 are schematic elevations of the main body portion of the gripper module shown in FIG. 14 to illustrate the operation; FIG. 20 is an end elevation of the rear centering and clamp-up jaw actuator module on the machine shown in FIG. 1; FIG. 21 is a plan view of the module shown in FIG. 20; FIG. 22 is a front elevation of the module shown in FIG. 20; FIG. 23 is a plan view of the clip feeding and presenting module on the machine shown in FIG. 1; FIG. 24 is an elevation of the clip feeding and presenting module shown in FIG. 23; FIG. 25 is a sectional elevation along lines 25--25 in FIG. 24; FIG. 26 is an elevation along lines 26--26 in FIG. 24; FIG. 27 is a sectional elevation of the clip presenter along lines 27--27 in FIG. 23; FIG. 28. is a sectional elevation of a portion of the clip presenter along lines 28--28 in FIG. 27; FIG. 29 is a schematic plan view of the clip presenter shown in FIG. 27, illustrating the function of the rollers; FIG. 30 is a perspective view of the articulated rollers and the back roller in the parts presenter shown in FIG. 27; FIG. 31 is a schematic view of the articulated rollers shown in FIG. 30, showing their function with a clip having a flat web and a clip having a stepped web; FIG. 32 is a front elevation of a positional mounting plate for the drill units of the clip-to-stringer modules shown in FIG. 5, FIG. 33 is an end elevation of the positional mounting plate shown in FIG. 32; FIG. 34 is a schematic of the computer architecture of the invention shown in FIG. 1; FIGS. 35-38 are schematic views illustrating the process of loading clips into the machine shown in FIG. 1; FIGS. 39-43 are schematic views showing the process used by the machine shown in FIG. 1 of centering the stringer and drilling a hole in the center of the stringer floor; FIGS. 44-48 are schematic views showing the process used by the machine shown in FIG. 1 of indexing a clip to a reference position for pick-up by the gripper module; FIGS. 49-51 are schematic views of the process used by the machine shown in FIG. 1, of drilling a clip-to-frame coordination hole and preparing to insert the clip into the stringer channel; and FIGS. 52 and 53 are schematic views showing the process used by the machine shown in FIG. 1 of spreading the stringer channel and inserting the clip for drilling. DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings, wherein like reference numerals designate identical or corresponding parts, and more particularly to FIGS. 1 and 1A thereof, a stringer and stringer clip drilling machine is shown for drilling coordination holes 10 in the floor 12 of a stringer 14, drilling a clip-to-frame coordination hole 16 in a stringer clip 18, inserting the clip 18 in the channel 20 of the stringer 14, and drilling four rivet holes 22 through the sides 24 of the stringer and the sides 26 of the clip 18. The machine has an elongated bed 30 supported on a floor 32 by a series of upright stanchions 34, each fastened between a floor engaging foot 36 and a capitol 38 engaging and supporting the bed on its underside. A carriage 40 is supported on the bed 30 for axial movement therealong. The carriage 40 includes a frame 42 connected to a truck 44 supported on bearings 46 that travel along a pair of parallel, vertically spaced rails 48 and 48' fastened to the back side of the box beam 31. A group of operating modules for performing operations on the stringer and stringer clips is mounted on the frame 42. The modules are a centering and channel floor drilling module 50, a clip gripper module 52, a clip-to-frame coordination hole drilling module 54, a rear stringer centering and clamp-up jaw actuator module 56, two clip-to-stringer hole drilling modules 58 and 58', and a clip feeding and presenting module 60. The construction and operation of these modules will be described in detail below. The frame 42 for supporting the modules 50-60 is a two part construction shown in FIG. 3, including a frame upright 62 and a frame bridge 64. The frame upright 62 and the frame bridge 64 are fastened together as shown in FIG. 4 to provide a rigid frame 42 having mounting points to which the operating modules are connected. The bridge 64 includes a front end extension 66 having a mounting plate 68 mounted on the right end face of the front end extension 66 to which the front clip-to-stringer hole drilling module 58 is fastened. A similar extension 66' is mounted on the back end of the bridge 64 projecting to the right and supporting a similar mounting plate 68' to which the back clip-to-stringer hole drilling module 58' is mounted, as shown is FIGS. 5 and 7. The clip-to-frame coordination hole drilling module 54 is mounted on a mounting plate 70 fastened to the top of the frame bridge 64, and the clip feeding and presenting module 60 is mounted on a stand-off mounting structure 72. fastened to the right side of the forward portion of the bridge 64. The centering and channel floor drilling module 50 is mounted on an mounting panel 74 at the front side of the frame upright 62 to the right of a opening 76 through the lower central portion of the frame upright 62. The clip gripper module 52 is mounted on a mounting panel 78 at the upper central portion of the frame upright 62 above the opening 76, and the rear stringer centering and clamp up jaw actuator module 56 is mounted on a narrow mounting panel 80 to the right of the central opening 76 in the frame upright 62. Turning now to FIG. 5, a positional motor 86 is shown mounted in the truck 44 and drives a pinion gear 88 which is engaged with a rack 90 fastened to the box beam 31 between the top and bottom rails 48 and 48'. The positional motor 86 is a servo motor with accurate feed back capability that enables it to provide information regarding the speed of translation of the carriage 40 along the bed 30. Power for the positional motor 46 and the drilling motors for the modules on the carriage 40, and also air and lubrication lines for the actuators on the modules is conveyed to the carriage 40 from a connector box 92 along a flexible cable carrier 94 to a connection 96 on the underside of the truck 44. The electrical and pneumatic lines are conveyed up through the center of the frame upright 62 and into an upper pneumatic control box 98 and a lower electrical control box 99, which boxes contain the electrical and pneumatic controls for the motors and actuators in the operating modules on the carriage 40. A positional scale 100 is mounted on the back side of the box beam 31 and a reader 102 is mounted on the underside of the truck 44 a position horizontally juxtaposed to the positional scale 100. The positional scale 100 and reader 102 in this preferred embodiment are elements of a Sony magnascale longitudinal position indicating system. The bed 30 includes a stringer holding fixture 104, shown in FIGS. 1 and 5, fastened to the top surface of the box beam 31 for holding a stringer 105 in position under the axis of the machine. An end stop 106 at the end of the stringer holding fixture 104 locates the end of the stringer when it is abutted against the end stop so the position of the stringer is established by that reference position. With use of the reference position established by the end stop 106 and the longitudinal position sensor system 100 and 102, the control system for the machine (to be described below) is able to position the carriage 40 lengthwise along the stringer held on the stringer holding fixture 104 with great accuracy lengthwise along the path of the stringer so that the holes are drilled at the correct position. Once a stringer 105 has been positioned on the stringer holding fixture 104 and secured in position at its right end against the stop 106, the carriage 44 is moved by energizing its positional motor to the first drilling location from the right hand end. The carriage is stopped with the axis 108 of the centering and channel floor drilling module 50 positioned over the location on the stringer where the hole is to be drilled. The centering and channel for drilling module 50 shown in FIG. 6 and shown enlarged in FIG. 8 includes two spreaders 110 each mounted on a shaft 112 supported on a actuator 114 for axial vertical movement and rotation about the vertical axis. Axial extension of the spreader 110 on its shaft 112 is caused by pneumatic pressure through a fitting 116 which pressurizes a pneumatic actuator 118 to extend the shaft 112 and the spreader 110 vertically downward into the channel of the stringer positioned under the axis 108. While in the extended position, the spreaders 110 can be rotated by pressurizing a rotary actuator 120 through a pneumatic fitting 122. After the spreaders 110 have been extended into the channel of the stringer and rotated to center the stringer under the access 108, motor 124 of a self feeding drill 126 is energized which rotates the shaft 128 of the drill and extends the quill 130 of the drill from its upper position illustrated in FIG. 8 to the lower position also illustrated in FIG. 8. A collet on 132 on the end of the shaft 128 holds a drill bit 134 which is supported in a drill bushing 136 fastened in the end of a drill guide 138 which is connected to the end of the quill 130. At the end of the plunge stroke, the quill 130 is retracted back up into the quill housing 140 and the motor 124 is automatically shut off. The spreader actuators 114 and 114' and the drill 126 are mounted on a support bracket 142 having a vertical plate 144 and a horizontal shelf 146. A o side brace 148 extends from the vertical plate forward to the front edge of the horizontal shelf and is welded to the vertical plate on the horizontal shelf to provide support to the horizontal shelf. The support bracket 142 is bolted to the mounting panel 74 at the four bolt holes shown in FIG. 4. As shown in FIG. 9, the support bracket 142 includes a center brace 150 35 welded between the vertical plate 144 and the horizontal shelf 146. An upright plate 152 is welded to the front end of the center brace 150 for supporting the quill housing 140 which is attached to the upright plate 152 by bolts 154. A clamp assembly 156 is attached to the right side of the side brace 148. The clamp assembly 156 includes two clamp arms 158 and 158' which are pivotally connected at a support block 160 which is bolted to the side of the side brace 148 as shown in FIGS. 9 and 10. A pneumatic cylinder 162 is pinned at 164 at an intermediate position on the arm 158'. A piston rod 166 extending from the pneumatic cylinder 162 is pinned at 168 to the intermediate portion of the other clamp arm 158. A pair of fittings 170 and 170' connects the pneumatic cylinder 162 to sources of pneumatic pressure controlled by valves in the control box 98 so that the cylinder 162 on opposite sides of the piston connected to the piston rod 166 can be selectively pressurized to open and close the arms 158 and 158' of the clamp 156. A sensor 172 is mounted in the support block 160 for detecting when the clamp arm 158 has moved to its clamped position. This is a signal to the control system that a stringer clip is clamped in the stringer and ready for drilling, as will be explained in detail below. The gripper module 52, shown in the FIGS. 14-19, includes a mounting plate of 180 fastened to the mounting panel 78 above the opening 76 in the frame upright 62. A clamp actuator housing 182 is mounted on linear bearings 184 and 184' for vertical movement along a vertical axis 186. Vertical movement is effected by rotation of a ball screw 188 engaged with a ball nut 190 fastened to the top of the housing 182. The bottom end of ball screw 188 is held in a bearing in a end support 192, and the upper end of the ball screw 188 is driven by a servomotor 194 having highly accurate feedback capabilities to enable accurate positioning of the housing 182 and the clamp 196 supported in the housing 182, as described below. An upper limit switch 198 and an identical lower limit switch 200 are provided to cut the power to the servomotor 194 in the event that an aberration in the control system causes the servo motor 194 to drive the housing 182 beyond its normal limits toward a hard stop at either end of the travel along the rail 185, which could cause damage to the ball screw and/or ball nut. A home pulse switch 202 is provided in line with a trip vane 204 to provide an electrical signal when the body 182 reaches a reference position indicated by the height of the home pulse switch 202 on the mounting plate 180. Turning now to FIG. 16, an air cylinder 206 is mounted on top of the body 182 for raising and lowering a rod 208 for operation of the clamp 196. The rod 208 is connected through a clevis 210 to the piston rod of the air cylinder 206. A clamp body 214 is mounted on bearings 216 and 218 in the housing 182 for rotational motion about the axis 186. Rotational motion of the clamp body 214 is effected by a rotary actuator 216 coupled to a gear 218 journaled in the housing 182. The gear 218 is engaged with a gear 220, equal in diameter to the gear 218, fastened to the upper end of the clamp body 214. Operation of the rotary actuator 216 by pneumatic pressure delivered through a fitting 222 rotates the rotary actuator 216 through 180° which rotates the gear 220 through 180° . This rotational capability enables the clamp 186 to position the a clip 18 in the channel 20 of the stringer 14 in either of two 180° rotated positions. A jaw cam 224 is pinned to the bottom end 226 of the rod 208 and is guided for vertical motion in the bottom end of the clamp body 214 by a miniature linear bearing 228 engaged with a rail 230 mounted on the clamp body 214. The jaw cam 224 engages a roller 232 pivotally mounted on the upper end of a jaw 234. The jaw 234 is mounted on a pivot pin 236 mounted in the clamp Is body 214. A pad 238 of resilient material such as polyurethane is mounted on the lower end of the jaw 234 for engaging and holding a clip 18 when the jaw cam 224 is lowered to force the roller 232 outward away from the axis 186 and pivot the jaw 234 about the pivot pin 236. A spring 240 opens the jaw 234 when the jaw cam 224 is lifted by the air cylinder 206 as illustrated in FIG. 17. A sensor 242 having a probe 244 detects when a clip is present in the jaws when the jaws close to provide feedback to the control system that a clip has been captured by the clamp 196 when the jaws close. In operation, when the time in the cycle has arrived for a clip 18 to be picked up, the servomotor 194 rotates the ball screw 188, and the ball nut 190 engaged with a ball screw 188 travels down the ball screw carrying the housing 182 vertically downward guided by the bearings 184 and 184' on the rail 185. When the clamp has reached the correct vertical position as indicated by the control system monitoring the feedback from the servomotor 194, pneumatic pressure is delivered to the air cylinder 206 through a fitting 246 to drive the piston 248 in the air cylinder 206 downward, which drives the rod 208 and its connected jaw cam 224 downward into engagement with the roller 232 on the jaw 234, rotating about is pivot 236 to clamp the clip 18 between the jaw 234 and the lower end of the clamp body 214. The servomotor 194 is reversed to rotate the ball screw in the opposite direction to lift the clip to the desired height, as explained below. Turning now to FIG. 20, the rear stringer centering and clamp jaw actuator module 56 is shown having a clamp support block 250 in which a pair of clamp arms 252 and 252' are supported for a pivotal motion about a pivot pins 254 and 254'. The clamp arms are actuated by a pneumatic cylinder 256 which is pressurized through a fitting 258. The cylinder 256 is pinned at one end to the arm 252' and a piston rod 259 connected to a piston in the cylinder is pinned to the other arm 252. The clamp support block 250 is fastened to the left side of a projecting vertical leg 260 of an L-shaped mounting bracket 261, as shown in FIG. The body of a rotary actuator 262, identical to the rotary actuators 120 on the centering and channel floor drilling module 50, is fastened to the other side of the leg 260. The mounting bracket 261 has an orthogonal leg 263 extending parallel to the front surface of the frame upright 62. A pair of linear bearings 278 are connected to the orthogonal leg 263 for vertically movable connection of the module 56 to the frame upright 62. Pneumatic power for the rotary actuator 262 is conveyed to the actuator 262 through a cable control chain 264 extending from a fixed flange 266 at the top end of a support plate 282 mounted on the frame upright 62 at the mounting panel 78. The cable control chain 264 is connected at the other end to a bracket 268 fastened to the clamp support block 250. Operation of the rotary actuator 262 rotates a spreader 269 projecting down from the rotary actuator to a position rotated 90° from the position illustrated in FIGS. 20 and 22.. The spreader 269 is identical in design to the spreaders 110 on the module 50. The module 56 is vertically moveable under control of a three position air cylinder 270. Air to the air cylinder 270 is provided through fittings 272, 272' and 272". The three positions are provided to give an upper raised position to enable the machine to return to its home position clearing all of the stringer clips that have been inserted, an intermediate position used as to clear the way for the parts presenter (to be described below) when clips 18 are to be removed from a parts magazine and inserted in the stringer 14, and a lower operating position illustrated in FIG. 20 in which the spreader is positioned in the channel of the stringer and the clamp engages the stringer 14. A piston rod 274 extends from a piston inside the air cylinder 270 to a threaded hole in the top of the orthogonal leg 263 of the mounting bracket 261. Two bearing blocks 276 are fastened to the back side of the orthogonal leg 263 and are engaged with a rail 280 of a linear bearing which guides the vertical motion of the module 56. The rail 280 is fastened to the support plate 282 which is bolted to the mounting panel 78 on the frame upright 62. In operation, the module 56 starts in its retracted position with the piston rod retracted fully into the air cylinder 270 and with the clamp and the spreader 273 in their fully elevated positions. When the air valve in the control box 98 controlling air flow to the air cylinder 270 is opened by the control system, the air cylinder 270 is pressurized above the piston attached to the piston rod 274, driving the piston and attached piston rod 274 downward to lower the spreader 263 into the channel of the stringer 14. The control system similarly pressurizes the rotary actuator 262 through fittings 284 which rotates the spreader 269 through 90° from the position shown in FIGS. 20 and 22. The spreader 269 slightly spreads the legs of the stringer 14 to the spread position indicated in Fig. 20 which facilitates the insertion of a clip 18 by the gripper module 52. The spreader 269 is then rotated back into its 0° position illustrated in FIG. 20 and the clamp arms 252 in 252' are closed to engage the sides of the stringer 14 to clamp the clip 18 securely within the stringer 14. While in this position and still held securely by the jaw 234 of the gripper module, four holes are drilled horizontally through the side of the stringer 14 and the sides of the clip 18, as will be described below, by the clip-to-stringer hole drilling modules 58 and 58'. Thereafter, the clamp arms 252 and 252' are released and the module 56 is raised back to its home position, leaving the drilled clip in place in the drilled stringer 14. Turning now to FIGS. 23 through 25, the clip feeding and presenting module 60 as shown mounted on the stand-off mounting structure 72 by a set of linear bearings which enable the module 60 to move laterally toward and away from the central line of the machine, enabling the gripper module 52 to grip and remove a clip 18 from the pads presenting modules 60 and then carry the clip 18 straight down into the stringer after the pads presenting module 60 has traveled laterally away from the center line of the machine and clear of the path of the gripper module 52. The linear bearing 290 includes a pair of bearing blocks 292 fastened to the projecting ends of a flange 294 on the left side of the standoff mounting structure 72. The bearing blocks 292 are engaged with a rail 296 fastened to the vertical sidewall 298 of a pads presenter housing 300. A pneumatic cylinder 302 provides the motive force for moving the pads presenter laterally toward and away from the center line of the pads gripper 52. The pneumatic cylinder 302 is connected to a mounting block 304 which is screwed to the side of the vertical sidewall 298 of the housing 300. A piston rod 306 extends from the cylinder 302 and is fastened at its distal end to a connector block 308 fastened to the front end of the flange 294. Air lines are connected to a pair of fittings 310 and 310' for selectively providing air pressure to one side or s the other of a piston in the cylinder 302 connected to the piston rod 306 for selectively moving the parts presenter laterally inward or outward toward or away from the center line of the gripper 52. A cartridge bed 312 is screwed to the top plate 314 of the housing 300. The cartrige bed 312 is actually made of 2 mirror image parts 316 and 318 each having an upwardly extending flange 320 and 320' on their outside edges and a slot 322 and 322' milled along the inner facing edges to produce a cruciform slot 324 between the parts 316 and 318. The slot 324 and an aligned slot in the top plate 314 of the housing 300 receives a pusher arm 328 which is attached at its lower end to a shuttle 330 of a rodless cylinder 332. An air fitting 334 is connected to the rodless cylinder 332 through the vertical sidewall 298 of the housing 300 for energizing the rodless cylinder and driving the shuttle 330 and the attached pusher arm 328 longitudinal along the housing 330 toward the center line of the gripper 52. The air fitting 334 connects flexible air lines to the housing 300 so that the rodless cylinder 332 remains connected to a source of air pressure despite its lateral movement toward and away from the center line of the gripper 52. A clip cartrige 340 is removable mounted on a cartrige bed 312. The clip cartrige 340 includes an elongated U shape channel 342 and an enlarged end plate 344. The clip cartrige 340 has an elongated slot through the floor of the channel from the rear end to the adjacent the front end to receive the pusher arm 328 which pushes the clips 18 forward in the U shape channel 342. An outer end plate 348 having a slot in the bottom aligned with a slot 346 in the floor of the U shape channel 342 is screwed to the end of the U shape channel 342. The outer end plate includes a bridge 350 at its top end which spans the channel and provides rigidity to the structure of the clip cartridge 340. A clip presenter 360 is mounted at the front end of the module 60 for receiving clips 18 pushed in from the clip cartridge 340, and for lifting and aligning the clips 18 to an index position to be gripped by the gripper module 52. The parts presenter, shown in FIG. 27, includes a clip presenter housing 362 having an outwardly and upwardly opening central cavity 364 positioned and aligned opposite to the channel of the clip cartridge 340 when it is latched into the cartridge bed 312 for receiving clips 18 one at a time as they are pushed into the cavity 364 from the cartridge 340 by the pusher bar 328. An elevator 366 is positioned in the floor of the cavity of 264 and includes an elevator body 368 having depending sides 370 and 372 of for guidance of s vertical motion in the cavity 364. A block 374 is attached to the sidewall of the cavity 364 and supports an air cylinder 376, and an air fitting (not shown) connects an air supply line to the cylinder 376 for pressurizing the cylinder and extending a piston rod and the attached elevator body 368 to the limit indicated by the upper limits of a recess 380 milled in the side of the cavity 364. When the clip 18 is raised by the elevator 366, a spring loaded roller 382 presses the clip against the inner face of the cavity 364, and another spring loaded roller 384 engages the lower protruding lobe 386 of the clip 18 and pushes the clip 18 against a pair of articulated rollers 388. The articulated rollers establish the reference plane to which the clip 18 is to be moved and is allows the clips with a stepped webbed 390 to remain in the vertical position, as illustrated in the upper view of FIG. 31, as well as clips with a flat web flat web 392, as shown in the lower view of FIG. 31. In operation, the clip cartridge 340 with a load of clips is inserted in the cartridge bed 312 and two holes 394 at the base of the end plate 344 are aligned with a pair of tapered location pins 396 mounted in holes 398 in the housing 362. The clip cartridge 340 is pushed against the face of the housing 362 and a spring loaded cam 400 mounted on the end of a shaft of 402 which in turn is mounted on the underside of the top plate 314, snaps into place behind the end plate 344 to hold it in place against the face of the housing 362. When it is desired to release the clip cartridge, a handle 404 on the end of the shaft 402 is lifted to lower the cam and release the clip cartridge 340 for removal from the cartridge bed 312. With the clip cartridge 340 latched in place, the machine at the appropriate time energizes the rodless cylinder 332 to drive the shuttle 330 and the attached pusher arm 328 along the slot 326 and the cruciform slot 324 in the cartridge bed 312. The pusher arm 328 is guided in the cruciform slot 324 by two laterally spaced pins (only one which is shown is FIG. 26) extending through the pusher arm 328. The pusher arm 328 pushes the clips laterally toward the center line of the gripper module 52 and the inner clip enters the cavity 364. At the appropriate time, the air cylinder 376 of the elevator 366 is energized to raise the clip 18 to the index position. When the clip is raised, the roller 382 bears against the inside of the lobe 408 of the clip 18 to hold the clip against the inner face of the cavity 364, and the roller 394 bears against the outside curved surface of the lobe 386 of the clip 18 to push the clip against the indexing articulated rollers 388. The clip is now held in a accurately known index position for pickup by the gripper module 52. When the gripper module has removed the clip 18 from the clip presenter 360, the air pressure in the air cylinder 376 is reversed to lower the elevator 366, and the air pressure in the cylinder 302 is reversed to retract the piston and its attached piston rod 306 into the cylinder 302 to withdraw the clip feeding and presenting module 60 from its forward position back to its retracted position. The clip to frame coordination hole drilling module 54 and the clip to stringer hold modules 58 and 58' are based on the same structure used in the centering and channel floor drilling module 50. Turning back to FIG. 6, the modules 50 and 54 each have an identical drill unit 410 which includes a drill motor 412, a connector housing 414 rigidly connected to the drill motor 412 and a quill housing 416. A drive belt in the connector housing 414 connects a sheave fastened to the motor shaft to another sheave connected to a parallel drill drive shaft (not shown) rotatably supported in a quill 417. The quill is longitudinally supported in the quill housing 416 and can be advanced and retracted in the housing 416 by air pressure delivered through fittings 418 and 420 respectively. The feed speed of the quill 417 in the quill housing 416 is adjustable to allow rapid feed toward the work piece and then slow drilling feed as the drill contacts and drills through the work piece. The drill units 410 for the modules 50 and 54 are commercially available under the trade name Suhner BEM Monomaster. The opposed clip-to-stringer hole drilling modules 58 and 58' use similar drill units from the same source, but use a slightly more powerful motor because they each drill 2 holes simultaneously. Each of the drill unit 422 and 422' on the modules 58 and 58' is mounted on a positional mounting plate of 424 the plate 424 is mounted on the mounting plate 68 secured to the front end extension of the frame bridge 64. The positional mounting plate 424 includes a pair of linear bearings 426 and 428 to which the drill units 422 are fastened as indicated by the dotted lines in FIG. 33. The linear bearings 426 and 428 prevent limited vertical motion of the drill unit 422 under control of air cylinder 430 to enable the vertical position of the holes drilled are the drill units 422 and 422' to be elevated slightly when the clip 18 is to be placed in the stringer 14 at the position of a joggle, or step in the base of the stringer 14. The cylinder 430 has a piston rod 432 which bears against the underside of the drill unit 422 to lift the drill unit 422 vertically upward when then air cylinder 430 is pressurized. An upper adjustable stop of 434 and a lower adjustable stop 436 are attached to flanges 438 and 440 respectively at the upper and lower edges of the positional mounting plate 424. A sensor 442 is mounted in the flange 438 in line to sense the upper edge of the base plate 444 by which the drill unit 422 is attached to the positional mounting plate 424. The sensor 442 sends a signal to the control system that the drill unit 422 is its raised position so that operation of the unit 422 to drill holes in the stringer and clip at a joggle position may proceed. A conventional gearbox 444 is mounted on the end of the quill 417 and the drill shaft is coupled to the input shaft of the gearbox. The gearbox 444 has internal gearing that drive a pair of parallel collets which hold parallel drills for drilling two holes simultaneously in each side of the stringer 14 and the clip 18 held in place by the jaws of the gripper module 60. Turning now to FIG. 34, the computing architecture for control of the machine is shown schematically to include computer functions which are performed on the CAD/CAM main frame 446 where the original engineering digital product definition is recorded and available as the ultimate product definition authority. A numerical control 448 converts this data into a form that is usable by a post processor 450, which converts the digital parts definition data into a form that is compatible with the computer controller for the machine and stores the parts information on an IMS Database 452. The IMS Database 452 is a large capacity storage bank for storing all the pads programs that will be used by the stringer/clip drilling machine. The other computing functions are performed at computer hardware stations adjacent the stringer/clip drilling machine, and are performed by two separate computer hardware units, an HP 9000/710 MDMS DNC server 454, and the machine controller 456 which in the case of the preferred embodiment is an Allen Bradley 9/260 CNC. The server 454 is connected to the IMS database 452 through a suitable computer connection such as a phone connection such as a DEC DEMSA and a DEC Microvax SNA Gateway, or preferably through an Ethernet TCP/IP. In operation, the clip cartridge 344 is first loaded, as illustrated in FIG. 35, by inserting clips 18 into a cartridge from the open front end of the cartridge in reverse order from which the clips 18 are to be removed, that is, "last in, first out" order. The loaded cartridge, illustrated in FIG. 36, is loaded onto the cartridge bed 312 by aligning the holes 394 in the cartridge end plate 344 with the locating pins 396 on the housing 362 and sliding the cartridge 344 against the face of the housing 362 until the cam latch 400 snaps behind the end plate 344 to hold it in position, as shown in FIG. 38. A stringer 14 is loaded onto the stringer holding fixture 104 and is secured against the end stop 106, as shown in FIG. 6, by a clamp at the other end of the stringer. In the fixture 104, the stringer 14 is positioned under the line of action of the spreaders 110 and the drill quill 130 of the drill 126, as shown in FIG. 39. To ensure that the drill 126 drills a coordination hole in the floor of the stringer 14 where specified (usually in the center) the spreaders are plunged into the channel 20 of the stringer 14 by the cylinders 118 as shown in FIG. 40, and are rotated 90° as illustrated in FIGS. 41 and 42 to center the stringer under the centerling of the drill 126. The air cylinder in the quill housing for the drill 126 is now pressurized by the control system and the quill plunges into the stringer channel 20 to drill a coordination hole 10 in the floor of the stringer 14. After drilling, the quill 130 is retracted and the servomotor 86 is energized to move the carriage to the next hole position, where the next hole is drilled automatically. All the coordination holes are drilled in the floor of the stringer in this manner and the carriage is moved back to the home position in preparation for insertion and drilling of the stringer clips 18. On signal from the control computer 456, clip feeding and presention module is moved inward by a signal to the air valve that controls the air to the air cylinder 302, and the module 60 slides inward on the linear bearing 290. Simultaneously, the rodless cylinder 332 is pressurized, moving the shuttle 330 and the pusher arm 328 to the left in FIG. 44, pushing the stack of clips 18 to the left and pushing the first clip into the central cavity 364 of the clip presenter 360. The air cylinder 376 is pressurized by the control computer 456 opening the appropriate valve, and the piston rod 378 extends to raise the elevator body 368, as shown in FIG. 45, to the index position. As the clip rises in the central cavity 364, the roller 382 engages the inside face of the lobe 408 to hold the clip against the inside face of the cavity 364, as shown in FIG. 46, and the roller 384 engages the edge of the lobe 386 to push the clip against the index surface established by the articulated rollers 388, as shown in FIGS. 46-48. The rollers and the elevator 366 position the clip precisely in an index position to be gripped and lifted by the gripper module The servomotor 194 of the gripper module 60 is commanded by the control computer to drive the ball screw 188 to lower the gripper jaws 234 over the clip 18. As the module 60 descends, the air cylinder retracts the piston and withdraws the rod 208 and the connected jaw cam 224 upward. The spring 240 opens the jaw 234 so that the jaw is open when it reached the index position of the clip 18. The precise feedback system of the servomotor 194 enables the computer controller 456 to position the jaw 234 at precisely the right height to pick up the clip 18 with an exactly known portion of the clip extending below the jaw 234 for positioning in the stringer channel 20. The air pressure in the air cylinder 206 is reversed, lowering the rod 208 and driving the jaw cam against the jaw roller 232, closing the jaw 234 on the clip 18, as shown in FIG. 49. The computer controller 456 now commands the servomotor 194 to drive the ball screw 188 to raise the jaw 234 and the gripped clip 18 out of the central cavity 364 and up to a position opposite the clip-to-frame hole drilling module 54, as illustrate in FIG. 50. The cylinder in the quill housing 416 is pressurized on command of the computer controller 456 and the quill 417 advances and drills a hole through the clip 18 while it is held in the correct position by the jaws 234. To prevent an excessive moment from being exerted on the clip 18 while it is being drilled, a slot 235 is cut in the center of the ends of the jaw 234 and the facing jaw on the clamp body 214, and the coordination hole is drilled through the slot. The clip feeding and presenting module 60 is withdrawn away from the gripper module by pressurizing the opposite side of the cylinder 302 to extend the piston rod and push the housing 300 back along the rail 296. When the computer controller is informed that the housing 300 is withdrawn, by a signal from a sensor in the bearing block 292, the servomotor 194 is reversed to rotate the ball screw to drive the gripper module and the gripped clip down toward the channel 20 of the stringer 14. Simultaneously, cylinder 270 of the rear stringer centering and clamp-up module 56 is pressurized to lower the spreader 269 into the channel 20 of the stringer 14, and the cylinder 118' of the centering and floor drilling module 50 is pressurized to lower the spreader 110' into the channel 20 of the stringer 14. Both rotary actuators 122' and 262 are pressurized to rotate the spreaders 110' and 269 by 90° to spread the sidewalls 24 of the stringer 14 to facilitate the entry of the clip as it is carried into the channel 20 by the gripper module. When the computer controller detects that the clip has reached the correct position in the channel 20, it commands the clamp actuator cylinders 162 and 256 to close the clamp arms 158 and 252 on the sidewalls 24 of the stringer to press the sidewalls against the sides of the clip 18, thereby increasing the security of the position against any slippage while the stringer and clip are being drilled, and also eliminating drilling burrs between the clip and the stringer sidewalls. When the sensors 172 257 in the clamp bracket 160 and 250 indicate that the clamp has closed, the computer controller turns on the drill motors on the drill 422 and 422' and pressurizes the air cylinders in the quill housings to advance the quills toward the stringer. The two parallel drills in each gearbox 444 simultaneously drill the four holes through the stringer sidewalls 24 and the stringer clip 18, and then retract. The computer controller commands the jaw to release the clip and retract and the clamps release the stringer sidewalls, and the module 56 retracts. The cycle is then repeated until all the clips 18 are place in the stringer at the designated positions in the engineering part definition and drilled, and the computer controller 456 commands the carriage to retract to home position. The controller signals the the operator that the operations are completed and the stringer is ready for removal from the holding fixture and replacement with the next stringer. Obviously, numerous modifications and variations of the described preferred embodiment will occur to those skilled in the art.

A machine for positioning clips in channel-shaped airplane fuselage stringers, and drilling holes in the stringers and clips, includes an elongated beam support having a box beam supported on five floor engaging legs and supporting a carriage assembly positioned on said beam and supported on bearings traveling along rails on the beam for longitudinal movement therealong. A motive mechanism, including a servomotor in the carriage and driving a pinion engaged with a rack fastened to the beam moves carriage longitudinally along the beam. An index mechanism including a fixed end stop at a known position indexes a stringer on the beam at a fixed reference position thereon. The stringer is centered under a drill by a centering mechanism mounted on the carriage, and a drill system drills a series of vertical holes along the channel floor of the stringer at locations specified in a digital product definition of said part. A multiplicity of clips is held in a clip cartrige for feeding the clips in order to a gripper for gripping, moving and placing a series of clips in the stringer channel and holding the clips in a specified position while they are drilled by two opposed drills disposed on a horizontal axis orthogonal to the stringer axis for drilling through side walls of the stringer and the clip positioned in said stringer. A pads positioner mounted for lateral movement toward and away from the axis of the stringer receives the clip cartrige and positions clips from the cartrige at a specified position to be gripped and picked up by the gripper. A position feedback and control system receives product definition information from a central product definition repository and translates the product definition information into machine instructions for moving elements of the machine to correct positions for drilling holes in the stringer and stringer clip to match corresponding holes drilled in airplane fuselage panels and frames to enable the parts to be positioned accurately with respect to each other without use of hard tooling.

CROSS REFERENCE TO RELATED APPLICATIONS This application is related to L&P 629865-2, U.S. patent application Ser. No. 14/041,667 filed Sep. 30, 2013, and U.S. Pat. No. 8,853,709, issued Oct. 7, 2014, which are incorporated herein by reference as though set forth in full. STATEMENT REGARDING FEDERAL FUNDING None TECHNICAL FIELD This disclosure relates to GaN complementary metal-oxide-semiconductor (CMOS) technology. BACKGROUND GaN N-channel transistors are known in the prior art to have excellent high-power and high-frequency performance. However, there are applications in which it is desirable to have a P-channel GaN transistor that can work with a GaN N-channel transistor on the same integrated circuit or substrate so that a high performance complementary metal-oxide-semiconductor (CMOS) integrated-circuit (IC) can be realized. The embodiments of the present disclosure answer these and other needs. SUMMARY In a first embodiment disclosed herein, a semiconductor device comprises a substrate, a III-nitride buffer layer on the substrate, an N-channel transistor comprising a III-nitride N-channel layer on one portion of the buffer layer, and a III-nitride N-barrier layer for providing electrons on top of the N-channel layer, wherein the N-barrier layer has a wider bandgap than the N-channel layer, a P-channel transistor comprising a III-nitride P-barrier layer on another portion of the buffer layer for assisting accumulation of holes, a III-nitride P-channel layer on top of the P-barrier layer, wherein the P-barrier layer has a wider bandgap than the P-channel layer, and a III-nitride cap layer doped with P-type dopants on top of the P-channel layer. In another embodiment disclosed herein, a method for providing a semiconductor device comprises forming a III-nitride (III-N) layer buffer layer on a substrate, forming a III-N N-channel layer on the buffer layer, forming a III-N N-barrier layer on the N-channel layer, forming a first dielectric layer on top of the N-barrier layer, etching the first dielectric layer, the N-barrier layer, and the N-channel layer to form a first mesa for an N-channel transistor and to expose a portion of the buffer layer, forming a second dielectric layer over the first mesa and over a first area of the exposed portion of the buffer layer, wherein the first area is adjacent the first mesa, and wherein a remaining portion of the buffer layer is exposed, forming on top of the remaining exposed portion of the buffer layer a III-N P-barrier layer, forming on top of the III-N P-barrier layer a III-N P-channel layer, forming on top of the III-N P-channel layer a III-N P-cap layer, wherein the III-N P-barrier layer, the III-N P-channel layer, and the III-N P-cap layer form a second mesa for a P-channel transistor, and wherein the first and second mesa are separated by the first area on the buffer layer, removing the second dielectric, and implanting ions in the buffer layer between the first mesa and the second mesa for providing isolation between the N-channel transistor and the P-channel transistor. These and other features and advantages will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features, like numerals referring to like features throughout both the drawings and the description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-section of a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure; and FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O show a process flow for fabrication a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure. DETAILED DESCRIPTION In the following description, numerous specific details are set forth to clearly describe various specific embodiments disclosed herein. One skilled in the art, however, will understand that the presently claimed invention may be practiced without all of the specific details discussed below. In other instances, well known features have not been described so as not to obscure the invention. The present disclosure describes a GaN CMOS technology which integrates N-channel and P-channel GaN transistors on the same wafer. The result is a high performance GaN-based complementary metal-oxide-semiconductor (CMOS) integrated circuit. CMOS IC is the preferred topology for many circuit applications, due to its high noise immunity and low power consumption. L&P 629856-2, which is incorporated by reference, describes a P-channel transistor. The GaN ICs of the present disclosure integrate N-channel and P-channel transistors on a common substrate and have better performance than a circuit with discrete GaN N-channel and/or P-channel transistors because more functionality can be achieved with less power consumption. An advantage of the GaN ICs of the present disclosure is that their performance is better than what can be attained with Si CMOS, because high performance N-channel and P-channel GaN transistors are used. FIG. 1 shows a cross-section of a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure. The substrate 10 can be GaN, AlN, Sapphire, SiC, Si or any other suitable substrate material. FIG. 1 is further described below with reference to FIG. 2O . FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O show a process flow for fabrication a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure. FIG. 2O is the same as FIG. 1 , but is also shown in the process flow for completeness. Referring now to FIG. 2A , a III-N layer buffer layer 12 is on the substrate 10 , and may be grown by chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). The buffer layer 12 may be GaN. On top of the buffer layer 12 is III-N N-channel layer 14 , which may be GaN, and which may be grown by MOCVD or MBE. On top of the III-N N-channel layer 14 is a III-N N-barrier layer 16 , which may be grown by MOCVD or MBE. The barrier layer 16 can be AlGaN, AlInN, AlInGaN, AlN, or a combination of these layers. The barrier layer 16 has a wider bandgap than the N-channel layer 14 , and the thickness of the barrier layer 16 is typically in the range of 1˜100 nm. A layer of dielectric 18 is deposited on top of the N-barrier layer 16 . The dielectric 18 may be SiN, SiO 2 , SiON, AlN, or any combination of those, and may have a thickness of 1˜500 nm. Next with reference to FIG. 2B , the dielectric 18 , the barrier layer 16 , and the channel layer 14 are etched to create a mesa 52 of the channel layer 14 , the barrier layer 16 and the dielectric 18 and to expose a portion of the buffer layer 12 . Then as shown in FIG. 2C , a dielectric 60 is formed over the mesa 52 and over an area 54 of the exposed portion of the buffer layer 12 . Next with reference to FIG. 2D , on top of the remaining portion 56 of the buffer layer 12 , a III-N P-barrier layer 20 may be grown by MOCVD or MBE. The P-barrier layer 20 can be AlGaN, AlInN, AlInGaN, AlN, or a combination of these. The thickness of the P-barrier layer 20 is typically in the range of 1˜100 nm. The P-barrier layer 20 assists in the accumulation of holes. On top of the III-N P-barrier layer 20 , a III-N P-channel layer 22 may be grown by MOCVD or MBE. The P-channel layer 22 is typically GaN, with a narrower bandgap than the P-barrier layer 20 . The thickness of the P-channel layer 22 is typically in the range of 1˜100 nm. On top of the III-N P-channel layer 22 , a III-N P-cap layer 24 may be grown by MOCVD or MBE. The III-N P-cap layer 24 is typically GaN doped with Mg. The Mg concentration can vary across the P-cap layer 24 . The thickness of the P-cap layer 24 is typically 1˜100 nm. Then, as shown in FIG. 2E , the dielectric 60 , which masked the mesa 52 and the area 54 of the buffer layer 12 while forming the P-barrier layer, the P-channel layer, and the P-cap layer, is removed. The result, as shown in FIG. 2E is the mesa 52 for an N-channel transistor, and a mesa 58 for a P-channel transistor. Next, as shown in FIG. 2F , the mesa 52 may be isolated from the mesa 58 by ion implantation 50 in the area 54 and on the sides of mesas 52 and 58 . Then, as shown in FIG. 2G , a dielectric 26 is deposited over the P-cap layer 24 of mesa 58 , and over a portion of area 54 between the mesa 52 and the mesa 58 . Next, as shown in FIG. 2H , a P-gate trench 62 is formed in dielectric 26 . The bottom of the P-gate trench 62 may extend partially or entirely through the P-cap layer 24 , and may also extend partially through the P-channel layer 22 . Then, as shown in FIG. 2I , a N-gate trench 64 is formed in dielectric 18 . The bottom of the trench 64 may extend partially or entirely through the dielectric 18 , partially or entirely through the barrier layer 16 , and partially or entirely through the N-channel layer 14 , so that the N-gate trench stops anywhere between the top surface of dielectric 18 and the top surface of the buffer layer 12 . Next, as shown in FIG. 2J , a dielectric 28 is formed over the device, so that the dielectric 28 is on top of dielectric 18 , covering the bottom and sides of N-gate trench 64 , on top of dielectric 26 , and covering the bottom and sides of P-gate trench 62 . The dielectric 28 is typically a stack of AlN/SiN layer, grown by MOCVD. The dielectric 28 may also be only deposited in the N-gate trench 64 and the P-gate trench 62 to insulate the N-gate electrode 32 and the P-gate electrode 42 , respectively, for low gate leakage current. Then, as shown in FIG. 2K , N-ohmic openings 70 and 72 are made on opposite sides of the N-gate trench 64 . The openings 70 and 72 are made through the dielectric 28 , and may be made partially or entirely through the dielectric 18 , and in some cases partially or entirely through the N-barrier layer 16 . Next, as shown in FIG. 2L , the openings 70 and 72 are filled with metal to form N-ohmic electrodes 74 and 76 , forming source and drain contacts, respectively, for the N-channel transistor. Then, as shown in FIG. 2M , P-ohmic openings 80 and 82 are formed on opposite sides of the P-gate trench 62 . The openings 80 and 82 are made through the dielectric 28 , through the dielectric 26 , and in some cases partially or entirely through the P-cap layer 24 . Next, as shown in FIG. 2N , the openings 80 and 82 are filled with metal to form P-ohmic electrodes 84 and 86 , forming source and drain contacts, respectively, for the P-channel transistor. Finally, as shown in FIG. 2O , the N-gate trench 64 is filled with metal 32 to form a gate contact for the N-channel transistor, and the P-gate trench 62 is filled with metal 42 to form a gate contact for the P-channel transistor. The result is a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors, as shown in FIG. 1 , which is the same as FIG. 2O . Referring now to FIG. 1 , the substrate 10 may be but is not limited to GaN, AlN, Sapphire, SiC, or Si. The III-N buffer layer 12 is on the substrate 10 . As shown in FIG. 1 , on top of one portion of the buffer layer 12 , is the III-N N-channel layer 14 on the buffer layer 12 , and the III-N N-barrier layer 16 on the N-channel layer 14 . On top of another portion of the buffer layer 12 , is the III-N P-barrier layer 20 on the buffer layer 12 , the III-N P-channel layer 22 on the P-barrier layer 20 , and the III-N P-Cap layer 24 on the P-channel layer 22 . The dielectric 28 covers the bottom and sides of N-gate trench 64 , and the bottom and sides of P-gate trench 62 , as described above. Metal 32 fills gate trench 64 to form a gate contact for the N-channel transistor, and metal 42 fills gate trench 62 to form a gate contact for the P-channel transistor. N-ohmic electrodes 74 and 76 provide source and drain contacts, respectively, for the N-channel transistor, and P-ohmic electrodes 84 and 86 provide source and drain contacts, respectively, for the P-channel transistor. Ion implantation 50 in the area 54 between the N-channel transistor and the P-channel transistor provides isolation of the N-channel transistor from the P-channel transistor. A person skilled in the art will understand that the order of the steps of the process flow of FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O may be in another order to achieve the GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit shown in FIG. 1 . A person skilled in the art will also understand that well known steps of patterning and etching may be used in the process flow, such as for example to remove a layer or portion of a layer. Such well known processes are not described in detail, because they are widely used in semiconductor processing. Having now described the invention in accordance with the requirements of the patent statutes, those skilled in this art will understand how to make changes and modifications to the present invention to meet their specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention as disclosed herein. The foregoing Detailed Description of exemplary and preferred embodiments is presented for purposes of illustration and disclosure in accordance with the requirements of the law. It is not intended to be exhaustive nor to limit the invention to the precise form(s) described, but only to enable others skilled in the art to understand how the invention may be suited for a particular use or implementation. The possibility of modifications and variations will be apparent to practitioners skilled in the art. No limitation is intended by the description of exemplary embodiments which may have included tolerances, feature dimensions, specific operating conditions, engineering specifications, or the like, and which may vary between implementations or with changes to the state of the art, and no limitation should be implied therefrom. Applicant has made this disclosure with respect to the current state of the art, but also contemplates advancements and that adaptations in the future may take into consideration of those advancements, namely in accordance with the then current state of the art. It is intended that the scope of the invention be defined by the Claims as written and equivalents as applicable. Reference to a claim element in the singular is not intended to mean “one and only one” unless explicitly so stated. Moreover, no element, component, nor method or process step in this disclosure is intended to be dedicated to the public regardless of whether the element, component, or step is explicitly recited in the Claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for . . . ” and no method or process step herein is to be construed under those provisions unless the step, or steps, are expressly recited using the phrase “comprising the step(s) of . . . .”

A semiconductor device includes a substrate, a III-nitride buffer layer on the substrate, an N-channel transistor including a III-nitride N-channel layer on one portion of the buffer layer, and a III-nitride N-barrier layer for providing electrons on top of the N-channel layer, wherein the N-barrier layer has a wider bandgap than the N-channel layer, a P-channel transistor including a III-nitride P-barrier layer on another portion of the buffer layer for assisting accumulation of holes, a III-nitride P-channel layer on top of the P-barrier layer, wherein the P-barrier layer has a wider bandgap than the P-channel layer, and a III-nitride cap layer doped with P-type dopants on top of the P-channel layer.

CROSS REFERENCE TO RELATED APPLICATIONS Cross references to related application, 08/432,559, filed May 1, 1995, (attorney docket 6500 AUS) relates to the general field of the present invention. BACKGROUND OF THE INVENTION I. Field of the Invention The invention relates to the determination of the content of specified oxygenated components in a variety of liquids, particularly the concentrations of various alcohols and ethers in hydrocarbon liquids. Recent U.S. government environmental legislation has resulted in stringent regulatory agency guidelines for product makeup for the chemical and petroleum industries. The guidelines require light control of the chemical composition of these industries' products particularly the composition of gasoline. The oxygenate content of gasoline has received particular attention, with the requirement that reformulated gasolines contain between 2.0 and 2.7 percent by weight of oxygen it is possible to estimate the volume percentage of oxygenate, or the total weight percentage of oxygen in blended gasolines, based on known or estimated blend compositions, level and purity of oxygenate addition. However, it is not always possible to obtain the information required for an accurate calculation. Because it is likely that governmental regulation of the chemical composition of various products and fuels will increase in the future, efficient chemical, refined, and blending operations will require improved analytical procedures to insure compliance with the guidelines. II. Description of the Prior Art Prior patents related to the analysis of aromatics in hydrocarbon streams include U.S. Pat. No. 4,963,745 to Maggard, issued Oct. 16, 1990; U.S. Pat. No. 5,223,714 to Maggard, issued Jun. 29, 1993, U.S. Pat. No. 5,243,546 to Maggard, issued Sep. 7, 1993; U.S. Pat. No. 5,145,785 to Maggard and Welch, issued Sep. 8, 1992; international application WO 93/24823, published Dec. 9, 1993. U.S. Pat. No. 5,349,188 to Maggard, issued Sep. 20, 1994, teaches the determination of octane generally, and U.S. Pat. No. 5,349,189 to Maggard, issued Sep. 20, 1994, teaches the determination of hydrocarbon groups by group type analysis. Prior art teachings of the determination of oxygenated species can be found in prior literature and patents. A preferred technique is gas liquid chromatography with Oxygen Flame Ionization Detection (OFID), wherein a sample is injected into a partitioning column swept by an elutriating inert gas, e.g., 5% hydrogen in helium. Separated oxygenates in effluent from the partitioning column are converted to carbon monoxide by a cracking reactor, and then to methane by a methanizer. A flame ionization detector detects the several methane bands so produced from each of the oxygenates. The elapsed time for elutriation through the system is measured for the methane band representing each oxygenate. Non-oxygenated hydrocarbons do not interfere with this analysis because they are converted to elemental carbon and deposited on the catalyst contained in the cracker. The OFID procedure and apparatus used for this analysis are illustrated hereinafter in Example 5 and FIG. 4. Conventionally, the percentages of each of the individual oxygenated compounds is determined in weight percent total oxygen, and volume percent of each oxygenate as required. An example of this procedure is that taught by Wasson ECE Instrumentation, Inc. (1305 Duff Drive Suite 7, Fort Collins, Colo. 80524, Operations Manual Serial Number 930931). Although precise, gas chromatography is time consuming and labor intensive, and the considerable lag time involved can result in unacceptable cost when productions errors occur. Recently, near-infrared (NIR) spectrophotometric analysis has been used to perform oxygenate analysis. U.S. Pat. No. 5,362,965 to Maggard teaches the determination of oxygenate content in gasolines and other hydrocarbon fuels, with selection of wavelength ranges and data preprocessing to minimize the temperature dependence of the calibrations. As far back as 1948, Raman spectroscopy was considered for determination of aromatics content in hydrocarbon mixtures (U.S. Pat. No. 2,527,121). For a variety of reasons, however, extensive use of this procedure as a quantitative technique has not occurred to the degree of mid-IR or near-IR absorbance/reflectance spectroscopic methods. One reason for this may be that a significant limitation of Raman spectroscopy has been the presence of interfering fluorescence signals (with the exception of aviation fuel) due to excitation by visible lasers. Recently, FT-Raman spectrometers have been developed which eliminate the fluorescence problem in many cases by exciting in the NIR spectral region. This capability has sparked renewed interest in the use of Raman spectroscopy in the analysis of petroleum samples. For example, Shope, Vickers and Mann (Appl. Spectrosc., 1988, 42, 468) have demonstrated that when analytes are present in liquid mixtures as minor components, Raman spectroscopy is a viable quantitative technique. Using NIR-FT-Raman spectroscopy in combination with multivariate analysis techniques, Scasholtz, Archibald, Lorber and Kowalski (Appl. Spectrosc., 1989, 43, 1067) have demonstrated that quantitative analysis of percentage of fuel composition is possible for liquid fuel mixtures of unleaded gasoline, super-unleaded gasoline, and diesel fuels. In addition, Williams and co-workers (Anal. Chem., 1990, 62, 2553) have shown that NIR-FT-Raman spectroscopy in combination with multivariate statistics can be used to determine gas oil octane number and octane index. Chung, Clarke, and others have shown that Raman spectroscopy can be used in the quantitative analysis of aviation fuel in the determination of general hydrocarbon makeup, aromatic components, and additives (Appl. Spectrosc., 1991, 45, 1527; J. of Raman Spectrosc., 1991, 22, 79). Recently, Allred and McCreery described an NIR dispersive Raman instrument utilizing a GaAIAs NIR diode laser, a single-stage imaging spectrograph, CCD detection, and a fiber-optic probe (Appl. Spectrosc., 1990, 44, 1229; Appl. Spectrosc., 1993, 46, 262) for benzene and KNO 3 analysis. More recently, Cooper and co-workers have demonstrated (Spectrochimica Acta, 1994, 50A, 567) that low-cost CCD detection is feasible for remote fiber-optic Raman detection. While NIR technique is a viable analytical method for the majority of oxygenated species, the spectral similarity of the oxygenates in the NIR absorbance region make quantitation of individual compounds difficult with NIR when more than one compound is present in significant concentrations. Accordingly, there has remained and for a more effective procedure tier measurement of oxygenates in a variety of liquids, particularly in fuels. The invention addresses this need. SUMMARY OF THE INVENTION Accordingly, the invention relates, in one embodiment, to a process for preparing an analytical model for analyzing specified liquid mixtures for the presence and concentrations of certain oxygenated hydrocarbon compounds. Broadly, in this process, multiple samples of liquid mixtures each comprising one or more of certain oxygenates in varying known or determined concentrations are irradiated with near infrared or other radiation, producing scattered Raman radiation omitted from each sample mixture. As used herein, the expressions "known concentration" or "known concentrations" indicate merely that the content of a particular mixture is known or defined, as, for example, by making up the mixture, or by appropriate analysis, which may be before or after the irradiation of the samples. The wavelengths present in the scattered light are characteristic of the molecules present, and the intensity of the scattered light is dependent on their concentrations. The Raman scattered radiation omitted from the respective samples is collected and then dispersed or transformed into spectra with intensities representing the chemical composition of the components of the mixtures of said samples and the concentrations of said components. Multivariate analysis or other mathematical manipulation is performed on some or all of the spectra, or mathematical functions thereof; e.g., to derive a regression model representative of mixtures containing one or more of the specified compositions. The resulting model is useful, as described more fully hereinafter, in analyzing a variety of liquid mixtures, particularly hydrocarbon liquids or mixtures, for the presence and concentrations of oxygenated hydrocarbons. A variety of oxygenates may be speciated, but the invention is particularly suited to determining the presence and concentrations of alcohols and ethers, more preferably methanol, ethanol, methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE) and tertiary amyl methyl ether (TAME). The model is especially useful for analyzing oxygenate-containing hydrocarbon mixtures, such as petroleum liquids or mixtures, or synthetic petroleum mixtures. Fuels (including reformulated gasolines) may be analyzed as described hereinafter. In one specific aspect of this embodiment, the multiple samples of liquid mixtures, each comprising or containing one or more oxygenates in varying predetermined concentrations, may be prepared as synthetic petroleum mixtures for the analysis. The respective samples of the mixtures are then, as described supra, radiated individually with near-infrared radiation, producing scattered Raman radiation emitted from each sample mixture, and arc analyzed in the manner described. In a second aspect of this embodiment, samples of oxygenate-containing liquid are recovered from a suitable source, such as a chemical plant stream or refinery stream. In a manner similar to that described previously, the respective samples of the mixtures are radiated individually with near-infrared radiation, producing scattered Raman radiation emitted from each sample mixture. Prior or subsequent to irradiation, at least a portion of the samples are analyzed by suitable conventional analysis, such as chromatographic analysis, to determine the nature and concentrations of the various components of interest in the samples. Based on the known concentrations and the spectra obtained, a model is produced, in the manner described previously, this model being based, to great advantage, on actual plant or refinery stream concentrations from the source or site chosen. As will be recognized by those skilled in the art, this procedure can produce an analytical model which eliminates having to perform conventional analysis more than once in the plant or refinery setting. The use of the models produced, of course, is the great advantage of the invention. Accordingly, the invention, in another embodiment, relates to a process tier determining the concentration of one or more oxygenates, in a specified liquid sample, comprising irradiating the liquid sample with near infrared radiation, producing scattered Raman radiation emitted from said sample. The Raman scattered radiation emitted from the sample is collected, transferred, and dispersed or transformed into spectral intensities corresponding to the chemical composition of the components of the sample and concentration of said components. The concentrations of one or more oxygenates present are then determined by processing the spectral intensities from the sample according to the models previously mentioned, with the proviso or understanding that the source radiation wavelength in this embodiment is the same as or is correlated to that employed in establishing the models. As those skilled in the art will be aware, a sample may be static or dynamic, i.e., may vary over time. The terms "sample" or "samples", in this context, include flowing streams of such mixtures, which are particularly preferred for real-time control of processes in response to frequent analysis according to the invention. Temporal discrimination of a dynamic stream requires that spectra be acquired during a finite time interval. The shorter the interval, the higher temporal resolution of the changing concentration. Thus, spectra may be acquired over a very short time (seconds), or over a longer time (minutes), the term "spectra" herein encompassing also a single spectrum. Again, only selected portions of the spectra obtained need be processed, as will be evident to those skilled in the art; language hereinafter indicating processing of spectra is to be understood to indicate processing of all or of selected spectral regions. The speed of analysis obtainable by the present invention (less than one minute) enables on-line control response times not possible with past prior art chromatographic methods. The determination or different components may be made simultaneously and nearly continuously, providing on-line (or at-line) analysis without the need to return samples to control laboratories in refineries. The invention thus provides, particularly with the use of modern fiber optics, a quick and efficient method of monitoring the concentration of an oxygenated hydrocarbon, such as MTBE, on-line, and the monitoring system may be coupled, in the most preferred aspects of the invention, with a computer and other equipment to regulate the parameters of a process, e.g., to control the concentration of a particular component, e.g., MTBE, in the liquids, such as hydrocarbon fuels, produced or to feed-forward the compositions of starting materials being fed to a process. I. General Statement of the Invention According to the invention, concentrations of oxygenates in various liquids, including hydrocarbon fuels, can be determined with great accuracy, e.g., ±0.2% wt or better, from a remote location using fiber-optic Raman spectroscopy with near-infrared laser excitation, utilizing multivariate regression analysis. II. Utility of the Invention This invention will find its greatest application in the petroleum refining industry, the techniques described being useful to monitor and control the amounts of individual oxygenate species in gasoline. Another preferred application is the regulation of the required oxygenate content for reformulated the in gasoline blending systems using a blending program such as Ashland Petroleum's BOSS™ (Blend Optimization and Scheduling System), Chevron's GINO (Gasoline In-line Optimization), Oil Systems, Inc., MG Blend, or other similar blending optimization programs. Blending systems for use with the present invention, to provide blends having desired species analysis, can be of conventional design, usually involving the use of proportioning pumps or automatic control valves which control the addition rate for each of a series of components fed from different tanks or other sources. A preferred blending system comprises, for example, a system wherein a signal controls the feeding and blending of streams, including one or more which contains an oxygenate, into a common zone, whereby a product having a desired oxygen content is produced. A computer receiving the output signal from the spectrometer used to determine the concentration of a given oxygenate can readily process the information to not only provide the oxygenate analysis in the finished blended hydrocarbon, e.g., gasoline, but also to provide the target blend at minimum cost, given the relative costs or species analysis enhancement values of all streams being fed to the blending system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates schematically the fuel blending process described in Example 1. FIG. 2 of the drawing schematically illustrates a suitable Dispersive Raman apparatus, with fiber optic probe, for carrying out embodiments of the invention. FIG. 3a schematically illustrates a suitable FT-Raman apparatus for carrying out embodiments of the invention. FIG. 3b schematically illustrates a suitable FT-Raman apparatus, equipped with a fiber optic probe, for carrying out embodiments of the invention. FIG. 4 illustrates an OFID chromatogram of a typical gasoline spiked with several oxygenates and an internal standard for use as a standard sample to calibrate the chromatograph for oxygenate analysis by the prior art chromatographic technique of Example 5. In FIG. 4, detector signal is plotted on the vertical axis as a function of time (in minutes), which is on the horizontal axis. FIG. 5 contains FT-Raman spectra for fifty-one non-fluorescing MFBE gasoline samples used as a validation set in Example 4, for statistical analysis of calibrations. FIG. 6 contains FT-Raman spectra for five fluorescing MTBE gasoline samples used as a validation set in Example 4, for statistical analysis of calibrations. FIG. 7 contains FT-Raman spectra (fingerprint region) for methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, MTBE and 2-butanol. DETAILED DESCRIPTION OF THE INVENTION The source of radiation used to produce the Raman scattering will be varied according to the liquid treated. In the case of oxygenate-containing liquids (and other non-fluorescing liquids), the type of radiation source may be varied considerably, and a laser of suitable visible wavelength may be used. With petroleum liquids or other fluorescing samples, however, laser systems of near infrared wavelength are preferred. Despite the lower degree of fluorescence obtained by choosing a near-infrared laser, highly colored samples may still fluoresce and interfere with Raman shifts corresponding to the fingerprint ("FP") region (i.e., about 1900-175 cm -1 ). It is still possible to obtain Raman information in the C-H stretch ("CH") region (i.e., about 3300-2500 cm -1 ) using a Fourier Transform spectrometer; and oxygenate determination is still possible. In addition to the spectrometers specifically discussed hereinafter, other suitable dispersive and Fourier Transform spectrometers are available and may be used. The number of samples utilized for the model will vary with the application and desire for accuracy. For example, in the case of a synthetic fuel mixture, from 20 to 50 samples will be adequate, with more or less being used as desired or needed. In the case of dispersive Raman spectroscopy, if a Fabry-Perot type diode laser is used for laser excitation, "mode hopping" may occur. This may be minimized by keeping the excitation laser, over the course of operations, in constant current mode while its temperature is stabilized. Mode hopping causes frequency shifts or line broadening in the Raman spectra. Since mode hopping of diode lasers is a function of both temperature and drive current, use of a diode laser in constant power mode often forces the drive current into regions of instability at given temperatures, thus inducing a mode hop. Since the spectra may be acquired over a one-minute integration period, the average change in laser intensity while in constant current mode over a total integration period is typically very small. Diode lasers with either internal or external gratings, e.g, distributed Bragg reflector diode lasers, are preferred over Fabry-Perot diode lasers since diode lasers with internal or external gratings eliminate mode hopping. Table A lists preferred, more preferred and most preferred dispersive Raman spectral regions for determining the components according to the invention. Table B lists preferred, more preferred and most preferred FT-Raman spectral regions for determining specific components according to the invention. TABLE A__________________________________________________________________________HIGH CORRELATION DISPERSIVE RAMANSPECTRAL REGIONSComponent Units Preferred More Preferred Most Preferred__________________________________________________________________________Methanol cm.sup.-1 3300-2500, 3127-2733, 2964-2814, 1900-175 1682-959 1477-1014Ethanol cm.sup.-1 3300-2500, 3151-2668, 2955-2895, 1900-175 1535-851 1324-8661-propanol cm.sup.-1 3300-2500, 3059-2673, 2958-2858, 1900-175 1573-400 1477-4462-propanol cm.sup.-1 3300-2500, 3079-2681, 2995-2860, 1900-175 1557-323 1473-8001-butanol cm.sup.-1 3300-2500, 3087-2660, 2961-2859, 1900-175 1657-309 1475-3822-butanol cm.sup.-1 3300-2500, 3101-2624, 2990-2861, 1900-175 1650-301 1477-481isobutanol cm.sup.-1 3300-2500, 3079-2681, 2995-2860, 1900-175 1557-323 1473-800tert-butanol cm.sup.-1 3300-2500, 3070-2690, 3000-2898, 1900-175 1530-300 1470-320tert-amyl alcohol cm.sup.-1 3300-2500, 3070-2690, 3000-2898, 1700-175 1530-300 1470-320methyl tert-butyl cm.sup.-1 3300-2500, 3278-2510, 3011-2791,ether (MTBE) 1900-175 1661-196 892-466ethyl tert-butyl ether cm.sup.-1 3300-2500, 3278-2510, 3011-2791,(ETBE) 1900-175 1661-196 892-466tert-amyl methyl cm.sup.-1 3300-2500, 3278-2510, 3011-2791,ether (TAME) 1900-175 1661-196 892-466diisopropyl ether cm.sup.-1 3300-2500, 3079-2681, 2995-2860,(DIPE) 1900-175 1557-323 1473-800__________________________________________________________________________ TABLE B__________________________________________________________________________HIGH CORRELATION FT-RAMAN SPECTRAL REGIONSComponent Units Preferred More Preferred Most Preferred__________________________________________________________________________Methanol cm.sup.-1 3300-2500, 3127-2733, 2964-2814, 1900-175 1682-959 1477-1014Ethanol cm.sup.-1 3300-2500, 3151-2668, 2955-2895, 1900-175 1535-851 1324-8661-propanol cm.sup.-1 3300-2500, 3059-2673, 2958-2858, 1900-175 1573-400 1477-4462-propanol cm.sup.-1 3300-2500, 3079-2681, 2995-2860, 1900-175 1557-323 1473-8001-butanol cm.sup.-1 3300-2500, 3087-2660, 2961-2859, 1900-175 1657-309 1475-3822-butanol cm.sup.-1 3300-2500, 3101-2624, 2990-2861, 1900-175 1650-301 1477-481isobutanol cm.sup.-1 3300-2500, 3079-2681, 2995-2860, 1900-175 1557-323 1473-800tert-butanol cm.sup.-1 3300-2500, 3070-2690, 3000-2898, 1900-175 1530-300 1470-320tert-amyl alcohol cm.sup.-1 3300-2500, 3070-2690, 3000-2898, 1700-175 1530-300 1470-320methyl tert-butyl cm.sup.-1 3300-2500, 3278-2510, 3011-2791,ether (MTBE) 1900-175 1851-196 892-466ethyl tert-butyl ether cm.sup.-1 3300-2500, 3278-2510, 3011-2791,(ETBE) 1900-175 1661-196 892-466tert-amyl methyl cm.sup.-1 3300-2500, 3278-2510, 3011-2791,ether (TAME) 1900-175 1661-196 892-466diisopropyl ether cm.sup.-1 3300-2500, 3079-2681 2995-2860,(DIPE) 1900-175 1557-323 1473-800__________________________________________________________________________ Correlation of the spectra to the species concentrations of interest is accomplished using multivariate analysis. As utilized herein, the form "multivariate analysis" is understood to include all types of multivariate statistical analysis, with the procedures known as partial least squares (PLS), principal component regression (PCR), multiple linear regression (MLR) by classical or inverse least squares being preferred. MLR, PCR and PLS can be performed without any data preprocessing, or (alternatively), using several different data preprocessing techniques including: derivative (Savitzky and Golay, Anal. Chem 1964, 36, 1627), normalization, mean centering, variance scaling, autoscaling (mean-centering followed by variance scaling), and range scaling. Calibrations may also be made based on Raman intensity differences, whereby the intensity spectrum for a blendstock prior to oxygenate addition, is subtracted from the intensity spectrum of the same blendstock after the oxygenate is added. Using a single-beam instrument with data storage capability, a spectrum of the unoxygenated blendstock may be acquired for use as the reference, prior to running the samples. This technique is especially useful when undesirable interferences are present in spectral regions used in the calibrations. Spectral subtraction was used by Tackett, U.S. Pat. No. 5,412,581, liar double-beam, NIR measurements of physical properties of hydrocarbons, with a reference hydrocarbon placed in the reference beam. Care was taken in the instrument design to ensure that the sample and reference cells were maintained at the same temperature. This was necessary to eliminate any artifacts due to the temperature dependence of NIR measurements. Raman measurements are not affected by temperature, providing an additional advantage to the use of the Raman technique for such measurements. By the MLR method, a Raman analyzer determines the concentration or other property of interest for the sample, based on calibrations which set forth in the equation below, the constants k(0), k(1), k(2), . . . , k(m), for m wavenumbers at which Raman intensity is measured: Value of Interest=k(0)+k(1)×f(A.sub.1)+k(2)×f(A.sub.2)+. . . +k(m)×f(A.sub.m) Where k(0)=bias coefficient k(i)=coefficient for wavenumber i f(A i )=Raman intensity, a derivative of intensity with respect to wavenumber, or some other function of the intensity at wavenumber i, for i=1, 2, . . . , m (wavenumbers 1, 2, . . . , m). By the PCR method, each spectrum (or one or more portions) in the calibration sample set is represented as an n-dimensional vector, where n is the number of points to be used in each spectrum. To each point is associated a wavenumber at which Raman intensity was measured. Each vector is broken down into one or more components, plus an error vector to account for variation not explained by the components. By this mathematical treatment or "decomposition," the spectrum is represented as the weighted vector sum of the components plus the error vector. Each successive component accounts for the variation remaining in the calibration set, after subtracting the weighted contributions of all preceding components. The coefficients in the weighted sums (also known as "scores") are then correlated with the properties of interest (i.e., species concentrations) using multilinear regression. PLS is similar to PCR in that the spectra are decomposed in components ("latent variables"). However, by the PLS method, the spectra are weighted by the species concentrations prior to the decomposition step. The regression is accomplished during the decomposition, making a separate regression step unnecessary. There are two PLS methods in common use: PLS-1, which calculates a separate set of scores for each species concentration; and PLS-2, which, as does PCR, calculates a single set of scores for all species of interest. More detailed information on these methods can be found in the literature (Geladi, P. and B. R. Kowalski, Partial Least-Squares Regression: A Tutorial, Anal. Chim. Acta 1986, 185, 1-17). A cross validation of the data is used to evaluate the quality of the calibration by leaving out one spectrum at a time while performing a partial least squares regression on the remaining spectra and using the resultant regression to predict the value for the left-out spectrum. Alternatively, spectra for a separate set of samples not included in the calibration set, may be used for independent validation. Outlier diagnostics (Thomas and Kaaland, Anal. Chem. 1990, 62, 1091) are used to generate leverage plots for the different spectra for each partial least squares regression analysis. The leverage of each spectral sample is indicative of how much of an effect each sample has on influencing the regression model. The leverage plots are useful for detecting artifacts (due to mode hopping, back-scattering of Raman modes from the excitation fiber into the collection fiber, cosmic rays or sampling errors). Results from MLR, PLS or principal component analysis can be used directly or incorporated into a neural network to obtain the final model. Neural networks are discussed in several publications, including Long, J. R., V. G. Gregoriou, and P. J. Gemperline, Anal. Chore. 1990, 62, 1791-1797. Use of PCA and PLS scores as inputs to neural networks are discussed by Borggaard, C. and H. H. Thordberg (Anal. Chore. 1992, 64, 545-551). As indicated, the procedures of the invention are applicable to any liquid mixture containing one or more oxygenates. However, the invention is most adapted to use with petroleum mixtures, such as gasolines, aviation libel, and diesel fuels. As used herein, the term "synthetic fuel mixture" means a prepared mixture of refinery components to cover the composition range in actual fuel blends. DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLE 1 (Invention Controlling a Fuel Blender) FIG. 1 represents a control scheme for an on-line blender in a refinery, with both feed-forward and feedback control loops, utilizing Raman spectral analysis of oxygenate levels to provide control. In FIG. 1, the use of multistreaming, whereby the component streams are switched sequentially to a single probe, using valves, is illustrated. However, multiplexing, whereby a probe is located at each control point, or a combination of both, can also be used. In a multistreaming operation such as that illustrated in FIG. 1, component streams 410, 420, 430, 440, 450 and 460 are sequentially routed to the sample cell or sample in line probe of Raman spectrometer 470 which analyzes each stream for properties or components of interest, e.g., wt % oxygen. An output signal for each stream (proportional to wt % oxygen) is then transmitted to optimizing software such as GINO. The GINO software, resident in blending computer 480, then continuously analyzes the signal, optimize and update the blend recipe in response thereto, and downloads the updated recipe to Blend Ratio Control (BRC) software which is resident in Distributed Control System (DCS) 490. The BRC software is capable of controlling DCS 490 which in turn may adjust the position of valves 405, 415, 425, 435, 445, and 455 to change the flow rates of component streams 410, 420, 430, 440, 450 and 460, respectively. Another Raman spectrometer 500 can also be used in a feedback mode. That is, a slip stream 465 of the finished blend is directed to the sample probe or sample cell of Raman spectrometer 500, which analyzes the finished blend for wt % oxygen and other components of interest. DCS 490 then receives the feedback signal from Raman spectrometer 500 in the same manner as it receives the feed-forward signals from Raman spectrometer 470. The DCS 490 is configured to allow direct control of valves 405, 415, 425, 435, 445 and 455 by the feedback control loop to override the recipe established by the feed-forward control loop when necessary. Raman spectrometer 500 may be the same instrument as Raman 470, with feed-forward and feedback functions operating in a multiplexing or multistreaming mode. In each the following examples 2 through 4, a model is formulated, utilizing the sampling and multivariate analysis procedure described herein, for the liquid or liquids to be monitored. As will be appreciated by those skilled in the art, in the individual processes described, a radical change in liquid content, as for example, the substitution of a substantially different feedstock, e.g., substitution of oil shale liquid for Arabian light, would require derivation of a new model representing the ranges of variation of that feed. EXAMPLE 2 (Oxygen levels by Dispersive Raman Spectroscopy PLS Calibration) In order to describe the invention more fully, reference is made to FIG. 2. The setup shown is analogous to that described in the aforementioned McCreery et al publication, which is hereby incorporated by reference. Accordingly, there is shown a radiation source 1, in this case a GaAIAs DBR diode laser (Spectra Diode Labs) which emits radiation in the near infrared. The radiation is filtered with dielectric band pass filter 2 (Janos) and is sent into the proximal end 3 of the excitation fiber 4 (200 micron quartz fiber optic, Polymicro). The probe tip 5 consists of the distal ends of the excitation fiber 4 and a parallel collection fiber 6, both fibers being sealed into a stainless steel tube 7 with epoxy and the ends polished. At the probe tip 5, the laser energy exits the excitation fiber 4 and the Raman scattered light thus produced is collected by the distal end of the parallel collection fiber optic 6. Light from the proximal end 8 of the collection fiber 6 is collimated with an f/2 plano-convex NIR reflection coated lens 9 and then filtered with a 850 nm holographic notch filter 10 (Kaiser Optical) to remove Rayleigh scattering before focusing the Raman signal with an f/4 lens 11 onto the slits (60 micron slit width) of an image corrected 1/4 meter spectrograph 12 (Chromcx). A 300 groove/mm grating blazed at 1 micron was used to disperse the Raman signal. A ST6UV charge coupled detector (CCD) 13 (Santa Barbara Instruments Group) thermoelectrically cooled to -35 C was used to detect the dispersed signal. The detector 13 consists of 750 horizontal pixels (12 micron widths)×350 vertical pixels. The pixels are binned on chip by two in the horizontal direction and by 350 in the vertical direction giving a total of 375 superpixels. According to the invention, Raman spectra are acquired by placing the probe tip 5 directly into a sample which is provided in container or vessel 14 and integrating over 60 seconds for a size perspective, the fiber-optic length for fiber 4 is 2 meters from the laser to the probe tip, and the length of fiber 6 is 3 meters from the probe tip to the spectrograph 12. All spectra arc recorded the same day over a four hour period during which the diode laser setting (805 nm) remains constant and the room temperature remains constant at 23° C. The incident power from laser 1 at the sample is ˜50 mW, and the spectral resolution for the described system is ˜10 cm -1 . Spectral processing and partial least squares regression analysis are performed using Pirouette multivariate soilware (Infometrix) or QuantIR (Nicolet). Values for wt % oxygen were calculated based on oxygenate addition levels. In the case of probes which utilize lengthy fibers, e.g., several meters, a second dielectric band pass filter will be required near the distal end of excitation fiber 4. For example, approximately one-half meter from the distal end of excitation fiber 4, the fiber may be cleaved, and the laser beam may be collimated with a lens, directed through a band pass filter, and refocused with a second lens into the other cleaved end of excitation fiber 4. Table C is a statistical summary for Dispersive Raman PLS calibrations for ethanol and MTBE in synthetic gasoline mixtures. Calibration weight percentage values for calibration were determined by calculation from oxygenate addition levels. Listed for each calibration are number of calibration standards, number of PLS factors, Standard Error of Validation, wavenumber range and range of data for each component. TABLE C__________________________________________________________________________Summary of PLS Factors for Dispersive Fiber-optic Ramanof Ashland Petroleum Synthetic Gasoline Mixtures SEV.sup.1 Wave-number Range of # of # of (Wt % or Range DataSpeciesCalibration Standards Factors Vol %) (cm.sup.-1) (Wt % or Vol %)__________________________________________________________________________EthanolWt % 10 4 0.377 1534.5-851.8 0.000-4.486OxygenEthanolVol % 10 4 1.14 1534.5-851.8 0.00-12.00EthanolMTBE Wt % 36 5 0.244 1661.0-685.9 0.3594-3.2026Oxygen__________________________________________________________________________ .sup.1 SEV is the square root of the sum of the squares of the residuals divided by (n - k - 1), where n is the number of standards in the model and k is the number of factors in the model. Performed using "leave one out" technique. Similarly, calibrations may be made for other oxygenates commonly found in hydrocarbon fuels, including such species as methanol, tertiary butyl alcohol (TBA), ethyl tert-butyl ether (ETBE), tertiary amyl methyl ether (TAME), diisopropyl ether (DIPE), and other oxygen-containing hydrocarbons. EXAMPLE 3 (Oxygen levels by FT-Raman Spectroscopy--PLS Calibration) Alternatively (FIG. 3), a FT-Raman (Fourier transform, near-infrared, Raman spectrometer) may be used, wherein the grating is replaced by a Michelson interferometer or other device capable of producing an interferogram from the Raman scattered light from the sample. By appropriate software, the Fourier transform of the interferogram is calculated to produce the spectrum. In the FT-Raman spectrometer, shown in 3a, the petroleum sample 4 in a glass container is placed in a holder in compartment 5. The sample is then irradiated with near infrared radiation (wavelength 1064 nm) from a Nd:YAG laser 1, using mirror 2, through an opening in parabolic collection mirror 3. Mirror 3 collects the scattered Raman and Rayleigh radiation at 180 degrees and collimates it for optimum collection efficiency. The collimated beam is sent to interferemeter 6, filtered with a holographic notch filter 7 (to remove the Rayleigh scattered laser light) and finally detected by a high-purity, germanium detector 8. Alternatively, the FT-Raman spectrometer can be coupled to a fiber-optic probe for remote sampling. In this configuration (FIG. 3b), the laser beam from laser 1 is focused by lens 2 into the proximal end of excitation fiber 3. The distal end of excitation fiber 3 delivers the laser radiation to the remote sample 4. The Raman and Rayleigh scattered light is then collected by a collinear collection fiber 5 which delivers the radiation back to the spectrometer. The radiation exits the collection fiber 5 and is collimated by lens 6. As before, the collimated beam is sent to interferometer 7, filtered by holographic notch filter 8, and detected by detector 9. In the case of probes which utilize lengthy fibers, e.g., several meters, a dielectric band pass filter will be required near the distal end of excitation fiber 3. For example, approximately one-half meter from the distal end of excitation fiber 3, the fiber may be cleaved, and the laser beam may be collimated with a lens, directed through a band pass filter, and refocused with a second lens into the other cleaved end of excitation fiber 3. The spectra of both configurations are substantially the same with the exception that the fiber-optic configuration results in a slightly lower intensity signal. Although FIGS. 1 and 2 illustrate the use of single fiber excitation and collection, those skilled in the art will appreciate that multiple fiber excitation and collection, with the optic fibers properly angled is preferred, such equipment being known. Table D is a statistical summary for FT-Raman calibrations for ethanol and MTBE in synthetic gasoline mixtures. Listed for each calibration are number of calibration standards, number of PLS factors, Standard Error of Validation, wavenumber range and range of data for each component. Calibration weight percentage values for calibration were determined by calculation from oxygenate addition levels. TABLE D__________________________________________________________________________Summary of PLS Factors for FT-Ramanof Ashland Petroleum Synthetic Gasoline Mixtures SEV.sup.1 Wave-number Range of # of # of (Wt % or Range DataSpeciesCalibration Standards Factors Vol %) (cm.sup.-1) (Wt % or Vol %)__________________________________________________________________________EthanolWt % 10 5 0.345 3150.6-2669.4, 0.00-4.486Oxygen 1534.5-851.8EthanolVol % 10 4 0.87 3150.6-2668.4, 0.00-12.00Ethanol 1534.5-851.8MTBE Wt % 77 4 0.143 3277.9-2510.3, 0.182-3.288Oxygen 1850.8-196.1__________________________________________________________________________ .sup.1 SEV is the square root of the sum of the squares of the residuals divided by (n - k - 1). where n is the number of standards in the model and k is the number of factors in the model. Performed using "leave one out" technique. Similarly, calibrations may be made for other oxygenates commonly found in hydrocarbon fuels, including such species as methanol, tertiary butyl alcohol (TBA), ethyl tert-butyl ether (ETBE), tertiary amyl methyl ether (TAME), diisopropyl ether (DIPE), and other oxygen-containing hydrocarbons. EXAMPLE 4 (Oxygen Levels by FT-Raman Spectroscopy--MLR Calibration) Table E is a statistical summary for FT-Raman MLR calibrations for ethanol and MTBE in synthetic gasoline mixtures. A multiple linear regression analysis was performed on intensities or their first derivatives at the wavenumbers indicated in Table E, for Raman spectra collected using the procedure and apparatus described previously in Example 3. For the MTBE calibrations, additional samples without oxygenate were included in the calibrations, for a total of 155 calibration samples. Calibrations were made using the fingerprint region (1900-175 cm-1), the C-H stretch region (3300-2500 cm- 1 ), or both (indicated respectively by "FP", "CH", or "both" in Table E). Also shown in Table E for each calibration are number of calibration standards, wavenumbers used, coefficient of determination (R 2 ), Standard Error of Estimate, pretreatment method, and range of data for each component (calculated for this calibration set by conventional well-known statistical techniques). TABLE E__________________________________________________________________________Summary of MLR Calibration for FT-Ramanof Ashland Petroleum Synthetic Gasoline Mixtures Region (FP or CH): Wave- SEE.sup.1 Range of # of numbers R (Wt % or Pretreatment Data (Wt %SpeciesCalibration Standards used (cm.sup.-1) squared Vol %) Method or Vol %__________________________________________________________________________EthanolWt % 10 FP: 886.5, 1303.1 0.9986 0.068 none 0.000-4.486OxygenEthanolWt % 10 CH: 2915.3 0.9777 0.247 none 0.000-4.486OxygenEthanolWt % 10 Both: 2915.3, 0.9954 0.120 none 0.000-4.486Oxygen 963.5EthanolVol % 10 FP: 1303.1, .9984 0.19 none 0.00-12.00Ethanol 886.5EthanolVol % 10 Both: 2934.6, .9982 0.20 none 0.00-12.00Ethanol 890.4MTBE Wt % 156 FP: 728.4, 535.5 .9914 0.090 none 0-3.2616OxygenMTBE Wt % 156 CH: 2811.1, .9829 0.128 first derivative 0-3.2616Oxygen 2830.4__________________________________________________________________________ .sup.1 SEE is the Standard Error of Estimate, or the root mean square value for deviations between results by the calibration and those by the primary method, for samples in the calibration set. Two separate sets of spectra (from five fluorescing samples and from 51 non-fluorescing samples) arc used as prediction sets for validation of the two MTBE wt % oxygen calibrations described in Table E, the first calibration being based on the FP region, and the second being based on the CH stretch region. Samples used in the prediction sets were not included in the calibrations. For both calibrations, the same pretreatment used for the calibration is applied to the prediction sets. The intensities (or pretreatment functions thereof) are then used as independent variables in the multiple linear regression equations obtained from the calibration set. The intensity or pretreatment fiction value at each wavenumber is multiplied by its respective weighting constant, and the products arc summed with the bias constant to provide a weighted value which is characteristic of the predicted weight percentage of oxygen. Both sample sets are used to validate both calibrations, tier a total of four validations. Table F contains the results as measured by the Standard Error of Prediction (SEP), which is the root mean square value for deviations between results by the calibration and those by the primary method, for samples not in the calibration set. For the non-fluorescing prediction set, it can be seen in Table F that there is good agreement between actual values and those predicted by the calibration, as indicated by the standard errors of prediction for both the FP and the CH calibrations. The standard errors of prediction for the fluorescing prediction set show that fluorescence interferes severely with the FP calibration. However, even when the samples fluoresce, it is seen that the CH calibration with first derivative pretreatment can be used with satisfactory results. TABLE F______________________________________Validation of MTBE Weight Percent Oxygen CalibrationsValidation (Prediction) Calibration Standar Error ofSample Set Wave numbers Prediction (SEP)______________________________________Non-fluorescing FP: 728.4, 535.5 0.1230Non-fluorescing CH: 2811.1, 2830.4 0.1835Fluorescing FP: 728.4, 535.5 5.7033Fluorescing CH: 2811.1, 2830.4 0.1299______________________________________ Similarly, calibrations may be made for other oxygenates commonly found in hydrocarbon fuels, including such species as methanol, tertiary butyl alcohol (TBA), ethyl tert-butyl ether (ETBE), tertiary amyl methyl ether (TAME), diisopropyl ether (DIPE), and other oxygen-containing hydrocarbons. EXAMPLE 5 (Comparative with Species Analysis Using Conventional Gas Liquid Chromatography) The chromatogram for a synthetic gasoline mixture containing five oxygenates used in gasoline blending, is shown in FIG. 4, was obtained using a Hewlett Packard Model 5890 temperature programmed gas chromatograph with a methyl silicone capillary column (fused silica, 60M×0.25 mm i.d., df=0.1 uM), and a Wasson ECE OFID detector consisting of a cracker, methanizer and a flame ionization detector Chromatographic conditions were adjusted according to the standard methods established by the instrument manufacturer and Wasson ECE Instrumentation, Inc. This prior art method is useful for the determination of individual species as well total wt % oxygen, and can serve as the primary method for calibration of the Raman instruments used in the present invention. However, as shown by the time elapse in FIG. 4, this method is slow. FIG. 4, is an OFID chromatogram of a typical gasoline spiked with five oxygenates and an internal standard. Retorting to FIG. 4, the order for elution of the peaks is: Methanol 1; Ethanol 2; MTBE 3; ETBE 4; 1,2-Dimethoxyethane (internal standard) 5; TAME 6; and artifact 7. The elutriation time for the last fractions is about 20 min, a much slower analysis time as contrasted to an analysis time of less than one minute for on-line Raman analysis. The OFID procedure requires sample weighing and running of each sample in duplicate. Also, a predetermined amount of an internal standard of known oxygenate content must be added manually to each sample. Finally, a quality control standard must be run by this method every 12 hours or after every set of five duplicate samples, whichever occurs first, according to Federal Register Vol. 59 No. 32 (Feb. 16, 1994), Section 80.46, paragraph g (oxygen and oxygenate analysis), p. 7828. The OFID method is thus seen to be too slow for efficient use in closed loop control for many refinery processes. EXAMPLE 6 (Illustrations of Raman Spectra for some Oxygenates of lnterest) FIG. 5 contains Raman spectra for the fifty-one non-fluorescing samples used for validation in Example 4. It can be seen that both the CH region and the FP region is suitable for quantitative analysis. Of particular interest in these spectra is a Raman band at 728.4 cm -1 , characteristic of symmetric O-CC 3 stretching. This band shows a strong correlation with wt % oxygen in gasoline blends containing MTBE (R=0.9514, SEE=0.299 wt % oxygen). FIG. 6 contains Raman spectra for the five fluorescing samples used for validation in Example 4. It can be seen in FIG. 6 that fluorescence interferes significantly in the FP region, but only slightly in the CH region. It can be seen by this illustration and by the standard errors of prediction in Table F for fluorescing validation samples, that calibrations based on the CH region provide an alternative when calibrations based on the FP region cannot be used when fluorescence is present. FIG. 7 contains the fingerprint regions of the FT-Raman spectra for seven oxygenates and (for reference) a spectrum for a typical, regular-grade gasoline with no oxygenate. Included in FIG. 7, arc methanol spectrum 1, ethanol spectrum 2, 1-propanol spectrum 3, 2-propanol spectrum 4, 1-butanol spectrum 5, 2-butanol spectrum 6, and MTBE spectrum 7, and gasoline spectrum 8. Referring to FIG. 7, it is seen that distinct features are present in the spectra, particularly in the FP region. Unique features in each oxygenate spectrum, not present in the gasoline spectrum, enable the creation of calibration models capable of distinguishing various oxygenates. Modifications Though fundamental bands have been recited, overtones and derivatives of both overtones and fundamental bands may sometimes be substituted if of sufficient strength. This invention can control other refinery and chemical process units, e.g., MTBE, and can also be part of a simultaneous on-line determination of several species and properties (e.g., research and motor octane, benzene, aromatics, etc.). Specific compositions, methods, or embodiments discussed are intended to be only illustrative of the invention disclosed by this specification. Variations on these compositions, methods, or embodiments are readily apparent to a person of skill in the art based upon the teachings of this specification and are therefore intended to be included as part of the inventions disclosed herein. For example, surface-enhanced Raman, ultraviolet-Raman and Hadamard transform Raman techniques can also be used. Reference to documents made in the specification is intended to result in such patents or literature being expressly incorporated herein by reference.

Oxygenated hydrocarbons can be predicted within ±0.2% wt or better, using Raman NIR spectroscopy and multivariate analysis, with optional fiberoptics multistreaming. The resulting signal can be used to control concentration of such compounds in product to desired levels.

BACKGROUND OF THE INVENTION The invention relates to a torsional vibration damper, especially for clutch discs of motor vehicles, consisting inter alia of at least two spring systems having different spring characteristic curves, in which in the transition from the spring system with the less steep spring characteristic curve to the spring system with the steeper spring characteristic curve the system with the less steep spring characteristic curve is bridged over by stops and at least some torsion springs of the spring system with the steeper spring characteristic curve are installed under pre-stress. STATEMENT OF THE PRIOR ART From German Patent Specification No. 1,801,969 a torsional vibration damper is known in which a two-part hub with toothing is provided, the two toothings engaging in one another with play in the circumferential direction. Springs having a flat characteristic spring curve are arranged between the two parts of the toothing. A further set of springs with a steeper spring characteristic curve comes into use when the play between the two toothings is used up. It is usual here to arrange at least one of the springs of the spring system with the steeper spring characteristic curve so that they are inserted in the circumferential direction with pre-stress into the windows of the corresponding components, in order to avoid chattering noises and wear at this point. Now when the spring system with the steeper characteristic curve comes into action the spring pre-stress leads to a point of unsteadiness in the course of the characteristic curve and thus also to noise generation in the transit of this zone. OBJECT OF THE INVENTION It is a main object of the present invention to improve the known torsional vibration damper such that the chattering noises resulting from the transition between the two sets of springs can be eliminated, and this with minimum possible expense. SUMMARY OF THE INVENTION In view of the above object a torsional vibration damper of this invention, especially for clutch discs of motor vehicles comprises at least two spring systems with different spring characteristic curves. In the transition from the spring system with the less steep spring characteristic curve to the spring system with the steeper spring characteristic curve the system with the less steep spring characteristic curve is bridged over by stops. At least some torsion springs of the spring system with the steeper spring characteristic curve are installed under pre-stress. The abutment torque of the spring system with the less steep spring characteristic curve (i.e. the torque exerted by this system on abutment of the stops) is made by design equal to or greater than the pre-stress torque of the spring system with the steeper spring characteristic curve (i.e. the torque which is exerted by the pre-stressed springs in the zero-load condition). Due to the increase of the abutment torque of the spring system with the less steep spring characteristic curve to a value equal to or greater than the pre-stress torque of the spring system with the steeper spring characteristic curve the unsteadiness as objected above can be eliminated completely. In this case in a mixed zone the two spring systems work in series, whereby firstly a slightly less steep spring characteristic curve is achieved in this mixed zone than in the zone with the less steep spring characteristic curve, and also the travel of the spring system with the less steep spring characteristic curve is enlarged by a specific amount. The otherwise usual unsteadiness is thus completely avoided practically without additional expense. It is further proposed that in the spring system with the steeper spring characteristic curve, which comprises a parallel-acting friction device, the above-defined abutment torque of the spring system with the less steep spring characteristic curve is made by design equal to or greater than the sum of the pre-stress torque as defined above and the friction torque (i.e. the torque exerted by the friction device). In this case, where a friction torque is superimposed upon the steeper spring characteristic curve, it is likewise possible by appropriate increase of the abutment torque as defined above of the spring system with the less steep spring characteristic curve to avoid an unsteadiness. In a clutch disc having a two-part hub and a toothing with play in the circumferential direction between the two hub parts, where the angle of rotation of the idling system is determined by the play between the two toothings, it is proposed in accordance with the present invention to form the spring system for the idling system so that two different sets of springs come into action in succession and thus an angled spring characteristic is achieved in the idling range. So only in the second zone of the idling system an abutment torque is achieved which is made by design equal to or greater than the sum of the pre-stress torque and the frictional torque of the under-load system. According to another aspect of the invention, a vibration-damped load-transmitting rotor system comprises a first rotor member, a second rotor member and a third rotor member rotatable with respect to each other about a common axis of rotation. The first rotor member has a zero-load angular relative position with respect to the second rotor member, and the second rotor member has a zero-load relative angular position with respect to the third rotor member. Cooperating abutment means are provided on the first rotor member and the second rotor member. These abutment means define in abutment condition an abutment-defined angular relative position of the first rotor member and the second rotor member. First load-transmitting spring means are provided between the first rotor member and the second rotor member. Second load-transmitting spring means are provided between the second rotor member and the third rotor member. The second load transmitting spring means are pre-stressed such as to supply a pre-stress transmission torque value in the zero-load relative angular position of the second rotor member and the third rotor member. The first load-transmitting spring means supply an increasing transmission torque in response to the first and the second rotor members approaching the abutment-defined angular relative position under a circumferential load applied to the first and the third rotor members. The second load-transmitting spring means supply an increasing transmission torque beyond the pre-stress transmission torque value in response to the second and third rotor members being rotated with respect to each other beyond their zero-load relative angular position under a circumferential load applied to the first and the third rotor members. The increase of transmission torque per unit of angular movement of the respective rotor members is smaller for the first load-transmitting spring means than for the second load-transmitting spring means. The transmission torque supplied by the first load-transmitting spring means becomes equal to the pre-stress transmission torque value when or before the abutment means enter into abutting condition. According to a further development of this invention, cooperating frictional damping means are provided on the second rotor member and the third rotor member. These frictional damping means supply a frictional torque value resisting to relative angular movement of the second and the third rotor members. In this case, the advantages of the invention are achieved when the transmission torque supplied by the first load-transmitting spring means becomes equal to the sum of the pre-stress transmission torque value and the frictional torque value when or before the abutment means enter into abutting condition. According to a still further development of the invention, the first load-transmitting spring means comprise at least two spring units. One of these spring units is stressed only in a section of angular relative movement of the first rotor member and the second rotor member, which section is angularly spaced from the zero-load relative angular position towards the abutment-defined angular relative position of the first and the second rotor members. The first rotor member may be a primary hub member of a clutch disc unit and the second rotor member may be a secondary hub member of a clutch disc unit. The third rotor member may be a friction lining carrier of the clutch disc unit. In this case, the abutment means may be defined by toothings of the primary hub member and the secondary hub member, which toothings permit a circumferential play of the primary hub member and the secondary hub member. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWING The invention will be explained in greater detail below by reference to some examples of embodiments illustrated in the drawings, wherein FIG. 1 shows a spring characteristic curve according to the prior art; FIG. 2 shows a spring characteristic curve according to the invention; FIG. 3 shows a spring characteristic curve taking consideration of a friction device; FIGS. 4, 5 and 6 show diagrammatic representations of principle of the arrangement of two different spring systems to achieve a spring characteristic curve according to FIG. 3; FIG. 7 shows the longitudinal section through a clutch disc with a torsional vibration damper of this invention; and FIG. 8 shows the complete spring characteristic curve according to FIG. 7. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the representation of principle of a spring characteristic curve of a torsional vibration damper of the prior art in which α is the angular relative movement of the input member (first rotor member) and the output member (third rotor member) and M d is the torque applied by a load to be transmitted during such angular movement. Such a torsional vibration damper can be arranged in a clutch disc such as appears by way of example from the section according to FIG. 7, which will be described in detail in due course hereinafter. C 1 designates the flat spring characteristic curve of the idling system, which ordinarily passes through the zero point in the co-ordinate system as represented. The maximum angle of rotation of the idling spring system with the flat spring characteristic curve is pre-determined by the angle α 0 by appropriate stops within the torsional vibration damper. Under control by these stops, next a spring system with a steeper spring characteristic curve according to C 2 is set into action. The springs of this latter spring system are held without play in the circumferential direction in appropriate windows with a selected pre-stress, and the pre-stress effects a pre-stress transmission torque value M V which is greater than the abutment torque value M A of the spring system with the less steep spring characteristic curve C 1 (the abutment torque value is the transmission torque supplied by the spring system with the less steep spring characteristic when the stops engage each other). The jump of torque of the magnitude M V -M A occurring after the travelling of the angle α 0 effects abutment noises on every passage through this range. The course of the spring characteristic curve according to the present invention is illustrated in FIG. 2. The flat spring characteristic curve with the spring constant C 1 passes through the zero point. The steeper spring characteristic curve with the spring constant C 2 comes into effect at a torque corresponding to the value M V , the pre-stress transmission torque value of the springs with the steeper spring characteristic curve C 2 . After the angle α v has been travelled the transmission torque of the spring system with the flat spring characteristic curve C 1 achieves the value M V and that signifies that from this rotation angle onwards, on further torque loading both spring systems are in action in series connection. Thus in a mixed zone a spring characteristic curve C 3 results which has a somewhat less steep course than the spring characteristic curve C 1 . The pre-determined rotation angle according to the angle α 0 between the zero-load angular position and the abutment-defined angular position of the spring system with the flat spring characteristic curve is increased by the value Δα by additional angular movement of the spring system with the steep spring characteristic curve according to C 2 . Only after α 0 +Δα has been travelled the stops come into engagement and now the spring system with the steeper spring characteristic curve according to C 2 only is still effective. It can easily be understood that with such a course of the spring characteristic curves, compared with the illustration in FIG. 1, a more uniform transition can be achieved on increase of the load. The conditions are somewhat more complicated when the steeper spring characteristic curve is superimposed by the effect of a friction device. This case is however to be encountered especially frequently in practice. The resultant relationships are reproduced in FIG. 3. Three different points on the curve according to FIG. 3, namely the points 4, 5 and 6, correspond respectively to the diagrammatic illustrations according to FIGS. 4, 5 and 6. These each show a spring 14 of the spring system with the flat spring characteristic curve C 1 and a spring 6 of the spring system with the steep spring characteristic curve C 2 . The hub 7 (primary hub--see e.g. FIG. 7) has a profile which co-operates with the hub disc 8 (secondary hub). The angular play between the hub 7 and the hub disc 8 is α 0 . The torsion spring 6 of the spring system with the steeper spring characteristic curve C 2 is arranged between the hub disc 8 and the cover plates 4 and 5 (lining carrier--see e.g. FIG. 7). The spring 6 is held at a pre-stress transmission torque value by means of the bracket 17. The two arrows by the hub 7 and the cover plates 4 and 5 symbolize the torque loading and the transmission torque within the clutch disc. A friction device 10 is arranged between the hub disc 8 and the cover plates 4 and 5. As long as the transmission torque value transmitted by the spring 14 on the spring characteristic curve C 1 does not exceed the pre-stress transmission torque value M V of the torsion spring 6 increased by the frictional torque value M R of the friction device 10, only the spring 14 is in action. Incidentally, the springs 6 per se (see FIG. 7) are helical compression springs rather than torsion springs. The term "torsion springs" is only used because they resist the torsion between the hub disc on the one hand and the cover plates 4, 5 on the other hand. On exceeding of the sum M V +M R the transition takes place to the mixed zone with the spring characteristic curve C 3 , which has a less steep course than C 1 and in the region of which the hub disc 8 lifts away from the bracket 17. By way of example at the point 5 according to FIG. 3 a condition is reached as represented in FIG. 5. On the one hand the spring system with the spring characteristic curve C 1 is not yet locked by abutment of the stops, on the other hand the spring 6 is already under loading and the friction device 10 is already effective. In the region of the spring characteristic curve C 3 the angle α 0 is travelled, which represents an exact measure of the play between the hub 7 and the hub disc 8. The actual abutment between the hub 7 and the hub disc 8 according to FIG. 6 admittedly takes place only when the abutment torque M A is reached. As from this abutment torque M A onwards--that is beyond an angular movement α 0 +Δα--only the spring system with the steep spring characteristic curve C 2 is effective. The friction device 10 which is also effective in this range is illustrated in FIG. 3 by parallel lines above and below the pure spring characteristic curve. In this case, the upper line is used on increase of torque and angle α, while the lower line is travelled on decrease of torque and angle α. The points 6 according to FIG. 6 lie on these two lines. During the increase of the torque a curve course has established itself which is similar in principle to that of FIG. 2. On decrease of torque this curve is not maintained. Decrease of torque is represented by the lower line in the region of C 2 . A larger mixed zone occurs between the angle values α VR1 and α VR2 . This is easily explained by the fact that in the return movement from large angles α towards small angles α the frictional torque M R acts against the pre-stress torque of the springs 6. Thus while in increase of the angle α the mixed zone commences at the angle α vv , the end of the mixed zone on decrease of the angle is only at the angle α vR2 . The gradual torque build-up visible especially from FIG. 3 and the correspondingly gradual diminution of the torque result in a torque-angle course which displays very uniform transitions. Thus abutment noises are avoided and at the same time the stimulation of torsional vibrations is suppressed. An example of embodiment with its complete characteristic curve is to be discussed again briefly with reference to FIGS. 7 and 8. FIG. 7 shows a clutch disc 1 with a torsional vibration damper 2. The friction linings 3 are firmly connected with a friction lining carrier formed as cover plate 4. A further cover plate 5 is formed as a friction pad carrier and is fast in rotation by means of connecting rivets 15 with the lining carrier 4. Between the cover plates 4, 5 the hub disc 8 is located which engages by toothings 9 with the hub 7, namely with a play corresponding to the angle α 0 . Torsion springs 6 are arranged between the hub disc 8 and the cover plates 4 and 5. Likewise an ordinary friction device 10 is associated to the torsion springs 6. The torsional vibration damper 2 further comprises a spring system 14, 16 for the idling range. These springs are accomodated by two cover plates 11, 12 fast in rotation with the hub 7 and a hub disc 13 fast in rotation with the hub disc 8. It is here to be noted as a particular feature that the idling system comprises different springs 14 and 16 which come into action in succession. This results in a course of the characteristic curve as represented in FIG. 8. The illustration shows both the traction side and the thrust side, only the traction side being represented with the frictional torque effective there, while the thrust side reproduces only the principle of the course of the spring characteristic curve. Due to the two-stage design of the idling system the spring characteristic C 1' is obtained in an angular area α 1' . Adjacent this angular area α 1' all springs of the idling spring system become effective and this results in a steeper spring characteristic curve C 1 . This steeper spring characteristic curve is effective as long as the transmission torque supplied by the spring system 14, 16 becomes equal to the sum M V +M R . At this moment the spring system with the steep characteristic curve C 2 becomes effective. As a result thereof, one obtains in a mixed zone a spring characteristic curve C 3 . After an angle α 0 +Δα or α 1' +α 1" the hub 7 and the hub disc 8 are locked with respect to each other by the toothing 9. On decrease of the load torque the lower line as shown in the left part of FIG. 8 becomes effective which is displaced with respect to the upper line by 2 M R as shown in FIG. 3. On the thrust side the same behaviour is possible, however not necessary. One can see from the preceding examples that the effective angular displacement is increased by the amount Δα without increase of the play of the toothing 9. This is a great advantage in view of the narrow constructional situation in the hub disc. While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. The reference numerals in the claims are only used for facilitating the understanding and are by no means restrictive.

According to an example embodiment of this invention, a clutch disc comprises a primary hub, a seconday hub and a lining carrier. The primary hub is angularly movable with respect to the secondary hub and the secondary hub is angularly movable with respect to the lining carrier. First load transmitting springs are provided between the primary hub and the secondary hub. Second load transmitting springs are provided between the secondary hub and the lining carrier. The second springs have a steeper spring characteristic than the first springs. Abutments are provided on both the primary hub and the secondary hub. The second springs are pre-stressed. When an increasing load is transmitted the angular movement of the secondary hub with respect to the lining carrier begins before the abutments of the primary and the secondary hubs engage each other.

BACKGROUND OF THE INVENTION The present invention relates to fasteners in general, and, more in particular, to fasteners that are permanently installed in a workpiece and which typically cooperate with another fastener to hold objects to the workpiece. Inserts installed in parent material of a workpiece provide a means for attachment of an object to the workpiece through a second fastener. Inserts are used as when the stress requirements of a connection are greater than that provided by the parent material of the workpiece. An insert can distribute the stress over an area of the workpiece larger than would be available to the second fastener acting alone. An example of an insert is a plug-like object having male threads for receipt in female threads of the parent material of a workpiece. The insert has an internally threaded bore for receiving male threads of a cooperating fastener. Typically, studs provide an anchor for attachment of objects to parent materials of the workpiece. A stud secures to the workpiece with male threads just like an insert does, but itself provides male threads for cooperation with a female threaded nut or the like. Obviously, separation of the fastener from parent material of the workpiece is not desired. The threads between the two prevent the fastener from being pulled out of the workpiece. It is not uncommon to also provide against the backing out of the threads of the fastener from the threads of the workpiece. The provision which prevents the fastener from unthreading from the workpiece has taken several forms. One form has provided radial teeth which plow or broach workpiece material as the fastener is driven essentially axially into a bore in the material. Workpiece material then occupies spaces between the teeth of the fastener and interferes with the teeth to resist relative rotation. This type of arrangement is complicated when the means for attaching the fastener to the workpiece is by threads. Clearly the provision to prevent rotation of the fastener with respect to workpiece cannot come into effect until the fastener is fully threaded into the workpiece. Standoff devices have been used to keep the teeth of the locking device from broaching workpiece material until the fastener is otherwise set. A different technique to accomplish the same result is to drive a locking device into position after the fastener is otherwise set by forcing the locking device axially into a space provided for it. The locking device in the latter technique can be an expander ring to expand material of the fastener radially against the workpiece. Alternatively, the locking device itself can directly contact the workpiece. Another technique allows the fastener to rotate with respect to a lock ring as the fastener tightens in threads of the workpiece, and the lock ring cannot rotate with respect to the workpiece. When set, the lock ring interferes directly or indirectly with the workpiece to prevent unthreading of the fastener. The interference between the workpiece and the lock ring effected during installation has produced consequential broaching, peening or swedging of the workpiece. These actions on the workpiece can remove protective coatings and subject the workpiece to corrosion. These actions can also create stress risers in the workpiece which ultimately lead to a failure, as through fatigue. Furthermore, the lock employed in this technique may always be under stress, and the structure with which it cooperates may also be under stress in a sense which could lead to failure. SUMMARY OF THE INVENTION The present invention provides a means for anchoring a stud or an insert to a workpiece characterized by a lock ring engaging the workpiece only when the fastener experiences rotational moments tending to loosen it from the workpiece. The lock ring and the fastener rotate together. Radial, externally extending teeth of the lock ring wipe without biting into the wall of a bore of a workpiece when rotated during setting of the fastener. The tooth form causes biting of the teeth into the workpiece in response to rotational moments in the opposite direction. The lock ring expands during this type of rotation because a gap in its circumference permits such expansion. Thus, when the teeth bite into the workpiece, the lock ring is stressed by the bore wall and fastener and in response to this stress there is an increase in lock ring circumference and an increase in the bite of the teeth into the wall. The gap also permits contraction of the lock ring to a diametrical dimension no greater than the maximum dimension of the fastener which is to be within the workpiece. The lock ring rotationally couples to the balance of the fastener through meshing internal and external teeth of the lock ring and fastener respectively. A particular form of the present invention contemplates an insert externally threaded for threaded receipt in a workpiece. The insert has a head in the form of a washer pad which faces outwardly from the workpiece. A circular groove at the base of the head receives the lock ring. The groove axially neighbors external threads of the insert. The external threads and pad axially capture the lock ring. The lock ring has internal serrations meshing with external serrations of the insert to rotationally couple the two together. The meshing serrations may take many forms, for example, square form, ramp-like, or gear-like. Internal threads in a bore of the insert are to receive male threads of a cooperating fastener element. A ramp-step external tooth form of the lock ring permits rotation of the ring freely with respect to a bore of a workpiece during installation of the insert but biting into the wall of the bore when rotational moments act in the opposite direction. The gap in the lock ring slants at an angle to both the radius of the lock ring and its circumference so that facing edges of the gap slip along each other during expansion or contraction of the lock ring. In repose, the ring has a diameter which produces a slight pressure on the wall of the workpiece bore and an inner mesh geometry not in direct bearing with the serrations of the groove bore so that the ring can contract freely in response to workpiece pressure. An external chamfer as a leading edge of the lock ring guides the lock ring-insert assembly into the bore of the workpiece and abuts against a cooperating surface of the workpiece, say the flank of the first internal thread of the workpiece, to positively position the insert in its set position. This positive location assures insert material at the faying surface between the workpiece and an attached structure. The positive axial indexing also prevents threading the insert through the workpiece during installation. These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an elevational view partly in half section showing the preferred form of an insert constructed in accordance with the present invention; FIG. 2 views along lines 2--2 of FIG. 1 and illustrates the external tooth form of the lock ring and the serrations that rotationally couple the ring and insert together; FIG. 3 shows an alternate preferred form of the insert of the present invention installed in a workpiece. This illustration is in elevation and partly in half section; FIG. 4 views along lines 4--4 of FIG. 3 and shows an alternate form of the lock ring and insert coupling serrations, with the lock ring serrations being ramp- or wedge-like to promote lock ring expansion in response to rotational moments tending to loosen the insert; and FIG. 5 illustrates a stud and lock ring installed in a workpiece, all in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIGS. 1 and 2, an insert 10 in accordance with the present invention has an externally threaded section 12 extending a major portion of the insert's length. A bore 14 of the insert is internally threaded at 16. There, internal threads extend substantially the length of the insert. A bolt pilot or chamfer 19 guides a male threaded fastener into the bore of the insert. A cylindrical head 18 caps an outside end of the insert. This head has a radial surface 20 as a faying surface for a cooperating piece of structure which is to be attached to the workpiece in which the insert is anchored by the insert and a male fastener. An example of such a structure and workpiece is a crankcase mounting flange and an engine block. A circular, external groove 22 between head 18 and threads 12 receives a lock ring 24. Head 18 has an external chamfer 25 at the corner of groove 22 to lead the lock ring into the groove. The major diameter of the lock ring does not exceed the major diameter of the balance of the insert, in this case the major diameter of the external threads and the head. Thus no special accommodation in a workpiece must be made to accommodate the diameter of the lock ring. Groove 22 is bottomed by a plurality of axially extending serrations 26. These serrations, as seen to best effect in FIG. 2, define axially oriented grooves and splines. Lock ring 24 has internal serrated teeth 28 for meshing in the grooves between the splines of the insert. These teeth are shown to be gear-shaped in FIG. 2, with convex sides which converge toward and meet a crest, the crest being a surface on a cylinder. The teeth may take other forms, as will subsequently be developed. In any event the internal radially extending teeth of the lock ring mesh in the grooves of the insert so that the lock ring and the insert are rotationally coupled together and one cannot rotate with respect to the other. An external chamfer 29 of the lock ring pilots the latter into the bore of a workpiece and bottoms at the junction of the bore with the major diameter of the top thread in the bore. The bottoming also fixes the installed position of the insert in the workpiece. To avoid premature bottoming, the angle of the chamfer of the ring could be made, say 44°, and the angle of the chamfer of the thread could be made, say 46°. This provides a clearance which closes only where desired contact occurs. External ramp and step-form teeth 30 of the lock ring extend radially from its axis. A ramp is shown by reference numeral 32 and a step by reference numeral 34. The ramp provides a gentle, continuous transition from a base 36 of a step 34 to a crest 38 of the step. The base is on a circle of minor diameter and the crest on a circle of a major diameter, both circles having a center on the axis of the lock ring. The slope or rise of the external teeth allows rotation of the lock ring in a counterbore of a bore of a workpiece without digging or biting into the wall of the bore or otherwise marring the wall surface. Thus, when the wall is covered with a protective coating, rotation of the lock ring clockwise as viewed from the top in FIG. 2 will not damage the protective coating and there will be no chance of protective breakdown and corrosion attack because of the passage of the lock ring into the counterbore. The rise of the steps, however, is comparatively sudden and defines a sharp corner where the steps join the ramps. This corner or edge is capable of biting or digging into the wall of the bore in the workpiece when the lock ring experiences a rotational moment in a direction which advances the teeth into the wall. In FIG. 2 this direction would be counterclockwise when viewed from the top. The lock ring has a gap, void or split 40 all the way through it so that the ring can freely contract and expand in groove 22 of the insert. Sides 42 and 44 face each other across the gap. The relaxed outer diameter of the ring is greater than the diameter of the bore so that the ring applies a slight pressure to the bore well. The inner diameter is such as to allow the ring to respond to the slight pressure and contract without being resisted by the insert. The diameter of the base of the groove and the inner diameter of the lock ring which permit this free contraction are still close enough for rotational engagement of the serrations of the groove and lock ring so that the lock ring cannot rotate with respect to the groove. The gap also allows the lock ring to expand when the edge of its teeth bite into raw material in response to moments tending to unthread the insert from the workpiece. This expansion or contraction can readily be viewed in FIG. 2. When side 42 slips with respect to side 44, the ring expands or contracts with the sides touching. The gap slants to both the radius of the lock ring and a tangent to its circumference. This orientation produces the slippage with engagement of the sides with respect to one another during expansion and contraction of the ring. This engagement assures the concentricity of the lock ring with respect to the workpiece bore and constant uniform engagement therewith during performance of its locking function and concentricity with the insert when no locking function is necessary. When these functions are not necessary, the gag can be a space with purely radial sides. As seen in FIG. 3, the insert is used in a workpiece 50 and while the insert illustrated there differs slightly from that shown in FIGS. 1 and 2, its function in the workpiece is the same. The workpiece is internally threaded at 52 to receive the external threads of the insert. A smooth, right cylindrical counterbore 54 is coaxial with and leads into these threads. The insert is threaded into the workpiece and the lock ring occupies a portion of the counterbore. The insert finds application where the strength of its threads must exceed the strength available in the parent material of the workpiece. The increase in engagement area between the external threads and the parent material of the workpiece accommodates the expected extra load on the internal threads of the insert. FIGS. 3 and 4 show an insert 60 similar to insert 10 of FIGS. 1 and 2 but with internal teeth 62 of a lock ring 64 in the form of ramps or wedges. These teeth engage with axial splines or serrations 66 of the insert. Insert 60 is externally threaded at 68 and internally threaded at 70 in the manner of the insert of FIGS. 1 and 2. An annular, circular groove 72 receives lock ring 64. Again, as in the previous embodiment, the lock ring is provided with an external piloting chamfer 74 for ease of entry of the ring into bore 54 of the workpiece. As can be seen in FIG. 3, this piloting chamfer enables the workpiece to apply a radially inward force on the ring to effect its contraction and easy passage into the bore. This piloting chamfer also provides a bumper and axial locater for the insert at the base of a counterbore 75 of the parent material. Again, as in the FIGS. 1 and 2 embodiment, the insert has a head 76 having as one end a washer bearing surface 78 extending radially from the axis of the insert. Head 76 has an external chamfer 80 at the corner between it and groove 72 to facilitate the location of lock ring 64 in the groove. Internal teeth 62 of lock ring 64 in ramp or wedge form engage splines 66 bottoming groove 72 and rotationally couple the lock ring and the balance of the insert to prevent rotation of one with respect to the other. Lock ring 64 has an external tooth form 82 similar to the form in FIG. 2, except that there are more teeth on the circumference. A gap or slit 86 separates the lock ring and permits its comparatively free expansion and contraction with relative movement taking place along a slip plane defined by the slit and with the concentricity of the ring maintained by the contact of the adjacent sides of the gap. In the case of both FIGS. 1 and 2 and FIGS. 3 and 4, the insert is threaded into threads of a workpiece of parent material and the lock ring enters an unthreaded portion of the bore proximate its entrance. The lock ring contracts slightly because of the parent material on it. This contraction is facilitated by the lead-in chamfer of the lock ring. The elasticity of the lock ring is such, however, that only a slight pressure between its external teeth and the wall of bore 54 occurs. When the lock ring bottoms at the base of the bore, the insert is installed. The function of the insert is to receive a male threaded fastener and to distribute the load applied by that fastener through the insert at the junction between the external threads and parent material. In the event that a torque or moment tends to rotate the insert in a direction which would tend to unthread it from the parent material, external teeth 82 will bite into the wall of the counterbore with ever increasing pressure as the unthreading torque increases. This is so because the ring is capable of comparatively free expansion because of gap 86. The lock ring being coupled to the insert by the engagement of the splines of the latter with the internal teeth of the former prevents rotation of the insert. The principles of the present invention readily apply to a stud, as illustrated in FIG. 5. In this Figure, a stud 100 has external threads 102 for receipt in internal threads 104 of a workpiece of parent material 106. The workpiece is bored and threaded for this purpose at 108. As before, a counterbore 110 leads into threads 108 of the workpiece parent material to provide an axially extending wall against which a lock ring 112 can act to rotationally secure the stud to parent material. A head 114 juxtaposed to one side of a lock ring receiving groove 116 provides a bearing surface on the outside of the stud. Lock ring 112, received in groove 116 couples to the stud by engagement between axial serrations 120 at the base of the groove and internal teeth 122 on the inside axial surface of the ring, in a manner described in context with the insert species of the invention. The external axial surface of the lock ring has teeth 124 for biting into the wall of the counterbore in the parent material, again in the manner of the insert embodiment of the present invention. The stud has a shank 126 extending coaxially from head 114. Shank 126 is threaded at 128 for receipt of a nut. Thus the present invention provides a means for anchoring an insert or a stud into parent material which comes into play only when it is necessary. Necessity arises only when the fastener experiences a torque or moment tending to unthread it from the parent material. Insertion of the insert or stud does not bring into play the biting or gripping function of the teeth of the lock ring and therefore any protective coating present on the parent material is not damaged. Accordingly, there is not likelihood that the locking device of the fastener will affect any corrosion inhibitor. Also, the locking function of the ring not coming into play until required makes the ring passive in that it does not induce any stresses in the parent material, the ring, or the fastener with which the ring cooperates. Accordingly, there is an absence of stress risers which can lead to failure, as in fatigue. No special tool is required for setting the fastener. The lock ring accommodates the installation process by contraction to a diameter acceptable in the counterbore of the parent material. The present invention has been described with reference to a certain preferred embodiment. The spirit and scope of the appended claims should not, however, necessarily be limited to the foregoing description.

A mechanically locking fastener has external threads for installation in the threaded bore of a workpiece. A lock ring has internal radial serrations locked in serrations of the fastener proper, and external radial teeth of a form for gripping the wall of the workpiece bore when turning moments tend to loosen the fastener and to pass over the bore wall upon rotation in the opposite direction. The lock ring has a slip plane to permit contraction of the ring to a diameter no greater than the major diameter of the fastener and expansion of the ring when the fastener undergoes moments tending to loosen it. The fastener proper may be a stud or an insert. An external chamfer of the ring bears against a cooperating internal surface of the workpiece to positively determine the axial location of the insert with respect to the workpiece.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to light emitting elements using electroluminescence. In addition, the present invention relates to a light emitting device and an electronic device having the light emitting element. 2. Description of the Related Art In recent years, research and development has been extensively conducted on light emitting elements using electroluminescence. In a basic structure of these light emitting elements, a substance having a light emitting property is interposed between a pair of electrodes. By application of voltage to these elements, light emission can be obtained from the substance having a light emitting property. Since such a light emitting element is of self-light emitting type, it is considered that the light emitting element has advantages over a liquid crystal display in that visibility of pixels is high, backlight is not required, and the like and is therefore suitable for a flat panel display element. Another major advantage of such a light emitting element is that it can be manufactured to be thin and lightweight. In addition, extremely high response speed is also a feature. Since the light emitting element can be formed into a film shape, planar light emission can be easily obtained by forming a large-area element. This is a feature that is hard to be obtained in point sources typified by an incandescent lamp and an LED or linear sources typified by a fluorescent light. Therefore, the light emitting element has a high utility value as a surface light source that can be applied to lighting and the like. Light emitting elements using electroluminescence are classified broadly according to whether they use an organic compound or an inorganic compound as a substance having a light emitting property. When an organic compound is used as a substance having a light emitting property, electrons and holes are injected into a layer including an organic compound having a light emitting property from a pair of electrodes by voltage application to a light emitting element, so that current flows therethrough. Then, the carriers (electrons and holes) are recombined, and thus, the organic compound having a light emitting property is excited. The organic compound having a light emitting property returns to a ground state from the excited state, thereby emitting light. Owing to this mechanism, such a light emitting element is referred to as a current-excitation light emitting element. Note that the excited state generated by an organic compound can be types of a singlet excited state and a triplet excited state, and light emission from the singlet excited state is referred to as fluorescence, and light emission from the triplet excited state is referred to as phosphorescence. In improving the element characteristics of such a light emitting element, there are many problems caused by the material, and in order to solve such problems, an improvement of the element structure, a development of materials, and the like have been carried out. For example, in Non-Patent Document 1, a light emitting element with high efficiency is realized by using a method called Triplet Harvesting. REFERENCE [Non-Patent Document 1] M. E. Kondakova, et al., SID 08 DIGEST, pp. 219-222 (2008) However, as for the structure disclosed in Non-Patent Document 1, a light-emitting layer (Yellow LEL) containing a yellow emissive phosphorescent compound is provided on a cathode side of a light-emitting layer (Blue LEL) containing a blue emissive fluorescent compound. Therefore, a part of the triplet excitation energy of the blue emissive fluorescent compound is transferred to the cathode side, which allows the yellow emissive phosphorescent compound in the Yellow LEL to emit light. On the other hand, since an electron blocking layer (EBL) having greater triplet-excitation energy than that in the Blue LEL is provided on the anode side of the Blue LEL, the transfer of the triplet excitation energy of the blue emissive fluorescent compound to an anode side is impossible. Thus, a part of the triplet excitation energy of the blue emissive fluorescent compound is consumed through the nonradiative process and does not contribute to the light emission. Thus, it is an object of one embodiment of the present invention to improve luminous efficiency of a light emitting element by using triplet exciton energy more effectively. In addition, it is another object of one embodiment of the present invention to reduce power consumption of a light emitting element, a light emitting device, and an electronic device. SUMMARY OF THE INVENTION The present inventors found that triplet exciton energy generated in a light emitting layer which exhibits short wavelength fluorescence can be effectively utilized by use of a structure in which the light emitting layers which exhibit short wavelength fluorescence are sandwiched between light emitting layers each including a substance which exhibits phosphorescence (hereinafter referred to as a phosphorescent compound). In addition, when light emitting layers which simply exhibit short wavelength fluorescence are sandwiched only by light emitting layers each including a phosphorescent compound, carriers go through the light emitting layer which exhibits fluorescence, and the emission intensity balance collapses. However, they found that the emission intensity balance is improved between the light emitting layer including a phosphorescent compound and the light emitting layer which exhibits fluorescence by the devising of the structure of the light emitting layer which exhibits fluorescence. Therefore, a light emitting element according one feature of an embodiment of the present invention includes a first layer, a second layer, a third layer, and a fourth layer which are sequentially provided on an anode side between the anode and a cathode; the first layer and the second layer each include a hole transporting property; the third layer and the fourth layer each include an electron transporting property; the first layer includes a first phosphorescent compound and a first organic compound having a hole transporting property; the second layer includes a first fluorescent compound and a second organic compound having a hole transporting property; the third layer includes a second fluorescent compound and a first organic compound having an electron transporting property; and the fourth layer includes a second phosphorescent compound and a second organic compound having an electron transporting property. The triplet excitation energy of the second organic compound having a hole transporting property is higher than or equal to the triplet excitation energy of the first organic compound having a hole transporting property, and the triplet excitation energy of the first organic compound having an electron transporting property is higher than or equal to the triplet excitation energy of the second organic compound having an electron transporting property. In the above structure, it is preferable that the first organic compound having a hole transporting property and the second organic compound having a hole transporting property be the same organic compound. Since the first organic compound having a hole transporting property and the second organic compound having a hole transporting property are the same organic compound, an energy barrier due to carrier transfer is reduced. In the above structure, it is preferable that the first organic compound having an electron transporting property and the second organic compound having an electron transporting property be the same organic compound. Since the first organic compound having an electron transporting property and the second organic compound having an electron transporting property are the same organic compound, an energy barrier due to carrier transfer is reduced. In the above structure, it is preferable that a spacing layer formed using one or both of the first organic compound having a hole transporting property and the second organic compound having a hole transporting property be provided between the first layer and the second layer. In addition, it is preferable that a spacing layer formed using one or both of the first organic compound having an electron transporting property and the second organic compound having an electron transporting property be provided between the third layer and the fourth layer. By provision of the spacing layers, energy transfer from the second layer to the first layer and from the third layer to the fourth layer can be adjusted. In the above structure, the total thickness of the second layer and the third layer is preferably from 5 nm to 20 nm. When the total thickness of the second layer and the third layer is too large, light emission from the first layer and the fourth layer is reduced, and when the total thickness of the second layer and the third layer is too small, light emission from the second layer and the third layer is reduced. The thickness lies within the range, whereby light emission from each layer of the first layer, the second layer, the third layer, and the fourth layer can be balanced well. In the above structure, the concentration of the first fluorescent compound in the second layer is preferably from 0.1 wt % to 10 wt %. In addition, the concentration of the second fluorescent compound in the third layer is preferably from 0.1 wt % to 10 wt %. The concentration lies within the range, whereby strong light emission of the second layer or the third layer can be prevented and weak light emission of the first layer or the fourth layer can be prevented, so that light emission from each layer of the first layer, the second layer, the third layer, and the fourth layer can be balanced well. In the above structure, the first fluorescent organic compound and the second fluorescent organic compound are preferably the same organic compound. When the first fluorescent organic compound and the second fluorescent organic compound are the same organic compound, a light emitting element is easily manufactured. In the above structure, the emission color of each of the first fluorescent organic compound and the second fluorescent organic compound is preferably blue, and the emission color of the first phosphorescent compound is preferably green and the emission color of the second phosphorescent compound is preferably red. With such a structure, a white light emitting element can be obtained. In the above structure, the first phosphorescent compound and the second phosphorescent compound are preferably the same organic compound. When the first phosphorescent compound and the second phosphorescent compound are the same organic compound, a light emitting element is easily manufactured. In the above structure, it is preferable that the first fluorescent organic compound and the second fluorescent organic compound be the same organic compound, the first phosphorescent compound and the second phosphorescent compound be the same organic compound, and the emission color of the first phosphorescent compound and the second phosphorescent compound, the emission color of the first fluorescent compound and the second fluorescent compound be made to be complementary colors. With such a structure, a white light emitting element can be obtained. Moreover, an embodiment of the present invention includes a light emitting device having the above-described light emitting element. The light emitting device in this specification includes an image display device, a light emitting device, or a light source (including a lighting device). Further, the following are all included in a light emitting device: a module in which a connector, for example, a flexible printed circuit (FPC), a tape automated bonding (TAB) tape, or a tape carrier package (TCP) is attached to a panel provided with a light emitting element; a module provided with a printed wiring board at the end of the TAB tape or the TCP; and a module in which an integrated circuit (IC) is directly mounted to a light emitting element by a chip on glass (COG) method. Further, an electronic device using the light emitting element according to an embodiment of the present invention in a display portion is also included in the scope of the present invention. Consequently, one feature of an electronic device according to an embodiment of the present invention is to include a display portion, in which the display portion is provided with the above-described light emitting element and a control means to control light emission of the light emitting element. By application of an embodiment of the present invention, the singlet exciton and the triplet exciton which are generated in the light emitting layer can be effectively used, and a light emitting element with high luminous efficiency can be realized. In addition, by application of an embodiment of the present invention, power consumption of a light emitting element, a light emitting device, and an electronic device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a light emitting element according to an embodiment of the present invention. FIG. 2 is a band diagram illustrating a light emitting element according to an embodiment of the present invention. FIG. 3 is a band diagram illustrating a light emitting element according to an embodiment of the present invention. FIG. 4 illustrates a light emitting element according to an embodiment of the present invention. FIGS. 5A to 5C illustrate a light emitting element according to an embodiment of the present invention. FIG. 6 illustrates a light emitting element according to an embodiment of the present invention. FIG. 7 illustrates a light emitting element according to an embodiment of the present invention. FIGS. 8A and 8B illustrate a light emitting device according to an embodiment of the present invention. FIGS. 9A and 9B illustrate a light emitting device according to an embodiment of the present invention. FIGS. 10A to 10D each illustrate an electronic device according to an embodiment of the present invention. FIG. 11 illustrates an electronic device according to an embodiment of the present invention. FIG. 12 illustrates an electronic device according to an embodiment of the present invention. FIG. 13 illustrates an electronic device according to an embodiment of the present invention. FIG. 14 illustrates a lighting device according to an embodiment of the present invention. FIG. 15 illustrates a lighting device according to an embodiment of the present invention. FIGS. 16A to 16C illustrate an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiment of the present invention is not limited to the following description, and various changes and modifications for the modes and details thereof will be apparent to those skilled in the art unless such changes and modifications depart from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to what is described in the embodiments described below. Note that like portions or portions having a similar function are denoted by the same reference numerals through drawings, and therefore, description thereof is omitted. Embodiment 1 A mode of a light emitting element according to an embodiment of the present invention is described with reference to FIGS. 1 , 2 , 3 , and 4 . The light emitting element according to an embodiment of the present invention has a plurality of layers between a pair of electrodes. In this specification, the plurality of layers formed between the pair of electrodes is collectively referred to as an EL layer. The EL layer has at least a light emitting layer. In this embodiment, the light emitting element includes a first electrode 102 , a second electrode 104 , and an EL layer 103 formed between the first electrode 102 and the second electrode 104 , as illustrated in FIG. 1 . Note that in this embodiment, the first electrode 102 serves as an anode and the second electrode 104 serves as a cathode. In other words, when voltage is applied to the first electrode 102 and the second electrode 104 such that potential of the first electrode 102 is higher than that of the second electrode 104 , light emission can be obtained. Such a case is described below. A substrate 101 is used as a support of the light emitting element. The substrate 101 can be formed with, for example, glass, plastic, or the like. Note that materials other than glass or plastic can be used as long as they can function as a support of the light emitting element. The first electrode 102 is preferably formed using a metal, an alloy, an electrically conductive compound, a mixture of these, or the like each having a high work function (specifically, a work function of 4.0 eV or higher is preferable). Specifically, indium tin oxide (ITO), indium tin oxide including silicon or silicon oxide, indium zinc oxide (IZO), indium oxide including tungsten oxide and zinc oxide (IWZO), or the like can be used. These conductive metal oxide films are generally formed by sputtering; however, the films may be manufactured by applying a sol-gel method. For example, indium zinc oxide (IZO) can be formed by a sputtering method using indium oxide into which 1 wt % to 20 wt % of zinc oxide is added, as a target. Indium oxide including tungsten oxide and zinc oxide (IWZO) can be formed by a sputtering method using a target in which 0.5 wt % to 5 wt % of tungsten oxide and 0.1 wt % to 1 wt % of zinc oxide are mixed with indium oxide. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), nitride of a metal material (such as titanium nitride), and the like can be given. The second electrode 104 can be formed using a metal, an alloy, an electrically conductive compound, a mixture of these, or the like each having a low work function (specifically, a work function of 3.8 eV or lower is preferable). As a specific example of such a cathode material, an element belonging to Group 1 or Group 2 in the periodic table, that is, an alkali metal such as lithium (Li) or cesium (Cs); an alkaline earth metal such as magnesium (Mg), calcium (Ca), or strontium (Sr); an alloy including any of these (MgAg, AlLi); a rare-earth metal such as europium (Eu) or ytterbium (Yb); an alloy of these; and the like can be given. However, when an electron injecting layer is provided between the second electrode 104 and an electron transporting layer, the second electrode 104 can be formed using various conductive materials such as Al, Ag, ITO, or indium tin oxide including silicon or silicon oxide regardless of its work function. There is no particular limitation on the stacked structure of the EL layer 103 , and layers formed with substances having a high electron transporting property, a substance having a high hole transporting property, a substance having a high electron injecting property, a substance having a high hole injecting property, a bipolar substance (a substance having high electron transporting and hole transporting properties) and/or the like may be combined with the light emitting layer described in this embodiment, as appropriate. For example, a hole injecting layer, a hole transporting layer, a hole blocking layer, an electron transporting layer, an electron injecting layer, and the like may be combined as appropriate with the light emitting layer described in Embodiment 1. Specific materials to form each of the layers are given below. FIG. 1 illustrates a structure in which the first electrode 102 , a hole transporting layer 112 , a light emitting layer 113 , an electron transporting layer 114 , and the second electrode 104 are sequentially stacked, as an example. The hole transporting layer 112 is a layer including a substance having a high hole transporting property. As examples of the substance having a high hole transporting property, there are aromatic amine compounds such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), and 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), and the like. The substances described here are mainly substances having a hole mobility of 10 −6 cm 2 /Vs or more. Note that any other substance having a hole transporting property which is higher than an electron transporting property may be used. Note that the layer including a substance having a high hole transporting property is not limited to a single layer, and two or more layers including the above-described substances may be stacked. Furthermore, for the hole transporting layer 112 , a high molecular compound can be used. Examples of high molecular compounds include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), poly[N,N-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine (abbreviation: Poly-TPD), and the like. The light emitting layer 113 is a layer including a substance having a high light emitting property. In the light emitting element according to an embodiment of the present invention, the light emitting layer 113 includes a first layer 121 , a second layer 122 , a third layer 123 , and a fourth layer 124 which are sequentially provided from the side of the first electrode 102 that functions as an anode. The first layer 121 has a hole transporting property and includes a first substance which exhibits phosphorescence (hereinafter referred to as a phosphorescent compound) and a first organic compound having a hole transporting property. The triplet excitation energy of the first phosphorescent compound is the same as or lower than the triplet excitation energy of the first organic compound having a hole transporting property. The second layer 122 has a hole transporting property and includes a first substance which exhibits fluorescence (hereinafter referred to as a fluorescent compound) and a second organic compound having a hole transporting property. The singlet excitation energy of the first fluorescent compound is the same as or lower than the singlet excitation energy of the second organic compound having a hole transporting property. The third layer 123 has an electron transporting property and includes a second fluorescent compound and a first organic compound having an electron transporting property. The singlet excitation energy of the second fluorescent compound is the same as or lower than the singlet excitation energy of the first organic compound having an electron transporting property. The fourth layer 124 has an electron transporting property and includes a second phosphorescent compound and a second organic compound having an electron transporting property. The triplet excitation energy of the second phosphorescent compound is the same as or lower than the triplet excitation energy of the second organic compound having an electron transporting property. With such a structure, when voltage is applied to the first electrode 102 and the second electrode 104 such that the potential of the first electrode 102 is higher than that of the second electrode 104 , a recombination region is formed in the vicinity of the interface between the second layer 122 and the third layer 123 . In other words, as illustrated in FIG. 2 , holes injected from the first electrode 102 are transported through the hole transporting layer 112 to the first layer 121 . Because the first layer 121 has a hole transporting property, the holes are transported through the first layer 121 to the second layer 122 . Because the second layer 122 also has a hole transporting property, the holes are transported to the vicinity of the interface between the second layer 122 and the third layer 123 . On the other hand, electrons injected from the second electrode 104 are transported through the electron transporting layer 114 to the fourth layer 124 . Because the fourth layer 124 has an electron transporting property, the electrons are transported through the fourth layer 124 to the third layer 123 . Because the third layer 123 also has an electron transporting property, the electrons are transported to the vicinity of the interface between the third layer 123 and the second layer 122 . Then, in the vicinity of the interface between the second layer 122 and the third layer 123 , the holes and the electrons are recombined. In this recombination region 131 , an exciton of a singlet excited state (S*) and an exciton of a triplet excited state (T*) are generated, and the statistical generation ratio is thought to be S*:T*=1:3. The energy of the exciton of a singlet excited state is transferred to a singlet excited state of the first fluorescent compound included in the second layer 122 and a singlet excited state of the second fluorescent compound included in the third layer 123 , whereby the first fluorescent compound and the second fluorescent compound emit light. On the other hand, in a conventional light emitting element, an exciton of a triplet excited state generated in the recombination region 131 is deactivated without contribution to light emission, or only a part is used as disclosed in Non-Patent Document 1. In the light emitting element according to an embodiment of the present invention, the triplet excitation energy (an energy difference between a ground state and a triplet excited state) of the second organic compound having a hole transporting property is the same as or higher than the triplet excitation energy of the first organic compound having a hole transporting property. The triplet excitation energy of the first organic compound having an electron transporting property is the same as or higher than the triplet excitation energy of the second organic compound having an electron transporting property. With such a structure, exciton energy of a triplet excited state generated in the recombination region 131 can be transferred through the second layer to the first layer 121 , and the energy of the exciton can be transferred to the triplet excited state of the first organic compound having a hole transporting property included in the first layer 121 . In addition, exciton energy of a triplet excited state generated in the recombination region 131 can be transferred through the third layer to the fourth layer 124 , and the energy of the exciton can be transferred to a triplet excited state of a second organic compound having an electron transporting property included in the fourth layer 124 . As a result, energy is transferred from the triplet excited state of the first organic compound having a hole transporting property to the triplet excited state of the first phosphorescent compound, whereby the first phosphorescent compound emits light. In addition, energy is transferred from the triplet excited state of the second organic compound having an electron transporting property to the triplet excited state of the second phosphorescent compound, whereby the second phosphorescent compound emits light. In other words, by application of an embodiment of the present invention, the exciton of the singlet excited state and the exciton of the triplet excited state which are generated in the recombination region 131 can be effectively used for light emission. As for the light emitting element according to an embodiment of the present invention, the above-mentioned structure of the light emitting layer 113 is adopted, whereby the recombination region 131 can be limited to the vicinity of the center of the light emitting layer 113 , and carrier penetration can be suppressed, so that the emission intensity balance can be improved. In addition, the thickness of each layer (the first layer 121 , the second layer 122 , the third layer 123 , and the fourth layer 124 ) is adjusted, whereby the distance from the recombination region 131 to each layer can be adjusted; therefore, the emission balance can be improved. In the above structure, it is preferable that the first organic compound having a hole transporting property included in the first layer 121 and the second organic compound having a hole transporting property included in the second layer 122 be the same organic compound. By use of the same organic compound, the excitons of the triplet excited state generated in the recombination region 131 are easily diffused, and the energy is more smoothly transferred to the triplet excited state of the first organic compound having a hole transporting property included in the first layer 121 . In addition, manufacture of a light emitting element also becomes easy. In a similar manner, it is preferable that the first organic compound having an electron transporting property included in the third layer 123 and the second organic compound having an electron transporting property included in the fourth layer 124 be the same organic compound. By use of the same organic compound, the excitons of the triplet excited state generated in the recombination region 131 are easily diffused, and the energy is more smoothly transferred to the triplet excited state of the second organic compound having an electron transporting property included in the fourth layer 124 . In addition, manufacture of a light emitting element also becomes easy. As illustrated in FIG. 3 , it is preferable that a spacing layer 141 formed using one or both of the first organic compound having a hole transporting property and the second organic compound having a hole transporting property be provided between the first layer 121 and the second layer 122 . In FIG. 3 , the spacing layer 141 formed using the second organic compound having a hole transporting property is illustrated as an example. By provision of the spacing layer 141 , the distance between the recombination region 131 and the first layer 121 is easily adjusted, whereby light emission intensity from the first layer 121 is easily adjusted in accordance with the transfer of the energy from the triplet excited state. In addition, the singlet excitation energy of the first fluorescent compound included in the second layer 122 can be prevented from transferring to the first phosphorescent compound included in the first layer 121 due to the energy transfer by the Förster mechanism. Further, one or both of the first organic compound having a hole transporting property and the second organic compound having a hole transporting property is used for the spacing layer 141 , whereby the energy from the triplet excited state can be smoothly transferred. In addition, the spacing layer can be easily formed. In a similar manner, it is preferable that a spacing layer formed using one or both of the first organic compound having an electron transporting property and the second organic compound having an electron transporting property be provided between the third layer 123 and the fourth layer 124 . In FIG. 3 , a spacing layer 142 formed using the first organic compound having an electron transporting property is illustrated as an example. By provision of the spacing layer, the distance between the recombination region 131 and the fourth layer 124 is easily adjusted, whereby light emission intensity from the fourth layer 124 is easily adjusted in accordance with the transfer of the energy from the triplet excited state. In addition, the singlet excitation energy of the second fluorescent compound included in the third layer 123 can be prevented from transferring to the second phosphorescent compound included in the fourth layer 124 due to the energy transfer by the Förster mechanism. Further, one or both of the first organic compound having an electron transporting property and the second organic compound having an electron transporting property is used for the spacing layer, whereby the energy from the triplet excited state can be smoothly transferred. In addition, a spacing layer can be easily formed. Further, the total thickness of the second layer 122 and the third layer 123 is preferably greater than or equal to 5 nm and less than or equal to 20 nm. When the total thickness of the second layer 122 and the third layer 123 is too small, carriers penetrate, and the recombination region expands. When the total thickness of the second layer 122 and the third layer 123 is too large, the triplet excitation energy from the recombination region is not transferred to the first layer 121 and the fourth layer 124 , so that the first phosphorescent compound and the second phosphorescent compound do not emit light. Therefore, the total thickness of the second layer 122 and the third layer 123 is preferably greater than or equal to 5 nm and less than or equal to 20 nm. In addition, the concentration of the first fluorescent organic compound in the second layer 122 is preferably greater than or equal to 0.1 wt % and less than or equal to 10 wt %. When the concentration of the first fluorescent organic compound is too low, light emission from the first fluorescent organic compound is reduced. Further, when the concentration of the first fluorescent organic compound is too high, the energy from the triplet excitation energy from the recombination region is received by the first fluorescent organic compound, thereby deactivating excitons without light emission. Therefore, the concentration of the first fluorescent organic compound in the second layer 122 is preferably greater than or equal to 0.1 wt % and less than or equal to 10 wt %. In a similar manner, the concentration of the second fluorescent organic compound in the third layer 123 is preferably greater than or equal to 0.1 wt % and less than or equal to 10 wt %. When the concentration of the second fluorescent organic compound is too low, light emission from the second fluorescent organic compound is reduced. In addition, when the concentration of the second fluorescent organic compound is too high, the energy from the triplet excitation energy from the recombination region is received by the second fluorescent organic compound, thereby deactivating excitons without light emission. Therefore, the concentration of the second fluorescent organic compound in the third layer 123 is preferably greater than or equal to 0.1 wt % and less than or equal to 10 wt %. It is preferable that the first fluorescent organic compound included in the second layer 122 and the second fluorescent organic compound included in the third layer 123 be the same organic compound. By use of the same organic compound, the energy of the exciton generated from the recombination region 131 is more equally transferred to the second layer 122 and the third layer 123 . Therefore, the emission balance can be improved. In addition, manufacture of a light emitting element also becomes easy. Since light emission can be obtained from a plurality of substances each having a high light emitting property, the light emitting element according to an embodiment of the present invention is suitable for a white light emitting element. The light emitting element according to an embodiment of the present invention is applied to the white light emitting element, whereby a white light emitting element with high efficiency can be obtained. For example, the emission color of the first fluorescent organic compound and the emission color of the first phosphorescent compound are made to be complementary colors, whereby a white light emitting element can be obtained. In addition, the emission color of the second fluorescent organic compound and the emission color of the second phosphorescent compound are made to be complementary colors, whereby a white light emitting element with an excellent color rendering property can be obtained. Note that “complementary color” means a relation between colors which becomes an achromatic color when they are mixed. That is, white light emission can be obtained by mixture of light from substances whose emission colors are complementary colors. In addition, for example, the emission color of the first fluorescent organic compound and the emission color of the second phosphorescent compound are made to be complementary colors, whereby a white light emitting element can be obtained. Further, the emission color of the second fluorescent organic compound and the emission color of the first phosphorescent compound are made to be complementary colors, whereby a white light emitting element with an excellent color rendering property can be obtained. The emission color of the first fluorescent organic compound and that of the second fluorescent organic compound are blue, and the emission color of the first phosphorescent compound is green and the emission color of the second phosphorescent compound is red, whereby a white light emitting element with an excellent color rendering property can be obtained. When the first fluorescent organic compound and the second fluorescent organic compound are the same organic compound, and the first phosphorescent compound and the second phosphorescent compound are the same organic compound, the emission color of the first phosphorescent compound and the second phosphorescent compound and the emission color of the first fluorescent organic compound and the second fluorescent organic compound are made to be complementary colors, whereby a white light emitting element can be obtained. Since the first fluorescent organic compound and the second fluorescent organic compound are the same organic compound, the energy from the recombination region to the second layer 122 and the third layer 123 is more equally transferred, whereby the emission balance can be improved. In addition, manufacture of a light emitting element also becomes easy. Further, when the first phosphorescent compound and the second phosphorescent compound are the same organic compound, a white light emitting element can be more easily formed. Various kinds of materials can be used for the phosphorescent compounds of the second layer 122 and the third layer 123 . For example, as a blue light emitting phosphorescent compound, organometallic complexes such as bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ ]iridium(III)tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ ]iridium(III)picolinate (abbreviation: FIrpic), bis[2-(3′,5′bistrifluoromethylphenyl)pyridinato-N,C 2′ ]iridium(III)picolinate (abbreviation: Ir(CF 3 ppy) 2 (pic)), and bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ ]iridium(III)acetylacetonate (abbreviation: FIr(acac)) can be given. As a green light emitting phosphorescent compound, organometallic complexes such as tris(2-phenylpyridinato-N,C 2′ )iridium(III) (abbreviation: Ir(ppy) 3 ), bis(2-phenylpyridinato-N,C 2′ )iridium(III)acetylacetonate (abbreviation: Ir(ppy) 2 (acac)), bis(1,2-diphenyl-1H-benzimidazolato)iridium(III)acetylacetonate (abbreviation: Ir(pbi) 2 (acac)), and bis(benzo[h]quinolinato)iridium(III)acetylacetonate (abbreviation: Ir(bzq) 2 (acac)), can be given. As a yellow light emitting phosphorescent compound, organometallic complexes such as bis(2,4-diphenyl-1,3-oxazolato-N,C 2′ )iridium(III)acetylacetonate (abbreviation: Ir(dpo) 2 (acac)), bis[2-(4′-(perfluorophenylphenyl)pyridinato]iridium(III) acetylacetonate (abbreviation: Ir(p-PF-ph) 2 (acac)), and bis(2-phenylbenzothiazolato-N,C 2′ )iridium(III)acetylacetonate (abbreviation: Ir(bt) 2 (acac)) can be given. As an orange light emitting phosphorescent compound, organometallic complexes such as tris(2-phenylquinolinato-N,C 2 )iridium(III) (abbreviation: Ir(pq) 3 ), bis(2-phenylquinolinato-N,C 2 )iridium(III)acetylacetonate (abbreviation: Ir(pq) 2 (acac)), and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me) 2 (acac)] can be given. As a red light emitting phosphorescent compound, organometallic complexes such as bis[2-(2′-benzo[4,5-a]thienyl)pyridinato-N,C 3′ )iridium(III) acetylacetonate (abbreviation: Ir(btp) 2 (acac)), bis(1-phenylisoquinolinato-N,C 2′ )iridium(III)acetylacetonate (abbreviation: Ir(piq) 2 (acac)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq) 2 (acac)), and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: PtOEP) can be given. In addition, a rare-earth metal complex such as tris(acetylacetonato)(monophenanthroline)terbium(II) (abbreviation: Tb(acac) 3 (Phen)); tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM) 3 (Phen)); or tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA) 3 (Phen)) performs light emission (electron transition between different multiplicities) from a rare-earth metal ion; therefore, such a rare-earth metal complex can be used as the phosphorescent compound. Various kinds of materials can be used for the fluorescent compounds of the first layer 121 and the fourth layer 124 . For example, as a blue light emitting fluorescent compound, there are N,N′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N-diphenylstilbene-4,4′-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP), and the like. As a green light emitting fluorescent compound, there are N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1′-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), and the like. As a yellow light emitting fluorescent compound, there are rubrene, 5,12-bis(1,1′-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), and the like. As a red light emitting fluorescent compound, there are N,N,N′,N′-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,13-diphenyl-N,N,N′,N′-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), and the like. Various kinds of materials can be used for the organic compound having a hole transporting property in each of the first layer 121 and the second layer 122 . For example, an aromatic amine compound such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), 4,4′,4″-tris(N,N′-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), or 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), or the like can be used. The substances described here are mainly substances having a hole mobility of 10 −6 cm 2 /Vs or more. Note that any other substance having a hole transporting property which is higher than an electron transporting property may be used. A high molecular compound such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA); or poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can be used. Various kinds of materials can be used for the organic compound having an electron transporting property in each of the third layer 123 and the fourth layer 124 . For example, a metal complex having a quinoline or benzoquinoline skeleton, such as tris(8-quinolinolato)aluminum (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq 3 ), bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: BeBq 2 ), or bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (abbreviation: BAlq), or the like can be used. Alternatively, a metal complex having an oxazole-based or thiazole-based ligand, such as bis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX) 2 ) or bis[2-(2-hydroxyphenyl)-benzothiazolato]zinc (abbreviation: Zn(BTZ) 2 ), or the like can be used. Further alternatively, besides the metal complexes, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]carbazole (abbreviation: CO11), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), or the like can be used. The substances described here are mainly substances having an electron mobility of 10 −6 cm 2 /Vs or more. Note that any other substance having an electron transporting property which is higher than a hole transporting property may be used. Alternatively, a high molecular compound such as poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py) or poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-pyridine-6,6′-diyl)] (abbreviation: PF-BPy) can be used. A white light emitting element to which an embodiment of the present invention is applied can be obtained by using the following example. As the first phosphorescent compound in the first layer, (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq) 2 (acac)) which emits red light is used. As the first organic compound having a hole transporting property, 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA) is used. As the first fluorescent compound in the second layer, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP) which emits blue light is used. As the second compound having a hole transporting property, TCTA which is the same as that used for the first compound having a hole transporting property is used. As the second fluorescent compound in the third layer, TBP which is the same as that used for the first fluorescent compound is used. As the first organic compound having an electron transporting property, 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]carbazole (abbreviation: CO11) is used. As the second phosphorescent compound in the fourth layer, bis(2-phenylpyridinato-N,C 2′ )iridium(III)acetylacetonate (abbreviation: Ir(ppy) 2 (acac)) which emits green light is used. As the second organic compound having an electron transporting property, CO11 which is the same as that used for the first organic compound having an electron transporting property is used. The electron transporting layer 114 is a layer including a substance having a high electron transporting property. For example, a metal complex having a quinoline or benzoquinoline skeleton, such as tris(8-quinolinolato)aluminum (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq 3 ), bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation: BeBq 2 ), or bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (abbreviation: BAlq), or the like can be used. Alternatively, a metal complex having an oxazole-based or thiazole-based ligand, such as bis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX) 2 ) or bis[2-(2-hydroxyphenyl)-benzothiazolato]zinc (abbreviation: Zn(BTZ) 2 ), or the like can be used. Further alternatively, besides the metal complexes, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-biphenylyl)-1,2,4-triazole (abbreviation: TAZ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), or the like can be used. The substances described here are mainly substances having an electron mobility of 10 −6 cm 2 /Vs or more. Note that any other substance having an electron transporting property which is higher than a hole transporting property may be used. Furthermore, the electron transporting layer is not limited to a single layer, and two or more layers made of the above-described substances may be stacked. Alternatively, as the electron transporting layer 114 , a high molecular compound such as poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py) or poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-pyridine-6,6′-diyl)] (abbreviation: PF-BPy) can be used. As illustrated in FIG. 4 , a hole injecting layer 111 may be provided between the first electrode 102 and the hole transporting layer 112 . As the substance having a high hole injecting property, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, or the like can be used. In addition, it is possible to use a phthalocyanine-based compound such as phthalocyanine (abbreviation: H 2 Pc) or copper phthalocyanine (abbreviation: CuPc), a high molecule such as poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid) (PEDOT/PSS), or the like to form the hole injecting layer. Alternatively, a composite material in which an acceptor substance is included in a substance having a high hole transporting property can be used for the hole injecting layer 111 . Note that, by using the substance in which an acceptor substance is included in a substance having a high hole transporting property, a material used to form an electrode can be selected regardless of its work function. In other words, besides a material with a high work function, a material with a low work function can also be used as the first electrode 102 . As the acceptor substance, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F 4 -TCNQ), chloranil, and the like can be given. In addition, transition metal oxide can be given. Further, oxide of metals that belong to Group 4 to Group 8 in the periodic table can be given. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of a high electron accepting property. Among these, molybdenum oxide is especially preferable since it is stable in the air and its hygroscopic property is low so that it can be easily treated. Note that, in this specification, “composition” means not only a simple mixture of two materials but also a mixture of a plurality of materials in a condition where electric charge is given and received among the materials. As the organic compound used for the composite material, various compounds such as an aromatic amine compound, a carbazole derivative, aromatic hydrocarbon, and a high molecular compound (oligomer, dendrimer, polymer, or the like) can be used. Note that the organic compound used for the composite material is preferably an organic compound having a high hole transporting property. Specifically, a substance having a hole mobility of 10 −6 cm 2 /Vs or more is preferably used. Note that any other substance having a hole transporting property which is higher than an electron transporting property may be used. The organic compound that can be used for the composite material is specifically given below. For example, the followings can be given as the aromatic amine compound: N,N′-bis(4-methylphenyl)-N,N′-diphenyl-p-phenylenediamine (abbreviation: DTDPPA); 4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB); 4,4′-bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (abbreviation: DNTPD); 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B); and the like. As specific examples of the carbazole derivative which can be used as the composite material, the following can be given: 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1); 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2); 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1); and the like. Moreover, as carbazole derivatives which can be used for the composite material, 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP); 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB); 9-[4-(10-phenyl-9-anthracenyl)phenyl]- 9 H-carbazole (abbreviation: CzPA); 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene; or the like can also be used. As aromatic hydrocarbon which can be used for the composite material, the following can be given for example: 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA); 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA); 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA); 9,10-di(2-naphthyl)anthracene (abbreviation: DNA); 9,10-diphenylanthracene (abbreviation: DPAnth); 2-tert-butylanthracene (abbreviation: t-BuAnth); 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA); 9,10-bis[2-(1-naphthyl)phenyl]-2-tert-butylanthracene; 9,10-bis[2-(1-naphthyl)phenyl]anthracene; 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene; 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene; 9,9′-bianthryl; 10,10′-diphenyl-9,9′-bianthryl; 10,10′-bis(2-phenylphenyl)-9,9′-bianthryl; 10,10′-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9′-bianthryl; anthracene; tetracene; rubrene; perylene; 2,5,8,11-tetra(tert-butyl)perylene; and the like. In addition, pentacene, coronene, or the like can also be used. As these aromatic hydrocarbons listed here, an aromatic hydrocarbon having a hole mobility of 1×10 −6 cm 2 /Vs or more and having 14 to 42 carbon atoms is more preferable. Note that aromatic hydrocarbon that can be used for the composite material may have a vinyl skeleton. As an aromatic hydrocarbon having a vinyl group, for example, 4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA), and the like can be given. In addition, a high molecular compound such as poly(N-vinylcarbazole) (abbreviation: PVK) or poly(4-vinyl triphenylamine) (abbreviation: PVTPA) can also be used. As illustrated in FIG. 4 , an electron injecting layer 115 may be provided between the electron transporting layer 114 and the second electrode 104 . As the electron injecting layer 115 , an alkali metal, an alkaline earth metal, or a compound of these such as lithium fluoride (LiF), cesium fluoride (CsF), or calcium fluoride (CaF 2 ) can be used. For example, a layer formed using a substance having an electron transporting property including an alkali metal, an alkaline earth metal, or a compound of these, such as Alq which includes magnesium (Mg), can be used. When a layer formed using a substance having an electron transporting property including an alkali metal or an alkaline earth metal is used as the electron injecting layer 115 , electrons can be efficiently injected from the second electrode 104 , which is preferable. As a formation method of the EL layer 103 , various methods can be employed, and either a wet process or a dry process can be used. For example, a vacuum evaporation method, an inkjet method, a spin coating method, or the like may be used. Further, each electrode or each layer may be formed by a different method. In the light emitting element according to an embodiment of the present invention having the above structure, to allow current to flow due to a potential difference between the first electrode 102 and the second electrode 104 and holes and electrons are recombined in the EL layer 103 so that light is emitted. More specifically, a light emitting region is formed in the light emitting layer 113 in the EL layer 103 . The emitted light is extracted out through one or both of the first electrode 102 and the second electrode 104 . Accordingly, one or both of the first electrode 102 and the second electrode 104 is/are an electrode having a light transmitting property. When only the first electrode 102 is an electrode having a light transmitting property, light is extracted from the substrate side through the first electrode 102 as illustrated by an arrow in FIG. 5A . In addition, when only the second electrode 104 is an electrode having a light transmitting property, light is extracted from the opposite side to the substrate side through the second electrode 104 as illustrated by an arrow in FIG. 5B . Further, when the first electrode 102 and the second electrode 104 are both electrodes having light transmitting properties, light is extracted to opposite sides, i.e., the substrate side and the opposite side, through the first electrode 102 and the second electrode 104 as illustrated by an arrow in FIG. 5C . The structure of EL layer 103 provided between the first electrode 102 and the second electrode 104 is not limited to the above example. A structure other than the above-described one may also be used as long as a light emitting region in which holes and electrons are recombined is provided in a portion apart from the first electrode 102 and the second electrode 104 so that quenching caused by the light emitting region and the first electrode 102 or the second electrode 104 coming close to each other is suppressed, and moreover, as long as the light emitting layer 113 includes the above structure. In other words, there are no particular limitations on the stacked structure of the EL layer 103 , and layers formed using a substance having a high electron transporting property, a substance having a high hole transporting property, a substance having a high electron injecting property, a substance having a high hole injecting property, a bipolar substance (a substance having high electron transporting and hole transporting properties), a hole block material, and the like may be freely combined with the light emitting layer 113 of an embodiment of the present invention. The light emitting element illustrated in FIG. 6 has a structure in which the second electrode 104 functioning as the cathode, the EL layer 103 , and the first electrode 102 functioning as the anode are sequentially stacked over the substrate 101 . The EL layer 103 has the hole transporting layer 112 , the light emitting layer 113 , and the electron transporting layer 114 . In the light emitting layer 113 , the first layer 121 , the second layer 122 , the third layer 123 , and the fourth layer 124 are sequentially stacked from the first electrode 102 side. In this embodiment, the light emitting element is manufactured over a substrate formed with glass, plastic, or the like. By formation of a plurality of such light emitting elements over a substrate, a passive matrix light emitting device can be manufactured. Alternatively, for example, a thin film transistor (TFT) may be formed over a substrate formed with glass, plastic, or the like, and a light emitting element may be manufactured over an electrode that is electrically connected to the TFT. Thus, an active matrix light emitting device which controls the driving of a light emitting element by a TFT can be manufactured. Note that a structure of the TFT is not particularly limited. The TFT may be either of staggered type or inverted staggered type. As for a driver circuit formed on the TFT substrate also, one or both of n-channel transistors and p-channel transistors may be used. In addition, the crystallinity of a semiconductor film used for the TFT is not particularly limited. Either an amorphous semiconductor film or a crystalline semiconductor film may be used. The light emitting element according to an embodiment of the present invention can achieve high luminous efficiency by efficiently using an exciton of a singlet excited state and an exciton of a triplet excited state which are generated in the recombination region. Since high luminous efficiency is obtained, power consumption of the light emitting element can be reduced. Note that this embodiment can be combined with any of other embodiments, as appropriate. Embodiment 2 In this embodiment, a light emitting element (a stacked type element) in which a plurality of light emitting units according to an embodiment of the present invention is stacked will be described with reference to FIG. 7 . This light emitting element is a light emitting element having a plurality of light emitting units between a first electrode and a second electrode. As the light emitting units, at least a light emitting layer may be included, and a structure similar to that of the EL layer described in Embodiment 1 can be used. In other words, the light emitting element described in Embodiment 1 is a light emitting element having one light emitting unit, and a light emitting element having a plurality of light emitting units will be described in this embodiment. In FIG. 7 , a first light emitting unit 511 and a second light emitting unit 512 are stacked between a first electrode 501 and a second electrode 502 . A charge generation layer 513 is provided between the first light emitting unit 511 and the second light emitting unit 512 . To the first electrode 501 and the second electrode 502 , similar electrodes to those described in Embodiment 1 can be applied. The first light emitting unit 511 and the second light emitting unit 512 may have the same structure or different structures, and the structures, described in Embodiment 1 can be applied. The charge generation layer 513 includes a composite material of an organic compound and metal oxide. The composite material of an organic compound and metal oxide is the composite material described in Embodiment 1, and includes an organic compound and metal oxide such as vanadium oxide, molybdenum oxide, or tungsten oxide. As the organic compound, various compounds such as an aromatic amine compound, a carbazole derivative, aromatic hydrocarbon, and a high molecular compound (oligomer, dendrimer, polymer, or the like) can be used. Note that the organic compound having a hole mobility of 10 −6 cm 2 /Vs or more is preferably used as an organic compound having a hole transporting property. Note that any other substance having a hole transporting property which is higher than an electron transporting property may be used. The composite material of an organic compound and metal oxide is superior in carrier injecting property and carrier transporting property, and accordingly, low-voltage driving and low-current driving can be realized. Note that the charge generation layer 513 may be formed with a combination of a composite material of an organic compound and metal oxide and other materials. For example, the charge generation layer 513 may be formed with a combination of a layer including the composite material of an organic compound and metal oxide and a layer including a compound having a high electron transporting property and an electron donating substance with respect to the compound having the high electron transporting property. Further, the charge generation layer 513 may be formed with a combination of a layer including the composite material of an organic compound and metal oxide and a transparent conductive film. In any cases, the charge generation layer 513 interposed between the first light emitting unit 511 and the second light emitting unit 512 is acceptable as long as electrons are injected to a light emitting unit on one side and holes are injected to a light emitting unit on the other side when voltage is applied to the first electrode 501 and the second electrode 502 . For example, in FIG. 7 , any layer can be employed as the charge generation layer 513 as long as the layer injects electrons into the first light emitting unit 511 and holes into the second light emitting unit 512 when voltage is applied so that the potential of the first electrode 501 is higher than that of the second electrode 502 . In this embodiment, the light emitting element having two light emitting units is described; however, similarly, an embodiment can be applied to a light emitting element in which three or more light emitting units are stacked. When a plurality of light emitting units is arranged to be partitioned from each other with a charge generation layer between a pair of electrodes, like the light emitting element according to this embodiment, light emission from a region of high luminance can be realized at a low current density, and thus, an element with a long life can be achieved. Note that this embodiment can be combined with any of other embodiments, as appropriate. Embodiment 3 In this embodiment, a light emitting device having a light emitting element according to an embodiment of the present invention will be described. A light emitting device having the light emitting element according to an embodiment of the prevent invention in a pixel portion will be described in this embodiment with reference to FIGS. 8A and 8B . FIG. 8A is a top view illustrating the light emitting device, and FIG. 8B is a cross sectional view taken along line A-A′ and line B-B′ of FIG. 8A . This light emitting device includes a driver circuit portion (source side driver circuit) 601 , a pixel portion 602 , and a driver circuit portion (gate side driver circuit) 603 which are illustrated by dotted lines in order to control the light emission of the light emitting element. Reference numeral 604 denotes a sealing substrate; reference numeral 605 denotes a sealing material; and a portion surrounded by the sealing material 605 corresponds to a space 607 . Note that a leading wiring 608 is a wiring for transmitting signals input in the source side driver circuit 601 and the gate side driver circuit 603 . The leading wiring 608 receives video signals, clock signals, start signals, reset signals, and the like from a flexible printed circuit (FPC) 609 that serves as an external input terminal. Although only the FPC is illustrated here, the FPC may be provided with a printed wiring board (PWB). The light emitting device according to this specification includes not only a light emitting device body but also a state in which an FPC or a PWB is attached thereto. Next, the sectional structure will be described with reference to FIG. 8B . The driver circuit portion and the pixel portion are formed over an element substrate 610 , and the source side driver circuit 601 , which is one of the driver circuit portions, and one pixel in the pixel portion 602 are illustrated. Note that as the source side driving circuit 601 , a CMOS circuit in which an n-channel TFT 623 and a p-channel TFT 624 are combined is formed. The driver circuit may be formed by various CMOS circuits, PMOS circuits, or NMOS circuits. Although a driver-integration type device, in which a driver circuit is formed over the substrate provided with the pixel portion, is described in this embodiment, a driver circuit is not necessarily formed over the substrate provided with the pixel portion, but can be formed outside a substrate. The pixel portion 602 has a plurality of pixels, each of which includes a switching TFT 611 , a current control TFT 612 , and a first electrode 613 which is electrically connected to a drain of the current control TFT 612 . Note that an insulator 614 is formed so as to cover an end portion of the first electrode 613 . Here, the insulator 614 is formed using a positive photosensitive acrylic resin film. In order to prevent adverse influence on a light-emitting element 618 , the insulator 614 is provided such that either an upper end portion or a lower end portion of the insulator has a curved surface with a curvature. For example, in the case of using positive photosensitive acrylic as a material for the insulator 614 , it is preferable that the insulator 614 be formed so as to have a curved surface with a curvature radius (0.2 μm to 3 μm) the upper end portion of the insulator 614 . Note that the insulator 614 can be formed using either negative photosensitive acrylic that becomes insoluble in an etchant due to light irradiation, or positive photosensitive acrylic that becomes soluble in an etchant due to light irradiation. An EL layer 616 and a second electrode 617 are formed over the first electrode 613 . Here, the first electrode 613 can be formed with various metals, alloys, electrically conductive compounds, or mixture thereof. If the first electrode 613 is used as an anode, it is preferable to use a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like with a high work function (a work function of 4.0 eV or higher) among such materials. For example, a stacked-layer structure of a film including a titanium nitride film and a film including aluminum as its main component, a three-layer structure of a titanium nitride film, a film including aluminum as its main component, and a titanium nitride film, or the like can be used in addition to a single layer of indium tin oxide including silicon, indium zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, a Pt film, or the like. The EL layer 616 is formed by various methods such as an evaporation method using an evaporation mask, an inkjet method, a spin coating method, or the like. The EL layer 616 has the light emitting layer described in Embodiment 1. Further, the EL layer 616 may be formed using another material including a low molecular compound or a high molecular compound (including oligomer and dendrimer). As the material for the EL layer 616 , not only an organic compound but also an inorganic compound may be used. The second electrode 617 can be formed with various metals, alloys, electrically conductive compounds, or mixtures of these. If the second electrode is used as a cathode, it is preferable to use a metal, an alloy, an electrically conductive compound, a mixture of these, or the like with a low work function (a work function of 3.8 eV or lower) among such materials. As an example, an element belonging to Group 1 or Group 2 in the periodic table, that is, an alkali metal such as lithium (Li) or cesium (Cs); an alkaline earth metal such as magnesium (Mg), calcium (Ca), or strontium (Sr); an alloy including any of these (MgAg, AlLi); and the like can be given. In the case where light generated in the EL layer 616 is transmitted through the second electrode 617 , the second electrode 617 can be formed using a stacked layer of a metal thin film whose thickness is made small, and a transparent conductive film (indium tin oxide (ITO), indium tin oxide including silicon or silicon oxide, indium zinc oxide (IZO), indium oxide including tungsten oxide and zinc oxide (IWZO), or the like). By attaching the sealing substrate 604 to the element substrate 610 with the sealing material 605 , a light emitting element 618 is provided in the space 607 which is surrounded by the element substrate 610 , the sealing substrate 604 , and the sealing material 605 . Note that the space 607 is filled with a filler and may be filled with an inert gas (such as nitrogen or argon), the sealing material 605 , or the like. As the sealing material 605 , an epoxy resin is preferably used. In addition, it is desirable to use a material that allows permeation of moisture or oxygen as little as possible. As the sealing substrate 604 , a plastic substrate formed with Fiberglass-Reinforced Plastics (FRP), polyvinyl fluoride (PVF), polyester, acrylic, or the like can be used besides a glass substrate or a quartz substrate. As described above, the light emitting device having the light emitting element according to an embodiment of the present invention can be obtained. The light emitting device according to an embodiment of the present invention includes the light emitting element described in Embodiment 1 or Embodiment 2. Therefore, a light emitting device with high luminous efficiency can be obtained. In addition, power consumption of the light emitting device can be reduced. Although an active matrix light emitting device in which driving of a light emitting element is controlled by thin film transistors is described in this embodiment as described above, the light emitting device may be replaced with a passive matrix light emitting device. FIGS. 9A and 9B illustrate a passive matrix light emitting device which is manufactured by application of an embodiment of the present invention. Note that FIG. 9A is a perspective view illustrating the light emitting device, and FIG. 9B is a cross-sectional view of FIG. 9A taken along line X-Y. In FIGS. 9A and 9B , over a substrate 951 , an EL layer 955 is provided between an electrode 952 and an electrode 956 . The end portion of the electrode 952 is covered with an insulating layer 953 . A partition layer 954 is provided over the insulating layer 953 . The sidewalls of the partition layer 954 are aslope so that a distance between both sidewalls is gradually narrowed toward the surface of the substrate. That is, a cross section in the direction of a narrow side of the partition layer 954 has a trapezoidal shape, and a lower side (which faces a surface of the insulating layer 953 and is in contact with the insulating layer 953 ) is shorter than an upper side (which faces the surface of the insulating layer 953 and is not in contact with the insulating layer 953 ). A cathode can be patterned by providing the partition layer 954 in this manner. In addition, in a passive matrix light emitting device, a light emitting device with low power consumption can be obtained by including a light emitting element with high luminous efficiency according to an embodiment of the present invention. Note that this embodiment can be combined with any of other embodiments, as appropriate. Embodiment 4 In this embodiment, an electronic device according to an embodiment of the present invention including the light emitting device described in Embodiment 3 as part thereof will be described. The electronic device according to an embodiment of the present invention has the light emitting element described in Embodiment 1 or Embodiment 2, and a display portion with high luminous efficiency. Moreover, a display portion having low power consumption is included. As an electronic device manufactured using the light emitting device according to an embodiment of the present invention, a camera such as a video camera or a digital camera, a goggle type display, a navigation system, an audio reproducing device (car audio set, audio component set, or the like), a computer, a game machine, a portable information terminal (mobile computer, cellular phone, portable game machine, e-book reader, or the like), and an image reproducing device provided with a recording medium (specifically, a device provided with a display device that can reproduce a recording medium and display the image such as a Digital Versatile Disc (DVD)), and the like can be given. Specific examples of these electronic devices are illustrated in FIGS. 10A to 10D . FIG. 10A illustrates a television device according to this embodiment, which includes a housing 9101 , a support base 9102 , a display portion 9103 , a speaker portion 9104 , a video input terminal 9105 , and the like. In the display portion 9103 of this television device, the light emitting elements described in Embodiment 1 or Embodiment 2 are arranged in matrix. One feature of the light emitting element is that luminous efficiency is high and power consumption is low. Since the display portion 9103 constructed of such light emitting elements has similar characteristics, this television device consumes less power. With such characteristics, the number or scale of power supply circuits in the television device can be drastically reduced, and therefore, the size and weight of the housing 9101 and the support base 9102 can be reduced. In the television device according to this embodiment, reduction in power consumption and reduction in size and weight are achieved; therefore, a product which is suitable for living environment can be provided. FIG. 10B illustrates a computer according to this embodiment, which includes a main body 9201 , a housing 9202 , a display portion 9203 , a keyboard 9204 , an external connection port 9205 , a pointing device 9206 , and the like. In the display portion 9203 of this computer, the light emitting elements described in Embodiment 1 or Embodiment 2 are arranged in matrix. One feature of the light emitting element is that luminous efficiency is high and power consumption is low. Since the display portion 9203 constructed of such light emitting elements has similar characteristics, this computer consumes less power. With such characteristics, the number or scale of power supply circuits in the computer can be drastically reduced, and therefore, the size and weight of the main body 9201 and the housing 9202 can be reduced. In the computer according to this embodiment, reduction in power consumption and reduction in size and weight are achieved; therefore, a product which is suitable for environment can be provided. FIG. 10C illustrates a camera that includes a main body 9301 , a display portion 9302 , a housing 9303 , an external connection port 9304 , a remote control receiving portion 9305 , an image receiving portion 9306 , a battery 9307 , an audio input portion 9308 , operation keys 9309 , an eyepiece portion 9310 , and the like. In the display portion 9302 of this camera, the light emitting elements described in Embodiment 1 or Embodiment 2 are arranged in matrix. One feature of the light emitting element is that luminous efficiency is high and power consumption is low. Since the display portion 9302 constructed of such light emitting elements has similar characteristics, this camera consumes less power. With such characteristics, the number or scale of power supply circuits in the camera can be drastically reduced, and therefore, the size and weight of the main body 9301 can be reduced. In the camera according to this embodiment, reduction in power consumption and reduction in size and weight are achieved; therefore, a product which is suitable for being carried around can be provided. FIG. 10D illustrates a cellular phone according to this embodiment, which includes a main body 9401 , a housing 9402 , a display portion 9403 , an audio input portion 9404 , an audio output portion 9405 , operation keys 9406 , an external connection port 9407 , an antenna 9408 , and the like. In the display portion 9403 of this cellular phone, the light emitting elements described in Embodiment 1 or Embodiment 2 are arranged in matrix. One feature of the light emitting element is that luminous efficiency is high and power consumption is low. Since the display portion 9403 constructed of such light emitting elements has similar characteristics, this cellular phone consumes less power. With such characteristics, the number or scale of power supply circuits in the cellular phone can be drastically reduced, and therefore, the size and weight of the main body 9401 and the housing 9402 can be reduced. In the cellular phone according to this embodiment, reduction in power consumption and reduction in size and weight are achieved; therefore, a product which is suitable for being carried around can be provided. FIGS. 16A to 16C illustrate an example of a structure of a cellular phone, which is different from the structure of the cellular phone of FIG. 10D . FIG. 16A is a front view, FIG. 16B is a rear view, and FIG. 16C is a development view. The cellular phone illustrated in FIGS. 16A to 16C is a so-called smartphone which has both a function as a phone and a function as a portable information terminal, and incorporates a computer to conduct a variety of data processing in addition to voice calls. The cellular phone illustrated in FIGS. 16A to 16C has two housings 1001 and 1002 . The housing 1001 includes a display portion 1101 , a speaker 1102 , a microphone 1103 , operation keys 1104 , a pointing device 1105 , a camera lens 1106 , an external connection terminal 1107 , and the like, while the housing 1002 includes a keyboard 1201 , an external memory slot 1202 , a camera lens 1203 , a light 1204 , an earphone terminal 1008 , and the like. In addition, an antenna is incorporated in the housing 1001 . In addition to the above structure, the cellular phone may incorporate a non-contact IC chip, a small size memory device, or the like. In the display portion 1101 , the light emitting device described in Embodiment 3 can be incorporated, and a display direction can be changed as appropriate depending on the usage mode. The cellular phone is provided with the camera lens 1106 on the same surface as the display portion 1101 , and thus it can be used as a video phone. Further, a still image and a moving image can be taken with the camera lens 1203 and the light 1204 by using the display portion 1101 as a viewfinder. The speaker 1102 and the microphone 1103 are not limited to use for verbal communication, and can be used for a videophone, recording, reproduction, and the like. With use of the operation keys 1104 , operation of incoming and outgoing calls, simple information input of electronic mails or the like, scrolling of a screen, cursor motion, and the like are possible. Furthermore, the housing 1001 and the housing 1002 ( FIG. 16A ), which are overlapped with each other, are slid to expose the housing 1002 as illustrated in FIG. 16C , and can be used as a portable information terminal. In this case, smooth operation is possible with use of the keyboard 1201 and the pointing device 1105 . The external connection terminal 1107 can be connected to an AC adapter or a variety of cables such as a USB cable, and can be charged and perform data communication with a computer or the like. Moreover, a large amount of data can be stored by inserting a storage medium into the external memory slot 1202 and can be moved. In addition to the above-described functions, the cellular phone may also have an infrared communication function, a television reception function, or the like. FIG. 11 illustrates an audio reproducing device, specifically, a car audio system, which includes a main body 701 , a display portion 702 , and operation switches 703 and 704 . The display portion 702 can be realized by the (passive matrix or active matrix) light emitting device described in Embodiment 3. Further, the display portion 702 may employ a segment type light emitting device. In any case, the use of a light emitting element according to an embodiment of the present invention makes it possible to form a bright display portion while achieving low power consumption, with the use of a vehicle power source (12 V to 42 V). Although an in-car audio system is described in this embodiment, an embodiment may be used for a portable audio device or an audio device for household use. FIG. 12 illustrates a digital player as an example of an audio reproducing device. The digital player illustrated in FIG. 12 includes a main body 710 , a display portion 711 , a memory portion 712 , an operation portion 713 , earphones 714 , and the like. Note that headphones or wireless earphones can be used instead of the earphones 714 . The display portion 711 can be realized by the (passive matrix or active matrix) light emitting device described in Embodiment 3. Further, the display portion 711 may employ a segment type light emitting device. In any case, the use of a light emitting element according to an embodiment of the present invention makes it possible to form a bright display portion which can display images even when using a secondary battery (a nickel-hydrogen battery or the like) while achieving low power consumption. As the memory portion 712 , a hard disk or a nonvolatile memory is used. For example, a NAND type nonvolatile memory with a recording capacity of 20 gigabytes (GB) to 200 gigabytes (GB) is used, and by operating the operation portion 713 , an image or sound (e.g., music) can be recorded and reproduced. Note that power consumption of the display portions 702 in FIG. 11 and the display portion 711 in FIG. 12 can be suppressed through display of white characters on the black background. This is particularly effective for portable audio systems. As described above, the applicable range of the light emitting device manufactured by applying an embodiment of the present invention is so wide that the light emitting device is applicable to electronic devices in various fields. By applying an embodiment of the present invention, an electronic device which has high luminous efficiency and a display portion consuming less power can be manufactured. The light emitting device according to an embodiment of the present invention can also be used as a lighting device. An example using the light emitting element according to an embodiment of the present invention as a lightning device will be described with reference to FIG. 13 . FIG. 13 illustrates a liquid crystal display device using the light emitting device to which an embodiment of the present invention is applied as a backlight, as an example of the electronic device using a light emitting device according to an embodiment of the present invention as a lighting device. The liquid crystal display device illustrated in FIG. 13 includes a housing 901 , a liquid crystal layer 902 , a backlight 903 , and a housing 904 . The liquid crystal layer 902 is connected to a driver IC 905 . The light emitting device to which an embodiment of the present invention is applied is used as the backlight 903 , and current is supplied through a terminal 906 . Since the light emitting device according to an embodiment of the present invention is thin and has high luminous efficiency and low power consumption, reduction in thickness and power consumption of a display device is possible by using a light emitting device according to an embodiment of the present invention as a backlight of the liquid crystal display device. Moreover, a light emitting device according to an embodiment of the present invention is a plane emission type lighting device and can have a large area. Thus, the backlight can have a large area, and a liquid crystal display device having a large area can also be obtained. FIG. 14 illustrates an example in which a light emitting device according to an embodiment of the present invention is used as a desk lamp, which is one of lighting devices. The desk lamp illustrated in FIG. 14 includes a housing 2001 and a light source 2002 , and a light emitting device according to an embodiment of the present invention is used as the light source 2002 . The light emitting device according to an embodiment of the present invention have high luminous efficiency and low power consumption; thus, the desk lamp also has low power consumption. FIG. 15 illustrates an example of using the light emitting device, to which an embodiment of the present invention is applied, as an indoor lighting device 3001 . Because the light emitting device according to an embodiment of the present invention can have a large area, a light emitting device according to an embodiment of the present invention can be used as a lighting device having a large area. Moreover, because the light emitting device according to an embodiment of the present invention has high luminous efficiency and low power consumption, the light emitting device according to an embodiment of the present invention can be used as a lighting device which consumes less power. As illustrated in the drawing, a television device 3002 according to an embodiment of the present invention as illustrated in FIG. 10A may be set in a room where the light emitting device to which an embodiment of the present invention is applied is used as the indoor lighting device 3001 , and public broadcasting or movies can be appreciated there. In such a case, since both devices consume less power, environmental load can be reduced. Note that this embodiment can be combined with any of other embodiments, as appropriate. This application is based on Japanese Patent Application serial No. 2008-223217 filed with Japan Patent Office on Sep. 1, 2008, the entire contents of which are hereby incorporated by reference.

An object is to improve luminous efficiency of a light emitting element using triplet exciton energy effectively. Another object is to reduce power consumption of a light emitting element, a light emitting device, and an electronic device. Triplet exciton energy generated in a light emitting layer which exhibits short wavelength fluorescence can be effectively utilized by use of a structure in which the light emitting layers which exhibit short wavelength fluorescence are sandwiched between light emitting layers each including a phosphorescent compound. Further, the emission balance can be improved between the light emitting layer including a phosphorescent compound and the light emitting layer which exhibits fluorescence by the devising of the structure of the light emitting layer which exhibits fluorescence.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to manufacturing method of an impeller used in a centrifugal rotor such as a centrifugal compressor. [0003] Priority is claimed on Japanese Patent Application No. 2009-015451, filed on Jan. 27, 2009, the contents of which are incorporated herein by reference. [0004] 2. Description of the Related Art [0005] As an impeller used for a centrifugal rotor such as a centrifugal compressor, an impeller (a closed impeller) is known to which a cover is attached, which includes a disc attached to a rotation shaft, a cover opposed to the disc so as to have a space, and a plurality of blades connecting the disc with the cover. In the cover-attached impeller, the space which is enclosed by the surfaces of the plurality of blades and surfaces of the cover and the disc which are opposed to each other, functions as a passage for compressing gas. The impeller provided in the centrifugal compressor is manufactured by a method such as integral molding by casting, bonding by welding, or bonding by brazing (or transient liquid phase diffusion bonding, solid-phase diffusion bonding). [0006] Specifically, the integral molding is a method which involves integrally forming the cover, the blades, and the disc by the machining of materials. However, in the impeller generally provided in the centrifugal compressor, as the passage has a complex shape which is curved in both the axial direction (the rotation shaft direction) and the radial direction, the integral molding is difficult. [0007] Bonding by welding is a method which involves bonding an integral member made by forming blades integrally with either a cover or a disc to the other one of the cover and the disc by welding, or involves bonding the blades, the cover, and the disc to each other by welding. In this case, it is necessary to insert a welding torch into a passage, and in a case where the passage is narrow, inserting it into the passage is difficult. Therefore, there is a problem in that welding defects are more likely to occur. [0008] The bonding by brazing is a method used when a cover to which blades are attached is bonded to a disc, and involves disposing a brazing filler metal such as foil, powder, or wire at the bonding points, placing the cover and the disc to overlap with each other in the furnace, and bonding them by heating (for example, refer to JP-A-2003-328989). The bonding by brazing has an advantage in that it can be easily performed compared with the bonding by welding described above even in cases where the passage is narrow. [0009] Conventionally, there is an impeller, in which a portion around a rotation shaft (inner periphery) of a disc which is bond part bonded with a blade, is formed with a curved surface in order to enhance aerodynamic performance. FIG. 7 is a side cross-sectional view illustrating the shape of an impeller having such a configuration. The impeller 10 illustrated in FIG. 7 has a passage R of which an outer peripheral side is formed along a radial direction by a disc 11 and a cover 12 and which increasingly curves toward the cover 12 in the direction toward the inner peripheral side. The disc 11 and the cover 12 are provided with curved surfaces 11 a and 12 a along a curved surface Ra of the passage R. [0010] However, the structure of the existing impeller has the following problems. [0011] In the above-mentioned impeller provided in the centrifugal compressor, tensile force acts on the bond part between the blade and the disc or the cover due to rotation in a direction in which the cover and the disc are separated from each other by centrifugal force, and bending stress occurs in a direction relative to the rotation direction. Accordingly, excess concentrated stress acts on the bond part corresponding to base portions of the blade and the disc. Particularly, in the bond part, rotation stress on the inner peripheral side in the radial direction increases. [0012] Therefore, reliable bonding is required on the inner peripheral side of the bond part. However, in the case of the existing impeller 10 described above, in which the curved surface 11 a is formed in the vicinity of the rotation shaft (inner periphery) of the disc 11 of the bond part with the blade 13 as illustrated in FIG. 7 , bonding is performed in a state where the disc 11 faces down. That is, bonding is performed in a state where the outer peripheral side of the curved surface 11 a of the disc 11 is lower than the inner peripheral side thereof. Accordingly, when the brazing filler metal 14 disposed between the blade 13 and the disc 11 is melted and liquefied, the brazing filler metal 14 flows from the inner peripheral side toward the outer peripheral side (in an arrow direction G) along the curved surface 11 a. Therefore, the brazing filler metal 14 is insufficiently supplied to the inner peripheral side of the bond part, such that there is a problem in that the bonding strength of the bond part on the inner peripheral side, which requires a reliable bonding, is reduced. [0013] The present invention is designed to solve the above-mentioned problems. An object of the present invention is to provide a manufacturing method of an impeller, which ensures bonding strength by preventing insufficient supply of bonding material. SUMMARY OF THE INVENTION [0014] According to an aspect of the present invention, there is provided a manufacturing method of an impeller which includes a disc, a cover opposed to the disc, a plurality of blades provided between the disc and the cover, and a plurality of passages formed between the disc and the cover, each of the passages having an inlet formed on a surface of the cover of the impeller and an outlet formed on an outer peripheral surface of the impeller, and the direction of each of the passages being changed so as to follow a radial direction of the impeller as it proceeds from the inlet to the outlet, the manufacturing method includes: forming the plurality of blades integrally on a blade attachment surface of one of the disc and the cover; placing the cover on a floor so as to face up the blade attachment surface of the cover; disposing the disc on the cover so as to face down the blade attachment surface of the disc; and bonding the plurality of blades to the blade attachment surface of the other of the disc and the cover which is not formed integrally with the plurality of blades by using a bonding material. [0015] In addition, the impeller according to the present invention is manufactured by the above-mentioned manufacturing method of the impeller. [0016] According to the present invention, the blade attachment surface of the cover is disposed to face up, so that the inner peripheral bond part end of the cover or the blade formed integrally with the cover, which is positioned at the curved portion of the passage, is disposed on the lower side of the curved portion. That is, the inner peripheral bond part end is disposed at a position on the downstream side when the bonding material is melted and flowed by heating and liquefied. Therefore, the bonding material which is melted during the bonding flows toward the inner peripheral bond part end and the two are bonded to each other. Accordingly, in the bond part on the inner peripheral side in the radial direction of the impeller, which is a bond part between the blade, the cover, and the disc and on which rotational stress is concentrated during the impeller operation, insufficient supply of the bonding material does not occur, such that it is possible to eliminate the problem of a reduction in the bonding strength. [0017] A protruding portion or a recess portion may be provided near an inner peripheral bond part end where the passage is curved, in a bond part with the blades, on the blade attachment surface of the cover so as to prevent the bonding material from spilling. [0018] In the case where the protruding portion is provided, the flow of the bonding material is stanched by the protruding portion during the bonding. In the case where the recess portion is provided, the bonding material flows into the recess portion. Accordingly, the flow of the bonding material is restricted. Therefore, it is possible to more reliably prevent spill out of the bonding material and increase the bonding strength of the bond part. [0019] A surface opposite to the blade attachment surface of the cover may be made flat, and after the plurality of blades is bonded to one of the disc and the cover, the surface opposite to the blade attachment surface of the cover may be formed into a predetermined shape. [0020] In this case, the cover can be disposed in a stable state by allowing the flat surface of the cover to face down. Accordingly, during the bonding, the bonding material uniformly flows toward the inner peripheral bond part end which is positioned at the curved portion of the passage along the curved surface of the cover or the blade which is formed integrally with the cover. In this aspect, the problem that the bonding material is partially insufficient can be eliminated, therefore more reliable bonding can be performed. [0021] According to the manufacturing method of an impeller of the present invention, the bonding material which is melted during bonding is bonded while flowing toward the inner peripheral side of the bond part between the blade, and the cover or the disc. Therefore, it is possible to prevent insufficient supply of the bonding material on the inner peripheral bond part end, such that the bonding strength of the bond part can be ensured and the reliability of the bond part can be increased. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 is a side cross-sectional view schematically illustrating the configuration of an impeller manufactured by a manufacturing method of an impeller according to the present invention. [0023] FIG. 2 is a partial enlarged view illustrating the impeller in FIG. 1 . [0024] FIG. 3 is a side cross-sectional view illustrating a manufacturing process of the impeller. [0025] FIG. 4 is a side cross-sectional view illustrating a manufacturing process of an impeller according to a first modified embodiment. [0026] FIG. 5 is a side cross-sectional view illustrating a manufacturing process of an impeller according to a second modified embodiment. [0027] FIG. 6 is a side cross-sectional view illustrating a manufacturing process of an impeller according to a third modified embodiment. [0028] FIG. 7 is a side view illustrating a manufacturing process of an existing impeller. DETAILED DESCRIPTION OF THE INVENTION [0029] A manufacturing method of an impeller according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3 . [0030] Reference numeral 1 in FIG. 1 denotes an impeller manufactured by the manufacturing method of the impeller according to the embodiment, and the impeller is mounted, as a rotor assembled with the rotation shaft, in a compressor such as a centrifugal compressor. [0031] As illustrated in FIGS. 1 and 2 , the impeller 1 includes a disc 2 which has a substantially disc shape and is mounted coaxially with a rotation shaft (not shown), plural wing-shaped blades 3 of which ends are fixed to the disc 2 and which are arranged radially from the center axis O of the rotation shaft, a cover 4 which is opposed to the disc 2 so as to have a space and fixed to the other ends of the blade 3 . A space, which is formed between the side surfaces of the blades 3 and the flow surfaces (surfaces opposed to each other) of the disc 2 and the cover 4 , functions as a passage R for gas compressed by the compressor. [0032] In addition, the right side on FIG. 2 when viewed from the plan view represents an inner peripheral side (on a side toward the center axis O illustrated in FIG. 1 ) of the impeller 1 , and the left side represents an outer peripheral side. In addition, in FIGS. 1 and 2 , with regard to a direction (an arrow direction E) in which gas flows in the passage R, the upper side on the plane represents an upstream side, and the lower side on the plane represents a downstream side. In addition, the rotation shaft direction of the impeller 1 is referred to as a Y direction, and similarly the radial direction is referred to as an X direction. This will be commonly applied in the following description. [0033] The disc 2 forms the outer shape of the impeller 1 , is made of metal such as carbon steel or stainless steel, and is constituted by a cylindrical portion 21 into which the rotation shaft (not shown) described above is inserted and a main body portion 22 which extends from an end (that is, the lower side from the planes of FIGS. 1 and 2 ) of the cylindrical portion 21 in the rotation shaft direction Y toward the outer peripheral side in the radial direction X. The cylindrical portion 21 and the main body portion 22 are formed integrally with each other. Here, in the disc 2 , an upper surface (a side toward the passage R of gas) which is opposed to the cover 4 on the planes illustrated in FIGS. 1 and 2 is referred to as a front surface 2 a, and a lower surface opposed thereto is referred to as a rear surface 2 b in the following description. The front surface 2 a of the main body portion 22 is curved from the outer peripheral side toward the inner peripheral side so as to gradually protrude in the rotation shaft direction Y toward a front end 21 a of the cylindrical portion 21 . That is, on the inner peripheral side of the front surface 2 a of the disc 2 , a curved surface 2 d is formed which has a shape that follows a curved portion Ra of the passage R. [0034] Each blade 3 provided between the disc 2 and the cover 4 is smoothly curved along the front surface 2 a of the disc 2 toward the inner peripheral side in the radial direction (the arrow direction X) so as to protrude toward the front end in the rotation shaft direction (the arrow direction Y), and also curved on a side in the circumferential direction of the disc 2 . The curved portion (the curved surface 3 d ) has a shape that follows the curved portion Ra of the passage R. [0035] Here, in the blade 3 , an edge disposed toward the disc 2 is referred to as a disc-side blade edge 3 a, and an edge disposed toward the cover 4 is referred to as a cover-side blade edge 3 b in the following description. [0036] In this embodiment, the disc-side blade edge 3 a of the blade 3 is formed integrally with the front surface 2 a of the disc 2 , and the cover-side blade edge 3 b thereof is bonded to a blade attachment surface 4 a of the cover 4 by brazing using a brazing filler metal 5 (bonding material) such as foil, powder, or wire. In addition, the bonding structure is not limited thereto, and in the case where the blade attachment surface 4 a of the cover 4 is formed integrally with the cover-side blade edge 3 b, a structure may be employed in which the disc-side blade edge 3 a is bonded to the front surface 2 a of the disc 2 by brazing using the brazing filler metal 5 such as foil, powder, or wire. [0037] The lower surface (the blade attachment surface 4 a ) of the cover 4 is integrally fixed to the cover-side blade edge 3 b of the blade 3 , and curved from the outer peripheral side toward the inner peripheral side in the radial direction (the arrow direction X) so as to protrude toward the front end in the rotation shaft direction Y. That is, on the inner peripheral side of the blade attachment surface 4 a of the cover 4 , a curved surface 4 d is formed which has a shape that follows the curved portion Ra of the passage R. [0038] As described above, between the adjacent blades 3 , the passage R is formed so as to generate compressed air with the rotation of the impeller 1 , and the passage R is curved in both the rotation shaft direction Y and the circumferential direction according to the shapes of the disc 2 , the blade 3 , and the cover 4 . [0039] When the impeller 1 of the compressor, which is configured as described above is driven and rotated by a driving unit (not shown) about the center axis O, there is a flow of air, indicated by the arrow E, from the inner peripheral side to the outer peripheral side in the radial direction in the passage R, and the air is accelerated by centrifugal force generated by the rotation. Accordingly, air sucked from an inlet R 1 of the passage R is compressed in the passage R and discharged from an outlet R 2 , and then sent to an external device (not shown) on the downstream side. [0040] Next, a manufacturing method of the impeller 1 described above will be described with reference to FIG. 3 and so on. [0041] First, as illustrated in FIG. 3 , the disc 2 is formed integrally with the plural blades 3 by the machining of materials. A flat surface 4 b is placed on the floor (bed) 6 such that the blade attachment surface 4 a of the cover 4 faces up, and the brazing filler metal 5 is disposed on an attachment region of the blade attachment surface 4 a of the cover 4 , to which the blade 3 is to be attached. Subsequently, in the state where the disc 2 provided with the blades 3 is positioned on the cover 4 , the blade attachment surface 4 a of the cover 4 and the cover-side blade edge 3 b of the blade 3 are bonded to each other using the brazing filler metal 5 . Thereafter, a step is performed for finishing the flat portion 4 b of the cover 4 into a predetermined shape. [0042] Specifically, the cover 4 is disposed such that the blade attachment surface 4 a of the cover 4 faces up, an inner peripheral bond part end 4 c of the cover 4 positioned on the curved portion Ra of the passage R is disposed on the lower side of the curved potion Ra, and disposed at a downstream position of the brazing filler metal 5 that is melted by, for example, heating and liquefied. Accordingly, the brazing filler metal 5 that is melted during bonding flows toward the inner peripheral bond part end 4 c (arrow direction F), so that the cover 4 and the blade 3 can be bonded to each other. That is, at the bond part between the blade 3 and the cover 4 , which is a bond part on the inner peripheral side in the radial direction of the impeller 1 (see FIG. 1 ) on which rotational stress during the impeller operation is concentrated, sufficient supply of the brazing filler metal 5 is secured. Accordingly, it is possible to avoid the problem of a reduction in bonding strength. [0043] In addition, in this embodiment, the side opposite to the blade attachment surface 4 a of the cover 4 is the flat surface 4 b, so that a stable state during the bonding can be achieved by allowing the flat surface 4 b to face down. Accordingly, there is an advantage in that the brazing filler metal 5 uniformly flows toward the inner peripheral bond part end 4 c along the curved surface 4 d of the cover 4 . [0044] In addition, in this embodiment, during the bonding of the blade 3 and the cover 4 , the brazing filler metal 5 is disposed on the blade attachment surface 4 a of the cover 4 . However, the disposition is not limited thereto, and the brazing filler metal 5 may be attached to the cover-side blade edge 3 b of the blade 3 . [0045] In the manufacturing method of an impeller according to the first embodiment described above, since the brazing filler metal 5 is bonded while flowing toward the inner periphery from the bond part of the blade 3 and the cover 4 during bonding, it is possible to prevent an insufficient amount of the brazing filler metal 5 from being supplied to the inner peripheral bond part end 4 c. Therefore, it is possible to ensure the bonding strength at the bond part and increase the reliability of the bond part. [0046] Next, an embodiment modified from the above-mentioned embodiment will be described with reference to the accompanying drawings. Same elements or similar elements of the above-mentioned embodiment are denoted by same reference numerals, and a detailed description thereof will be omitted. Other configurations different from those of the embodiment will be described. [0047] The first modified embodiment illustrated in FIG. 4 is different from the manufacturing method of the above-mentioned embodiment in that a protruding portion 7 for preventing spill of the brazing filler metal 5 is provided on the inner peripheral bond part end 4 c of the cover 4 which is positioned at the curved portion Ra of the passage R in the bond part with the blade 3 . The protruding portion 7 protrudes from the inner peripheral bond part end 4 c of the cover 4 toward the front surface 2 a of the disc 2 , and the length (in a direction perpendicular to the plane) thereof is equal to or greater than the width of the blade 3 . The protruding portion 7 is provided during the bonding, and removed along with any excess thickness of the brazing filler metal 5 after the bonding. As described above, in the first modified embodiment having the protruding portion 7 , the flow of the brazing filler metal 5 is restricted by the protruding portion 7 during the bonding, so that it is possible to reliably prevent the spill of the brazing filler metal 5 . Therefore, there is an advantage in that it is possible to increase the bonding strength of the bond part of the cover 4 and the blade 3 . [0048] Next, in the second modified embodiment illustrated in FIG. 5 , instead of the protruding portion 7 (see FIG. 4 ) of the above-mentioned first modified embodiment, a recess portion 8 is provided. That is, the recess portion 8 is provided in the inner peripheral bond part end 4 c of the cover 4 which is positioned at the curved portion Ra of the passage R in the bond part with the blade 3 so as to allow an opening 8 a to face the front surface 2 a of the disc 2 and has a function of preventing spill of the brazing filler metal 5 during manufacturing. [0049] The length (in the direction perpendicular to the plane) of the recess portion 8 is equal to or greater than the width of the blade 3 (or the brazing filler metal 5 provided on the cover 4 ). The recess portion 8 is provided during the bonding. After the bonding, the brazing filler metal 5 that flows over the recess portion 8 is removed along with any excess thickness of the brazing filler metal 5 or processed so as to be suitably buried and brought back up. As described above, in the second modified embodiment having the recess portion 8 , the brazing filler metal 5 flows into the recess portion 8 during the bonding, so that the flow thereof can be restricted. Therefore, as in the first modified embodiment described above, it is possible to reliably prevent the spill of the brazing filler metal 5 and increase the bonding strength of the bond part of the cover 4 and the blade 3 . [0050] A third modified embodiment illustrated in FIG. 6 replaces the manufacturing method of the above-mentioned embodiment. [0051] Specifically, in the manufacturing method of an impeller according to the above-mentioned embodiment, the blade 3 , which is formed integrally with the disc 2 in advance, is bonded to the cover 4 . However, in the third modified embodiment, a flat surface 4 b of a cover 4 formed integrally with a blade 3 in advance is placed on a floor 6 , and in this state, a brazing filler metal 5 is disposed on a disc-side blade edge 3 a of the blade 3 , and the disc 2 is disposed on and bonded to the blade 3 (the brazing filler metal 5 ) using the brazing filler metal 5 . In addition, the position of the brazing filler metal 5 is not limited to the disc-side blade edge 3 a, and the brazing filler metal 5 may be attached to the front surface 2 a of the disc 2 so as to bond the blade 3 and the disc 2 to each other. [0052] In the third modified embodiment, the cover 4 is disposed such that the blade attachment surface 4 a faces up, so that an inner peripheral bond part end 3 c of the blade 3 which is positioned at the curved portion Ra of the passage R is disposed on the lower side of the curved portion Ra and on the downstream side of the brazing filler metal 5 which is melted by, for example, heating and liquefied. Therefore, the brazing filler metal 5 which is melted during the bonding flows toward the inner peripheral bond part end 3 c (in an arrow direction F), so that the two members (the cover 4 and the blade 3 ) are bonded to each other. That is, at the bond part between the blade 3 and the disc 2 , which is a bond part on the inner peripheral side in the radial direction of the impeller 1 (see FIG. 1 ) on which rotational stress during the impeller operation is concentrated, as in the above-mentioned embodiment, there are advantages in that insufficiency of the brazing filler metal 5 does not occur, and the problem of the reduction in the bonding strength can be eliminated. [0053] While the manufacturing method of an impeller according to the embodiments and the modified embodiments of the present invention have been described and illustrated above, it should be understood that the present invention is not limited to the embodiments and the modified embodiments and can be modified without departing from the spirit and scope of the present invention. [0054] For example, in the embodiment and the modified embodiments, bonding by brazing is employed. However, they are not limited thereto, and for example, transient liquid phase diffusion bonding may be employed. [0055] In addition, in the embodiment and the modified embodiments, during the bonding, the cover 4 is configured such that the surface opposite to the blade attachment surface 4 a is the flat surface 4 b but is not limited to a shape with the flat surface 4 b. The point is that in the impeller, the cover 4 may be disposed at a lower position in a stable state during the bonding of the members. Accordingly, during the bonding, the shape of the cover 4 may have an arbitrary finishing shape, and while this is in a stable state, the bonding may be performed. [0056] In addition, the shapes and the sizes of the disc 2 , the blade 3 , and the cover 4 may be suitably set. [0057] In addition, in the second modified embodiment, the protruding portion 7 is provided on the inner peripheral bond part end 4 c of the cover 4 . However, the position thereof is not limited thereto, and in the case of the cover 4 formed integrally with the blade 3 as in the above-mentioned second modified embodiment (see FIG. 6 ), a protruding portion protruding toward the blade attachment surface 4 a of the cover 4 may be provided on the inner peripheral bond part end at a position attached to the blade 3 in the front surface 2 a of the disc 2 . [0058] While preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are exemplary of the present invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the present invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.

A manufacturing method of an impeller includes: forming a plurality of blades integrally on a blade attachment surface of one of a disc and a cover; placing the cover on a floor so as to face up the blade attachment surface of the cover; disposing the disc on the cover so as to face down the blade attachment surface of the disc; and bonding the plurality of blades to the blade attachment surface of the other of the disc and the cover which is not formed integrally with the plurality of blades by using a bonding material.

CROSS-REFERENCE [0001] This application is a continuation of U.S. patent application Ser. No. 14/554,606 [Attorney Docket No. 33999-739.201], filed Nov. 26, 2014, which is incorporated herein by reference in its entirety. BACKGROUND [0002] The present disclosure relates generally to hearing systems, devices, and methods. Although specific reference is made to hearing aid systems, embodiments of the present disclosure can be used in many applications in which a diagnostic, treatment, or other device is placed in the ear. [0003] Hearing is an important sense for people and allows them to listen to and understand others. Natural hearing can include spatial cues that allow a user to hear a speaker, even when background noise is present. [0004] Hearing devices can be used with communication systems to help the hearing impaired. Hearing impaired subjects need hearing aids to verbally communicate with those around them. In-canal hearing aids have proven to be successful in the marketplace because of increased comfort and an improved cosmetic appearance. Many in-canal hearing aids, however, have issues with occlusion. Occlusion is an unnatural, tunnel-like hearing effect which can be caused by hearing aids which at least partially occlude the ear canal. In at least some instances, occlusion can be noticed by the user when he or she speaks and the occlusion results in an unnatural sound during speech. To reduce occlusion, many in-canal hearing aids have vents, channels, or other openings. These vents or channels allow air and sound to pass through the hearing aid, specifically between the lateral and medial parts of the ear canal adjacent the hearing aid placed in the ear canal. [0005] In some cases, occlusion vents in current in-canal hearing aids are less than ideal. For example, many in-canal hearing devices have occlusion vents with fixed sizes, limiting the effectiveness of the occlusion vents. Generally, a user selects, with the help of an audiologist or doctor, the best sounding hearing aid from a choice of multiple hearing aids. The user then selects a set of vented or non-vented ear tips to provide the best sound at the point of sale. However, in daily life, the acoustic environment will change, and the sound provided by the chosen ear tips may not be best for every situation. Historically, when the acoustic environment changes, the user has only been able to adjust the loudness or volume of the hearing instrument or change the vented tips. Changing the volume can be done quickly without removing the hearing instrument. In contrast, changing the vents is cumbersome, requires removing the hearing instrument, and is best done with the help of a professional fitter, which make the adjustment process even less convenient. Moreover, merely replacing the ear tips in use will not compensate for changes to hearing that can occur in a dynamic environment. [0006] The hearing systems, devices, and methods described herein will address at least some of the above concerns. SUMMARY [0007] Generally, a variety of devices and methods for reducing occlusion for an in-canal hearing device are provided in the present disclosure. In various embodiments, in situ adjustable venting via manual or automatic, for example, electronic means, will provide another powerful way to improve sound quality in real time. [0008] According to some embodiments, the devices will generally comprise a gel (or a gel-filled bladder) or other malleable element or structure which is shaped to define one or more channels for ear canal venting when placed in the ear canal. The gel or other malleable element may be deformed to vary the size of the channel(s) and thereby the degree of venting provided. The degree of venting may be adjusted in response to a variety of cues such as for feedback or for the ambient acoustic environment. Also, the gel or other malleable element or structure may be soft and conformable such that placement in the sensitive, bony portion of the ear canal minimally irritates the tissue therein. [0009] According to one aspect disclosed herein, an ear tip apparatus may comprise a malleable structure. The malleable structure may be sized and configured for placement in an ear canal of a user. For instance, the malleable structure may have a cross-section shaped to define at least one channel between an inner wall of the ear canal and an outer surface of the malleable structure for venting of the ear canal. The malleable structure may be deformable to adjust the cross-section thereof so as to vary a size of the at least one channel to adjust a degree of venting provided by the at least one channel. [0010] In various embodiments, the ear tip apparatus may further comprise an actuator coupled to the malleable structure and operable to cause the malleable structure to deform. The actuator may comprise a slider configured for translation and/or rotation relative to the malleable structure. For example, the slider may comprise one or more threads to facilitate rotation relative to the malleable structure. Translating and/or rotating the slider toward the malleable structure may deform the malleable structure to increase the size of the at least one channel to reduce the degree of venting provided by the at least one channel. The actuator may further comprise an elongate element coupled to the malleable structure and the slider. The malleable structure may be disposed over the elongate element and the slider may be translatable over the elongate element. The elongate element may comprise one or more of a shaft, wire, or a post. [0011] In various embodiments, the actuator may be configured to vary the degree of venting provided by the at least one channel in response to one or more of detected feedback or an environmental cue. The actuator may comprise one or more of a circuitry, a processor, or a mechanical element adapted to be responsive to one or more of the detected feedback or the environmental cue. The detected feedback or the environmental cue may be indicated from a sensor in communication with the actuator. The sensor may comprise one or more of a microphone, an accelerometer, a vibration sensor, an internal sensor of the ear tip apparatus, or a sensor of a control device external of the ear tip apparatus (e.g., a BTE unit). The communication may be at least partially electronic and/or wireless. The actuator may be configured to vary the degree of venting provided by the at least one channel in response to one or more of a volume or a sound directionality of an ambient environment. The actuator may be configured to increase the degree of venting in a loud ambient environment, thereby allowing the user to hear more unprocessed sound, or to decrease the degree of venting in a loud ambient environment, thereby allowing the user to hear more processed sound. [0012] In various embodiments, the malleable structure may be deformable between a low cross-sectional area configuration and a high cross-sectional area configuration. The channel(s) may provide more venting when the malleable structure is in the low cross-sectional area configuration than when in the high cross-sectional area configuration. The malleable structure may be biased to assume the low cross-sectional area configuration. The malleable structure may have one or more of a Y-shaped, X-shaped, or cross-shaped cross-section. [0013] In various embodiments, the malleable structure may comprise a gel. The malleable structure may comprise in certain embodiments a fluid-filled bladder. The fluid-filled bladder may comprise a bladder wall and a bladder fluid, and the bladder wall may comprise one or more of a stiff plastic or an elastomeric material. The stiff plastic or elastomeric material may comprise one or more of silicone, parylene, nylon, a PEBA material, Pebax, or polyurethane. The bladder fluid may comprise one or more of a gas, a liquid, or a gel. The bladder fluid may comprise air or nitrogen. The gel may comprise one or more of a silicone gel, a viscous hydrophilic fluid, a viscous hydrophobic material, a thixotropic material, a viscoelastic material, a dilatant material, a rheopectic material, Nusil MED-6670, Nusil MED-6346, Nusil MED-6345, a polyurethane gel, a polyvinylpyrrolidone gel, a polyethylene glycol gel, glycerol, thickened glycerol, petroleum jelly, mineral oil, lanolin, silicone oil, or grease. [0014] Typically, the ear tip apparatus is inserted into the ear canal as a stand-alone unit contacting the inner wall of the ear canal. In various embodiments, however, the ear tip apparatus may be provided as a component of a greater hearing device. This hearing device may comprise a body configured for placement within an ear canal of a user. The body may define an inner channel, and the ear tip apparatus may be placed within the inner channel of the body. The channel(s) may be defined between an inner wall of the body and an outer surface of the malleable structure of the ear tip. [0015] According to another aspect disclosed herein, a method for reducing occlusion in a hearing device placed in an ear canal of a user may comprise a step of deforming a malleable structure placed in the ear canal. Such deformation may vary a size of at least one channel to adjust a degree of venting provided by the at least one channel. The malleable structure may be sized and configured for placement in the ear canal and may have a cross-section shaped to define the at least one channel between the inner wall of the ear canal and an outer surface of the malleable structure. The malleable structure may comprise a gel. [0016] In various embodiments, the malleable structure is deformed by translating or rotating a slider relative to the malleable element. The slider may be translated or rotated over an element, wherein one or more of the slider or the malleable structure is disposed over the element. Translating and/or rotating the slider relative to the malleable structure may transition the malleable structure from a low cross-sectional area configuration to a high cross-sectional area configuration and/or move the slider toward the malleable structure. [0017] In various embodiments, the method may further comprise a step of adjusting the degree of venting in response to one or more of detected feedback or an environmental cue. The detected feedback or the environmental cue may be indicated from a sensor. The sensor may comprise one or more of a microphone, an accelerometer, a vibration sensor, an internal sensor of the hearing device, or a sensor of a control device external of the hearing aid. The degree of venting may be increased in a loud ambient environment, thereby allowing the user to hear more unprocessed sound; or, the degree of venting may be decreased in a loud ambient environment, thereby allowing the user to hear more processed sound. [0018] According to one aspect disclosed herein, a hearing device may comprise a body and first and second baffles. The body may be configured for placement within an ear canal of a user. The first and second baffles may each be coupled to the body and may each have at least one opening for venting of the ear canal. One or more of the first or second baffles may be rotatable relative to one another to vary the alignment of their openings with one another to adjust a degree of venting through the body of the hearing device. Each baffle may have a plurality of openings. [0019] In various embodiments, the first and second baffles are rotatable to fully align the opening(s) of the first baffle and the opening(s) of the second baffle with one another to allow full venting through the aligned openings. The first and second baffles may be rotatable to misalign the opening(s) of the first baffle with the opening(s) of the second baffle such that no venting or a partial/reduced venting is allowed through the openings and baffles. [0020] In various embodiments, the hearing device further comprises an actuator configured to vary the alignment of the opening(s) of the first baffle and the opening(s) of the second baffle with one another. The actuator may be configured to vary the alignment of the opening(s) of the first baffle and the opening(s) of the second baffle with one another in response to detected feedback or an environmental cue. The detected feedback or the environmental cue may be indicated from a sensor in communication with the actuator. The sensor may comprise one or more of a microphone, an accelerometer, a vibration sensor, an internal sensor of the hearing device, or a sensor of a control device external of the hearing device (e.g., a BTE unit). The actuator may be in electronic communication with the sensor. The actuator may be configured to vary the alignment of the opening(s) of the first baffle and the opening(s) of the second baffle with one another in response to one or more of a volume or a sound directionality of an ambient environment. The actuator may be configured to more closely align the opening(s) of the first baffle and the opening(s) of the second baffle with one another in a loud ambient environment, thereby allowing the user to hear more unprocessed sound; or the actuator may be configured to less closely align the opening(s) of the first baffle and the opening(s) of the second baffle with one another in a loud ambient environment, thereby allowing the user to hear more processed sound. [0021] According to another aspect disclosed herein, an ear tip apparatus (e.g., hybrid ear tip) comprising a hard core and a gel portion is provided. The hard core may be configured for placement in an ear canal and may have a lateral portion and a medial portion. The gel portion is disposed over at least the medial portion of the hard core and configured to deform and conform to the ear canal. [0022] In various embodiments, the medial portion is configured to conform to a cartilaginous portion of the ear canal. [0023] In various embodiments, an exposed outer surface of the hard core is configured to end at a location of the ear tip apparatus configured to be placed at the isthmus of the ear canal when the ear tip apparatus is inserted in the ear canal. [0024] In various embodiments, an outer surface of the gel portion may be configured or shaped to define one or more channels for venting of the ear canal. [0025] In various embodiments, the ear tip apparatus further comprises one or more transducers for transmitting sound to the user. The one or more transducers may be housed within the hard core. [0026] In various embodiments, the gel portion comprises one or more of a silicone gel, a viscous hydrophilic fluid, a viscous hydrophobic material, a thixotropic material, a viscoelastic material, a dilatant material, a rheopectic material, Nusil MED-6670, Nusil MED-6346, Nusil MED-6345, a polyurethane gel, a polyvinylpyrrolidone gel, a polyethylene glycol gel, glycerol, thickened glycerol, petroleum jelly, mineral oil, lanolin, silicone oil, or grease. [0027] Other features and advantages of the devices and methodology of the present disclosure will become apparent from the following detailed description of one or more implementations when read in view of the accompanying figures. Neither this summary nor the following detailed description purports to define the invention. The invention is defined by the claims. INCORPORATION BY REFERENCE [0028] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS [0029] It should be noted that the drawings are not to scale and are intended only as an aid in conjunction with the explanations in the following detailed description. In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings of which: [0030] FIG. 1 is a section view of a hearing instrument or ear tip placed within the ear canal of a human ear, according to some embodiments; [0031] FIGS. 2A and 2B are examples of perspective views of an ear tip in a high venting configuration ( FIG. 2A ) and a low venting configuration ( FIG. 2B ) placed within the ear canal, according to some embodiments; [0032] FIGS. 3A and 3B are side views of the ear tip of FIG. 2A in the high venting configuration ( FIG. 3A ) and the low venting configuration ( FIG. 3B ), according to some embodiments; [0033] FIGS. 4A and 4B are perspective views of the ear tip of FIG. 2A in the high venting configuration ( FIG. 4A ) and the low venting configuration ( FIG. 4B ), according to some embodiments; [0034] FIG. 5A is a perspective view of an example of the ear tip in the high venting configuration, according to some embodiments; [0035] FIG. 5B is a front view of the ear tip adjusted to the high venting configuration, according to some embodiments; [0036] FIG. 6 shows a section view of another example of the ear tip in the high venting configuration, according to some embodiments; [0037] FIG. 7A shows a perspective front view of yet another example of a double-baffled ear tip in a high venting configuration, according to some embodiments; [0038] FIG. 7B shows a perspective view of the back of the ear tip of FIG. 7A , according to some embodiments; [0039] FIGS. 8A, 8B, and 8C show perspective views of the back of the ear tip of FIG. 7A as the ear tip is transitioned from the high venting configuration ( FIG. 8A ) to a low venting configuration ( FIG. 8B ) to a no venting configuration ( FIG. 8C ), according to some embodiments; [0040] FIGS. 9A and 9B show section views of a double-baffled ear tip with baffle(s) translated to adjust venting from a minimal venting configuration ( FIG. 9A ) to a high venting configuration ( FIG. 9B ), according to some embodiments; [0041] FIGS. 10A and 10B show side views of known rigid ear tips placed in the ear canal; [0042] FIGS. 11A, 11B, and 11C show side views of examples of hybrid ear tips having a gel portion surrounding a hard core or shell and being placed in the ear canal, according to some embodiments; [0043] FIG. 12A shows a perspective view of a hybrid ear tip placed in the ear canal, according to some embodiments; [0044] FIG. 12B shows a perspective view of the hybrid ear tip of FIG. 12A , according to some embodiments; [0045] FIG. 12C shows a front view of the hybrid ear tip of FIG. 12A , according to some embodiments; [0046] FIGS. 13A and 13B show perspective views of yet another example of an ear tip having a handle portion, according to some embodiments; [0047] FIGS. 14A and 14B show perspective view of a wax ear tip mold, according to some embodiments; [0048] FIGS. 15A, 15B, and 15C show perspective views of an example of a complete ear tip assembly, according to some embodiments; [0049] FIG. 16A shows a perspective view of a thin shell ear tip, according to some embodiments; and [0050] FIG. 16B shows a front view of the thin shell ear tip of FIG. 16A . DETAILED DESCRIPTION [0051] In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, some examples of embodiments in which the disclosure may be practiced. In this regard, directional terminology, such as “right”, “left”, “upwards”, “downwards”, “vertical”, “horizontal” etc., are used with reference to the orientation of the figure(s) being described. Because components or embodiments of the present disclosure can be positioned or operated in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. [0052] The term “gel” as used herein refers to any number of materials that are soft and viscoelastic. The mechanical properties of a “gel” as used herein may range from a viscous liquid such as honey or mineral oil to a soft elastic solid, such as gelatin. For example, a “gel” may comprise a soft, weakly cross-linked solid that can deform and flow under applied force and may spring back slowly upon removal of the applied force. One example is Nusil MED-6346 silicone gel. The “gels” of the present disclosure may be homogenous or heterogeneous (as in slurries, colloids, and emulsions). The “gels” of the present disclosure may be hydrophobic or hydrophilic. Heterogeneous gels may include different phases that have different solubility and transport properties; for example, a hydrophobic, contiguous, soft polymer filled partially with particles of hydrophilic polymers. Such a composite material may accrue performance advantages from each material, such as elasticity, chemical resistance, and moisture transport. The “gels” of the present disclosure may include any low-shear modulus material based on chemistries such as silicone, polyurethane, polyvinylpyrrolidone, and polyethylene glycol. The “gels” of the present disclosure may also include foam materials such as those made of silicone, polyurethane, or the like and/or foam materials impregnated with liquids or gels. Additional examples of “gels” are further described below in reference to various embodiments. [0053] The terms “operatively connected,” “coupled,” or “mounted,” or “attached” as used herein, means directly or indirectly coupled, attached, or mounted through one or more intervening components. [0054] FIG. 1 shows a cross sectional view of outer ear 30 , middle ear 32 and inner ear 34 (part). The outer ear comprises primarily of the pinna 16 and the ear canal 14 . The middle ear is bounded by the tympanic membrane (ear drum) 10 on one side, and contains a series of three tiny interconnected bones: the malleus (hammer) 18 ; the incus (anvil) 20 ; and the stapes (stirrup) 22 . Collectively, these three bones are known as the ossicles or the ossicular chain. The malleus is attached to the tympanic membrane 10 while the stapes, the last bone in the ossicular chain, is coupled to the cochlea 24 of the inner ear. [0055] Many hearing instruments or hearing aids include “ear tips” that fit inside the external auditory canal or ear canal 14 to deliver sound to the eardrum or tympanic membrane 10 . Ear tips are support structures that suspend and retain a sound tube or receiver inside the ear canal. A sound tube, for example, may be a hollow plastic tube that guides sound generated in an external hearing instrument, while a receiver is a miniature speaker that is connected to an external hearing instrument via wires. To minimize occlusion, such ear tips generally provide venting through the ear canal through an opening, channel, or vent along its length. As discussed above, many current ear tips have fixed vent sizes that may limit their effectiveness. Another types of hearing instruments, for example, completely-in-canal (CIC) hearing instruments could also benefit from adjustable venting. [0056] As shown in FIG. 1 , a hearing device or ear tip 100 may be placed within the ear canal 14 , for example, between the lateral cartilaginous part and the medial body part. The hearing device 100 may include one or more openings, channels, or vents 110 to allow the ear canal 14 to vent. [0057] FIGS. 2A and 2B show the hearing device 100 in place in the ear canal 14 . FIG. 2A shows the hearing device 100 in a low cross-sectional area, high venting configuration. FIG. 2B shows the hearing device 100 in a high cross-sectional area, low venting configuration. The hearing device or ear tip 100 may comprise a malleable element or structure 120 , a slider 140 , and an element 160 . The hearing device 100 may also comprise an output transducer 180 . For example, the output transducer 180 may comprise a laser photodiode or other emitter for emitting an optical signal to be received by a device placed on the tympanic membrane 10 such as the Contact Hearing Device available from EarLens Corporation of Menlo Park, Calif. Systems and methods for photo-mechanical hearing transduction are also described in co-assigned U.S. Pat. Nos. 7,668,325, 7,867,160, 8,396,239, 8,696,541, 8,715,152, 8,824,715, and 8,858,419, the full contents of which are incorporated herein by reference. In further examples and embodiments, the output transducer may comprise a miniature speaker or receiver. [0058] The malleable element 120 may be conically shaped. The malleable element 120 may have a distal or medial portion adapted or configured to be in contact with and be flush with the inner wall of the ear canal 14 and a tapered proximal or lateral portion. The malleable element 120 in the low cross-sectional area, high venting configuration may be shaped to define one or more channels 110 . In one example shown in FIG. 2A , the malleable element 120 has a cross-shaped cross-section to define four channels 110 between the outer surface of the malleable element and the inner wall of the ear canal 14 . The cross-shaped cross-section further defines four ear canal wall contacting extensions 114 as shown in FIGS. 5A, 5B . The malleable element 120 may also have other cross-sectional shapes, such be I-shaped, Y-shaped, or X-shaped, or have a plurality of channels 110 , to name a few. While the malleable element 120 is shown and described as being configured to be in contact with the inner wall of the ear canal 14 , in some embodiments, the malleable element 120 may be housed, for example, in a shell, housing or other device body that may be molded to fit within the ear canal. [0059] FIGS. 3A and 3B show side views of an example of the transition of the ear tip 100 from the low cross-sectional area, high venting configuration, shown by FIG. 3A , to the high cross-sectional area, low venting configuration, shown by FIG. 3B . In this example the slider 140 may be advanced toward the malleable element 120 (or toward the tympanic membrane 10 ) over the element 160 (for example, a wire or a shaft) as shown by arrow 141 in FIGS. 2B and 3B . As a result, the material of the malleable element 120 , for example gel, is then urged radially outward to decrease the cross-sectional area of the channels 110 . In particular, relief or “cut-away” areas 112 (shown, for example, in FIGS. 4A and 4B ) which in part define the channels 110 may bulge outwardly. FIGS. 5A and 5B show a perspective view and a front view of the ear tip 100 and the relief or “cut away” areas 112 . [0060] FIG. 6 shows an alternative embodiment of the malleable element 120 . In this embodiment, the malleable element 120 comprises a gel or fluid 122 surrounded by a thin bladder 124 . In various embodiments, the malleable element 120 may be biased to assume the low cross-sectional area, high venting configuration. The malleable element 120 may be disposed radially over the element 160 . Advancing the slider 140 in the distal or medial direction may squeeze the bladder 124 to force the gel 122 radially outward. The slider 140 may be movable continuously toward or away from the malleable element 120 . Alternatively or in combination, the slider 140 may be movable between a plurality of discrete locations toward or away from the malleable element 120 to achieve specific size and/or configuration of the channels 110 . The output transducer 180 may be coupled, for example, to distal ends of the element 160 and the malleable element 120 . The element 160 may comprise a shaft, a post, or a wire, to name a few exemplary structures. In some embodiments, the element 160 may be elongated and may comprise a shaft and/or one or more wires to provide power and/or signals to the output transducer 180 . [0061] The gel 122 may be comprised of one or more of a silicone gel, a viscous hydrophilic fluid, a viscous hydrophobic material, or a gas, to name a few. Examples of silicone gels that may be used as the gel or fluid 122 include NuSil MED-6670, NuSil MED-6346, and NuSil MED-6345, available from NuSil Technology LLC of Carpintera, Calif., and polyurethanes, to name a few. Examples of viscous hydrophilic fluids that may be used as the gel 122 include glycerol and glycerol thickened with thickening agents such as carbopol, polyvinylprolidone, poly (ethylene glycol), etc., to name a few. Examples of viscous hydrophobic materials that may be used as the gel or fluid 122 include petroleum jelly, mineral oil, lanolin, silicone oils, and grease, to name a few. Examples of gases which may be used as the gel or fluid 122 include air or nitrogen. Examples of other filler materials that may be used as the gel or fluid 122 include viscous fluids and viscoelastic materials (including thixotropic and dilitant), to name a few. [0062] In some embodiments, the malleable element 120 comprises the gel 122 without the thin bladder 124 . In such embodiments, the gel or 122 may comprise a soft elastic or viscoelastic (including solid) material. [0063] The thin bladder 124 may have different thickness and/or stiffness in some areas versus others. For example, the relief or “cut away” areas 112 , as shown by FIGS. 5A and 5B , may be more elastic than the contact areas 114 which are configured to contact the inner wall of the ear canal 14 . The thin bladder 124 may be comprised of a stiff plastic or an elastomeric material. Examples of stiff plastics include parylene, nylon, PEBA materials (such as Pebax), and polyurethane, to name a few. Examples of elastomeric materials include silicone, polyurethane, PEBA, and nylon, to name a few. [0064] The outer surface of the malleable element 120 , including the outer surface of the thin bladder 124 , may be amenable to sliding, for example, by the exemplary slider 140 . To be amenable to sliding, the outer surface of the malleable element 120 may have medium to low friction and little or no track. [0065] In some embodiments, the element 160 may extend laterally or proximally to connect to an external support unit. The external support unit may be a device or an apparatus placed in the ear canal, within the pinna, or behind-the-ear (BTE). The external support unit may comprise components such as a microphone to capture sound, a signal processor to process the captured sound, a power source such as a battery, a sensor, a receiver and/or transmitter to receive/transmit signals or instructions from another internal device, and/or an actuator to operate the slider 140 . The sensor may comprise an accelerometer to capture movement and directionality, a thermometer to measure temperature, or a humidity sensor, to name a few. Such sensors may be in communication with the actuator, such as through a wired or a wireless connection. The actuator may comprise a mechanical and/or electrical actuator to operate the slider 140 and vary the venting provided by the malleable element 120 . The actuator may be a component of the ear tip 100 in at least some embodiments and applications. [0066] The slider 140 that is used to deform the malleable element 120 of the ear tip 110 is shown just as an example only, and many other appropriate means and mechanisms for actuating, deforming or changing the shape and configuration of the malleable element to adjust the venting is within the scope of the present disclosure. For example, in some embodiments, an electromechanical actuator may be configured to draw low amounts of power and/or consume low or no power to hold a given position or degree of venting. In some embodiments, the actuator may comprise a ratcheting mechanism with a plunger motion such as a solenoid. The ratcheting mechanism may be linear and/or rotational with a screw drive. In some embodiments, the actuator may comprise a pump to pressurize the fluid or gel 122 (for example, within the bladder 124 for those embodiments that comprise such bladder) to change the shape of the malleable element 120 . In some embodiments, an electric field may be used to change the size or shape of the gel 122 , and therefore, the malleable element. [0067] The actuator may be manually operated (such as by the user, the wearer, and/or a medical professional) or may operate automatically in response to programming, for example, to vary the venting provided based on sensor input. For example, the actuator may be placed in communication with an application loaded on a user-operated mobile computing device such as a smartphone, tablet computer, laptop computer, or the like to operate the slider 140 or any other alternative mechanism. Alternatively or in combination, the user may operate the slider 140 or other appropriate mechanism by hand or with a handheld tool. [0068] The actuator may be responsive to a variety of cues to vary the venting provided by the malleable element 120 . Generally, these cues may be environmental or indicative of feedback which may occur when an excess of ear canal venting is provided. The cue may be provided, for example, from a sensor of the hearing aid or ear tip 100 and/or from a sensor of the external support unit such as a BTE unit. For example, the degree of venting provided may be varied in response to the volume of the ambient environment or direction of origin of certain sounds. The degree of venting in a loud ambient environment, for instance, may cause venting to increase to allow the user to hear more unprocessed sound or to decrease to allow the user to hear more processed sound. Further non-limiting examples are as follows. [0069] Feedback may be sensed and the degree of venting provided may be varied to suppress feedback. For example, the ear tip 100 may be in communication with a BTE unit. The microphone of the BTE unit may be used to detect feedback. Feedback may be detected in many ways. Feedback may be detected by detecting a sound signature such as a narrow-band, high frequency sound (e.g., “whistling”) or a loudness greater than the ambient sound level, for example. Feedback may be detected based on sound directionality, such as sound detected as emanating from the ear canal. This directionality may be detected based on the phase difference between microphones (e.g., between a first microphone placed in the ear canal and a second microphone of the BTE unit) and/or the amplitude or loudness of the sound (e.g., absolute amplitude and/or the difference in amplitude detected between different microphones). Feedback may be detected, for example, with a sensor on the ear tip 100 . Such sensors may comprise a microphone, an accelerometer to detect vibration associated with high-intensity sound, or a vibrational spectrometer (e.g., MEMS-based), to name a few. Feedback may be detected based on the drive state of internal electronics or circuitry of the ear tip 100 . For example, the internal electronics or circuitry may detect when amplifier output is saturating in a given frequency band, which may indicate overdrive and a possible feedback state. Alternatively or in combination, the internal electronics or circuitry may detect when harmonic distortion becomes excessive, which may indicate clipping and feedback. [0070] The ambient acoustic environment may be sensed and the degree of venting provided may be varied accordingly. A loud environment may trigger, for example, increased venting so that the wearer can hear more of the unamplified or unprocessed sound directly or decrease venting to attenuate ambient sounds such that the ear tip 100 can deliver “selective” sound the user may prefer. Such “selective” sound may comprise, for example, the streaming of a telephone call or music from an external computing device such as a smart phone, tablet computer, personal computer, music player, media player, or the like. Other examples include sound from a directional microphone or a microphone array which may be beam forming. In some embodiments, the “selective” sound may be selected using an application loaded onto a computing device. The selection may be based on user settings adjustable in real time or based on chosen profiles that are stored and activated automatically or manually. For example, a profile may be chosen to be more appropriate for quiet environments. This quiet environment profile may trigger increased venting so that the user or wearer of the ear tip 100 may hear more clearly in a one-on-one conversation by taking advantage of the natural directional response of the pinna. Sensing of the acoustic environment can be performed in many ways, including without limitation, by local hearing instrument electronics such as of the ear tip 100 or an associated external unit, by a computing device in communication with the former, or by another server device such as a personal computer. [0071] According to another aspect of the present disclosure, FIGS. 7A and 7B show an alternative hearing device or ear tip 200 with adjustable venting. The ear tip 200 may comprise a proximal baffle 220 and a distal baffle or tip 240 . The proximal baffle 220 may have one or more openings 225 to provide ear canal venting, and the distal baffle 240 may have one or more openings 245 to provide ear canal venting. The proximal and distal baffles 220 , 240 may be coaxial and, either one or both, may be rotatable relative to one another to vary the alignment of the openings 225 , 245 . As shown in FIGS. 7A and 7B , the openings 225 , 245 are fully aligned to provide the maximum degree of venting. The distal baffle 240 may be elastomeric and flexible to be seated within the ear canal 14 . The proximal and distal baffles 220 , 240 may be disposed over an element 160 . The ear tip 200 may further comprise the output transducer 180 disposed on a distal tip of the distal baffle 240 . [0072] FIGS. 8A to 8C show the operation of the ear tip 200 . FIG. 8A shows the ear tip 200 in a configuration to provide maximum venting by fully aligning the openings 225 , 245 with one another. As shown in FIGS. 8B and 8C , the proximal baffle 220 may be rotated, for example, in a direction indicated by the arrow 250 to misalign the openings 225 , 245 to reduce the degree of venting provided. FIG. 8B shows the ear tip 200 having the proximal baffle 220 rotated to be in an intermediate configuration with less venting. Here, the surfaces of the baffles 220 , 240 partially cover the openings 225 , 245 . FIG. 8C shows the ear tip 200 having the proximal baffle 240 rotated to be in the completely closed configuration with no venting. Here, the surfaces of the baffles 220 , 240 fully cover the openings 225 , 245 . [0073] As shown in FIGS. 9A to 9B , the ear tip 200 may alternatively or in combination be configured to vary venting by translation of the baffles 220 , 240 . For example, the distal baffle 240 may have one or more openings 245 while the proximal baffle 220 may have no openings. The proximal baffle 220 may be advanced to contact the distal baffle 220 to close off venting as shown in FIG. 9A . The proximal baffle 220 may be retracted to allow access to the opening 245 to provide venting as shown in FIG. 9B . In some embodiments, the element 160 may include screw threads so that rotation of the proximal baffle 220 may translate into medial-lateral movement of the proximal baffle 220 . [0074] The ear tip 200 may be operated manually or automatically similarly to the ear tip 100 described above. The degree of venting provided by the ear tip 200 may be varied in response to a variety of cues similarly to the ear tip 100 above. For instance, the ear tip 200 may be coupled to an actuator and/or sensor(s), or a processor to vary the degree of venting provided in response to various cues. [0075] According to yet another aspect, the present disclosure further provides for alternative improved ear tips that conform to anatomy, as described below. Such ear tips may be used in various applications and implementations, for example, to suspend or retain output transducers such as a laser photodiode or other emitter for emitting an optical signal to be received by a device placed on the tympanic membrane 10 . [0076] Many currently used ear tips are made of a rigid plastic that is generally custom-shaped to the wearer's ear canal. These ear tips typically fit in the cartilaginous portion of the ear canal and are usually oversized such that the soft tissue in this region can stretch and conform to the ear tip to improve retention and sealing. Such soft tissue stretching, however, can cause discomfort in the short term and permanent tissue deformation in the long term. [0077] FIGS. 10A and 10B show an example of such known rigid ear tips 300 configured to be placed in the ear canal 14 . The ear tip 300 is typically oversized at the cartilaginous portion 14 a of the ear canal 14 before transitioning into a tapered tip 310 to be positioned at the bony portion 14 b of the ear canal 14 . The transition may be at the isthmus or second bend 14 c of the ear canal 14 . Most ear canals 14 will have a narrowing at the isthmus 14 c located just lateral to the beginning of the bony canal 14 b . The ear tip 300 may further comprise an output transducer 180 located at the distal or medial end of the ear tip 300 . [0078] In at least some cases, a tympanic membrane receiver 350 to receive power and/or signal from an optical signal, such as the Contact Hearing Device available from EarLens Corporation of Menlo Park, Calif., may require the photodiode or other output transducer 180 to be close and well-aligned with the receiver 350 to ensure good power transfer and optimal battery life. For example, the output transducer 180 may be positioned at a distance 360 , for example, of approximately 3 mm away from the receiver 350 as shown in FIG. 10B . For the photodiode or other output transducer 180 to be positioned at this distance 360 , the photodiode or other output transducer 180 will typically be located on the medial end of the ear tip located in the bony portion 14 b of the ear canal 14 . The tissue in the bony region is very thin (generally 0.1 to 0.2 mm) and sensitive. Pressure applied to the thin tissue should be less than about 20 mmHg to prevent capillary collapse and wound generation. The tissue in the bony region cannot conform to a rigid ear tip since it is surrounded by bone. Indeed, a rigid ear tip should not touch the tissue at all because of the high risk of generating “hot spots,” local regions of high pressure, and wounds, since the soft tissue cannot conform. [0079] To address at least this concern, ear tips of the present disclosure may be configured to conform to the anatomy with low wall pressure. FIGS. 11A, 11B, and 11C show ear tips 400 according to the present disclosure. The ear tips 400 are shown as placed in the ear canal 14 at one or more of the cartilaginous portion 14 a or the bony portion 14 b . The ear tips 400 may conform to the deep, bony ear canal 14 b to provide alignment with the receiver 350 and retention while maintaining low wall pressure to support ear health and prevent pressure sores. [0080] The ear tips 400 may be referred to as hybrid ear tips as they comprise a hard shell or core 410 and a gel portion 420 disposed over at least the distal or medial tip of the hard shell 410 . As shown in FIGS. 11A and 11B , the hard core 410 may conform to the cartilaginous portion 14 a of the ear canal 14 . The hard shell or core 410 may be substantially rigid and may be longer as in FIG. 11A , or shorter as in FIG. 11B . As shown in FIG. 11C , the hard shell 410 may be entirely housed within the gel portion 420 to be placed within the bony portion 14 b of the ear canal 14 . In some embodiments, an exposed outer surface of the hard core or shell 410 may have a length such that the hard core does not extend past an isthmus of the ear canal when the ear tip apparatus is inserted in the ear canal, as seen, for example, in FIGS. 11A-C . The gel of the gel portion 420 may comprise any of the gels described herein. The gel of the gel portion 420 may flow and conform to the bony portion 14 b of the ear canal. The gel of the gel portion 420 may provide low, uniform hydrostatic pressure to all parts of the canal 14 with little to no “hot spots,” or regions of high pressure. The gel portion 420 may provide gentle wall pressure for comfort (e.g., less than 20 mmHg) and ear health. In some embodiments, a membrane or a bladder can be used to surround and retain the gel as described in reference to the malleable element or malleable structure 120 above, particularly in cases where the gel may not be able to retain its own shape. Providing a surrounding membrane or bladder may also provide lubricity and/or some restoring force to help a soft gel fill and conform. The ear tips 400 may also provide mechanical retention via the isthmus 14 c . The gel portion 420 of the ear tips 400 may deform to ease the insertion of the ear tips 400 past the narrowing at the isthmus 14 c , and then widen back (e.g., return to its pre-biased or natural wider configuration) to provide gentle retention in the bony portion 14 b of the ear canal. As shown in FIGS. 11A and 11B , the hard shell 410 may be oversized so that only its tapered tip can be advanced past the isthmus 14 c and that the hard shell 410 is well seated in the cartilaginous portion 14 a of the ear canal 14 . The ear tips 400 may comprise the output transducer 180 positioned at the distal end of the hard shell 410 . [0081] FIGS. 12A, 12B, and 12C show another example of a hybrid ear tip 450 , which may be also combined and share features from the embodiments of the ear tips 100 and 300 described above. The ear tip 450 may comprise a hard shell 410 housed within a gel portion 420 . The distal end of the hard shell 410 may comprise an output transducer 180 to be aligned with a tympanic membrane receiver 350 . For example, in some embodiments the gel portion 420 may comprise a soft viscoelastic gel with a lubricous coating such as parylene. The hybrid ear tip 450 may be configured to be placed entirely within the ear canal 14 . The hybrid ear tip 450 may be custom sized and shaped for an individual user. Alternatively, the hybrid ear tip 450 may be provided in a variety of sizes to fit most potential users. [0082] The gel portion 420 may be shaped to define a plurality of channels 110 to provide venting for the ear canal 14 . Similarly to the malleable element 120 described above, these channels 110 may be defined between the inner wall of the ear canal 14 and the outer surfaces of the relief or “cut-away” portions 452 of the gel portion 410 . The gel portion 420 may be deformed much like the malleable structure or element 120 of the ear tip 100 described above to vary the degree of venting provided by the channels 110 . The gel portion 420 may comprise a cross-shape to align with the major and minor axes of the ear canal 14 . As shown in FIG. 12C , the gel portion 420 may comprise ridge portions 454 to contact the ear canal 14 along these axes. The ridge portions 454 may also define the relief or “cut-away” portions 452 . [0083] As shown in FIGS. 12B and 12C , the hard shell or core 410 provides convenience for driving/placing the tip within the ear canal and aligning it along the major canal axis. The hard core 410 may also comprise a proximal or lateral post 412 to facilitate the insertion and placement of the ear tip 450 . The hard core 410 may further comprise one or more light-gauge wires 414 at the proximal or lateral portion. The wires 414 may have a spiral stress relief and may be configured to be operatively coupled with an external unit such as a BTE unit. The output transducer 180 may receive signals from the external unit through the wires 414 , for example. [0084] As shown in FIGS. 13A and 13B , the ear tip 450 may further comprise a handle 455 coupled to the proximal or lateral portion of the ear tip 450 . The handle 455 may facilitate the insertion and placement of the ear tip 450 . [0085] Aspects of the present disclosure further provide methods of manufacturing or fabricating the various improved ear tips described herein. The improved ear tips may be fabricated using, for example, a sacrificial mold process. The sacrificially mold made be made in different ways such as direct machining, direct 3D printing or by casting from a rubber master which may be made by 3D printing. An exemplary sacrificial wax mold 14 is shown in FIGS. 14A and 14B . An emitter support 514 a may be placed into the wax mold 514 , and gel material may be injected into the wax mold and cured around the emitter support. The wax is then removed. The wax may be water-soluble and removed by dissolving in water. The sacrificial material may be another type of wax or plastic that can be removed by solvents and/or by heating. The wax mold 514 may be used to form the malleable element 120 or the gel portion 420 of the ear tips 100 , 400 , or 450 described above. The malleable element 120 or the gel portion 420 may be formed over the other components of the ear tips 100 , 400 , or 450 , such as the wires 160 , the output transducer 180 , or the hard shell or core 410 . [0086] As shown in FIGS. 15A, 15B, and 15C , the ear tips, such as ear tip 450 , may be provided as a component of a complete ear tip assembly 500 . The inventor has fabricated and tested the complete ear tip assembly 500 shown in FIGS. 15A, 15B, and 15C . The ear tip assembly 500 may comprise the ear tip 450 , the handle 455 , and a cable section 460 extending proximally or laterally outward from the ear tip 450 . When the ear tip 450 is placed in the ear canal, for instance, the cable section 460 may extend out of the ear canal to a “behind the ear” or BTE unit (not shown) that contains microphone, speaker, battery and electronic signal processing capability. The BTE unit may convert sound to a useful electrical signal that is delivered by cable section 460 to the output transducer 180 to generate an optical signal to a tympanic membrane receiver 350 , for example. [0087] FIGS. 16A and 16B show another embodiment of the ear tips, for example, an ear tip 600 which comprises a thin shell or core. The thin shell may have a thickness of 50 to 500 μm and comprise silicone, for example. The ear tip 600 may comprise a shaft portion 610 and an ear canal contact portion 620 . The thin shell may define several openings for venting the ear canal, a shaft opening 612 of the shaft portion 610 , a central opening 614 defined between the shaft portion 610 and the ear canal contact portion 620 , and a plurality of channels 616 to be defined between the outer surfaces of relief or cut-away portions of the ear canal contact portion 620 and the inner wall of the ear canal. The channels or folds 616 also serve to reduce radial pressure of the tip on the ear canal wall and to increase conformability of the ear tip to different ear-canal cross-section shapes. The folds 616 allow the structure to bend to reduce the radial pressure, circumventing potential generation of larger hoop stresses and pressure that could occur without folds. The ear canal contact portion 620 may be cross-shaped to be aligned with the major and minor axes of the ear canal through ear canal wall contacting extensions 622 which may define the aforementioned relief or cut-away portions disposed between adjacent extensions 622 . The ear tip 600 may be fabricated by injecting material such as silicone or silicone rubber into a simple, 3-D printed mold. [0088] Section 610 may be variable in cross section and may hold one or more wires that connect a BTE unit to a transducer 610 may also be curved to follow the shape of the ear canal. A transducer may be located in the tip 612 . The leading (medial) edge of the tip may be curved to help facilitate easy insertion in the ear canal. [0089] One or more processors may be programmed to perform various steps and methods as described in reference to various embodiments and implementations of the present disclosure. Embodiments of the systems of the present application may be comprised of various modules, for example, as discussed below. Each of the modules can comprise various sub-routines, procedures and macros. Each of the modules may be separately compiled and linked into a single executable program. [0090] It will be apparent that the number of steps that are utilized for such methods are not limited to those described above. Also, the methods do not require that all the described steps are present. Although the methodology described above as discrete steps, one or more steps may be added, combined or even deleted, without departing from the intended functionality of the embodiments. The steps can be performed in a different order, for example. It will also be apparent that the method described above may be performed in a partially or substantially automated fashion. [0091] As will be appreciated by those skilled in the art, the methods of the present disclosure may be embodied, at least in part, in software and carried out in a computer system or other data processing system. Therefore, in some exemplary embodiments hardware may be used in combination with software instructions to implement the present disclosure. Any process descriptions, elements or blocks in the flow diagrams described herein and/or depicted in the attached figures should be understood as potentially representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or elements in the process. Further, the functions described in one or more examples may be implemented in hardware, software, firmware, or any combination of the above. If implemented in software, the functions may be transmitted or stored on as one or more instructions or code on a computer-readable medium, these instructions may be executed by a hardware-based processing unit, such as one or more processors, including general purpose microprocessors, application specific integrated circuits, field programmable logic arrays, or other logic circuitry. [0092] While preferred embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments described herein may be employed in practicing the invention. By way of non-limiting example, it will be appreciated by those skilled in the art that particular features or characteristics described in reference to one figure or embodiment may be combined as suitable with features or characteristics described in another figure or embodiment. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

An ear tip apparatus for use with a hearing device is provided and comprises a malleable structure. The malleable structure is sized and configured for placement in an ear canal of a user. The malleable structure is deformable to allow an adjustable venting of the ear canal, thereby minimizing the occlusion effect. Methodology for adjusting a degree of venting of the ear canal is also provided, including the automatic adjustments. Adjusting the degree of venting may be done in response to one or more of detected feedback or an environmental cue.

This application is a US National Stage of International Application No. PCT/CN2013/076704, filed on Jun. 4, 2013, designating the United States and claiming the priority of Chinese Patent Application No. 201210181298.1, filed with the Chinese Patent Office on Jun. 4, 2012 and entitled “Method of and system and device for reporting a buffer state”, the content of which is hereby incorporated by reference in its entirety. FIELD The present invention relates to the technical field of wireless communications and particularly to a method of and system and device for reporting a buffer state. BACKGROUND There are significantly improved required peak rates of a Long Term Evolution-Advanced, LTE-A, system up to 1 Gbps in the downlink and 500 Mbps in the uplink as compared with an LTE system. The LTE-A system is also required to be well compatible with the LTE system. Carrier Aggregation, CA, has been introduced to the LTE-A system in view of the required improved peak rates, compatibility with the LTE system and full use of spectrum resources. With carrier aggregation, a user equipment can operate concurrently over a plurality of cells, where these cells can be consecutive or inconsecutive in frequency, and bandwidths of the respective cells may be the same or different. There is a limited bandwidth up to 20 MHz of each cell for compatibility with the LTE system. The number of cells that can be aggregated for the user equipment is typically up to 5 at present. In the carrier aggregation system, all of cells configured by a eNB for the user equipment can be referred to as serving cells, but all the functions of the different cells may not be the same, so the serving cells are further categorized in the LTE-A system as follows: A Primary Cell, PCell, where only one of the plurality of cells aggregated for the user equipment is defined as a Pcell, which is selected by the eNB and configured to the user equipment by Radio Resource Control, RRC, signaling. A Physical Uplink Control Channel, PUCCH, is configured only over the PCell; and A Secondary Cell, SCell, where all the other cells than the PCell aggregated for the user equipment are SCells. With the concept of carrier aggregation in the Release 10, R10 /Release 11, R11, only the cells served by the same eNB can be allowed to be aggregated for a User Equipment, UE, that is, intra-eNB (intra-eNB) aggregation. Both the LTE and LTE-A systems are scheduling-based systems, where the eNB allocates time and frequency resources to the UE for data transmission, and the user equipment receives downlink data or transmits uplink data according to a scheduling command of the eNB. Uplink data transmission is scheduled by the eNB, where a scheduler of the eNB notifies the user equipment of an uplink resource by an uplink, UL, grant after determining the allocation of the uplink resource. The scheduler of the eNB allocates the uplink resource in accordance with the amount of uplink data to be transmitted by the UE, i.e., a buffer state of the UE. The buffer is at the UE side, and the UE needs to make a Buffer State Report, BSR, to the eNB so that the eNB has knowledge of the state. As described above, carrier aggregation prior to the Release 11 , R11, refers to aggregation of cells served by the same eNB, i.e., intra-eNB aggregation. The Release 12, R12, may have inter-eNB aggregation introduced thereto. Inter-eNB aggregation has the following two modes: In a mode 1, the same RB of the same UE is transmitted by different eNBs. In a mode 2, different RBs of the same UE are transmitted by different eNBs. For the UE of the R11 and earlier releases, a BSR, is made based upon the size of a buffer of each logic channel group reported by the UE, but if inter-eNB aggregation is introduced to the R12, then two eNBs can perform uplink scheduling respectively, and apparently the existing BSR scheme is not applicable to the scenario of inter-eNB aggregation. In summary, there has been absent so far a solution to making a buffer state report in the scenario of inter-eNB aggregation. SUMMARY Embodiments of the invention provide a BSR solution so as to make a buffer state report in the scenario of inter-eNB aggregation. A method of reporting a buffer state provided by an embodiment of the invention includes: determining, by a user equipment for which resources of a plurality of network side devices are aggregated, buffer state information; and reporting, by the user equipment, the buffer state information to at least one of the network side devices participating in aggregation. Another method of reporting a buffer state provided by an embodiment of the invention includes: receiving, by a network side device, buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and performing, by the network side device, scheduling according to the buffer state information. A user equipment for reporting a buffer state provided by an embodiment of the invention includes: a determining module configured to determine buffer state information after resources of a plurality of network side devices are aggregated for the user equipment; and a reporting module configured to report the buffer state information to at least one of the network side devices participating in aggregation. A network side device for reporting a buffer state provided by an embodiment of the invention includes: a receiving module configured to receive buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and a processing module configured to perform scheduling according to the buffer state information. An embodiment of the invention provides a system for reporting a buffer state, the system device includes: a user equipment, for which resources of a plurality of network side devices are aggregated, configured to determine buffer state information and to report the buffer state information to at least one of the network side devices participating in aggregation; and the network side devices configured to receive the buffer state information from the user equipment for which the resources of the plurality of network side devices are aggregated and to perform scheduling according to the buffer state information. Another network side device provided by an embodiment of the invention includes: a receiver configured to receive buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and a processor configured to perform scheduling according to the buffer state oration. The user equipment for which resources of a plurality of network side devices are aggregated reports buffer state information to at least one of the network side devices participating in aggregation, so that a buffer state report can be made in the scenario of inter-eNB aggregation; and furthermore a plurality of eNBs in the case of inter-eNB aggregation can obtain the buffer state information and schedule the resources. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural diagram of a system for reporting a buffer state according to an embodiment of the invention; FIG. 2 is a schematic structural diagram of a user equipment in a system for reporting a buffer state according to an embodiment of the invention; FIG. 3 is a schematic structural diagram of a network side device in a system for reporting a buffer state according to an embodiment of the on; FIG. 4 is a schematic flow chart of a method of making a buffer state report by a user equipment according to an embodiment of the invention; and FIG. 5 is a schematic flow chart of a method of processing a butler state report by a network side device according to an embodiment of the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS In embodiments of the invention, a user equipment, for which resources of a plurality of network side devices are aggregated, reports buffer state information to at least one of the network side devices participating in aggregation. The user equipment for which the resources of the plurality of network side devices are aggregated reports buffer state information to at least one of the network side devices participating in aggregation so that a buffer state report can be made in the scenario of inter-eNB aggregation. The embodiments of the invention be described below in further details with reference to the drawings. In the following description, firstly an implementation with cooperation of the network side and the user equipment side will be described, and then implementations at the network side and the user equipment side will be described respectively, but this doesn't suggest required cooperation of bath the sides for an implementation, and in fact, problems present respectively at the network side and the user equipment side may also be addressed in the separate implementations at the network side and the user equipment side, although a better technical effect can be achieved in the implementation with cooperation of both the sides. As illustrated in FIG. 1 , a system for reporting a buffer state according to an embodiment of the invention includes a user equipment 10 and a network side device 20 . The user equipment 10 is configured to determine buffer state information and to report the buffer state information to at least one of the network side devices participating in aggregation, where resources of the plurality of network side devices are aggregated for the user equipment 10 . The network side devices 20 are configured to receive the buffer state information from the user equipment 10 and to perform scheduling according to the buffer state information. Preferably the user equipment 10 makes a buffer state report at the granularity of an Logic Channel Group, LCG, or, an Radio Bearer, RB. Particularly the report is made per LCG or RB dependent upon a required report granularity. If the report granularity is required to be precise, then the report can be made per RB; otherwise, the report can be made per LCG. Particularly the content of the BSR information is the size of the amount of data in a huller corresponding to each LCG or RB. For example, if an RB is scheduled concurrently by two eNBs, then different BSR information can be reported to different eNBs so as to make more efficient use of the resources. In an implementation, reference can be made to the 3GPP TS 36.321 protocol for scheduling by the network side device 20 according to the buffer state information, so a repeated description thereof may be omitted here. In an implementation, the user equipment 10 can report the buffer state information to one of the network side devices participating in aggregation or can report the buffer state information to at least two of the network side devices participating in aggregation as described below respectively. In a first case, the BSR triggering and reporting is performed per user equipment, in this case the network side devices participating in aggregation need to exchange the buffer state information with each other via internees between the network side devices. Particularly the user equipment 10 reports the buffer state information to one of the network side devices participating in aggregation; and Correspondingly the network side device 20 receiving the buffer state information needs to transmit the buffer state information to the other network side devices. Particularly a trigger mechanism and a report principle applied in the LTE R11 and earlier releases are applicable in the first case. In an LTE system, parameters configured at the RRC layer for a BSR include the following two timers, both of which are configured and maintained per UE: retxBSR-Timer which is a timer for prohibiting a BSR report; and periodicBSR-Timer which is a timer for a periodic BSR report. A BSR and a trigger mechanism thereof are categorized as follows: A regular BSR, which is triggered (1) when there is incoming data with a higher priority than the data in a current buffer or incoming data in an empty buffer; and (2) when the retxBSR-Timer expires and there is data in the buffer. A periodic BSR, which is triggered when the periodicBSR.Timer expires. A padding BSR, which can be triggered if there is a resource available (padding) in addition to data to be transmitted when the UE assembles a Medium Access Control Packet Data Unit, MAC PDU. A BSR report principle is as follows: For the regular BSR and the periodic BSR, if more than one Logical Channel Group, LCG; has data available, then a long BSR is reported; otherwise, a short BSR is reported; and For the padding BSR, if the number of padding bits is larger than or equal to a short BSR plus an MAC subheader but smaller than a long BSR plus an MAC subheader, and if more than one LCG of the UE has data available, then a truncated BSR is reported; otherwise, a short BSR is reported; and if the number of padding bits is larger than or equal to a long BSR plus an MAC subheader, then a long BSR is reported; and After the BSR is triggered, either of the periodic BSR or the padding BSR can be reported only if there is an uplink resource available, and if there is no uplink resource available for the regular BSR, then a Scheduling Request, SR, procedure may be triggered to request an eNB for allocating an uplink resource to the UE. After the eNB allocates the uplink resource to the UE, if the resource is just sufficient to transmit all the uplink data, then no BSR may be transmitted but the uplink data may be transmitted directly; and if the resource is not sufficient to transmit all the uplink data, then the regular BSR or the periodic BSR is reported preferentially, and the eNB further performs subsequent transmission scheduling according to the amount of uplink data required for the UE reported in the BSR. An MAC PDU includes at most one BSR. The order of BSR priorities is the regular BSR=the periodic BSR>the padding BSR, and if a plurality of BSRs are triggered concurrently, then the BSR with the highest priority is reported. Since the contents of the regular BSR and the periodic BSR are the same, where both of them include information about the amount of all the data available in the UE buffer, and the report formats of the regular BSR and the periodic BSR are totally the same, either of them can be selected to be reported. When the MAC layer assembles an MAC PDU, the MAC layer firstly places MAC Control Elements, CEs, of these two reports and then an MAC Service Data Unit, SDU. The priority of the padding BSR is lower than data, and the padding BSR and the regular/periodic BSR can be reported in different MAC PDUs in the same sub-frame. Particularly reference can be made to the 3GPP TS 36.321 protocol for a trigger mechanism and a report principle applied in the LTE R11 and earlier releases, so a repeated description thereof may be omitted here. In an implementation, BSR related RRC-layer parameters configured by the eNB for the UE include a retxBSR-Timer and a periodicBSR-Timer. The eNB configuring the BSR related parameters can be a macro eNB or a local node participating in aggregation, e.g., any eNB for aggregation or an eNB responsible for mobility management or an eNB providing macro coverage or an eNB responsible for receiving a BSR or an eNB deciding whether bearer splitting is performed for an RB or an eNB responsible for scheduling. Once a BSR is triggered, the user equipment 10 can report the buffer state information to one of the network side devices 20 participating in aggregation in one of the following approaches: The user equipment 10 reports the buffer state information over an activated cell participating in aggregation and with an uplink resource; or The user equipment 10 reports the buffer state information over an activated cell, with an uplink resource, managed by a network side device responsible for scheduling; or The user equipment 10 reports the buffer state information over a cell, with an uplink resource, served by a network side device responsible for bearer splitting; or The user equipment 10 reports the buffer state information over a cell, with an uplink resource, of a network side device responsible for configuring buffer state report parameters. In an implementation, if there is no uplink resource available (for example, there is no Physical Uplink Shared Channel, PUSCH) at present after the BSR is triggered, then the user equipment 10 transmits a Scheduling Request, SR, to the network side device to request the network side device for allocating an uplink resource for carrying the BSR; and then the user equipment 10 reports the buffer state information to at least one of the network side devices over the uplink resource allocated by the network side device. Preferably the user equipment 10 can transmit the SR to the network side device where an RB triggering the SR is located. In an implementation, the network side device 20 receiving the buffer state information exchanges the buffer state information via, interfaces between the eNBs (e.g., X 2 interfaces or other interfaces). The network side device 20 receiving the buffer state information can further modify the contents of the buffer state information while exchanging the buffer state information with the other network side devices. The contents to be modified can be the buffer size and the number of logical channel groups (when a BSR is reported per LCG) or the number of Radio Bearers, RBs (when a BSR is reported per RB). Preferably the logical channel groups can be configured so that the network side can separate uplink buffers of RBs served by different eNBs from the BSR, for examples, RBs carried by different eNBs may not be allocated to the same logical channel group. Particularly the network side device 20 receiving the buffer state information transmits the received buffer state information to the other network side devices; or The network side device 20 receiving the buffer state information modifies the buffer state information of a part of logical channel groups or the buffer state information of a part of RBs among the received buffer state information and transmits the modified buffer state information to the other network side devices; or The network side device 20 receiving the buffer state information transmits the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices; or The network side device 20 receiving the buffer state information modifies and then transmits the butler state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state motion to the corresponding network side devices. Particularly the other network side devices are network side devices receiving no buffer state information among the network side devices participating in aggregation, or network side devices receiving no buffer state information among the network side devices participating in aggregation and performing scheduling, or network side devices receiving no buffer state information among the network side devices participating in aggregation, performing scheduling and having a cell activated. In a second case, the UE reports BSRs respectively to the plurality of network side devices participating aggregation without any interaction between the eNBs. Particularly the second case further relates to two schemes. In a first scheme, a trigger mechanism and a report principle applied in the LTE R11 and earlier releases are applicable. Reference can be made to the 3GPP TS 36.321 protocol for a trigger mechanism and a report principle applied in the LTE R11 and earlier releases, so a repeated description thereof may be omitted here. Correspondingly once a BSR is triggered, the user equipment 10 determines BSR information to be reported to each network side device according to a relationship between an RB and a network device scheduling the RB, and report time for the different network side devices need to be the same. That is, the buffer state information of the user equipment 10 can be reported concurrently in the same sub-frame to the plurality of network side devices 20 participating in aggregation or participating in aggregation and performing scheduling. In an implementation, the user equipment 10 determines the network side devices participating in aggregation according to a relationship between aggregated cells and the network side devices or a relationship between RBs and the network side devices. Particularly the user equipment 10 can determine the network side devices participating in aggregation corresponding to the aggregated cells directly according to the relationship between the aggregated cells and the network side devices. Preferably the network side devices transmit the relationship between the aggregated cells and the network side devices and/or the relationship between the RBs and the network side devices to the user equipment 10 . Particularly the network side devices can notify the user equipment 10 of the relationships above by Radio Resource Control, RRC, signaling. In an implementation, buffer state information for the same logical channel group or buffer state information for the same RB among the buffer state information determined by the user equipment 10 to be reported to the different network side devices is the same or different. That is, buffer state information of the same logic channel group or RB reported by the user equipment 10 to the different network side devices 20 can be the same or different, for example, if a RB is scheduled concurrently by two eNBs, then buffer state information of the RB or buffer state information of an LCG, to which the RB belongs, reported to the different eNBs can be different; or Buffer state information determined by t le user equipment 10 to be reported to a different network side de rice includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. That is, buffer state information, to be reported to each network side device participating in aggregation or participating in aggregation and performing scheduling, includes only buffer state information of an RB or a logical channel group to be scheduled by the network side device. For a network side device A, for example, then buffer state information transmitted by the user equipment to the network side device A includes only buffer state information of an RB or a logical channel group scheduled by the network side device A. If an RB is scheduled by a plurality of network side devices, then buffer state information of the RB or an LCG corresponding to the RB reported to the different network side devices can be the same or different. Preferably the user equipment 10 determines an RB to be scheduled by each network side device 20 according to a relationship between the RB and the network side device. In a second scheme, a trigger is made per eNB, that is, for each network side device performing scheduling, the UE judges whether there is a BSR triggered under the network side device for an RB or an LCG that can be scheduled by the network side device in accordance with a BSR trigger mechanism of the LTE R 11 and earlier releases. In this scheme, a retxBSR-Timer and a periodicBSR-Timer are configured per UE and eNB and maintained per eNB. Particularly buffer state information determined by the user equipment 10 to be reported to a different network side device includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. That is, buffer state information, to be reported to each network side device participating in aggregation or participating in aggregation and performing scheduling, includes only buffer state information of an RB or a logical channel group to be scheduled by the network side device. Once a BSR is triggered, the user equipment 10 only reports the buffer state information over an activated cell served by the network side device and with an uplink resource. Preferably for a network side device, after the user equipment 10 reports the buffer state information to the network side device 20 , and if truncated buffer state information is reported, then a periodic BSR timer (periodicBSR-Timer) and a BSR retransmission timer (retxBSR-Timer) corresponding to the network side device are started or restarted, and if non-truncated buffer state information reported, then the retxBSR-Timer corresponding to the network side device is started or restarted. Preferably the user equipment reports the buffer state information to at least two of the network side devices: If a user equipment 10 has one set of a periodicBSR-Timer and a retxBSR-Timer, then a network side device participating in aggregation or participating in aggregation and performing scheduling configures the user equipment 10 with a periodic BSR timer (periodicBSR-Timer) and a BSR retransmission timer (retxBSR-Timer); If a user equipment 10 has a plurality of sets of periodicBSR-Timers and retxBSR-Timers, then each network side device participating in aggregation or participating in aggregation and performing scheduling configures the user equipment respectively with a periodic BSR timer (periodicBSR-Timer) and a BSR retransmission timer (retxBSR-Timer). In the first scheme and the second scheme, in an implementation, if there is no uplink resource available at present after a BSR is triggered, the user equipment 10 transmits a Scheduling Request, SR, to the net cork side device to request the network side device for allocating an uplink resource; and then the user equipment 10 reports the buffer state information to at least one of the network side devices over the uplink resource allocated by the network side device. Preferably the user equipment 10 can transmit the SR to the network side device where an RB triggering the SR is located. In the first scheme and the second scheme, when the user equipment 10 determines that a cell managed by the network side device 20 , to which the buffer state information needs to be reported, has no uplink resource available, the user equipment 10 transmits the buffer state information to at least one of the other network side devices to instruct the other network side device to transmit the buffer state information to the corresponding network side device. Particularly the network side device according to an embodiment of the invention can be a base station (e.g., a macro base station, a femtocell, etc.) or can be a Relay Node, RN, device or can be another network side device. As illustrated in FIG. 2 , a user equipment in a system for reporting a buffer state according to an embodiment of the invention includes a determining module 200 and a reporting module 210 . The determining module 200 is configured to determine buffer state information after resources of a plurality of network side devices are aggregated for the user equipment; and The reporting module 210 is configured to report the buffer state information to at least one of the network side devices participating in aggregation. Preferably if the buffer state information is reported to one of the network side devices participating in aggregation, then the reporting module 210 reports the buffer state information over an activated cell participating in aggregation and with an uplink resource; or reports the buffer state information over an activated cell, with an uplink resource, managed by a network side device responsible for scheduling; or reports the buffer state information over a cell, with an uplink resource, served by a network side device responsible for bearer splitting; or reports the buffer state information over a cell, with an uplink resource, of a network side device responsible for configuring buffer state report parameters. Preferably if the buffer state information is reported to at least of the network side devices, then the reporting module 210 reports the buffer state inform ion respectively to the network side devices participating in aggregation, or participating in aggregation and performing scheduling, or participating in aggregation, performing scheduling and having a cell activated, Wherein the user equipment reports the buffer state information to the different network side devices at the same or different time. Preferably the reporting module 210 determines the network side devices participating in aggregation as follows: The network side devices participating in aggregation are determined according to a relationship between aggregated cells and the network side devices or a relationship between Radio Bearers, RBs, and the network side devices. Preferably buffer state information for the same logical channel group or buffer state information for the same RB among the buffer state information determined by the determining module 200 to be reported to the different network side devices is the same or different. Preferably the determining module 200 determines an RB scheduled by a network side device as follows: An RB scheduled by each network side device is determined according to a relationship between the RB and the network side device. Preferably if the buffer state information is reported to at least two of the network side devices, then for a network side device, the reporting module 210 reports the buffer state information over an activated cell managed by the network side device and with an uplink resource. Preferably buffer state information determined by the determining module 200 to be reported to a different network side device includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. Preferably if the buffer state information is reported to the at least two of the network side devices, for a network side device, after the reporting module 210 reports the buffer state information to the network side device, if truncated buffer state information is reported, then a periodicBSR-Timer and a retxBSR-Timer corresponding to the network side device are started or restarted, and if non-truncated buffer state information is reported, then the retxBSR-Timer corresponding to the network side device is started or restarted. Preferably if the buffer state information is reported to at least two of the network side devices, after the reporting module 210 determines that a cell managed by the network side device, to which the buffer state information needs to be reported, has no uplink resource available, the reporting module 210 transmits the buffer state information to the other network side devices to instruct the other network side devices to transmit the buffer state information to the corresponding network side device. Correspondingly the network side device transmits buffer state information which is transmitted from the user equipment and should be reported to the other network side devices, to the corresponding network side devices upon reception of the buffer state information. Preferably after the reporting module 210 determines that there is no uplink resource available at present, the reporting module 210 transmits a Scheduling Request, SR, to the network side device to request the network side device for allocating an uplink resource; and the reporting module 210 reports the buffer state information to at least one of the network side devices over the uplink resource allocated by the network side device. Preferably the reporting module 210 transmits the SR to the network side device where an RB triggering the SR is located. Particularly the determining module 200 can be a processor and the reporting module 210 can be a transmitting device. Another user equipment according to an embodiment of the invention includes: A processor, which is configured to determine buffer state information after resources of a plurality of network side devices are aggregated for the user equipment; and A transmitting device, which is configured to report the buffer state information to at least one of the network side devices participating in aggregation. Preferably the transmitting device is particularly configured: If the buffer state information is reported to one of the network side devices participating in aggregation, to report the buffer state information over an activated cell participating in aggregation and with an uplink resource; or to report the buffer state information over an activated cell, with an uplink resource, managed by a network side device responsible for scheduling; or to report the buffer state information over a cell, with an uplink resource, served by a network side device responsible for bearer splitting; or to report the buffer state information over a cell, with an uplink resource, of a network side device responsible for configuring buffer state report parameters. Preferably the transmitting device is particularly configured: If the buffer state information is reported to at least two of the network side devices, to report the buffer state information respectively to the network side devices participating in aggregation, or participating in aggregation and performing scheduling, or participating in aggregation, performing scheduling and having a cell activated, where the user equipment reports the buffer state information to the different network side devices at the same or different time. Preferably the transmitting device determines the network side devices participating in aggregation according to a relationship between aggregated cells and the network side devices or a relationship between Radio Bearers, RBs, and the network side devices. Preferably the processor is particularly configured: To determine buffer state information for the same logical channel group or buffer state information for the same RB among the buffer state information to be reported to the different network side devices to be the same or different. Preferably the processor determines an RB scheduled by each network side device according to a relationship between the RB and the network side device. Preferably the transmitting device s particularly configured: If the buffer state information is reported to at least two of the network side devices, then for a network side device, to report the buffer state information over an activated cell managed by the network side device and with an uplink resource. Preferably the processor is particularly configured: To determine that buffer state information reported to a different network side device includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. Preferably the transmitting device s further configured: If the buffer state information is reported to the at least two of the network side devices, for a network side device, after reporting the buffer state information to the network side device if truncated buffer state information is reported, to start or restart a periodic BSR timer (periodicBSR-Timer) and a BSR retransmission timer (retxBSR-Timer) corresponding to the network side device, and if non-truncated buffer state information is reported, to start or restart the retxBSR-Timer corresponding to the network side device. Preferably the transmitting device is further configured: If the buffer state information is reported to at least two of the network side devices, after determining that a cell managed by the network side device, to which the buffer state information needs to be reported, has no uplink resource available, to transmit the buffer state information to the other network side devices to instruct the other network side devices to transmit the buffer state information to the corresponding network side device. Preferably the transmitting device is further configured: After determining that there is no uplink resource available at present, to transmit a Scheduling Request, SR, to the network side device to request the network side device for allocating an uplink resource; and to report the buffer state information to at least one of the network side devices over the uplink resource allocated by the network side device. Preferably the transmitting device is particularly configured: To transmit the SR to the network side device where an RB triggering the SR is located. As illustrated in FIG. 3 , a network side device in a system for reporting a buffer state according to an embodiment of the invention includes a receiving module 300 and a processing module 310 . The receiving module 300 is configured to receive buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and The processing module 310 is configured to perform scheduling according to the buffer state information. Preferably if the user equipment reports the buffer state information to one of the network side devices, then upon reception of the buffer state information from the user equipment for which the resources of the plurality of network side devices are aggregated, the processing module 310 transmits the received buffer state information to the other network side devices; or modifies the buffer state information of a part of logical channel groups or the buffer state information of a part of RBs among the received buffer state information and transmits the modified buffer state information to the other network side devices; or transmits the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices; or modifies and then transmits the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices. Preferably the other network side devices are network side devices receiving, no buffer state information among the network side devices participating in aggregation, or network side devices receiving no buffer state information among the network side devices participating in aggregation and performing scheduling, or network side devices receiving no buffer state information among the network side devices participating in aggregation, performing scheduling and having a cell activated. Preferably if the user equipment reports the buffer state information to at least two of the network side devices, then the processing module 310 transmits a relationship between aggregated cells and the network side devices and/or a relationship between RBs and the network side devices to the user equipment. Preferably the user equipment reports the buffer state information to at least two of the network side devices: If a user equipment has one set of a periodicBSR-Timer and a retxBSR-Timer, then the processing module 310 configures the user equipment with a periodicBSR-Timer and a retxBSR-Timer upon determining that this configuration is required for the user equipment; or if a user equipment has a plurality of sets of periodicBSR-Timers and retxBSR-Timers, then the processing module 310 configures the user equipment with one of the sets of periodicBSR-Timers and retxBSR-Timers. Based upon the same inventive idea, embodiments of the invention further provide a method of making a buffer state report by a user equipment and a method of processing a buffer state report by a network side device, and since these methods address the problem under a principle similar to that of the system for reporting a buffer state according to the embodiment of the invention, reference can be made to an implementation of the system for implementations of these methods, so a repeated description thereof will be omitted here. Particularly the receiving module can be a receiver, and the processing module can be a processor. Another network side device according to an embodiment of the invention includes: A receiver is configured to receive buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and A processor is configured to perform scheduling according to the buffer state information. Preferably when the user equipment reports the buffer state information to one of the network side devices, the processor is further configured: Upon reception of the buffer state information from the user equipment for which the resources of the plurality of network side devices are aggregated, to transmit the received buffer state information to the other network side devices; or to modify the buffer state information of a part of logical channel groups or the buffer state information of a part of RBs among the received buffer state information and to transmit the modified buffer state information to the other network side devices; or to transmit the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices; or to modify and then transmit the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices. When the user equipment reports the buffer state information to at least two of the network side devices, the processor is further configured: To transmit a relationship between aggregated cells and the network side devices and/or a relationship between RBs and the network side devices to the user equipment. When the user equipment reports the buffer state information to at least two of the network side devices, the processor is further configured: If a user equipment has one set of a periodicBSR-Timer and a retxBSR-Timer, to configure the user equipment with a periodicBSR-Timer and a retxBSR-Timer upon determining that this configuration is required for the user equipment; If a user equipment has a plurality of sets of periodicBSR-Timer and retxBSR-Timers, configure the user equipment with one of the sets of periodicBSR-Timers and retxBSR-Timers. As illustrated in FIG. 4 , a method of making a buffer state report by a user equipment according to an embodiment of the invention includes the following operations: The operation 401 : the user equipment, for which resources of a plurality of network side devices are aggregated, determines buffer state information; and The operation 402 : the user equipment reports the buffer state information to at least one of the network side devices participating in aggregation. Preferably the user equipment makes a buffer state report at the granularity of an LCG or an RB. In an implementation, the user equipment can report the buffer state information to one of the network side devices participating in aggregation or can report the buffer state information to at least two of the network side devices participating in aggregation as described below respectively. In a first case, the BSR triggering and reporting is performed per user equipment, in this case, the network side devices participating in aggregation need to exchange the buffer state information with each other via interfaces between the network side devices. Particularly the user equipment reports the buffer state information to one of the network side devices participating in aggregation. Particularly a trigger mechanism and a report principle applied in the LTE R11 and earlier releases are applicable in the first case, and reference can be made to the 3GPP TS 36.321 protocol for details thereof, so a repeated description thereof may be omitted here. Once a BSR is triggered, the user equipment can report the buffer state information to one of the network side devices participating in aggregation in one of the following approaches: The user equipment reports the buffer state information over an activated cell participating in aggregation and with an uplink resource; or The user equipment reports the buffer state information over an activated cell, with an uplink resource, managed by a network side device responsible for scheduling; or The user equipment reports the buffer state information over a cell, with an uplink resource, served by a network side device responsible for bearer splitting; or The user equipment reports the buffer state information over a cell, with an uplink resource, of a network side device responsible for configuring buffer state report parameters. In an implementation, if there is no uplink resource available at present after the BSR is triggered, then the user equipment transmits an SR to the network side device to request the network side device for allocating an uplink resource for carrying the BSR; and then the user equipment reports the buffer state information to at least one of the network side devices over the uplink resource allocated by the network side device. Preferably the user equipment can transmit the SR to the network side device where an RB triggering the SR is located. In a second case, the UE reports BSRs respectively to the plurality of network side devices participating in aggregation without any interaction between the eNBs. Particularly the second case further relates to two schemes. In a first scheme, a trigger mechanism and a report principle applied in the LTE R11 and earlier releases are applicable. Reference can be made to the 3GPP TS36.321 protocol for a trigger mechanism and a report principle applied in the LTE R11 and earlier releases, so a repeated description thereof may be omitted here. Correspondingly once a BSR is triggered, the user equipment reports the buffer state information respectively to the network side devices participating in aggregation, or participating in aggregation and performing scheduling, or participating in aggregation, performing scheduling and having a cell activated, wherein the user equipment reports the buffer state information to the different network side devices at the same or different time. That is, the buffer state information of the user equipment can be reported concurrently in the same sub-frame to the plurality of network side devices participating in aggregation or participating in aggregation and performing scheduling. In an implementation, the user equipment determines the network side devices participating in aggregation according to a relationship between aggregated cells and the network side devices or a relationship between RBs and the network side devices. Particularly the user equipment can determine the network side devices participating in aggregation corresponding to the aggregated cells directly according to the relationship between the aggregated cells and the network side devices. Particularly the relationship between the aggregated cells and the network side devices and/or the relationship between the RBs and the network side devices can be specified in the protocol or can be notified of by the network side. In an implementation, buffer state information for the same logical channel group or buffer state information for the same RB among the buffer state information determined by the user equipment to be reported to the different network side devices is the same or different; or Buffer state information determined by the user equipment to be reported to a different network side device includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. Preferably the user equipment determines an RB to be scheduled by each network side device according to a relationship between the RB and the network side device. In a second scheme, a trigger is made per eNB, that is, for each network side device performing scheduling, the UE judges whether there is a BSR triggered under the network side device for an RB or an LCG that can be scheduled by the network side device in accordance with a BSR trigger mechanism of the LTE R11 and earlier releases. In this scheme, a retxBSR-Timer and a periodicBSR-Timer are configured per UE and eNB and maintained per eNB. Particularly buffer state information determined by the user equipment to be reported to a different network side device includes only buffer state information corresponding to an RB served by the network side device or buffer state information of a logical channel group corresponding to the RB served by the network side device. Once a BSR is triggered, the user equipment only reports the buffer state information over an activated cell served by the network side device and with an uplink resource. Preferably for a network side device, after the user equipment reports the buffer state information to the network side device, if truncated buffer state information is reported, then a periodicBSR-Timer and a retxBSR-Timer corresponding to the network side device are started or restarted, and if non-truncated buffer state information is reported, then the retxBSR-Timer corresponding to the network side device is started or restarted. In the first scheme and the second scheme, in an implementation, if there is no uplink resource available at present after a BSR is triggered, the user equipment transmits an SR to the network side device to request the network side device for allocating an uplink resource; and then the user equipment reports the buffer state information to at east one of the network side devices over the uplink resource allocated by the network side device. Preferably the user equipment can transmit the SR to the network side device where an RB triggering the SR is located. In the first scheme and the second scheme, when the user equipment determines that a cell managed by the network side device, to which the buffer state information needs to be reported, has no uplink resource available, the user equipment transmits the buffer state information to at least one of the other network side devices to instruct the other network side device to transmit the buffer state information to the corresponding network side device. As illustrated in FIG. 5 , a method of processing a buffer state report by a network side device according to an embodiment of the invention includes the following operations: Operation 501 , the network side device receives buffer state information from a user equipment for which resources of a plurality of network side devices are aggregated; and Operation 502 , the network side device performs scheduling according to the buffer state information. In an implementation, the user equipment can report the buffer state information to one of the network side devices participating in aggregation or can report the buffer state information to at least two of the network side devices participating in aggregation as described below respectively. In a first case, the SSR triggering and reporting is performed per user equipment, in this case, the network side devices participating in aggregation need to exchange the buffer state information with each other via interfaces between the network side devices. Particularly the network side device receiving the buffer state information needs to transmit the buffer state information to the other network side devices. In an implementation, BSR related RRC-layer parameters configured by the eNB for the UE include a retxBSR-Timer and a periodicBSR-Timer. The eNB configuring the BSR related parameters can be a macro eNB or a local node participating in aggregation, e.g., any eNB for aggregation or an eNB responsible for mobility management or an eNB providing macro coverage or an eNB responsible for receiving BSR or an eNB deciding whether bearer splitting is performed for an RB or an eNB responsible for scheduling. In an implementation, the network side device receiving the buffer state information exchanges the buffer state information via interfaces between the eNBs (e.g., X 2 interfaces or other interfaces). The network side device receiving the buffer state information can further modify the contents of the buffer state information while exchanging the buffer state information with the other network side devices. The contents to be modified can be the buffer size and the number of logical channel groups (when a BSR is reported per LCG) or the number of Radio Bearers, RBs (when a BSR is reported per RB). Preferably the logical channel groups can be configured so that the network side can separate uplink buffers of RBs served by different eNBs from the BSR, for examples, RBs carried by different eNBs may not be allocated to the same logical channel group. Particularly the network side device receiving the buffer state inform ion transmits the received buffer state information to the other network side devices; or The network side device receiving the buffer state information modifies the buffer state information of a part of logical channel groups or the buffer state information of a part of RBs among the received buffer state information and transmits the modified buffer state information to the other network side devices; or The network side device receiving the buffer state information transmits the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices; or The network side device receiving the buffer state information modifies and then transmits the buffer state information of logical channel groups, or buffer state information of the RBs, which are related to the other network side devices, among the received buffer state information to the corresponding network side devices. Particularly the other network side devices are network side devices receiving no buffer state information among the network side devices participating in aggregation, or network side devices receiving no buffer state information among the network side devices participating in aggregation and performing scheduling, or network side devices receiving no buffer state information among the network side devices participating in aggregation, performing scheduling and having a cell activated. In a second case, the UE reports BSRs respectively to the plurality of network side devices participating in aggregation without any interaction between the eNBs. In the second case, the network side device transmits buffer state information, which is transmitted form the user equipment and should be reported to the other network side devices, to the corresponding network side devices upon reception of the buffer state information. Preferably the network side device transmits a relationship between aggregated cells and the network side devices and/or a relationship between RBs and the network side devices to the user equipment. Particularly the network side device can notify the user equipment of the relationships above by RRC signaling. Preferably the user equipment reports the buffer state information to at least two of the network side devices: If a user equipment has one set of a periodicBSR-Timer and a retxBSR-Timer, then a network side device participating in aggregation or participating in aggregation and performing scheduling configures the user equipment with a periodicBSR-Timer and a retxBSR-Timer; If a user equipment has a plurality of sets of periodicBSR-Timers and retxBSR-Timers, then each network side device participating in aggregation or participating in aggregation and performing scheduling configures the user equipment respectively with a periodicBSR-Timer and a retxBSR-Timer. Particularly FIG. 4 and FIG. 5 can be combined into a flow of a method of making buffer state report, that is, firstly the operation 401 and the operation 402 and then the operation 501 and the operation 502 are performed. The first case above may be described below in details by way of an example. Operation 1: configure BSR parameters: The eNB configures BSR related RRC-layer parameters for the UE, the parameters include a retxBSR-Timer and a periodicBSR-Timer. The eNB configuring the BSR related parameters can be a macro eNB or a local node participating in aggregation. Operation 2: trigger a BSR: A BSR trigger type and a trigger scheme can be performed in accordance with a BSR trigger mechanism in the releases earlier than the R12, and reference can be made to the Background. If a BSR is triggered and there is no UL resource available, then an SR is triggered, and an SR resource is configured per UE. Operation 3: report the BSR: A BSR reporting principle can follow a BSR reporting principle releases earlier than the R12, and reference can be made to the Background. A BSR report resource can be selected in the following options: The BSR is reported to the eNB over any one activated cell uplink resource; or The BSR is reported to the eNB over a cell served by an eNB responsible for bearer splitting; or The BSR is reported to the eNB over a cell managed by an eNB responsible for configuring BSR parameters. The BSR is reported to the eNB over a cell managed aged by an eNB responsible for scheduling. Operation 4: process the reported BSR: Once a BSR of the UE is triggered and can be reported, a periodicBSR-Timer and a retxBSR-Timer are started or restarted. It shall be noted that if only a truncated BSR is reported, then the periodicBSR-Timer can not be started/restarted while only the retxBSR-Timer can be started or restarted. Operation 5: exchange BSR information between eNBs; If only one of the different eNBs participating in aggregation is responsible for scheduling, then the eNB can simply schedule resources of the plurality of eNBs participating in aggregation according to the BSR information. If a plurality of eNBs among the different eNBs participating in aggregation need to perform scheduling, then the eNB obtaining the BSR information needs to forward the BSR information to the relevant eNBs via interfaces between the eNBs (e.g., X 2 interfaces), possibly in the following several forwarding schemes: The eNB forwards all the received BSR information to the other eNBs, and furthermore the eNB is allowed to modify buffer information of a part of RBs or logical channel groups among the BSR information, that is, if an RB is scheduled concurrently by two eNBs, then the eNB, which forwards the BSR, can modify buffer information of a corresponding RB or LCG according to its resource condition; and The eNB forwards only buffer state information of an RB or a logical channel group, which is related to some eNB, to a corresponding eNB, and furthermore the UE is allowed to modify buffer information of a part of RBs or logical channel groups among the BSR information, that is, if an RB is scheduled concurrently by two eNBs, then the eNB, which forwards the BSR, can modify buffer information of a corresponding RB or LCG according to its resource condition. The second case above may be described below in details by way of three examples. In a first example, a report is triggered per UE but reported respectively to eNBs participating in aggregation and performing scheduling, wherein the reported buffer information is BSR information per UE, although buffer contents corresponding to respective RBs or LCGs may be allowed to be different. Operation 1: obtain configuration information; The UE obtains the following configuration information: The UE needs to obtain a relationship between aggregated cells and eNBs by RRC signaling; The UE needs to obtain a relationship between RBs and transmitting eNBs by RRC signaling; and The UE obtains the configuration of a retxBSR-Timer and a periodicBSR-Timer by RRC signaling. The eNB configuring the BSR related parameters can be a macro eNB or a local node participating in aggregation. The configuration information can be transmitted by any eNB participating in aggregation or an eNB responsible for mobility management or an eNB providing macro coverage or an eNB responsible for receiving a BSR or an eNB deciding whether bearer splitting is performed for an RB or an eNB responsible for scheduling. Operation 2: trigger a BSR: A BSR trigger type and a trigger scheme can be embodied in accordance with a BSR trigger mechanism in the releases earlier than the R12, and reference can be made to the Background. If a BSR is triggered and there is no UL resource available, then an SR is triggered, and an SR resource is configured per UE. Operation 3: report the BSR; A BSR reporting principle differs from a BSR reporting principle in the releases earlier than the R12 in that: There are a plurality of MAC PDUs carrying regular BSRs and periodic BSRs in a Transmission Time Interval, TTI (there is only one MAC PDU carrying a regular/periodic BSR in a TTI in the releases earlier than the R12). For the same RB or LCG, the buffer size carried in each BSR can be the same or can be different (it is required to be the same in the releases earlier than the R12). A BSR report resource can be selected in the following options: The UE at least needs to transmit BSR information per that UE to each eNB participating in aggregation and performing scheduling. Buffer information of each RB or LCG transmitted to the different eNBs can be different or can be the same. In this solution, it is required that the eNB receiving an SR needs to coordinate the other scheduling eNBs to allocate BSR resources concurrently for the UE. Operation 4: process the reported BSR. Once a BSR of the UE is triggered and can be reported, a periodicBSR-Timer and a retxBSR-Timer are started or restarted. It shall be noted that if only a truncated BSR is reported, then the periodicBSR-Timer can not be started/restarted while only the retxBSR-Timer can be started or restarted. In a second example, a report is triggered per UE but reported respectively to eNBs participating in aggregation and performing scheduling, and the information reported to each eNB includes only BSR information of an RB or an LCG scheduled by the eNB. Operation 1: obtain configuration information; The UE obtains the following configuration information: The UE needs to obtain a relationship between aggregated cells and eNBs by RRC signaling; The UE needs to obtain a relationship between RBs and transmitting eNBs by RRC signaling; and The UE obtains the configuration of a retxBSR-Timer and a periodicBSR-Timer by RRC signaling. The eNB configuring the BSR related parameters can be a macro eNB or a local node participating in aggregation. The configuration information can be transmitted by any eNB participating in aggregation or an eNB responsible for mobility management or an eNB providing macro coverage or an eNB responsible for receiving a BSR or an eNB deciding whether bearer splitting is performed for an RB or an eNB responsible for scheduling. Operation 2: trigger a BSR; A BSR trigger type and a trigger scheme can be embodied in accordance with a BSR trigger mechanism in the releases earlier than the R12, and reference can be made to the Background. If a BSR is triggered and there is no UL resource available, then an SR is triggered, and an SR resource is configured per UE. Operation 3: report the BSR; A BSR reporting principle differs from a BSR reporting principle in the releases earlier than the R12 in that: There are a plurality of MAC PDUs carrying regular BSRs and periodic BSRs in a TTI (there is only one MAC PDI carrying a regular/periodic BSR in a TTI in the releases earlier than the R12). The UE needs to assemble BSR MAC CEs respectively for different eNBs participating in aggregation, or participating in aggregation and performing scheduling, and each BSR MAC CE includes only information of an RB or an LCG related to the eNB. If a plurality of BSR MAC CEs include buffer information of the same RB or LCG, then buffer states in the different BSR MAC CEs can take different values. A BSR report resource can be selected in the following options: The UE reporting BSR information corresponding to each eNB participating in aggregation or participating in aggregation and performing scheduling needs to select an uplink resource allocated over an activated cell served by the eNB. Even if there is no UL grant for the cell served by the eNB, the BSR. MAC CE is allowed to be forwarded by another eNB and an eNB indicator needs to be added to the BSR MAC CE so that a receiving eNB can determine to which eNB the received BSR MAC CE may be forwarded via interfaces between the eNBs. Operation 4: process the reported BSR; Once a BSR of the UE is triggered and can be reported, a periodicBSR-Timer and a retxBSR-Timer are started or restarted. It shall be noted that if only a truncated BSR is reported, Then the periodicBSR-Timer can not be started/restarted while only the retxBSR-Timer can he started or restarted. In a third example, a BSR is triggered and reported per eNB. Operation 1: obtain configuration information; The UE obtains the following configuration information: The UE needs to obtain a relationship between aggregated cells and eNBs by RRC signaling; and The UE needs to obtain a relationship between RBs and transmitting eNBs by RRC signaling. Each eNB participating in aggregation or participating in aggregation and performing scheduling configures the UE with a retxBSR-Timer and a periodicBSR-Timer corresponding to the eNB respectively by RRC signaling. The first two pieces of configuration information can be transmitted by any eNB participating in aggregation or an eNB responsible for mobility management or an eNB providing macro coverage or an eNB responsible for receiving a BSR or an eNB deciding Whether bearer splitting is performed for an RB or an eNB responsible for scheduling. If an eNB transmits a retxBSR-Timer and a periodicBSR-Timer of another eNB, then related eNB identification information needs to be carried. Operation 2: trigger a BSR: Whether there is a BSR triggered is judged for an RB served by each eNB respectively in accordance with a BSR trigger type and a trigger scheme in the releases earlier than the R12 as follows: A regular BSR is triggered if either of the following two conditions is satisfied for the RB scheduled by the eNB: (1) when there is incoming data with a higher priority than the data in a current buffer or incoming data in an empty buffer; and (2) when the retxBSR-Timer expires and there is data in the buffer. A periodic BSR is triggered when the periodicBSR-Timer corresponding to the eNB expires. A padding BSR can be triggered if there is a resource available (padding) in addition to a resource for data to be transmitted in the resources allocated by the eNB when the UE assembles an MAC PDU. Operation 3: report the BSR: If there is a BSR to be reported but no UL resource available, then the UE needs to trigger an SR for the eNB to request the corresponding eNB for allocating an UL resource thereto. The UE reports a BSR for each eNB for which a BSR is required respectively in accordance with a BSR report mechanism in the releases earlier than the R12. It shall be noted that if a plurality of eNBs require information of an RB or a logical channel group to be reported, then different contents are allowed to be reported to the different eNBs. The BSR can be reported over an activated cell served by the eNB and with an uplink available resource. Operation 4: process the reported BSR; For some eNB, if the UE reports a BSR to the eNB, then a periodicBSR-Timer and a. retxBSR-Timer configured by the eNB are started or restarted. It shall be noted that if only a truncated BSR is reported, then the periodicBSR-Timer can not be started/restarted while only the retxBSR-Timer can be started or restarted, There is no influence upon periodicBSR-Timers and retxBSR-Timers configured by the other eNBs. Those skilled in the art shall appreciate that the embodiments of the invention can be embodied as a method, a system or a computer program product. Therefore the invention can be embodied in the form of an all-hardware embodiment, an all-software embodiment or an embodiment of software and hardware in combination. Furthermore the invention can be embodied in the form of a computer program product embodied in one or more computer useable storage mediums (including but not limited to a disk memory, a CD-ROM, an optical memory, etc.) in which computer useable program codes are contained. The invention has been described in a flow chart and/or a block diagram of the method, the device (system) and the computer program product according to the embodiments of the invention. It shall be appreciated that respective flows and/or blocks in the flow chart and/or the block diagram and combinations of the flows and/or the blocks in the flow chart and/or the block diagram can be embodied in computer program instructions. These computer program instructions can be loaded onto a general-purpose computer, a specific-purpose computer, an embedded processor or a processor of another programmable data processing device to produce a machine so that the instructions executed on the computer or the processor of the other programmable data processing device create means for performing the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram. These computer program instructions can also be stored into a computer readable memory capable of directing the computer or the other programmable data processing device to operate in a specific manner so that the instructions stored in the computer readable memory create an article of manufacture including instruction means which perform the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram. These computer program instructions can also be loaded onto the computer or the other programmable data processing device so that a series of operational operations are performed on the computer or the other programmable data processing device to create a computer implemented process so that the instructions executed on the computer or the other programmable device provide operations for performing the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram. Although the preferred embodiments of the invention have been described, those skilled in the art benefiting from the underlying inventive concept can make additional modifications and variations to these embodiments. Therefore the appended claims are intended to be construed as encompassing the preferred embodiments and all the modifications and variations coming into the scope of the invention. Evidently those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus the invention is also intended to encompass these modifications and variations thereto so long as the modifications and variations come into the scope of the claims appended to the invention and their equivalents.

Embodiments of the present invention relate to the technical field of wireless communications, and more particularly to a buffer state reporting method, system, and device, so as to perform buffer state reporting regarding an inter-eNB aggregation scenario. A buffer state reporting method provided by an embodiment of the present invention comprises: a user equipment, that aggregates resources of multiple network side devices, determining buffer state information; the user equipment reporting the buffer state information to at least one network side device participating in the aggregation, so as to realize buffer state reporting regarding the inter-eNB aggregation scenario, and enable multiple eNBs to obtain the buffer state information in the case of inter-eNB aggregation, thereby realizing resource scheduling.

BACKGROUND OF THE INVENTION This invention relates to an enzyme electrode for assaying maltose, and particularly to a stable maltose sensor with a long life. Maltose is a dimer of glucose and is produced when polysaccharides such as starch, etc. are hydrolyzed by α-amylase (which will be hereinafter referred to as "amylase"), etc. Thus, the amount of amylase can be determined indirectly by allowing amylase to act on a system containing an excess and a predetermined amount of a substrate, and measuring the amount of maltose thus produced. Amylase is an enzyme capable of decomposing polysaccharides such as starch, dextrin, glycogen, pectin, etc. as a substrate into maltose, and exists in organs of animals including human being, plants and microorganisms. Diagnosis of various diseases can be made by quantitative analysis of amylase in biological fluids such as blood, etc., and thus the quantitative determination of amylase has been recently regarded as particularly important. Heretofore available methods for quantitative analysis of amylase include (1) an amyloclastic method for tracing gradual decomposition of starch by amylase according to iodine-starch reaction, (2) a saccharogenic method for measuring the reducibility of maltose produced through decomposition by amylase, (3) a chromogenic substrate method for colorimetry of soluble pigments freed from insoluble colored starch, as crosslinked with pigments, as a substrate under the action of amylase, etc. Particularly when the sample is a biological fluid, these methods have a drawback of poor assaying accuracy, because various substances contained in the biological fluid, for example, urea, ureic acid, protein, sugars, vitamin C, etc. act as assay-interferring substances, and also have further drawbacks of complicated assaying operation and prolonged assay time. To overcome these drawbacks, enzymatic methods have been recently developed, which include (4) a maltose phosphorylase method comprising decomposing maltose, which has been produced from soluble starch as a substrate by α-amylase, by maltophosphorylase and ultimately measuring the amount of NADH (reduced nicotinamid adenin dinucleotide) after further three enzyme reaction stages each using β-phosphoglucomutase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconic acid dehydrogenase, (5) an α-glucosidase method comprising decomposing maltose into glucose by α-glucosidase and assaying the glucose, etc. These enzymatic methods utilize the specificity of enzyme for substrates, and thus have such an advantage as no substantial susceptibility to the influence of the assay-interfering substances, as compared with said methods (1) to (3), but have such disadvantages as a prolonged assay time, an impossibility to assay the whole blood, use of expensive analytical reagents such as enzymes and coenzymes, complicated structures of analytical instruments. To improve the assaying accuracy and simplify the operating procedure, an enzyme sensor method for assaying amylase has been recently proposed [K. Yoda and T. Tsuchida: Proceedings of the International Meeting on Chemical Sensors, page 648 (1983)]. The principle of the method can be outlined by the following enzymatic reactions. ##STR1## That is, when oxidation reaction of glucose is carried out with glucose oxidase as an enzyme in the case of assaying glucose, oxygen O 2 is consumed to produce hydrogen peroxide H 2 O 2 according to said equation (III). Different from glucose, said oxygen or hydrogen peroxide can be a target of electrochemical measurement, and thus a glucose concentration can be indirectly measured by electrochemically measuring a decrease in the oxygen amount due to its consumption or an amount of hydrogen peroxide thus produced. In assaying maltose, α-maltose produced from the saccharides (substrate) by decomposition under the action of amylase contained in the sample according to said equation (I) reacts with water under the action of enzyme α-glucosidase to produce two molecules of glucose according to said equation (II), and the glucose reacts with water and oxygen under the action of enzyme glucose oxidase to produce gluconic acid and hydrogen peroxide according to said equation (III). In this case, the amount of glucose can be indirectly measured by electrochemically measuring an amount of hydrogen peroxide thus produced, or an amount of oxygen thus decreased in the same manner as described above referring to the assaying of glucose. However, the amount of glucose to be measured in this case is the total amount of the glucose derived from α-maltose produced from the substrate by decomposition by amylase and the glucose existing in the sample from the initial. Amylase can be assayed from a difference of an output signal obtained by assaying maltose corresponding to the total amount of glucose from an output signal corresponding to the initial glucose amount. An enzyme electrode for the enzyme sensor method comprises an immobilized enzyme membrane in which glucose oxidase and α-glucosidase are immobilized, and a transducer capable of electrochemically measuring a change in chemical reaction, occasioned by catalytic actions of these enzymes. The enzyme sensor method is much better than the conventional methods because of higher assay accuracy, shorter assay time, simple analytical instruments, and no requirements for analytical reagents such as coloring reagents, etc. and thus is a very promissing one. However, its effect cannot be fully attained so long as the conventional transducer is used. That is, a galvanic type oxygen electrode, which will be hereinafter referred to as "O 2 electrode", and a polarographic type hydrogen peroxide electrode, which will be hereinafter referred to as "H 2 O 2 electrode", are usually used as the transducer, and the H 2 O 2 electrode is better as a transducer than the O 2 electrode, because the H 2 O 2 electrode that detects the increasing H 2 O 2 has a higher signal/noise ratio and a higher stability in the reaction according to said equation (III) than the O 2 electrode that detects the decreasing O 2 . Thus, the H 2 O 2 electrode is preferable as the transducer. Generally, a H 2 O 2 electrode comprises a gold or platinum anode and a silver cathode. A maltose sensor has an enzyme membrane having the immobilized α-glucosidase and glucose oxidase, as described above, on the working surface of said electrode. When the ordinary H 2 O 2 electrode having a silver cathode is used, it has been found that a very small amount of silver is dissolved out of the cathode to deactivate the immobilized enzymes, particularly β-glucosidase, in the enzyme membrane. α-Glucosidase is deactivated within a few hours even in the immobilized state, whenever it is placed in an atmosphere containing Ag + at a concentration of about 10 -5 gram-equivalent/l. On the other hand, the concentration of Ag + dissolvable from H 2 O 2 electrode is 10 -5 to 10 -6 gram-equivalent/l at room temperature. Thus, the life of a maltose sensor comprising an H 2 O 2 electrode provided with a silver cathode is one day as the longest. SUMMARY OF THE INVENTION An object of the present invention is to provide a stable maltose sensor with a long life and a high sensitivity. This and other objects of the present invention can be attained by a maltose sensor comprising an enzyme membrane having immobilized α-glucosidase and glucose oxidase and an electrode, the electrode being a hydrogen peroxide electrode provided with a palladium cathode. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a maltose sensor according to one embodiment of the present invention. FIG. 2 is a diagram showing a calibration curve of maltose. FIG. 3 is a diagram showing the state of output current from a maltose sensor of the present invention when used for assaying amylase. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present maltose sensor comprises an enzyme membrane having immobilized α-glucosidase and glucose oxidase and an H 2 O 2 electrode provided with a palladium cathode. In the present invention, a H 2 O 2 electrode provided with a palladium cathode is used for the following reasons: (1) Palladium has a smaller solubility than silver, and cannot deteriorate the enzume activity. (2) Palladium ions less deteriorate the activity of α-glucosidase than silver ions, and the degree of deterioration by palladium ions is about 1/10--about 1/50 times that by silver ions. (3) Different from other metal species, for example gold, platinum, iridium, osmium, etc., palladium stably works when used as a H 2 O 2 electrode, though its exact reason has not been clarified yet. The palladium cathode can take just the same shape as that of the cathode in the Clark type H 2 O 2 electrode. It is preferable that the palladium has a high purity of at least 99%. Any membrane having immobilized α-glucosidase and glucose oxidase can be used in the present invention as an enzyme membrane. Well known art as to methods for immobilizing these enzymes and preparing immobilized membranes, for example, the art disclosed in "Immobilized Enzyme" compiled by I. Chihata and published by Kodansha Scientific Publishing Co., Tokyo (1975) can be used in the present invention. The present invention will be described in detail below, referring to the drawings and Examples. FIG. 1 is a schematic view of a maltose sensor according to one embodiment of the present invention, where numeral 1 is lead wires, 2 a sensor outside cylinder, 3 an insulator, 4 a platinum anode, and 5 a palladium cathode, and a H 2 O 2 electrode is constituted from the foregoing members 1 to 5. Numeral 6 is an O-ring for fixing an enzyme membrane 9 to working surface 7 of the H 2 O 2 electrode through an electrolyte 8. In the enzyme membrane 9, α-glucosidase and glucose oxidase are immobilized. Whenever glucose in a sample contacts the enzyme membrane 9, reaction takes place according to said equation (III). Whenever maltose contacts the enzyme membrane 9, reactions likewise occur according to said equations (II) and (III). H 2 O 2 formed through these reactions is converted to electric current at the H 2 O 2 electrode, and the amount of glucose or maltose can be measured. EXAMPLE 1 20 mg of α-glucosidase (100 mg/U, made by Toyobo Co., Ltd., Japan), 2.5 mg of glucose oxidase (100 mg/U, made by Toyobo Co., Ltd. Japan) and 2 mg of albumin (made by Sigma, Inc., U.S.A.) were dissolved in 400 μl of phosphate buffer solution (pH 6.8, 0.1 mole/l), and the solution was ice-cooled and admixed with 50 μl of 5% glutaraldehyde, followed by immediate stirring. 150 μl of the resulting solution was applied to polyester unwoven cloth having a diameter of 47 mm and a thickness of about 25 μm, and then the cloth was dried in the air for 15 hours, and washed to obtain an enzyme membrane having immobilized α-glucosidase and glucose oxidase. The enzyme membrane was fixed to a H 2 O 2 electrode (anode diameter: 1.5 mm, cathode outer diameter: 8 mm and inner diameter: 2.5 mm) having the structure as shown in FIG. 1 by means of O-ring to obtain a maltose sensor. Maltose at a concentration of 100 mg/dl was assayed, where 95% response time was 15 seconds. Then, maltose at various concentrations was assayed after dilution to 20-hold individually. Its calibration curve is shown in FIG. 2. On the other hand, another same maltose sensor as above was made except that silver was used for the cathode, and the durability of these two sensors was compared. The relative response of the maltose sensor provided with the silver cathode was reduced to 0 in a day. Whereas that of the sensor provided with the palladium cathode was maintained at 80% still after 80 days. EXAMPLE 2 Amylase was assayed with the maltose sensor provided with the palladium cathode, made in Example 1. That is, the sensor was mounted on an assay cell provided with a stirrer and a thermostat. The assay cell was kept at 37° C., and a phosphate buffer solution at 0.1 mole/l and pH 7.0 was filled therein, and 20 μl of control serum containing amylase and 80 mg/dl of glucose was added thereto as a sample. Then, glucose in the sample was assayed. Then, 20 μl of said phosphate buffer solution containing maltopentaose at a concentration of 0.2 g/l was added thereto as a substrate, and a rate of maltose produced by decomposition by amylase was measured. Relationship with output current from the sensor during the measurement is shown in FIG. 3, where t 1 is 15 seconds, i 1 100 nA, and ##EQU1## is 6 nA/min. When amylase was assayed in the same manner as above 30 days thereafter, ##EQU2## was a little changed, but the change was still in the measurable range at the same time intervals as the initial. EXAMPLE 3 Serum was assayed in the same manner as in Example 2, and the same sample was also assayed according to blue starch method (a kind of chromogenic substrate method) so far widely used as the conventional method at the same time to compare the results. Correlation coefficient at that time was 0.995 (n=20) and was in a good agreement with that of the conventional method. As described above, maltose can be assayed accurately and rapidly in the present invention, and the present sensor has a long durability and requires no replacement of the enzyme membrane for a long time, and thus is very economical. The present sensor can assay amylase particularly in a biological fluid and is very useful in the field of clinical examinations for diagnosis of diseases. Furthermore, the present sensor can assay not only glucose and maltose, but also maltose and glucose-producing substances other than amylase.

In a method for assaying maltose to quantitatively determine amylase, which comprises an enzyme membrane having immobilized α-glucosidase and glucose oxidase, the present invention is an improvement of the enzyme electrode for assaying maltose, where a hydrogen peroxide electrode provided with a palladium cathode is used.

FIELD OF THE INVENTION This invention relates to pneumatic tires having a carcass and a belt reinforcing structure, more particularly to high speed heavy load radial ply tires such as those used on aircraft. BACKGROUND OF THE INVENTION Pneumatic tires for high speed applications experience a high degree of flexure in the crown area of the tire as the tire enters and leaves the contact patch. This problem is particularly exacerbated on aircraft tires wherein the tires can reach speed of over 200 mph at takeoff and landing. When a tire spins at very high speeds the crown area tends to grow in dimension due to the high angular accelerations and velocity tending to pull the tread area radially outwardly. Counteracting these forces is the load of the vehicle which is only supported in the small area of the tire known as the contact patch. In U.S. Pat. No. 5,427,167, Jun Watanabe of Bridgestone Corporation suggested that the use of a large number of belt plies piled on top of one another was prone to cracks inside the belt layers which tended to grow outwardly causing a cut peel off and scattering of the belt and the tread during running. Therefore, such a belt ply is not used for airplanes. Watanabe found that zigzag belt layers could be piled onto the radially inner belt layers if the cord angles progressively increased from the inner belt layers toward the outer belt layers. In other words the radially inner belt plies contained cords extending substantially in a zigzag path at a cord angle A of 5 degrees to 15 degrees in the circumferential direction with respect to the equatorial plane while being bent at both sides or lateral edges of the ply. Each of the outer belt plies contains cords having a cord angle B larger than the cord angle A of the radially inner belt plies. In one embodiment each of the side end portions between adjoining two inner belt plies is provided with a further extra laminated portion of the strip continuously extending in the circumferential direction and if the radially inner belt plies have four or more in number then these extra laminated portions are piled one upon another in the radial direction. The inventor Watanabe noted the circumferential rigidity in the vicinity of the side end of each ply or the tread end can be locally increased so that the radial growth in the vicinity of the tread end portion during running at high speed can be reduced. SUMMARY OF THE INVENTION The method of forming a composite belt structure for a tire is disclosed. The method discloses the steps of applying a multicord reinforced strip having a strip width S W onto a rotating crowned building drum, the strips being wound in a zigzag configuration to form at least two zigzag layers wherein the crowned drum has non-overlapping portions of the strips placed in a central portion and extending in alternation to a pair of shoulder portions having portions of the strips overlapping, the central portion having a maximum diameter D o and the shoulder portions have a minimum diameter D i , the adjacent strips being placed apart from 0 to 2 mm in the central portion and the strips are increasingly overlapping in each shoulder portion as the strips extend from the central portion toward lateral ends of the belt structure to form belt layers of a composite belt structure having the cords per inch in the shoulder portion as measured axially inwardly from the axially inner edge of the strip adjacent the lateral ends of the narrowest radially outer belt layer radially inwardly greater than the cords per inch in the central portion as measured centered on the centerplane of the belt structure. Preferably the strips in the non-overlapping center region occupy at least 50% of the belt width and each overlapping shoulder portion occupies 25% or less of the belt width W, W being measured at the lateral extremes or edges of the widest belt layer. The overlapping of strips in each shoulder portion ranges from greater than 0% adjacent the central portion up to 100% at the outermost lateral edge of the respective belt layer. Preferably the overlap of each adjacent zigzag strip adjacent to a turning point at the lateral edge overlaps at a distance of 50% or more of the strip width S W . The resultant method produces a pneumatic tire having a tread, a carcass and a belt reinforcing structure, the belt reinforcing structure having a composite belt structure of cord reinforced layers including at least two radially inner zigzag belt layers, each outer zigzag belt layer having cords inclined at 5 to 30 degrees relative to the centerplane of the tire extending in alternation to turnaround points at each lateral edge, and at least one spirally wound belt layer having cords wound spirally at an inclination of 5 degrees or less relative to the tire's centerplane and located radially outward of the at least two radially inner zigzag belt layers, and the distance between the lateral edges of the widest belt layer defines the belt width W, and wherein each zigzag belt layer is formed by a continuous strip of two or up to 20 cords, the strips having edges spaced apart a distance of 0 to 2 mm in a central portion occupying at least 50% of the belt width W and in each shoulder portion occupying 25% or less of W the edges of the adjacent strips within a layer are overlapping to form a belt having the cords per inch greater in the shoulder portions than the central portion. The overlapping of the adjacent strips in each zigzag layer ranges from greater than 0% of the strip width S W to 100%. The preferred the belt reinforcing structure in addition to two radially inner zigzag layers has at least two radially outer zigzag layers and at least one spiral wound belt layer, the radially inner zigzag belt layers being positioned between the carcass and the at least one spiral wound belt layer and the radially outer zigzag layer being between the tread and the at least one spiral wound layer, each radially inner and radially outer zigzag belt layer having cords wound in alternation at an inclination of 5 degrees to 30 degrees relative to the centerplane of the tire to turnaround points at each lateral edge of the belt layer. One embodiment of the invention has at least five belt layers, two radially inner zigzag belt layers, one or more spirally wound belt layers, preferably three or more, and two radially outer zigzag belt layers. In another alternative embodiment the spiral wound layer can be positioned radially inward of at least one zigzag belt layer. Each of the resultant belt structures has X cords per inch as measured in the central portion centered on the centerplane in an area W C measuring one inch axially, and at a location in the shoulder portion at the axially inner edge of the strips adjacent the lateral end of the narrowest belt layer in an area W S measuring one inch wide axially inwardly extending, the cords per inch in the area defined W S being 101% to 200% times the cords per inch X in the area defined by W C . Definitions “Apex” means a non-reinforced elastomer positioned radially above a bead core. “Aspect ratio” of the tire means the ratio of its section height (SH) to its section width (SW) multiplied by 100% for expression as a percentage. “Axial” and “axially” mean lines or directions that are parallel to the axis of rotation of the tire. “Bead” means that part of the tire comprising an annular tensile member wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes, toe guards and chafers, to fit the design rim. “Cut belt or cut breaker reinforcing structure” means at least two cut layers of plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 10 degrees to 33 degrees with respect to the equatorial plane of the tire. “Bias ply tire” means a tire having a carcass with reinforcing cords in the carcass ply extending diagonally across the tire from bead core to bead core at about a 25°-50° angle with respect to the equatorial plane of the tire. Cords run at opposite angles in alternate layers. “Carcass” means the tire structure apart from the belt structure, tread, undertread, and sidewall rubber over the plies, but including the beads. “Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction. “Chafers” refer to narrow strips of material placed around the outside of the bead to protect cord plies from the rim, distribute flexing above the rim, and to seal the tire. “Chippers” mean a reinforcement structure located in the bead portion of the tire. “Cord” means one of the reinforcement strands of which the plies in the tire are comprised. “Equatorial plane (EP)” means the plane perpendicular to the tire's axis of rotation and passing through the center of its tread. “Flipper” means a reinforced fabric wrapped about the bead core and apex. “Footprint” means the contact patch or area of contact of the tire tread with a flat surface at zero speed and under normal load and pressure. “Innerliner” means the layer or layers of elastomer or other material that form the inside surface of a tubeless tire and that contain the inflating fluid within the tire. “Net-to-gross ratio” means the ratio of the tire tread rubber that makes contact with the road surface while in the footprint, divided by the area of the tread in the footprint, including non-contacting portions such as grooves. “Nominal rim diameter” means the average diameter of the rim flange at the location where the bead portion of the tire seats. “Normal inflation pressure” refers to the specific design inflation pressure and load assigned by the appropriate standards organization for the service condition for the tire. “Normal load” refers to the specific design inflation pressure and load assigned by the appropriate standards organization for the service condition for the tire. “Ply” means a continuous layer of rubber-coated parallel cords. “Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire. “Radial-ply tire” means a belted or circumferentially-restricted pneumatic tire in which the ply cords which extend from bead to bead are laid at cord angles between 65° and 90° with respect to the equatorial plane of the tire. “Section height” (SH) means the radial distance from the nominal rim diameter to the outer diameter of the tire at its equatorial plane. “Zigzag belt reinforcing structure” means at least two layers of cords or a ribbon of parallel cords having 2 to 20 cords in each ribbon and laid up in an alternating pattern extending at an angle between 5° and 30° between lateral edges of the belt layers. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 us a cross sectional view of one-half of a first embodiment of the tire according to the invention; FIG. 2 is a partially cutaway top view of the tire shown in FIG. 1 ; FIG. 3 is a schematically perspective view of an inner or outer zigzag belt layer in the middle of the formation on the crowned building drum; FIG. 4 is a schematically developed view of the inner or outer zigzag belt layers on the building drum in the start of the formation and FIG. 4A is a cross section view of the first zigzag belt layer formed on the building drum; FIG. 5 is an enlargedly developed view of the inner or outer zigzag belt layers in the vicinity of the side end of the belt layer in the start of the formation; FIG. 6 is an enlargedly developed view of another embodiment of the inner belt layer in the vicinity of the side end of the belt layer in the middle of the formation; FIGS. 7A and 7B are schematically enlarged section views of the composite belt layers in the vicinity of side end portions of the belt structure, one showing the spiral layer radially inward of a zigzag belt layer and the other showing the spiral belt layer radially outward of the zigzag belt layer; FIG. 8 is a schematically developed view of the preferred composite belt structure located at an outermost side; FIG. 9 is a plan view of a portion of the composite zigzag belt layers wherein the dashed lines depict the increasing overlap of each of the strips 43 as it approaches a lateral edge; FIG. 10 is a chart showing the lateral force in pounds versus degrees of yaw. DETAILED DESCRIPTION OF THE INVENTION In FIGS. 1 and 2 , numeral 21 is a radial tire of the preferred embodiment of the invention, as shown, to be mounted onto an airplane, which comprises a pair of bead portions 23 each containing a bead core 22 embedded therein, a sidewall portion 24 extending substantially outward from each of the bead portions 23 in the radial direction of the tire, and a tread portion 25 of substantially cylindrical shape extending between radially outer ends of these sidewall portions 24 . Furthermore, the tire 21 is reinforced with a carcass 31 toroidially extending from one of the bead portions 23 to the other bead portion 23 . The carcass 31 is comprised of at least two carcass plies 32 , e.g. six carcass plies 32 in the illustrated embodiment. Among these carcass plies 32 , four inner plies are wound around the bead core 22 from inside of the tire toward outside thereof to form turnup portions, while two outer plies are extended downward to the bead core 22 along the outside of the turnup portion of the inner carcass ply 32 . Each of these carcass plies 32 contains many nylon cords 33 such as nylon-6,6 cords extending substantially perpendicular to an equatorial plane E of the tire (i.e. extending in the radial direction of the tire). A tread rubber 36 is arranged on the outside of the carcass 31 in the radial direction. In FIG. 1 a belt 40 is shown arranged between the carcass 31 and the tread rubber 36 as a region having an upper boundary line having a plurality of layers 39 , 41 , 42 which are shown only in the right side of the figure for clarity, and is comprised of plural inner belt plies or layers 41 located near the carcass 31 , i.e. two radially inner belt layers 41 in the illustrated embodiment and plural radially outer belt layers 42 located near to the tread rubber 36 , i.e. two radially outer belt layers 42 in the illustrated embodiment. As shown in FIGS. 3 and 8 , each of the radially inner belt plies 41 is formed by providing a rubberized strip 43 of two or more cords 46 , winding the strip 43 generally onto a crowned building drum in the circumferential direction while being inclined to extend between side ends or lateral edges 44 and 45 of the layer forming a zigzag path and conducting such a winding many times while the strip 43 is shifted at approximately a width equal to or greater than the strip width W S in the circumferential direction so as to form a gap ranging from 0 to 2 mm between the adjoining strips 43 in a central portion occupying about 50% or more of the total belt width W. Thereafter, the strips overlap an adjacent strip of the respective belt layer in each shoulder portion, the overlap being slightly greater than 0% to 100% increasing as the strip extends from the central portion toward the lateral end of the respective belt layer. Each shoulder portion extends 25% or less of the total belt width W. As a result, the cords 46 extend substantially zigzag in the circumferential direction while changing the bending direction at a turnaround point at both ends 44 , 45 and are substantially uniformly embedded in the first inner belt layer 41 over the central portion of the first inner belt layer 41 and in the overlapping shoulder portion having an increasing cord density in each shoulder portion. Moreover, it is intended to form the radially inner belt layer 41 by the above method, the cords 46 lie one upon another, so that two, first and second inner belt layers 41 are formed while crossing the cords 46 of these plies with each other. Similarly the radially outer belt layers 42 are made using the same method. Interposed between the inner layers 41 and outer layers 42 is at least one spirally wound layer 39 of cords 46 , the cords being wound at an angle of plus or minus 5 degrees or less relative to the circumferential direction. In the pneumatic radial tire for airplanes, there are various sizes, the tire illustrated is a 42×17.0R18 with a 26 ply rating and the tire 21 has the belt composite reinforcing structure as shown in FIG. 9 . As shown the tire of FIG. 9 has two inner zigzag layers 41 and three spiral layers 39 and two outer zigzag layers 42 . As illustrated, the overall total belt width W from the lateral edges of the radially inner zigzag belt layer is about 320 mm. The central portion is about 50% W while each shoulder portion is 25% W. As shown, the total belt thickness of the central portion (excluding the overlay) is 8.5 mm. This thickness is reflective of the non-overlapping strips in the zigzag layers 41 , 42 in the shoulder portions where the strips overlap in the zigzag belt layers 41 , 42 . Thus the two belt layers increasingly overlap and go from 2.0 adjacent the central portion to greater than 2 to three strips to four strips at the turnaround locations. Conventional zigzag layers go from two layers to three at the turnaround locations. Thus the cord density in ends per inch is far less in a cylindrical flat built abutting strip method of forming zigzag layers. The present invention tire of FIG. 9 has 110 cords per inch at the centerplane of the belt structure and adjacent the turnaround location as measured axially inwardly in each shoulder portion the cord density is 150 cords per inch. In any such tire size, the cords 46 of the inner belt plies 41 cross with each other at a cord angle A of 5 degrees to 15 degrees with respect to the equatorial plane of the tire when the strip 43 is reciprocated at least once between both side ends 44 and 45 of the ply within every 360 degrees of the circumference as mentioned above. Typically the alteration occurs multiple times enabling the cord angles to typially fall in the 15° to 30° range for zigzag belts. In the illustrated embodiment, the widths of the inner belt layers 41 become narrower as the belt 40 is formed outward in the radial direction or approaches toward the tread rubber 36 . Further, when the inner belt layers 41 is formed by winding the rubberized strip 43 containing plural cords 46 arranged in parallel with each other as mentioned above, a period for forming the belt layer 41 can be shortened and also the cord 46 inclination can be made larger or smaller as desired. However, the strip 43 is bent at the side ends 44 , 45 of the belt layers with a small radius of curvature R as shown in FIG. 5 , so that a large compressive strain is produced in a cord 46 located at innermost side of the curvature R in the strip 43 to remain as a residual strain. When the cord 46 is nylon cord, if the compressive strain exceeds 25%, there is a fear of promoting the cord fatigue. However, when a ratio of R/SW (R is a radius of curvature (mm)) of the strip 43 at the side ends 44 , 45 of the layer, and SW is a width of the strip 43 ) is not less than 2.0 as shown in FIG. 6 , the compressive strain produced in the cord 46 can be controlled to not exceed 25%. Therefore, when the inner belt layer 41 is formed by using the rubberized strip 43 containing plural nylon cords 46 therein, it is preferable that the value of R/SW is not less than 2.0. In addition to the case where the strip 43 is bent at both side ends 44 , 45 of the ply in form of an arc as shown in FIG. 5 , the strip 43 may have a straight portion extending along the side end 44 ( 45 ) and an arc portion located at each end of the straight portion as shown in FIG. 6 . Even in the latter case, it is favorable that the value of R/SW in the arc portion is not less than 2.0. Furthermore, when the strip 43 is wound while increasingly overlapping an adjacent strip and simultaneously being bent with a given radius of curvature R at both side ends 44 , 45 of the belt layer, a zone 47 of a bent triangle formed by overlapping four strips 43 with each other at up to a full width of the strip as shown in FIG. 7 is repeatedly created in these bent portions or in the vicinity of both side ends 44 , 45 of the ply in the circumferential direction as shown in FIG. 5 . These strips 43 are overlapped with each other by each forming operation. The width of the overlap changes in accordance with the position in the circumferential direction continuously in the circumferential direction. Moreover, these laminated bent portions 47 turn inward in the axial direction as they are formed outward in the radial direction as shown in FIG. 7 because the widths of the inner belt layers 41 become narrower toward the outside in the radial direction as previously mentioned. In the bent portion 47 , the outer end in widthwise direction of the two middle strips 43 c sandwiched between upper and lower strips 43 a and 43 b overlaps with the zone 47 located inward from the middle strips 43 c in the radial direction as shown in FIG. 7 . When the belt 40 is constructed with these zigzag belt layers 41 , the total number of belt layers or plies can be decreased while maintaining total strength but reducing the weight and also the occurrence of standing wave during the running at high speed can be prevented. The middle layers 39 of the composite belt structure 40 are spirally wound around the radially inner zigzag belt layers 41 . As shown in FIG. 7 the spirally wound layer 39 extends completely across the two radially inner belt layers 41 and ends at 39 a just inside the end 41 a . The cords 46 within each strip 39 extend at an angle of 5 degrees or less relative to the circumferential equatorial plane. As shown, four cords are in each strip. In practice the strips 41 , 39 , and 42 could be wound using two cords 46 or up to 20 cords 46 in a strip or ribbon having plural cords in the range of 2 to 20 cords within each strip. In the exemplary tire 21 of the size 42×17.0R18 strips 43 having 8 cords per strip 42 were used. The strips 43 had a width S W , S W being 0.5 inches. It is believed preferable that the strip width S W should be 1.0 inch or less to facilitate bending to form the zigzag paths of the inner and outer layers 41 , 42 . In the most preferred embodiment the layers 41 , 39 , and 42 are all formed from a continuous strip 43 that simply forms the at least two radially zigzag layers 41 and then continues to form the at least one spirally wound layer 39 and then continues on to form the at least two radially outer layers 42 . Alternatively, the spirally wound layers 39 could be formed as a separate layer from a strip 43 . This alternative method of construction permits the cords 46 to be of different size or even of different materials from the zigzag layers 41 and 42 . The cords 46 in the preferred embodiment were made of 1890 2/2 nylon having a diameter of 1.2 mm (0048 inch). Aramid belt layers having a strength of 1500 denier/three filaments to as high as 3000 denier/three filaments can be used as well as high elongation steel cords. What is believed to be the most important aspect of the invention is the circumferential layer 39 by being placed between the zigzag layers 41 and 42 greatly reduces the circumferential growth of the tire 21 in not only the belt edges 44 , 45 but in particular the crown area of the tread 36 . The spirally wound circumferential layer 39 , by resisting growth in the crown area of the tire, greatly reduces the cut propensity due to foreign object damage and also reduces tread cracking under the grooves. This means the tire's high speed durability is greatly enhanced and its load carrying capacity is even greater. Aircraft tires using multiple layers of only zigzag ribbons on radial plied carcasses showed excellent lateral cornering forces. This is a common problem of radial tires using spiral layers in combination with cut belt layers which show poor cornering or lateral force characteristics. Unfortunately, using all zigzag layered belt layers have poor load and durability issues that are inferior to the more conventional spiral belt layers in combination with cut belt layers. The belt structure as described above is made by feeding the strip from a spool mounted on a linear slide onto a curved or crowned building drum 10 or mandrel. The crowned building drum 10 has a maximum diameter D 0 at the centerplane of a central portion, the central portion extending 50% of the belt width's maximum width W. The crowned drum has a small or minimum diameter D i in each shoulder portion. Preferably the curvature is such that a smooth or uniform curvature results. As the strip is applied to form a zigzag belt layer the strip is positioned inclined about 15° to 30° across the centerplane and spaced abutting at 0 mm gap or up to a 2.0 mm gap at the centerplane. As the strip extends to the shoulder region the strip overlaps an adjacent strip. The amount of overlap ranges from slightly above 0 mm to 100% of the strip width S W . As further illustrated the cord density X in the central portion as measured at the centerplane in the section identified as W C , W C being a one inch (25.4 mm) wide area encompassing all the belt layers has approximately 110 cords. In the area adjacent the turnaround point as measured at the axial inner edge of the strip and extending a distance of 1.0 inch (25.4 mm) the cord density increases to greater than X, preferably 10% to 200% of X, as shown to 136% of X or about 150 cords. The increase in cord density is due in part to the building of the belt on a curved building drum and allowing the strips to overlap in the shoulder portions. Assuming the diameter D 0 is a maximum of 37.5 inches at the crown for a tire size 42×17.0 R 18, then D i at the crown will be reduced to achieve the desired overlap and by selecting a proper reduction in curvature, the overlapping of the strips will be increasing as they extend toward the lateral edges. The concept relies on the feature that the distance of the centerplane of the circumference moves πD O while the distance at the shoulder moves πD i , the difference in π(D O -D i ) would require the strip 43 to have an excess in length at the shoulder. If the overlap did not occur, the angle of zigzag further adds to the circumferential differences, all of which are absorbed by the creation of the overlap. This uniquely creates a cord 46 density increase at each shoulder portion, dramatically increasing the strength of the tire 21 . As can easily be appreciated, the strength of the belt in the shoulder areas is increased by a very large amount yet the central portion has the advantage of lightweight. In fact the central portion by having the strips gap by as much as 2.0 mm can be made lighter than an abutting arrangement of zigzag layers such that the overall weight of the composite overlapping belt structure can be equal to a non-overlapping belt structure and yet provide substantially better strength and durability performance in the most sensitive shoulder portions of the tire. The present invention has greatly improved the durability of the zigzag type belt construction while achieving very good lateral force characteristics as illustrated in FIG. 10 . The all zigzag belted tire A is slightly better than the tire B of the present invention which is shown better than the spiral belt with a combination of cut belt layers of tire C in terms of lateral forces. Nevertheless the all zigzag belted tire A cannot carry the required double overload taxi and takeoff test whereas the tire B of the present invention easily meets these dynamic test requirements. The tire of the present invention may have a nylon overlay 50 directly below the tread. This overlay 50 is used to assist in retreading. As a further refinement of the present invention when one or more spiral layers 39 are employed the adjacent strips 43 can also be overlapped. Preferably, the overlap is at least greater than 0 to 100%, more preferably about 50% of the strip width 43 . As a still further refinement the amount of overlap can be adjusted at any location along the width of the belt 40 . By way of example, the overlaps of the spiral layers 39 can be increased at each of the shoulders to achieve a contributory cord density increase of the spiral layers 39 with the zigzag layers 41 , 42 . An important distinction of the zigzag layers 41 , 42 achievement of an overlap occurs as a function of the curvature of the crowned drum 10 . The changes in overlap of the spiral layer 39 can be achieved on a cylindrical drum or the crown drum 10 ; however, the linear movement of the feedout spool for the strips 43 needs to be adjusted to create the localized overlap increase or decrease.

A method of forming a composite belt structure for a tire is disclosed. The composite belt structure has cord reinforced layers including at least two radially outer zigzag belt layers. The cords per inch in the shoulder portion are greater than the cords per inch in the central portion as measured centered on the centerplane of the belt structure. The method discloses the steps of applying a multicord reinforced strip having a strip width SW onto a rotating crowned building drum, the strip being wound in a zigzag configuration to form at least two zigzag layers, wherein the crowned drum has non-overlapping portions of the strip placed in a central portion and extending in alternation to a pair of shoulder portions having portions of the strips overlapping to form belt layers.